Comparison between stock and JHM tuned B7 RS4 - VAGCOM TQ/HP PLOT

B6/7 S4/RS4
#1

So we logged Mistro’s car the other day, and logged mine the same day. One of the parameters we logged was engine torque, so I thought I would post up the plot.

FIRST OFF: The VAGCOM torque metric is not a dyno. It’s not crank torque. It’s just a parameter that the ECU calculates. So you can’t compare it to dynos. You can’t compare it to crank hp. The measure the ECU puts out is torque measured in newton metres. I converted it to ftlbs and then extrapolated the HP using the standard tq x RPM / 5252

We are looking for delta here…that’s it.

So here are the two cars

Sakimano - 08 RS4 bone stockwith no passenger and 1/2 tank of gas, never carbon cleaned

Mistro - 08 RS4, JHM 93 tuned, JHM Stage IV clutch+LW flywheel, JHM LWCP piggies, JHM intake spacers, ECS Hpipe, ONE passenger (ME 245 lbs), 1/8 tank of gas, carbon cleaned 10,000 miles ago

So the Mistro car has a weight disadvantage of about 200 lbs

[b]Sakimano - 304 tq @ 5680 RPM…378 hp @ 7760 RPM

Mistro - 340 tq @ 5400 RPM…446 hp @ 7760 RPM[/b]

Most interesting how much stronger his car is up top. Carbon for me I guess along with the piggies and the tune for him. He is 12% up on me in torque, however he is 18% up on me in peak hp…

http://i375.photobucket.com/albums/oo193/sakimano/mydy_zps27a9ca70.jpg

http://i375.photobucket.com/albums/oo193/sakimano/Mistro_zpsb838997f.jpg

#2

I especially like the background in Mistro’s graph. Nice touch :slight_smile:

#3

Nice info…can’t wait until Mistro and Axel make some passes soon!

#4

It’s interesting to note that on my car there’s a signiificant bump at 5600 when the throttle opens up.

These were done in third gear and the stock tune has the annoying throttle limiter. Mine was 52.5% until 56%. Mistro’s was at 99.6% from 2000-8000 and just pulls steady to redline. People complain when tuned that they feel like they’re missing some torque. Nope…you’ve just got more all the way through the rev range, so it’s not going to hit you in the face after being artificially limited.

#5

Yeah, that instant throttle response with the JHM tune took a bit of time for me to acclimate.
By the way which Vagcom group IDs did you guys use?

#6

I usually chart group 003 (RPM, MAF, Throttle and timing I think) and in this case with the torque I added group 120 I believe. It had engine torque and a couple of other things.

my normal logging involves group 003 and 020 (timing retardation on bank 1)

another thing we measured was RPMs per second. My car was in the 580-590 range and mistro was 660.

Translated another way, 3rd gear vagcom measured 3k to 8k, my car was 8.5 seconds and mistro was about 7.5. Big gap.

We will do a race and put it on tape. I am guessing it will look like the ‘supercharged’ races we see vs. stock cars. The one run I had against 2000S4 in his JHM tune/exhaust RS4 in November 2011 at the strip was a bloodbath. He got the jump on me, but if you take that out of the equation, he beat me by 6 tenths on that pass. His best of the day was 9 tenths faster than me. That’s 9 car lengths!

#7

Thanks. I typically use 003, 020, 031. I’ll take a closer look at the advanced measuring blocks and see what may be more useful than 031.

From the graphs it appears the Vagcomm turbo mode was not enabled? I found it provides greater granularity by increasing the sampling rate.

#8

I thought it was enabled.

What is 031?

#9

I’m assuming its because we logged a lot of stuff. The more things logged the slower the overall sample rate.

I believe advanced measuring blocks let’s you pick individual measurements (vs the whole block) so you can get rid of the excess ones taking up the read cycles.

#10

I thought it was funny that someone on audizoo (Mistro crossposted this data) was saying that these measures aren’t as good as using MAF grams per second readings. He was saying MAF is a good predicter of power. I have heard some people say total MAF / 0.80 = HP. Unfortunately that’s a load of shit as we’ve seen in testing the Rs4.

Cars with exhaust modifications will post wonky MAF data. They will accelerate MUCH faster (pbox, quartermile), dyno making MUCH more power. Show VAGCOM torque plots making MUCH more power. Show RPMs/seconds that is MUCH faster. But will show worse MAF than stock exhaust.

Here’s an example from Mick…

#11

OH! And another MAF comparison…these tests above between Mistro and my car.

My car = 155 peak MAF readings (so 310g/seconds for the two banks) = supposed 387.5 hp

Mistro = 156 g/sec (so 312 = supposed 390hp.

Let’s see what his 2.5 hp gets him over me

quartermile ET = 4 tenths (this was BEFORE he got tuned mind you lol)
quartermile MPH = 4 MPH (also before tune)
3000-8000 in VCDS = 1.0 second

Clearly relying on MAF will make you look silly.

#12

saki funny you should mention the MAF readings…, as you know but others might not i live in the uk and have an rs4 and full jhm exhaust.

i recently had my car into MRC for some work, 60,000 mile service and my second carbon clean ( i am already mrc tuned but before the jhm was fitted).

whilst at mrc i got them to swap out the cat sections of the downpipes to the test pipes so now im catless. i also wanted the secondary air injection deleting in the ecu for the quieter starts, so whilst doug was poking around the ecu i asked him to see if he could tweak my map to extract any more power now that im catless 2.75" jhm.

anyway the point im getting to was when i went to pick my car up doug mentioned my MAF was faulty and he had replaced it, he said it was flowing unusually low readings for a freshly carbon cleaned car with my spec… coincidence?..

i know a dyno numbers are not everybody’s cup of tea but here they are,

original pre jhm reults-
30,000 miles,
carbon clean,
mrc stage 1 manifold(flaps removed shaft locked in place and port and polish),
oem downpipes pre cat removed(piggies)
miltek cat-back,
mrc tune,

451ps 484nm.

post jhm results-
60,000 miles,
carbon clean,
stage 2 manifold(flaps and shaft removed, more aggressive port and polish),
full cat-less jhm exhaust,
mrc tune,

442ps 502nm.

i know its only dyno numbers but i thought they would be better, doug did say my winter tyres didnt help as they over heated real quick :P.

i have vag com and will do some logging soon.
would be good if we could get some logs from someone who is jhm tuned + full jhm exhaust and compare them to my mrc tuned + full jhm exhaust.

#13

Saki can you over lay your power vs the jhm tuned power graph…

The maf part is funny… the maf as I understood has a curve and isn’t a true relationship of actual incoming air

#14

Ironically the guy whose exhaust you bought did loads of logs a d stuff so we can compare to that.

P. S. Wonder what your car would do on the dyno with a Jhm tune. Mick I believe dynod 365 whp with the tune and your exhaust. That’s about 45 whp over stock… Or about 55 crank hp over stock.

What does a carbon clean car tend to dyno at mrc… 410 crank? So 465 I would suspect.

Of course I’d much rather see your car accelerate than see a dyno. No offense to mrc but it’s not exactly a reliable predictor of performance, for a variety of reasons.

#15

The two logs have different Rpm readings so it would be a pain in the ass. I guess I could if I was bored.

#16

Lol those logs weren’t joking

We did a pull and I got my ass whipped! I had a 180lb passenger but god damn this wasn’t remotely close. That was 45-110.

http://i375.photobucket.com/albums/oo193/sakimano/Screenshot_2013-04-20-23-54-01-1_zpsa0b719c9.jpg