Virtual Dyno plots for stock exhaust, downpipe only and full exhaust + water/meth

[ZimbutheMonkey]

So I thought I'd take a moment and share some data that I've been collecting as I upgraded my vehicle.

I've done a TON of datalogging and I've sifted through it all to give you all an idea of what you can expect to gain from different stages of hardware upgrades

Below, are 4 stages of upgrades. Unfortunately I haven't found any good data for a completely stock ECU and exhaust. However, I'd say that 250-255 AWHP is a reasonable estimate for a tiptronic S4 and it would be consistent with the 260-265 AWHP results that I have noted with the tune below.

A few things to note: First, the tuning between upgrades was changed. So that may account for some of the differences in the dyno plots.

Second, the upgraded exhaust was made from the catback portion (w RS4 resonators) of a used B7 RS4 exhaust that a buddy had given me. However, since the RS4 mufflers didn't fit, I used a set of Magnaflow ones.



As well, the RS4 exhaust is 2.5 OD, so the ID is something like 2.35 inches. I know that the common line is "blah blah blah, anything less than 2.5 in ID is choking off the car" I say BS, while a 2.5 in ID exhaust is preferable, I'd say that the results below indicate that a 2.35 ID or even a 2.25 ID exhaust will work just fine. The important part is putting in a balance pipe and getting rid of the damn cats.

Also, as you will note, I am also running a water/meth system. The reason being is that anyone who knows anything about tuning these cars will know that the S4 ECU is CRAZY knock sensitive. So being able to keep detonation at bay will make for some significant gains on this platform.

Finally, please note the yellow dyno line. This is what I observed when I installed my downpipes before changing the cam phasing (and before the H pipe). I started a thread on it here http://www.audizine.com/forum/showth...6#post11549426

But you can see the difference that simply retuning the cam phasing and manifold chageover made when you compare the yellow and grey dyno plots.

I cannot stress this enough, if you put a set of catless downpipes in and keep the stock exhaust, PUT IN AN H PIPE and retune the cam phasing!!!!!! These cross plane V8's need a balance pipe, otherwise they loose a bunch of low end torque. As well, you need to retune the cam phasing and manifold changeover.


Finally, you will note that the stock weight that I used was 2200 Kg, whereas the car gets progressively lighter as I do the exhaust upgrades. This is partly because the stock cats and mufflers are friggin' HEAVY. It is also due in part to the amount of fuel I had at the time and a bunch of tools that I removed from the trunk between dyno pulls.

So with no further ado........ here is is:

1) Stock exhaust with ECU tune (my own tune based partly on my old Fabspeed tune) *GREEN/BLUE

2) 2.5 in catless downpipes stock catback without an H pipe OR retune for cam phasing (aka "old cam phasing strategy") and manifold changeover *YELLOW

3) 2.5 in catless downpipes, stock catback without an H pipe but WITH retuned cam phasing and manifold changeover *GREY

4) 2.5 in catless downpipes, stock catback with H pipe and with retuned cam phasing/manifold changeover *RED

5) 2.5 in catless downpipes, RS4 catback piping, Magnaflow muffers, H pipe and water/meth (and my own ECU tune obviously) *ORANGE

Not too shabby if I say so myself



Peak differences between the stock exhaust system and the full exhaust + W/M set up are about 30 AWHP and 25 AWTq. Ill tell you, the car feels lightyears different than it did when it was stock.


As the dyno results indicate, I found that unless you make these changes, you will incur significant losses throughout much of the powerband.

[p3u]

I thought it's been proven, and even admitted by Snow Performance, that water meth injection is pointless on NA vehicles. If there was a benefit I'd think a company that specializes in such would be recommending it to maximize sales, not otherwise.

[ZimbutheMonkey]

I thought it's been proven, and even admitted by Snow Performance, that water meth injection is pointless on NA vehicles. If there was a benefit I'd think a company that specializes in such would be recommending it to maximize sales, not otherwise.

Yeahhhh, I don't think so lol....

http://www.snowperformance.net/category-s/168.htm

QUOTE: SNOW PERFORMANCE WEBSITE

2. Can the Boost Cooler be applied to naturally aspirated and nitrous engines?

• Naturally aspirated/high compression engines:
Water/Methanol injection allows the use of pump fuel in all but the most extreme situations which effects tremendous cost savings as well as horsepower increases due to air density increase and higher timing advance potential.

• Engines using nitrous:
With nitrous, water/methanol injection allows the use of more timing advance even with large (250HP+) quantities. The cooling effect of the water/methanol inside the combustion chamber also makes for reduced peak combustion temperatures.

• Naturally aspirated/stock compression:
With naturally aspirated engines using less than 10:1 compression, water/methanol is used often in warm climates to get the intake temps lower. Benefits include: 10-15 HP increases from air density increases and full timing as well as more effective air/fuel ratios, increased gas mileage, and carbon free combustion chambers.

While power gains are typically less in stock compression naturally aspirated vehicles compared to high compression or forced induction engines, benefits can still be realized due to more timing advance, leaner air/fuel ratios, cleaner engine components, lower temperatures, and the use of the methanol in the injection fluid as a secondary fuel source.

Notwithstanding the fact that it's a vendor stating this, I can tell you that adding timing on these engines = power.

Lest anyone say otherwise, how do you think that the JHM tune makes it's gains???? timing, pure and simple.

Quite frankly, I can't figure out where the "N/A engines don't benefit from W/M" myth originated. Virtually any modern performance engine is going to have at least a 10:1 CR (11:1 in our case). They're also going to have extremely sensitive knock sensors and conservative timing as the manufacturers have to account for that inevitable idiot car owner in a Southern climate who runs 87 octane in their cars on a 40C+ day.

[Jake@JHM]

Lest anyone say otherwise, how do you think that the JHM tune makes it's gains???? timing, pure and simple.

You think that is the only thing done in our software is a timing change?

[ZimbutheMonkey]

You think that is the only thing done in our software is a timing change?

No, there are also changes in other areas, would you like me to discuss them...?

[evildsmr]

Oh here we go...... Op. Very interesting research you have down there and I appreciate you sharing your logging and time. Let's not take this down the road of what jhm does and what anyone else can do. Seriously nip that in the bud immediately. I have to say your torque curve and HP curve of the yellow graph I which you state an H pipe is of the utmost importance i think if false. As the graph States yes you have maximized HP but in the end you've made your torque curve low and later onset. This is behaving exactly like charged cars... I for one would not be willing to sacrifice immediate onset of torque for a couple extra hps on the back end. All in all I appreciate once again the time you have put into sharing this information.

Sent from my Nexus 6 using Tapatalk

[ZimbutheMonkey]

Oh here we go...... Op. Very interesting research you have down there and I appreciate you sharing your logging and time. Let's not take this down the road of what jhm does and what anyone else can do. Seriously nip that in the bud immediately. I have to say your torque curve and HP curve of the yellow graph I which you state an H pipe is of the utmost importance i think if false. As the graph States yes you have maximized HP but in the end you've made your torque curve low and later onset. This is behaving exactly like charged cars... I for one would not be willing to sacrifice immediate onset of torque for a couple extra hps on the back end. All in all I appreciate once again the time you have put into sharing this information.

Sent from my Nexus 6 using Tapatalk

Yes, I'm inclined to agree with your initial statement.

Thank you for the kind words, I'm glad you found my info of some use

Just to be clear, the Yellow and Grey plots do NOT have an H-pipe, only the Red and Orange ones do.

[ZimbutheMonkey]

So I had a chance to do some more logging runs and here are the results. I've included two stock exhaust+tune runs as well as two runs with tune+catless downpipes(with H pipe)

I'd have to say that the data looks to be accurate as all three of the APR 19 full exhaust+tune+W/M runs are extremely close despite the one (APR 12) having been taken on a different day. As well, note how all 4 of the full exhaust torque peaks are virtually identical in there they occur. The closeness of the plots (even at #2 smoothing) suggests to me that the numbers for the full exhaust + tune + WM are pretty much spot on accurate.

Regardless of whether the absolute numbers are correct (which I think they are based on the stock exhaust + tune 265 AWHP numbers), I think it's safe to conclude that addition of the downpipes/RS4 catback/Water-meth is good for a peak gain of 30-35 AWHP and 25-30 AWtq.

What's also interesting are the gains from the addition of the 2.5 OD (2.36 in ID) RS4 catback and the water/meth. Although I can't say for certain what percentage of the gains were attributable to each modification, the difference between the stock catback and RS4 catback/water-meth curves shows a minimum gain of 10 AWHP and up to 20 AWHP after 6000 RPM.

I'd say that the gains seen here punches some significant holes in the often heard party line ("blah blah blah... can't make power without a 2.5in (ID) exhaust... blah blah blah... anything smaller is choking the engine)

Please also note that I was extra conservative when I entered the weights for the full stock exhaust (2200 Kg) and stock catback plots (2100 kg). The new exhaust system was definitely lighter, and there was some extra weight in the trunk at the time. However, the car may have been slightly lighter at the time. If this were the case, then the posted gains would be even greater. However, I wanted to err on the side of caution.


SMOOTHING 2


SMOOTHING 6

[jr1415us]

OK, I need this tune.

[ZimbutheMonkey]

OK, I need this tune.

One thing to note is that the tune that I'm running now is a pretty significant departure from the Fabspeed base file. With the water/meth, my timing values under full load are anywhere from 6-10 degrees higher.

That said, if you want to install a water/meth kit I'll be happy to send Steve-o the tune that I'm using and you guys can decide what timing values you think would be safe.

One other thing that I do want to point out though is that the peak differences of 25-30 AWHP that I'm seeing are above and beyond what I was seeing WITH the tune and stock exhaust.

While I do concede that without the baseline plots to verify what the car was putting out before any modifications it's speculation as to what numbers the car would have been putting out bone stock. With that said, it's probably safe to assume that the bone stock numbers would have been around 250-255 AWHP. If this were the case, then the delta between bone stock and where I am now would be somewhere between 35-40 AWHP.

If we take the rated stock HP number of 340 CHP (at baro 1.00) as a starting point, I don't think that it's unreasonable to assume that with a full exhaust and W/M that one could expect a healthy S4 to make an honest 380 CHP or so (again, at baro 1.00).

[SquiddyB6S4]

Your weight changes are extraordinary, and you are guessing on them while using a device that relies explicitly on weight to show power and torque. I think you are seriously overestimated gains here. I measured the weight of my car before each run, so if I had a passenger, stuff in the trunk, or a different amount of fuel, it was corrected for by an honest weight at a certified scale. I promise you that your car never weighed 2200kg, and it still doesn't weight 2060kg unless you have 3-4 people in the car. My car with a full tank of fuel and just me has never even touched 1900kg, and the change in exhaust weight is probably on the order of 10-15kg including downpipes.

As with anything else, pretty graphs are useless if the data used to create them is not correct.

[jr1415us]

Sent you a PM.

[ZimbutheMonkey]

Your weight changes are extraordinary, and you are guessing on them while using a device that relies explicitly on weight to show power and torque. I think you are seriously overestimated gains here. I measured the weight of my car before each run, so if I had a passenger, stuff in the trunk, or a different amount of fuel, it was corrected for by an honest weight at a certified scale. I promise you that your car never weighed 2200kg, and it still doesn't weight 2060kg unless you have 3-4 people in the car. My car with a full tank of fuel and just me has never even touched 1900kg, and the change in exhaust weight is probably on the order of 10-15kg including downpipes.

As with anything else, pretty graphs are useless if the data used to create them is not correct.

Yes, the weight of 2060 is absolutely correct as it was taken on a government owned and calibrated highway weight scale. These scales have to be dead accurate as they're used to determine whether or not you're going to get a fine for being overweight, so you can bet they're accurate if the measurements obtained are entered in evidence in Court. So with all due respect, don't go telling me that I haven't done my homework correctly....

The cabriolet with a tip transmission is a heavy friggin' car. Jesus, just google "audi s4 curb weight" and you'll see

Audi B6 S4 quattro

Kerb weight

saloon: 1,660 kg (3,660 lb)
estate: 1,720 kg (3,792 lb)
cabriolet: 1,855 kg (4,090 lb)

Wow, would you look at that, 430 lbs, or just under 200Kg difference.... You say your car has never touched 1900 Kg, which I assume to mean that it's more than 1800Kg and less than 1900 Kg, so let's say 1850, add 200 Kg and.... 'gasp' it's 2050 Kg, just like the old gypsy lady said.

So, take a curb wieght of 1855Kg, add to that, a trunk and back seat stuffed with 100-150 lbs of tools (I had just about every took I owned in the trunk for a week or so), a driver that weighs 220 lbs a tank of fuel that adds or subtracts 100 lbs and yes, 2200 Kg is absolutely possible.

As well, I used the 2200 Kg value to be extra conservative when estimating my gains. As I said, if it were actually lighter, then the the gains vis a vis the baseline numbers I was comparing my full exhaust runs to are even greater. suits me just fine.

I may seem a little hot under the collar about this, but I really don't appreciate being called out by someone who clearly didn't do his homework. A simple Google search would have came up with the information that I've referred to here. Can you explain to me why you didn't even bother to check this out...?

The numbers I've posted are accurate, whether you like them or not...

[SquiddyB6S4]

Yes, the weight of 2060 is absolutely correct as it was taken on a government owned and calibrated highway weight scale. These scales have to be dead accurate as they're used to determine whether or not you're going to get a fine for being overweight, so you can bet they're accurate if the measurements obtained are entered in evidence in Court. So with all due respect, don't go telling me that I haven't done my homework correctly....

The cabriolet with a tip transmission is a heavy friggin' car. Jesus, just google "audi s4 curb weight" and you'll see

Audi B6 S4 quattro

Kerb weight

saloon: 1,660 kg (3,660 lb)
estate: 1,720 kg (3,792 lb)
cabriolet: 1,855 kg (4,090 lb)

Wow, would you look at that, 430 lbs, or just under 200Kg difference.... You say your car has never touched 1900 Kg, which I assume to mean that it's more than 1800Kg and less than 1900 Kg, so let's say 1850, add 200 Kg and.... 'gasp' it's 2050 Kg, just like the old gypsy lady said.

So, take a curb wieght of 1855Kg, add to that, a trunk and back seat stuffed with 100-150 lbs of tools (I had just about every took I owned in the trunk for a week or so), a driver that weighs 220 lbs a tank of fuel that adds or subtracts 100 lbs and yes, 2200 Kg is absolutely possible.

As well, I used the 2200 Kg value to be extra conservative when estimating my gains. As I said, if it were actually lighter, then the the gains vis a vis the baseline numbers I was comparing my full exhaust runs to are even greater. suits me just fine.

I may seem a little hot under the collar about this, but I really don't appreciate being called out by someone who clearly didn't do his homework. A simple Google search would have came up with the information that I've referred to here. Can you explain to me why you didn't even bother to check this out...?

The numbers I've posted are accurate, whether you like them or not...

Sure, I'll spell it out for you:

1) I didn't know you were cabbie. That was nowhere in the post, so excuse me for not stalking you to find that out.

2a) How can your numbers be accurate if you "used the 2200 Kg value to be extra conservative when estimating my gains"? If we're nitpicking the difference between 5 or 10 hp - not the overall gain, but the difference between one tune and another, or the difference between water/meth and not - and guessing at an uncollected baseline, then how can guesstimating be accurate? Accurate means known value, not estimated with some safety cushion. Not that a baseline would perfect this - having the wrong weight on any run will mess up the gains.

2b) These devices work by measuring acceleration and using the weight to back calculate power. It takes more power to move more weight at the same rate of acceleration. If you guess too heavy, the device tells you that you have more power than you actually have, not less. But you could have googled that too.

So, what I'm getting at is that, because you guessed high on weight, your presumed gains are also overstated.

[ZimbutheMonkey]

Sure, I'll spell it out for you:

1) I didn't know you were cabbie. That was nowhere in the post, so excuse me for not stalking you to find that out.

2a) How can your numbers be accurate if you "used the 2200 Kg value to be extra conservative when estimating my gains"? If we're nitpicking the difference between 5 or 10 hp - not the overall gain, but the difference between one tune and another, or the difference between water/meth and not - and guessing at an uncollected baseline, then how can guesstimating be accurate? Accurate means known value, not estimated with some safety cushion. Not that a baseline would perfect this - having the wrong weight on any run will mess up the gains.

2b) These devices work by measuring acceleration and using the weight to back calculate power. It takes more power to move more weight at the same rate of acceleration. If you guess too heavy, the device tells you that you have more power than you actually have, not less. But you could have googled that too.

So, what I'm getting at is that, because you guessed high on weight, your presumed gains are also overstated.

1) I've mentioned it was a cabrio in numerous other threads, any of which can be searched in a matter of seconds. Further, if you look at the very first picture, you can clearly see the structural bracing on the underside of the car which is not present on the hard-tops, so no need to stalk me to find out lol.

2) ???? How are the presumed gains overstated? I'm comparing the delta between tune/tune+DP-stock catback/tune+fullback+water/meth. If the car had in fact been lighter than 2200 lb on the baseline runs, the baseline runs would have been LOWER and the delta of gains from the exhaust mods would have been GREATER. So would you be more inclined to believe that my numbers are accurate if I re-did the runs with all weights at 2060 Kg? Here you go: ***NOTE, THIS DYNO IS ONLY TO SHOW DELTA WITH THE BASELINE AT 2060 KG, I STILL ESTIMATE THE CAR WEIGHED MORE AT THE TIME OF TESTING AND THAT THE REAL DELTA IS CLOSER TO 40 AWHP, NOT 50 AWHP***


Wow, look at that my car is making up to 50 AWHP more than with a tune alone, awesome!!! So even if we assume that my tune gained me exactly 0 AWHP above and beyond stock and the baseline runs were making the advertised rating of 340 CHP, that must mean I'm cranking out about 410-420 CHP, time to go RS4 hunting woot woot!!!

Orrrrr, maybe my weight estimates were accurate the first time around hmm???

[p3u]

B6/B7 cabrio curb weight is 1855kg - 1890kg for the record...

[ZimbutheMonkey]

B6/B7 cabrio curb weight is 1855kg - 1890kg for the record...

Exactly what I said earlier...

I'll presume that the 1890kg is for the tiptronic (which I have), add 100kg for me, 40-50kg for the heavy ass toolbox I carry at all times (seriously, it weighs that much) and at a minimum, the car weighs 2030kg.

Then add to that minimum Lord knows how many Kg of weight from boxes of legal files that I would be travelling with to and from Court and any other tooling that may still be in the trunk from my frequent out of town trips to my folk's place where I work on the car.

Just to put the issue to rest, here's a picture I took a couple of days ago (with me standing next to the car on the scale)


Car had 2/3 of a tank of gas in that pic, I had also cleaned a bunch of tools out of the trunk relative to the date that I did the baseline pulls (20-30 kg). As well, the car no longer the weight of 4 catalytic converters (10-20 kg) and no longer has the 'heavy as shit' stock mufflers (20-25 kg) (seriously, I was amazed at how much they weighed relative to the Magnaflows). The combined

So, perhaps it was the case that the baseline pulls were done closer to 2100-2125 kg, If so, then that means that I picked up 40 AWHP (see graph with baseline run at 2125 kg) above and beyond any gains from the initial tune. Works for me as 40 AWHP added to 340 CHP stock ratings would suggest that I've managed to coax 380-390 CHP out of this car.

[p3u]

The power output isn't greater because of the delta of weight, you did however change the power to weight ratio which is giving incorrect data. This is what I believe squiddy is getting at.

Point is, graph A is useless compared to graph B.

While there is no doubt there is a improvement, the data compared on the graphs is flawed.

[VinnysS4]

hmm.... i don't know what numbers are right or what numbers are wrong. However...that being said. THANK YOU for doing this and actually putting up the info. (whether its speculation or not) Most people don't take the time out ot their days to sit down and type stuff out or to do much that helps the rest of us. Very well thought out posts. I don't really give a crap if its a 20 or 50 hp gain. if its over stock, then you're doing something right. Bravo for tuning your own ECU as most of the people in the world have no clue how that is done. I really hate coming here and seeing people trying to help out the community by doing stuff like this and to have everyone and their mom down-play it. I wont get into the "company X is better than Company Y" because i hate those discussions. Keep up the good work and the informative posts....
Vinny

[ZimbutheMonkey]

The power output isn't greater because of the delta of weight, you did however change the power to weight ratio which is giving incorrect data. This is what I believe squiddy is getting at.

Point is, graph A is useless compared to graph B.

While there is no doubt there is a improvement, the data compared on the graphs is flawed.

Sigh..... No.... the HP delta between stages (exhaust, fullback, just tune) has changed as a result of my changing the power/weight ratio.

Further, how on EARTH is the comparison flawed?????

1) have taken the time to post a bloody picture to prove that the vehicle weighs at least 2050 Kg

2) I know that a) there was a bunch more weight in the trunk of the vehicle at the time of the earlier runs, and b) the new exhaust system is substantially lighter than the stock one. so I have adjusted it accordingly so as not to inflate the gains.

3) For Christ sake, we're talking about 65kg here, not 650 Kg. If I'm at all wrong on my estimates, it's no more than 10-15Kg. Given that the tests were done on an actual road, minus any heat soak and with air moving over the entire front of the vehicle, these results are probably more representative of the actual gains than testing done on a dyno in a closed room, where heat soak and detonation can result in massive variances from run to run.

The results are what they are, and I submit that they are dead-on accurate. Whether or not you choose to believe them is up to you.

At this point, I personally couldn't care less what you believe, my purpose in responding to yours and Squiddy's posts are to address any possible deficiencies in my methodology for others who may be watching this thread and I feel that I have addressed the weight issue adequately.

[ZimbutheMonkey]

hmm.... i don't know what numbers are right or what numbers are wrong. However...that being said. THANK YOU for doing this and actually putting up the info. (whether its speculation or not) Most people don't take the time out ot their days to sit down and type stuff out or to do much that helps the rest of us. Very well thought out posts. I don't really give a crap if its a 20 or 50 hp gain. if its over stock, then you're doing something right. Bravo for tuning your own ECU as most of the people in the world have no clue how that is done. I really hate coming here and seeing people trying to help out the community by doing stuff like this and to have everyone and their mom down-play it. I wont get into the "company X is better than Company Y" because i hate those discussions. Keep up the good work and the informative posts....
Vinny

I'm saving this one for last, THANK YOU!!! for the kind words.

It's not that I don't think that anyone appreciates the effort, but it's nice to see someone take the time to do so in a well written post, so thanks again

Your point about taking the time to do these kinds of tests is bang on point too. I find it interesting when you look at the post history of a lot of the most vocal keyboard critics, that most of them have never done any kind of testing, write-ups, DIY, etc... If one actually had an idea just how much time it takes to do a proper round of testing and write-ups they would have a little more respect for the process.

That said, it's members like yourself who I know appreciate/benefit from the effort who make this all worthwhile.

So thank you very much and if you ever happen to have any questions, please feel free to ask and I'll answer to the best of my ability.

Cheers

[VinnysS4]

I'm saving this one for last, THANK YOU!!! for the kind words.

It's not that I don't think that anyone appreciates the effort, but it's nice to see someone take the time to do so in a well written post, so thanks again

Your point about taking the time to do these kinds of tests is bang on point too. I find it interesting when you look at the post history of a lot of the most vocal keyboard critics, that most of them have never done any kind of testing, write-ups, DIY, etc... If one actually had an idea just how much time it takes to do a proper round of testing and write-ups they would have a little more respect for the process.

That said, it's members like yourself who I know appreciate/benefit from the effort who make this all worthwhile.

So thank you very much and if you ever happen to have any questions, please feel free to ask and I'll answer to the best of my ability.

Cheers

absolutely man. I'm no expert or anything. Just a car guy who likes to work on his own ride, and likes helping others out. I realize just how long it takes to do testing and to post up the results. And that's not including writing any DIY's or writing long informative posts. I came to this site in seeking information, and in turn created an account. There are too many backyard "mechanics" that only drive down to the parts store and unload their wallet....because their check engine light said so... So any time i see someone actually take the time to help others out and write long replies with factual information.... i respect that. I've only written one real DIY because i couldn't find one out there( i didn't look hard enough) and other times, there are already other...better... DIY's, so i don't bother. ill just add to them to save someone the time of searching for the replys.
The virtual dyno programs are surprisingly accurate. Now, that being said, anything could sway the results one way or the other, (DA, Different fuel, Temperature, etc...) but it looks like you have been pretty fair up until this point. I don't really see the little weight variances really making a substantial difference. Maybe a few hp up or down, but either way, gains are gains. What i don't see is you coming on here, claiming you tune people's ECU's, and trying to sell your tune. It seems more like you would rather learn to turn your own ECU and not pay someone else to do it. I think that's pretty awesome. And on top of it, you are doing your own tests. I respect that too. Track times.... well they are what they are. If you increase your power, you should see it in the track times. I worry more about the street and real world numbers. I have never taken my S4 to the track, and i may or may not do that in the future.
Either way, props man. Keep up the good work. Weather people like your threads or not, or weather they agree with your results or not, i do appreciate the time that is taken to write this stuff. (and im sure atleast one other person feels the same way)
I look forward to more information! thanks
Vinny

[jr1415us]

This is the kind of thread that makes reading this forum interesting and worthwhile. I really appreciate all your work, and the generous sharing. Keep up the great work!

[event]

This is the kind of thread that makes reading this forum interesting and worthwhile. I really appreciate all your work, and the generous sharing. Keep up the great work!

I'll second this part of the post because seeing ZimbutheMonkey implode in every thread is hilarious. I imagine him with missing chunks of hair and scream lines.

[ZimbutheMonkey]

I'll second this part of the post because seeing ZimbutheMonkey implode in every thread is hilarious. I imagine him with missing chunks of hair and scream lines.

Well, no one ever said that it would be easy enlightening the Kool-Aid addled masses but hey you're welcome

[ZimbutheMonkey]

So I haven't had much good highway time lately, but I finally got a chance to compare the results of my modified intake manifold (smoothed out the flap and ported the runners.

Here are the results, I wanted to collect some consistent runs over different days. (NOTE: the 3rd run at 905 baro was mistakenly labelled as may 21, when in fact it was taken on May 13 in Calgary which is at 3500 ft elevation)

MAY 21 runs (tune, full exhaust, water/meth, modified intake manifold)
APR 12 runs (tune, full exhauust, water/meth)
Mar 22 run (tune, stock everything else)

The other May 21 runs were taken 60-120 seconds apart back to back. Nonetheless, the curves for the modified manifold runs show consistent gains despite the runs being taken in different elevations on different days.

So here's what you might expect from a modified intake manifold boys and girls

[q_dubz]

rev that bitch out! :D

[ZimbutheMonkey]

rev that bitch out! :D

Sad to say that I can't The TCU will override any rev increase that I can demand by reprogamming the ECU. Other than putting it in "S" mode, which will allow for a 6800 RPM redline if I engage the kickdown switch, I'm practically limited to 6500 RPM for testing purposes as I can't reliably ask the engine to rev from 2500-6800 in 3rd unless I have it in tiptronic mode.

That said, after looking at literally hundreds of 3rd gear pull MAF readings, I've noticed that these engines seem to hit a brick wall in terms of airflow right around 6200 RPM with the stock intake/heads/ports. I'm going to try out a modified intake manifold


I'm a little concerned about the possibility of the material cracking and falling out, so what I did was went in with a dremel and intentionally gouged/dimpled these areas before adding the SteelWeld putty. The logic being that it ought to adhere better than it would had I just simply rough sanded it.


I'm also going to finish port matching the intake manifold to the head.

[Hooblah]

Great thread! You've got me a bit confused at the end though, you said you're going o try out a modified inlet manifold but isnt that what you already have?

[p3u]

Sad to say that I can't The TCU will override any rev increase that I can demand by reprogamming the ECU. Other than putting it in "S" mode, which will allow for a 6800 RPM redline if I engage the kickdown switch, I'm practically limited to 6500 RPM for testing purposes as I can't reliably ask the engine to rev from 2500-6800 in 3rd unless I have it in tiptronic mode.

Are you not able to reprogram the TCU to allow different rpm limits?

Someone correct me if I'm wrong, but you can do up to 7200rpm on a manual?

[jakeoboy67]

Are you not able to reprogram the TCU to allow different rpm limits?

Someone correct me if I'm wrong, but you can do up to 7200rpm on a manual?

yes, but peak hp is slightly lower than that , iirc

[ZimbutheMonkey]

Are you not able to reprogram the TCU to allow different rpm limits?

Someone correct me if I'm wrong, but you can do up to 7200rpm on a manual?

You can reprogram the TCU via OBD on the B7 generation TCU. However on mine (B6 2005) you would need to pull the Mechatronic module out of the transmission and program it directly. I inquired about it on Nefmoto and to my knowledge, no one has ever done it on a B6.

To add to this, the only person who was really researching the TCU modules on these cars (Daz/Dillinger) has passed away, so I don't see this happening any time soon.

[ZimbutheMonkey]

Now, this is a perfect segue to discuss my latest round of logging results.

As I noted earlier, after seeing a picture of TarCabot's modifed manifold, I decided to try it out myself as I have a spare manifold kicking around.

Here's my version, not as slick as TarlCabot's, but it's fundamentally the same.

I also decided to port match the manifold to the gasket. Now, I warn you, this procedure is not for the faint of heart as you are cutting into the head with the valves still in place. But what I decided to do was

1) stuff the intake ports off with a shop towel each, then mask everything off to keep the shavings out.


2) clean any oily deposits out of the intake port with a wire brush, this is important for the next step to work

3) Open each port up and seal it off (in addition to the shop towel already inside the port) with a lump of modeling clay. As long as the port is squeaky clean, the modeling clay forms a complete, waterproof seal which catches the shavings and keeps the cutting fluid from leaking down the port. In addition, I would periodically evacuate the port of fluid and shavings with a shop-vac. Once you're done, carefully peel the modelling clay back and it will hold in the remainder of the shavings. (Same principle as clay bar detailing which is where I got the idea from).


And this is what you end up with


So with all this done, I set out and did some testing.

Now, I realize that the absolute numbers are slightly lower than some runs that I've seen. This could be a result of a bit of timing pull from the warmer conditions that these runs were taken in and the fact that I did about 10 back to back pulls in the space of about 5 minutes as well (which could have been heatsoaking the manifold and cylinder walls). What's worth noting is the SHAPE of the power curve.

What was surprising is that the HP/Tq numbers at redline remained largely unchanged. However, I now seem to get a second spike in HP/Tq around 5500 RPM (likely resonance based). However, you can see that the power seems to flatline from there. I don't have any explanation for it at the moment. However, what I'm suspecting is that I've reached a point where the airflow is choking at the intake port area.


Here's a closeup of the torque production


The bad news is that I don't know that there's much I can do to increase the absolute power production. The good news is that I may be able to broaden that second torque spike with a bit of cam phasing finesse. The other good news is that this suggests to me that some actual porting work could net me some good gains.

I don't see myself porting the heads on my Cabrio anytime soon, buuuttttt..... I do have a 2004 Sedan that has another motor waiting to go into it

[ZimbutheMonkey]

Well, I'm glad that I took the time to post what I did...

Just had my solid state laptop drive die on me.

God knows how many gigs of data I may have lost for good. As well as tuning file revisions .

I did do backups, so I'm not totally screwed, but who knows what got lost in the shuffle between back-ups

I just feel gutted right now, because since this was all data that was collected as I modded the car, I can't replicate any of it.

I'm in the middle of trying to find out what I can salvage. Guess I'll keep you all posted.

Anyway, it's been a shitty few days as it happened on the first day of my 10 day maritime vacation. The GF has been pretty good about it, but it's just been a constant source of tension. So I guess I'm just gonna try and get some sleep and forget about this fucking shit for now....

[q_dubz]

great work. Seems the power curve shifted left some but holds it longer as well. If you did manage to back up the data i'd love an overlay of stock, one 300whp run, and one post porting. There was a program i paid $80 and used to recover lost data but i'm not sure how well it would work on SSD.

[Fourpoint282]

Now, this is a perfect segue to discuss my latest round of logging results.

As I noted earlier, after seeing a picture of TarCabot's modifed manifold, I decided to try it out myself as I have a spare manifold kicking around.

Here's my version, not as slick as TarlCabot's, but it's fundamentally the same.

I also decided to port match the manifold to the gasket. Now, I warn you, this procedure is not for the faint of heart as you are cutting into the head with the valves still in place. But what I decided to do was

1) stuff the intake ports off with a shop towel each, then mask everything off to keep the shavings out.


2) clean any oily deposits out of the intake port with a wire brush, this is important for the next step to work

3) Open each port up and seal it off (in addition to the shop towel already inside the port) with a lump of modeling clay. As long as the port is squeaky clean, the modeling clay forms a complete, waterproof seal which catches the shavings and keeps the cutting fluid from leaking down the port. In addition, I would periodically evacuate the port of fluid and shavings with a shop-vac. Once you're done, carefully peel the modelling clay back and it will hold in the remainder of the shavings. (Same principle as clay bar detailing which is where I got the idea from).


And this is what you end up with


So with all this done, I set out and did some testing.

Now, I realize that the absolute numbers are slightly lower than some runs that I've seen. This could be a result of a bit of timing pull from the warmer conditions that these runs were taken in and the fact that I did about 10 back to back pulls in the space of about 5 minutes as well (which could have been heatsoaking the manifold and cylinder walls). What's worth noting is the SHAPE of the power curve.

What was surprising is that the HP/Tq numbers at redline remained largely unchanged. However, I now seem to get a second spike in HP/Tq around 5500 RPM (likely resonance based). However, you can see that the power seems to flatline from there. I don't have any explanation for it at the moment. However, what I'm suspecting is that I've reached a point where the airflow is choking at the intake port area.


Here's a closeup of the torque production


The bad news is that I don't know that there's much I can do to increase the absolute power production. The good news is that I may be able to broaden that second torque spike with a bit of cam phasing finesse. The other good news is that this suggests to me that some actual porting work could net me some good gains.

I don't see myself porting the heads on my Cabrio anytime soon, buuuttttt..... I do have a 2004 Sedan that has another motor waiting to go into it

What additional gains can we expect by also adding jhm headers? I've heard these are the piece de resistance for the s4 exhaust system. I plan to do the full exhaust in one swoop later this year and have been eager to find awhp and awtq quotes on that.


Sent from my iPad using Audizine

[q_dubz]

What additional gains can we expect by also adding jhm headers? I've heard these are the piece de resistance for the s4 exhaust system. I plan to do the full exhaust in one swoop later this year and have been eager to find awhp and awtq quotes on that.


Sent from my iPad using Audizine

well you're further increasing efficiency so cam timing could be adjusted more.

More efficiency, easier power production. How much would be pure speculation at this point.

[Fourpoint282]

well you're further increasing efficiency so cam timing could be adjusted more.

More efficiency, easier power production. How much would be pure speculation at this point.

Thus my quest for actual numbers continues. I can't believe someone doesn't have figures on this yet.


Sent from my iPad using Audizine

[q_dubz]

Thus my quest for actual numbers continues. I can't believe someone doesn't have figures on this yet.


Sent from my iPad using Audizine

Forge ahead and be the first!

[Fourpoint282]

Forge ahead and be the first!

That's my plan, but timeline is EoY. Will be happy to share before/ after Dyno charts when the time comes.


Sent from my iPad using Audizine