B8 Ko4 owners follow up thread

[Zach L]

That graph doesn't have Tq And HP cross at 5250 rpm. Is the Hp - Nm relationship different?

Only when the torque is measured in pound-force feet (lbsf.ft). That torque is measured in Newton-meters (Nm).

Even when measured in pound-force feet, the only graphs that will cross at 5252 RPM are graphs that have the same scale for both the torque and horsepower axes on the graph. The graph in question doesn't use the same scale on each side, so it wouldn't cross at that RPM even if measured in lbsf.ft

[Zach L]

NM is a higher number than TQ so it will cross sooner.

TQ is not a measurement unit. Newton-meter (Nm) and pound-force foot (lbsf.ft) are both torque, just different units to measure it.

[earhythmic]

It's how dynos are calibrated, 5252 is the standardized constant. I can't find the infographic I saved from years ago, but here's another good copy pasta from somewhere else:

Power is the amount of work that can be done in a certain amount of time and is calculated as Power = Work / Time. Power was originally defined by James Watt (inventor of the steam engine) who noted that a horse could lift at a rate of about 550 lb-ft per second in an 8 hour shift.

-and-

But where does the 5252 come from?

Watt’s definition for HP says: 1 HP = 550 lb-ft / sec, or 1 HP = 550 lb x 1 ft / 1 sec

If we convert straight-line work to its rotational equivalent the formula becomes:

1 HP = 550 lb-ft x 1 rad / 1 sec (a rad is a unit-less measure of a circular distance)

When we convert radians (rad) to revolutions and seconds to minutes the formula again evolves. Note: 6.28 rad per revolution (2 π) and 60 seconds in 1 minute

1 HP = (550 lb-ft x 1 rad / 1 sec) x (1 rev / 2 π rad) x 60 sec / 1 min)

Multiplying and canceling, the formula simplifies to:

1 HP = 5252 lb-ft x 1 rev / 1 min which is the same as: 1 HP = 5252 lb-ft x 1 RPM

So, Horsepower = Torque x RPM / 5252.

[AUDacIouS4]

It's how dynos are calibrated, 5252 is the standardized constant. I can't find the infographic I saved from years ago, but here's another good copy pasta from somewhere else:



-and-

Thanks bro!! I was having flashbacks of Physics 101 bubbling up through the bong resin

[Brandon K.]

It's how dynos are calibrated, 5252 is the standardized constant. I can't find the infographic I saved from years ago, but here's another good copy pasta from somewhere else:



-and-

...must have been a day I skipped class and slept in...come to think of it that was every day except the day before the tests my freshman year. Good thing those Physics test never had anything so simple;) lol


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[AUDacIouS4]

...must have been a day I skipped class and slept in...come to think of it that was every day except the day before the tests my freshman year. Good thing those Physics test never had anything so simple;) lol


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C's get degrees!!

But in all seriousness....k04+E85+meth hasn't been done yet.....what if......and it's a BIG what if... [email protected]....,@ Earythmic.......dialed that in and somehow broke into the magical world of elevensies???

[B8_Dude97]

Technically that's the first b8 2.0 into the 11's. I'm more curious how it pulls and see some vids of pulls from a dig. Granted it's an efr so it's a lil bigger than a k04 but I think a twinscroll efr will get the b8 into the mid 11's then add some meth


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[AllroadCorbin]

Technically that's the first b8 2.0 into the 11's. I'm more curious how it pulls and see some vids of pulls from a dig. Granted it's an efr so it's a lil bigger than a k04 but I think a twinscroll efr will get the b8 into the mid 11's then add some meth


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It’s more than a little bigger on top end flow.

Also adding meth isn’t going to shave .3 seconds off my time. That would be the equivalent of taking like 400lbs off my car.


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[spin0rz]

It’s more than a little bigger on top end flow.

Also adding meth isn’t going to shave .3 seconds off my time. That would be the equivalent of taking like 400lbs off my car.


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Meth will allow you to run a higher octane but I doubt that'll shave off 0.3.

People are ridiculous with their goal to see a b8 perform in the high 11. Half the cars on this forum can't even break 300awhp without flex fuel/meth etc.

Lettuce f23L has been the most consistent with these pulls before anyone started the hunt for the "let's get cts turbo kit owners on the track".. Ya, the f23L and.. 91 octane?

Now it's.. Let's prove 45+ buyers they didnt invest in the wrong turbo with the jhm k04r. ( Almost 2 month wait time If not more?)

Personally, I'd have gone with either f23L or hpa with a lovely turbo blanket if everyone went apeshit over that ceramic coating.


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[spin0rz]

Double posted.

[AUDacIouS4]

Ethanol based fuels make more power than any gasoline based race fuels. They carry more oxygen and with that the ability to run more spark advance which makes more power.

It's not just peak numbers either if you look at the average tq and hp in the column to the right.

Let's think this through for a second. Smellie: [email protected].
100oct + meth.
Allroadcorbin 12.3@111
93+ a splash of E85
Both ZF8
Car weights?? DA??

Smellie has tons of track experience and was running 12.7 a few months before his personal best.

Allroadcorbin went once for the first time with low ethanol content on 33lb ridiculously heavy wheel/tire combo and still managed to beat smellie on an OTS tune!! How much power is left on the table with that APR tune???

Reducing the unsprung weight by 10-13lbs per corner and yanking the spare/Jack will get you damn close to shaving off 125lbs of weight right there. Not to mention the drastic effect of acceleration with lighter wheels. Don't believe me? Poke your head over to the B8 S4 1/4 mile spreadsheet and ask those guys how much time they were able to shave off running light wheels. Plus they are all starting to run E40 blends + meth. See the trend?

I don't think it's irrational to see lower lower 1/4 mile times and trap speeds out of E85+ meth on the k04. In the mean time I want to remain optimistic until the data proves otherwise.

[Coldcarnival]

I'll have some more data tomorrow lol. Went to a no time event last week and got my trap up to 109. Running full e85*

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[AllroadCorbin]

There’s almost no power left on the table with APRs K04 file. They fueling is totally maxed out on E85. I logged A/F ratios a while back on a full tank of E and it gets a bit lean up top. The pump and injectors are at their limit.


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[Spawne32]

There’s almost no power left on the table with APRs K04 file. They fueling is totally maxed out on E85. I logged A/F ratios a while back on a full tank of E and it gets a bit lean up top. The pump and injectors are at their limit.


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well E85 requires 35-40% more fuel to make the same power as gasoline, thats ALOT more required fuel compared to what the system was designed for.

[AUDacIouS4]

There’s almost no power left on the table with APRs K04 file. They fueling is totally maxed out on E85. I logged A/F ratios a while back on a full tank of E and it gets a bit lean up top. The pump and injectors are at their limit.


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AFR/LAMBDA values you see are hitting fuel targets right? You would need to be able to compare the fuel target table vs actual lambda (which is what you should use for E85). Since we don't have access to the fueling tables that will be hard to do. So it's not an indicator of whether or not your fuel system is able to meet those requirements as much as it's telling you IT CAN. Its nor uncommon for direct injected motors to be able to run leaner, like 12.5:1 - 13.0:1 up top. You need to log fuel rail pressure and fuel pump duty cycle to determine whether your reaching the limits of the HPFP.

Also you need to see what your total timing advance is. You should be running 20*-25* or more up top and if your not your down on power.

Remember you can tune for boost or tune for power, not both. If APR is running that K04 near it's efficiency range to maximize boost pressure than more than likely they will be running lower timing. Conversely you can run a tad less boost and run more timing if fuel allows (e85) and make more power......and with meth you can have both!!

[B8_Dude97]

It’s more than a little bigger on top end flow.

Also adding meth isn’t going to shave .3 seconds off my time. That would be the equivalent of taking like 400lbs off my car.


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I was speaking of the bt a5 that is already on meth running a 11.7 with a single scroll efr. I was thinking a twinscroll plus a better dsg tune he could get into the 11.5's


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[AllroadCorbin]

I was speaking of the bt a5 that is already on meth running a 11.7 with a single scroll efr. I was thinking a twinscroll plus a better dsg tune he could get into the 11.5's


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DSG?


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[hyperunion]

DSG?


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Yeah ... "Rest of the world" b8's and 8.5's got the 7 speed dsg very similar to the one in the s4 .. tho personally I feel the zfhp8 55 is the better , more reliable and faster transmission!.

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[Brandon K.]

Yeah ... "Rest of the world" b8's and 8.5's got the 7 speed dsg very similar to the one in the s4 .. tho personally I feel the zfhp8 55 is the better , more reliable and faster transmission!.

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I agree that the 8 speed is a better “fit” for the B8. I like it 90% of the time, but think the downshifts seem a little slow when it is downshifting 3 or more gears.


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[hyperunion]

I agree that the 8 speed is a better “fit” for the B8. I like it 90% of the time, but think the downshifts seem a little slow when it is downshifting 3 or more gears.


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Definitely a great transmission!.

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[AUDacIouS4]

Looks like 6th gear is actually the 1:1 ratio gear in the zf8. 5th is pretty close, which is why it should be used for dyno pulls. All I know is that on the track 5th gear feels like a raped ape!

[Zach L]

Forget about all that. Here's how to get your easy and proper dyno right here... :)

[AllroadCorbin]

Looks like 6th gear is actually the 1:1 ratio gear in the zf8. 5th is pretty close, which is why it should be used for dyno pulls. All I know is that on the track 5th gear feels like a raped ape!

So what happens if you do a dyno run in 4th or if you do it in 7th? How would each sway the results


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[AllroadCorbin]

Follow up: started reading about the effects of using different gears on a dynoJet and there’s literally nobody that agrees on anything.


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[Coldcarnival]

Follow up: started reading about the effects of using different gears on a dynoJet and there’s literally nobody that agrees on anything.


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😂😂😂 lol

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[AllroadCorbin]

Apparently, on a dynoJet, especially with a turbo car, you actually end up losing power when you dyno in a gear shorter than 1:1. Makes sense I think. Turbos and boost rely on load. Heavier load over a longer time means more time for the turbo to spool across the same rpm band. I’m trying to find dyno graphs of people comparing same car in a different gear


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[Jake@JHM]

Apparently, on a dynoJet, especially with a turbo car, you actually end up losing power when you dyno in a gear shorter than 1:1. Makes sense I think. Turbos and boost rely on load. Heavier load over a longer time means more time for the turbo to spool across the same rpm band. I’m trying to find dyno graphs of people comparing same car in a different gear


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I believe you loose HP but gain torque, and then after 1:1 you loose torque and gain HP

[AllroadCorbin]

I believe you loose HP but gain torque, and then after 1:1 you loose torque and gain HP

My head is spinning reading all these keyboard physicists on various forums about this. Makes me want to go re do my dyno and try a few different gears


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[AUDacIouS4]

Apparently, on a dynoJet, especially with a turbo car, you actually end up losing power when you dyno in a gear shorter than 1:1. Makes sense I think. Turbos and boost rely on load. Heavier load over a longer time means more time for the turbo to spool across the same rpm band. I’m trying to find dyno graphs of people comparing same car in a different gear


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Here's my dyno from last week. Red/green is 5th gear, blue is 4th. Note the AFR though, 5th is almost a whole point richer which is more than likely the reason for the power differences.

........now @Allroadcorbin is thinking to himself......damnit! I dynoed in third, now I have to go back again and do it in 5th and make even more TQ!

[AllroadCorbin]

Here's my dyno from last week. Red/green is 5th gear, blue is 4th. Note the AFR though, 5th is almost a whole point richer which is more than likely the reason for the power differences.

........now @Allroadcorbin is thinking to himself......damnit! I dynoed in third, now I have to go back again and do it in 5th and make even more TQ!

I need to do it in 6th apparently. Apparently the gear I did it in would bring my peak whp number down since hp on a dyno jet is calculated from torque. Dang.

The chances of me driving up to NH to use the same dyno again are slim but I’d love to try


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[Perry01]

Here's my dyno from last week. Red/green is 5th gear, blue is 4th. Note the AFR though, 5th is almost a whole point richer which is more than likely the reason for the power differences.

A richer AFR doesn’t always mean more power. It really depends on your tune. A rich mixture can mean your ECU is dumping fuel to prevent knock due to high IAT’s or EGT’s. Lots of variables involved. My Gen 3 GTI makes more power with a leaner mixture.

I’m wondering why your TQ and HP numbers are a bit lower at the begining on your 4th gear run. Did the pull start at the same RPM? Maybe more load in 5th gear generates a quicker spool up?

[A4x]

Here's my dyno from last week. Red/green is 5th gear, blue is 4th. Note the AFR though, 5th is almost a whole point richer which is more than likely the reason for the power differences.

Generally a leaner mixture makes more power.

A richer mixture is safer for the engine.

[AUDacIouS4]

A richer AFR doesn’t always mean more power. It really depends on your tune. A rich mixture can mean your ECU is dumping fuel to prevent knock due to high IAT’s or EGT’s. Lots of variables involved. My Gen 3 GTI makes more power with a leaner mixture.

I’m wondering why your TQ and HP numbers are a bit lower at the begining on your 4th gear run. Did the pull start at the same RPM? Maybe more load in 5th gear generates a quicker spool up?

All pulls started at 2500rpm. I was talking about that with the tuner at the dyno. He thought the ECU is essentially running in closed loop the whole time and when the meth is on the ECU keeps trying to lean out the AFR. We learned that because we did 4 pulls with meth on and then 4 with meth off. If boost builds faster in 4th at those low RPM'S, that starts the meth injection earlier and the water/meth has less time to provide cooling/octane due to quicker spool up. In 5th that all happens slower.
You make some great points but I would still lean towards the AFR having the biggest impact in my situation.

What's interesting is that you could take two identical cars and tune each of them differently. One could tolerate richer fuel or more timing than the other or vice versa????

[hyperunion]

Looks like 6th gear is actually the 1:1 ratio gear in the zf8. 5th is pretty close, which is why it should be used for dyno pulls. All I know is that on the track 5th gear feels like a raped ape!

Definitely true about 5th gear! Feels like a 2nd set of afterburners go off!!!

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[Perry01]

Generally a leaner mixture makes more power.

A richer mixture is safer for the engine.

Generally speaking yes but lean AFRs don’t offer in-cylinder cooling to prevent engine knock. Richer AFR’s can result in less knock which in turn may result in the engine making more power and staying safer. Like I said earlier, there a lots of variables involved. It really depends on your tune and how your tuner generates the power

[Coldcarnival]

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[B8_Dude97]

Damn 140. How many Jdm stickers did you need to those extra 400 hp???

But seriously that's a nice e.t.


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[AllroadCorbin]

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Dang. Good 60’. I guess being in a lighter sedan and not an Allroad is helpful lol. If I had that same 60’ I would have been in the 12.2s.


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[Coldcarnival]

Dang. Good 60’. I guess being in a lighter sedan and not an Allroad is helpful lol. If I had that same 60’ I would have been in the 12.2s.


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Thanks felt a big difference in power just letting the car cool down for 30 mins in between runs. What did your car weight last time you went out? Cause I'm still at 3950 with half tank and me.

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[Coldcarnival]

Damn 140. How many Jdm stickers did you need to those extra 400 hp???

But seriously that's a nice e.t.


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Thanks lol

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