NCLA951

Had a moment today after sorting all my filters, belts, hoses, wheel bearings, oil pressure sender, etc, to do a quick run with the iphone dyno. Conditions weren't perfect for the phone, it was in the same place for the 2nd gear pull from 2-7k, but as soon as I got on the brakes it found its way to the passenger floor board, so will be done again soon with proper iphone mounting. Just wanted to post for feedback. Car has good old weltmeister TC8200 chips and WG shim, LBE, 3bar FPR, KN filter in stock air box, and 3" turbo back exhaust. Results were 267hp crank, 227hp wheel, which seems right and good for a 28 year old engine with 107,000 miles. I've attached the graph as well. Don't all tq/hp curves cross at 5200? Why would my graph cross 1000rpm lower? I double checked the gear ratios against Clarks garage numbers for my trans. How does perfexpert know rpm?

Also, I know the 26/6 won't hold boost to redline, which is probably one of the reasons power drops above 6000, but is the sine wave like fluctuation of the power above peak normal for these cars? For curiosities sake what might that indicate? For perfexpert users the graph is on low smoothing to show more the fluctuations.

Thanks!

Sam

Dave W.

The power looks good for minimal mods. HP and torque will cross at 5250 only when the HP and TQ are scaled the same. The sine wave at high rpm could be due to rounding errors in the software. Can you feel the power surge and dip at high rpm?

NCLA951

I used to feel a slight surging at part throttle that cleaned up when I put in a new fuel filter. Looked like it had been in there a while. I did not however notice a surge during this run, just a pronounced dip in power heading towards 7k, so not a lot of temptation to push it past 6500 now. I was a little surprised when I blasted right past the 6750 that the weltmeister chips are supposed to limit at.

When I do DIN correction instead of SAE (German car right?) it gives me almost 280hp calculated at the crank, free horsepower

And yes I see how the scales are different, they would in fact cross at 5250, thanks!

black944 turbo

It looks surprisingly good for an I-phone ap. I had my car dyno'd years ago with a similar setup but with a maf and a professional tune and yielded 246 whp at 15 psi max.

NCLA951

The only baseline reference I have is a pdf of the original weltmeister brochure which has the numbers of the chips/WG vs stock. Add the 3" exhaust and I think I'm in the ballpark.



The weltmeister PDFs torque curve does start much higher, maybe on their 1987 dyno run they had some boost built at low rpm. Otherwise the curves of this and the app curves seem to match pretty well. Doubt I'll get much more without WG/boost control/turbo upgrades. Then injector/inter cooler/clutch upgrades...