The links to the dynos are below.

I previously dyno'd stock, with y plus SI, and most recently after the addition of the Unorth. UDP.

The results: Comparing the UDP dyno with the Y/SI dyno, there was no change below 5100 rpms. Above 5100 rpms, it lost power (increasingly) all the way to redline. In fact, it lost the most at peak - about 13-14hp - and ended up basically back to stock peak.

I do not believe it was related to the dyno. I tested on the same dyno with the same operator as before - and ran it 4 times - all the same. I noticed that the fuelcut spike seems to be at a lower rpm (6300). However, it still cuts at 6600. This is the only thing that causes me to question the dyno.

Also, the intake manifold is switching over at 5200 as it should. (Madmax2k visually verified).

Madmax2k, the dyno operator, and I discussed the possibility that the computer was pulling timing. The UDP has a timing ring, could it be defective or somehow installed incorrectly?

I have not ruled out that this problem preceded the UDP. I stalled a couple of times prior. Basically, if I am accelerating hard and then suddenly brake and push in the clutch (i.e. catch a light), the car will stall sometimes. So, the problem could predate the UDP.

Any ideas? Sorry for the long post.




Dynos:
This one is an overlay of stock dyno, y/SI dyno, and the most recent y/SI/UDP.

http://web.tampabay.rr.com/maxgator/...revsafter2.bmp
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This is an overlay of just y/si dyno and y/si/udp.

http://web.tampabay.rr.com/maxgator/beforeVSafterUR.BMP
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This is the UDP with an air fuel plot as well.

http://web.tampabay.rr.com/maxgator/airfuel.BMP
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definately check your timing; it's possible that the marks on the pulley are off or your timing setting is off.

 

John, I know you must be disapointed with these results. I'd like to take my car back to have it re-dynoed too. The only thing I can think of is the high humidity we're having could possibly be giving you lower numbers. Is this also the first time you've dynoed since he's moved his shop?
Shoot me an email with his new address so I can bring mine in.

Terry

 

Terry, the results you saw were SAE corrected. My understanding is that should take care of temp/humid differences. I'd suspect the dyno more if there was a change below 5100 but there isn't. I really should have had Larry dyno that day for comparison.

However, I've confirmed from driving that the dyno is correct. It used to pull from 6000-6600 and want to go past there. It just doesn't seem to do that now. BUT - I think it started doing that before the pulley. So, I'm confused. What else could cause that problem?

I'll send you his address, but we'll have to set something up through Larry. I may go ahead and have Dave remove the UDP - then re-dyno.

Did you have yours dyno'd at the old shop before your UDP?

 

Yes, I did have my dyno done BEFORE the UDP. I just had the plugs and fuel filter changed, so the car should be in perfect running condition. I'd hate to see you have to get it uninstalled just to have it re-dynoed. I leave town on Thursday so maybe I can run it over before then.
We'll get to the bottom of this.....

Terry