Bad/Odd Day at the dyno

[andru1313]

Ok I am lost on this one. I took my S4 to the dyno today. Stg 2+. First time on the dyno.

Shit day hot and humid. about 90 Degrees. Let the car cool for an hour before I hopped on. It is an inertia(spelling?) dyno. Turn the car on strap it on and bam... First 4th gear pull 284 with 391 tq. I am like wtf? But this is where it gets odd...

I put the car in neutral let it cost back down rpms hit 1000 then all of the sudden start to go back up. I had to kill the ignition. I have no clue it did it on all 3 pulls. Each pull the numbers got worse.

I have a GIAC chip and miltek exhaust. Anyone have any sugestions? I am really puzzeled. I will post my dyno runs as soon as i get them as well as my vag log. The car when I drive does not do that at all with the throttle. I am starting to freak out about it.

[JDM EJ1 95]

wait.. whats wrong here/


power looks good..


wtf are you trying to say?

[lrg8683]

the numbers get wore because your intercoolers are miniscule and get heatsoaked.. and 284 seems a little high for just chip and catback.. but i could be wrong.

[S4-ORCE]

Usually dyno pulls are done in 3rd gear FYI

[speedydragon]

damn that's a lot of tq for a stg 2+!

[andru1313]

My issue is the rpms shooting back up after I was off the gas. It shot up on its own after it went back down to idle. I did a 3rd gear pull and numbers sucked. had better results in 4th gear.

[obviouspro]

how far up did they shoot? I have had instances when the rpms drop to idle then go up to about 1200 then come back down but that has only happened a few times.

[andru1313]

all the way back up to 6000rpms that is why I had to kill it.

[s vier]

you have almost 80 more tq than mine.....what? hp seems right though

[Das General]

the numbers get wore because your intercoolers are miniscule and get heatsoaked.. and 284 seems a little high for just chip and catback.. but i could be wrong.

he is 2+ the numbers seem very good. and yea they are going to drastically drop if you don't have intercoolers or give ample time in between the runs.

as for the revs going back up...not quite sure.

[andru1313]

Well the Rev thing is freaking me out. I had to kill the ignition to stop it from reving. It was the craziest thing i have ever seen. The only other thing i could think of was a bad ground when they hooked my car up. IDK.. It does not do this on the highway.

I am happy to see that the numbers were not as bad as I thought. I was thinking i would be closer to 300 atw. I will post up the dyno chart and vag when i get them.

[Sleeeper X]

how do you have that much tq

[S4evr]

yea that tq is crazy.. i hit 400 awtq on a dyno dynamics and im stage 3 which is fairly average.

[Das General]

What dyno were you on?

I barely hit 340 on stage 2+ at Philly Dyno Works

[Matt@JHM]

I wonder if it has anything to do with your cruise control malfunctioning. What else could explain the car reving by itself to that degree?

[Boris]

are you sure it doesnt have anything to do with the inertia dyno?
if it did it every time on the dyno and never off of it, theres got to be something about the dyno/session causing it

dont worry about it!

[s2the4]

My issue is the rpms shooting back up after I was off the gas. It shot up on its own after it went back down to idle. I did a 3rd gear pull and numbers sucked. had better results in 4th gear.

You numbers kept going down because 1.) you most likely have stock intercoolers. 2.) it was real humid in the new england area today. As far as your rpms shotting back up, is there anything wrong with the car after it came off the dyno?

[lrg8683]

last time i dynoed my car at stage 2+ i got 306 whp and 366 wtq. and i think dynoing in 4th gear inflates your numbers.

[AudiTechS4]

it shouldn't inflate your #'s using a longer gear , 3rd should result in larger number than 4th right ?

[Skydive@AI]

Ok I am lost on this one. I took my S4 to the dyno today. Stg 2+. First time on the dyno.

Shit day hot and humid. about 90 Degrees. Let the car cool for an hour before I hopped on. It is an inertia(spelling?) dyno. Turn the car on strap it on and bam... First 4th gear pull 284 with 391 tq. I am like wtf? But this is where it gets odd...

I put the car in neutral let it cost back down rpms hit 1000 then all of the sudden start to go back up. I had to kill the ignition. I have no clue it did it on all 3 pulls. Each pull the numbers got worse.

I have a GIAC chip and miltek exhaust. Anyone have any sugestions? I am really puzzeled. I will post my dyno runs as soon as i get them as well as my vag log. The car when I drive does not do that at all with the throttle. I am starting to freak out about it.

What kind of dyno were you on? I'm betting it was a Dynojet. Dynojets typically yield very high numbers.

Your third gear pull may have yielded numbers which "sucked" but they were probably more accurate. The numbers you have now are not useful as a comparison tool to any other car which was not also done in fourth gear.

As others have pointed out, your numbers fell on successive pulls because your intercoolers became heatsoaked and your IATs probably hit the moon.

What kind of cooling system was available?

It sounds to me as if your dyno operator wasn't particularly knowledgeable, so you may have made an experiment, but the results don't mean very much.

Sorry.



-Michael.

[sCeRaXn]

Yea...horsepower is a simple calculations of the amount of work(tq) done over a certain period of time(engine speed/rpm). Therefore, doing the same amount of work over a shorter period of time will usually net you more power. There are instances when this isnt the case, but its a good rule of thumb. Also, 3rd gear pulls on our cars dont give real world numbers. Theoretcally, you should always dyno in your open gear(1:1 ratio or clostest to it), that way your trans gearing isnt drastically altering your power output. With the 01e trans, the open gear is 4th with a .97:1 ratio. 3rd gear is good for impressive numbers, but dont give a true reading of real world numbers.

[Europowerhaus]

My issue is the rpms shooting back up after I was off the gas. It shot up on its own after it went back down to idle. I did a 3rd gear pull and numbers sucked. had better results in 4th gear.

no one is even answering his question? screw the hp/tq shit for now, he has a runaway accelerator...bad.

[JMTx86]

Usually dyno pulls are done in 3rd gear FYI

or 4th

no one is even answering his question? screw the hp/tq shit for now, he has a runaway accelerator...bad.

cruise control on the dyno! im just kidding.

[andru1313]

no one is even answering his question? screw the hp/tq shit for now, he has a runaway accelerator...bad.

Thanks. Doesn't seem that anyone knows. Appreaciate all the feedback but the throttle is an issue and just got my log numbers it appears that my car is starving for fuel as well. Alot of the injection percentages were over 100% went even as high as 116%.

Third Gear
RPM MAF RPM Inj PW CamOpen 80% Inj Inj %
(g/s) 4160 26.86 10.26 23.08 93.11
3960 213.78 4440 25.16 9.61 21.62 93.09
4160 221.44 4720 25.16 9.04 20.34 98.96
4240 225.00 4960 26.86 8.60 19.35 111.02
4440 215.22 5280 26.18 8.08 18.18 115.19
4520 216.33 5560 25.16 7.67 17.27 116.57
4720 225.53 5800 24.14 7.36 16.55 116.68
4800 232.53 6040 21.76 7.06 15.89 109.53
4960 243.92
5080 244.64 4080 23.46 10.46 23.53 79.76
5280 254.00 4480 23.8 9.52 21.43 88.85
5360 256.19 4920 23.46 8.67 19.51 96.19
5560 260.94 5360 24.82 7.96 17.91 110.86
5600 260.69 5800 23.8 7.36 16.55 115.03
5800 262.06
5880 257.31
6040 256.19

3760 196.33
4080 206.61
4200 215.19
4480 207.92
4640 210.31
4920 229.81
5040 242.44
5360 249.94
5480 256.31
5800 256.81
5920 255.83

[andru1313]

What dyno were you on?

I barely hit 340 on stage 2+ at Philly Dyno Works

It was dyno'd at philly dyno works. I am still waiting for the results via email.

[Skydive@AI]

no one is even answering his question? screw the hp/tq shit for now, he has a runaway accelerator...bad.

...because none of us were on the scene, and the problem as described does not have an obvious answer. The only thing I can think of is that the car may have been trying to respond to odd load factors created by a dynamometer which is incorrectly calibrated or poorly operated, but that's PURE speculation. The bottom line is, if the behavior is not occurring when the car is driven rather than strapped to a dyno, I'd find a different dyno facility and operator, and call it a day.

If the car exhibits the same behavior on another dyno, I'd dig further.

-Michael

[generationjdm]

Isn't 4 gear closer to 1-1? Theres 1 thing most of the unusually high hp cars have on the dyno and thats extremely high tq which is what they calculate hp by...

[sCeRaXn]

Yea like i said 4th gear is the open gear with a .97:1 ratio. I think 3rd gear is around 1.25-1.3:1...which will definitely make a difference in numbers. The only time 3rd gear should be used for a pull is if thats the open gear or if youre doing a gear based tune...other than that its just for bigger numbers. Alot of shops do third gear pulls to make their customer happy with more power than they were expecting.

[Skydive@AI]

Fourth is 0.967:1 whereas third is 1.231:1. Fourth is the closest to being an open gear, and will theoretically yield the most "accurate" result.

[andru1313]

Anyone have any thoughts on the throttle and the log i posted about the fuel?

[SoEvoL]

Other than the really high trq I dont see anything wrong, far as the revving up goes are you talking about idle seeking like from a manifold leak?

And you always do dyno pulls based on the gear that is 1:1 or close to it.

[damnthemansam]

maf seems low.. are you true stg2+? chip exhaust and dps? is so maf should be around 280 g/s..

[generationjdm]

the high TQ does effect the hp.. I've been saying pulls should be done in 4th for a year, but some people acting as if thats wrong...

[sCeRaXn]

Is there an echo in here or what? lol

[andru1313]

maf seems low.. are you true stg2+? chip exhaust and dps? is so maf should be around 280 g/s..

Here is acomplete list of mods done to the car as well as repairs that were done. I am not trying to come across as a n00b just would like some help with this before I go ripping stuff apart. Car has 62k on it now.

Maintenance or Repairs

• Newly rebuilt passenger side K03 turbo @ 38,200 miles (drivers side was checked out and tested ok)

• 6 new stock NGK spark plugs (3 months ago @ 37,495 miles)

• 6 new stock coil packs (3 months ago @ 37,495 miles)

•
• Mobil 1 0w-40 Synthetic oil and OEM filter used every 3-4k miles. It currently has Pennzoil 5w-40 Euro Synthetic Platinum

• Coolant flush performed @ 38,200 miles

• RS4 clutch kit with VAST resurfaced flywheel installed @ 38,200 miles

• New clutch slave cylinder, pilot bearing and throwout bearing installed @ 38,200 miles

• New coolant expansion tank

Modifications

• GIAC 93 octane chip

• Piggie Pipes (downpipes)

• Milltek SuperDual exhaust (Very sexy sound but not loud - I will miss this the most)

• UUC short shift kit (40% reduction) with shortened (rethreaded) shaft. Stock shift knob and boot are retained.

• UUC Drive train stabilizer bar

• STaSIS Tracksports 500/600 Front/Rear spring rates (shock adjustment holes have been drilled)

• H&R 17mm Rear Sway Bar

• AWE Intake

• Forge Diverter Valves

• Achtuning! Front Mount Oil Cooler

Additional Parts (not currently on the car)

• VAST manual boost controller.

22mm rear Neuspeed Sway bar

[Skydive@AI]

Here is acomplete list of mods done to the car as well as repairs that were done. I am not trying to come across as a n00b just would like some help with this before I go ripping stuff apart. Car has 62k on it now.

• 6 new stock NGK spark plugs (3 months ago @ 37,495 miles)

• 6 new stock coil packs (3 months ago @ 37,495 miles)

The car had 37,500 miles on it 3 months ago, and it has 62,000 miles on it now? Unless my math is gone, that's nearly 25,000 miles in 90 days. Damn, man... that's some driving you do!

I don't think you have a good reason to rip anying apart just yet. Take a deep breath, and find someone who can pull some logs with ECUx. Post the results, and proceed with diagnosis.

For II+, you car isn't making horrible power as is. Change your fuel filter, check your fuel pump, and fuel pressure regulator, and MAF, first.

-Michael

[andru1313]

The car had 37,500 miles on it 3 months ago, and it has 62,000 miles on it now? Unless my math is gone, that's nearly 25,000 miles in 90 days. Damn, man... that's some driving you do!

I don't think you have a good reason to rip anying apart just yet. Take a deep breath, and find someone who can pull so longs with ECUx. Post the results, and proceed with diagnosis.

For II+, you car isn't making horrible power as is. Change your fuel filter, check your fuel pump, and fuel pressure regulator, and MAF, first.

-Michael

Sorry that was from over a year and half ago. Forgot to take those figures out.
Here is the data from the other vag log. Might be hard to read.

[BurnAll4S4]

the high TQ does effect the hp.. I've been saying pulls should be done in 4th for a year, but some people acting as if thats wrong...

no you are right...on our cars and for mostly any 6 speed car dynos are done in 4th gear. 5 speeds are done in 3rd.

[sCeRaXn]

Actually most 5 speeds have 4th as the open gear as well. The Audi has basically 2 overdrive gears in 5th and 6th, in fact alot of 6spds do. Any gear that causes the wheels to rotate faster(or "overdrive") than the motor is an overdrive gear, so any gear past the open one is an overdrive gear. Some 6spds like the 08 and up Sti only have one overdrive, so they would dyno in 5th, but most older 6spds ive dealt with is like the s4.

[tike0rz]

So its better to dyno in 4th gear?