Dyno Results 07/03

Tested with Tube Header and T3/T4 turbo, stock MC Cam, 17psi boost pressure, 3" exhaust with/o cat, 8.4:1 compression, and 034EFI Stage IIb fuel/ignition system running 45lb injectors. Initial timing set at 12degrees BTDC. Ambient was about 85F, small 2' fan, 4-wheel DynoJet. Also upgrade/changed since the last pull is the much larger Stage II IC with 2.5" intake plumbing vs 2.25". Also, the equivalent of 95 octane fuel in the tank to prevent detonation.

Max Wheel Power: 256.1 @ 6100RPM

Max Wheel Torque 265.7 @ 4300 RPM

Note: Green lines indicate 08/02 dyno run for comparrison purposes

 

This equates to about 310-330 flywheel hp and 325-340 ft/lbs torque depending on your correction figures. Most interesting thing to note is that the motor made 26 more hp with 1 psi less boost, more on this later. Dyno tuning on the rollers is hardly the ideal enviromnent to make power, the small fan they have at ATP just doesn't do justince, and the air filter ends up really eating a lot of hot air, and the motor just really heats up in general due to the overall lack of airflow, I really felt this happening this time in particular.

Preface

Overall I was very happy with the results, I was anxious to get the car on the rollers ofter finishing development on the new 034efi Stage II controller, in its current configuration I call it the Stage IIb meaning distributor ignition control as well as sequential injection. The last time I was at the dyno I was running the original 034efi ECU that was fuel only, and had configured the CIS3 ignition system to handle ignition duties. Using the CIS 3 max boost timing is relatively easy to set, but that throws the rest of the curve off, resulting in too little advance under the rest of the load curve. Using the Stage IIb I now have the ability to tune my ignition curve based on RPM, MAP, and air temp. Also included in the mix are the centrifugal advance and the vacuum advance of the distributor. The car has never run better, and being able to tune the ignition to such a high degree has allowed for a very powerful, responsive, and most importantly, detonation free motor.

The First Few Runs

Well, as always, the first run is dissapointing. I tuned the car extensively on the street and was getting a rock solid 18.5psi, car has never been faster. First pull it barely registerd 14psi and made about 215hp, bummer. Looked at the lambda cure, everything looked a little lean, and it was going pig rich above 6200rpm. I made some more adjustments to the fueling, and turned the boost controller up a turn to get the boost back up. Second run, same story, I think it laid down maybe 218hp, better fueling across the curve, but boost didn't budge. After about 2 more runs in a row like this, wtih more boost adjustments and no boost increase, the fact that there was tons of heat around the airfilter was making me suspicious, and the fan just wasnt' getting any air to it. So, I pulled the pass. headlight and pointed a fan right at the filter, now there was a steady stream of cool air pushing the heat back away from the filter. Well, guess what? Ran the car up to speed again, floored it, and the boost spiked right up past 20psi, with no other changes to the boost controller...well damn! On that run, even though we let off right when we saw the spike, it still made like 208hp at 3500rpm, pretty cool.

On The Right Track

So, now we're making some boost, I turned the boost valve down 2 full turns and we did another run. This time a rock solid 16psi, and 245hp...now we're on the right track! So I said hell with it and pulled the air filter off all together. No changes to the boost controller and 17psi, 256hp, that air filter was worth 10hp alone. All the while I was making tweeks to the fuel and ignition curves, etc. So, now I know I've got to do something about that airfilter on there, so that will be the next project thanks to the dyno #'s. I was tempted to turn the boost up again and see what she would do, but after about 12 dyno runs in a row I figured we better let her rest, plus after 2hrs my bill was racking up.

Hoodlum Air Filter

Ok, so what's up with the air filter? Well, I'd like to believe that all the heat was causing a problem, but all the while I can monitor air temps on the 034efi monitor screen, and even sitting still accelerating on the rollers my intake temps weren't increasing more than 25F, so I don't really think it was the heat. It makes me wonder if the air filter isn't just trapped in a really restrictive part of the fender? On one side it butts up against the headlight, the top of it is square into the fender, and the other side is trapped by the turbo. On all sides its blocked by something, I think removing the headlight opened up a large amount of air to the filter and allowed the motor to breathe, thus resulting in 5psi more boost pressure. Removing the filter all together gave 1psi increase and even more power. So, no question, relocate the filter and something bigger, period.

Observations: Note, green line is the best 08/02 dyno pull

-Note that max. power over 250hp extends from 5200-to just over 6300 RPM, and torque stays above 250 ft/lbs from 3800 to 5400 RPM. Max power of 256hp lasts from 5300 to 6100rpm, lets see those "turbolag-less" NA cars do that =)

-Power comes on sooner than it did in the last dyno run as well, about 2-300rpm sooner, helping to equalize torque and hp closer to each other. I equate this increase with a better timing curve as well as the larger, freer flowing IC. Also, important to note, its making 25hp more with 1psi less pressure which I also equate with timing and IC flow and efficiency. And in all fairness, i was running the airfilter last time as well.

-You can see that the T3/T4 really comes into full song by about 3800rpm. Initially I thought the large new IC was causing a pressure drop, but according to the dyno plot, we're making more power sooner than with the old IC, so guess my butt is a little off.

-It was still going really rich above 6200rpm, and unfortunately I didn't get a chance to tune that out in dealing with all the other issues, but it didn't seem to effect power too much, you can see it glitches a little compared to the last run, the red line. Its clear that power starts to fall off above 6krpm, not terribly so compared to say a K24 equipped car, but in the future I'll be testing a 270/264 custom turbo cam to see if we can't extend that power out a ways.

-15psi is the max I've been able to run on the CA 91 octane, in order to go higher and to maintian some timing at WOT a mix of 100octane is a must. Granted URS4 guys run 20-25psi on 91, not sure exactly how that all plays out however, but I haven't seen an URS4 20v make this much power on even 20psi and 91. In the future I'd really like to get boost to 20psi with a 50% mix of 100, I believe that 300whp isn't too far off, and this is the amount of boost I plan to run at the track with 100oct is available.

Other 5 cylinder Dyno Plots:

-Tony Lum's 10-valve UrQuattro with K24 and CIS at 15psi made 152 wheel hp, download the PDF

-Brenden Rudack's 034efi equipped, RS2 turboed Type 44 quattro, made 259hp but interestingly only 219ft/lbs torque dyno plot

-Mike Pederson's 2.2 highly modified 20v UrS4 at 3 different boost levels - See Jpeg

Stay tuned for more upgrades and dyno testing in the future.

Email Javad Shadzi for any thoughts or questions