Got my car Dyno'd

[P10DET]

Originally posted by P11GT
He tell me that the figures are from the flywheel/crank. Its not the first time ive used his dyno, and on previous cars, all the figures have always been at the flywheel/crank. [/b]

We still don't know the conversion factor he is using. Until we have that and the answers to the atmospheric question, the info doesn't mean much. He must be entering a calculation to convert from wheel to crank hp.

Also, if you are using maps that you had before the cams, that may be your problem. The S3 cams do not like very much ignition advance. You may be having detonation problems that are preventing you from making the hp gains you should.

[P10DET]

This was posted to the SE-R Mailing List today by Rob Cadle:


A couple of comments on the recently published C-cam test results from SCC. As I was driving home from dyno'ing that night, I noticed some weird drivability problems/hesitation that I hadn't noticed before. I figured that with all the ECU swapping that was going on, I didn't ground the ECU chassis correctly (it actually wasn't even bolted in--just sitting on the floor), and that was causing the weirdness.


Anyway, I drove the car home and parked it, and didn't look at it again for some time (the car is actually rarely driven on the street any more). A couple weeks later, I fixed the ECU, but the problems persisted. WTF??? Upon closer inspection, I found a rather large crack in my header (gen2 Hotshot--predates new anti-cracking changes). Well, two days ago, I finally replaced the primary. GEEZ!!! That was causing all kinds of drivability problems! I think that a lot of the low-end losses shown in the testing were actually a result of the header crack.


I have summarized my own dyno testing and the results will appear in the next SERCA newsletter.


With the proper header, my gains with the C3 cams were 33 peak horsepower (going from 135 to 168 whp). Maximum horepower gain was about 45 whp at 7500 RPM. The C3's lost torque relative to the stock cams below 3600 RPM. They are even with the stock cams from 3600-4300 RPM, then they take off from there.


These cams really rock, but be warned: they are really a race cam. They may require some custom dyno tuning to work on your car (the car's performance becomes very sensitive with cams these wild), and they are tough to live with day to day.


For Street cars, I highly recommend the C2 cams. The C2 cams looked much worse than they really are in the SCC tests, because they were tested last (when the header crack was the biggest--I can see daylight through it!). In my testing, C2 cams only lost about 5 ft-lbs of torque relative to the stock cams at 2500 RPM. I still made 158 whp with the C2 cams. The C2 cams can be lugged in bumper to bumper traffic 5th gear at 1200 RPM, something you can't do with the C3's. I highly recommend these for powerful street cars.


You guys who are SERCA members will get the full low-down (including dyno plots), in the upcomming issue!


All of these test results are with the *STOCK* ECU. Custom ECU programs netted an additional 2-3 peak hp with improved drivability.

[P11GT]

i was thinking of removing the Unichip piggy back ECU and doing something with the timing maually (i.e. turning the dizzy) instead of using electronics, what d'you guys think??? How many degrees should i aim for???

[Anthony]

Well, on a stock SR20DE you'll want about 17 degrees BTDC.

I'm not sure why you are removing the Unichip - last time I spoke to you, getting it tuned did increase power like it was supposed to, so I don't believe that is at fault. Removing it will almost certainly LOSE you power.

I'd get another dyno done at a different company before you go assuming that something is definately wrong and removing/fiddling/replacing bits.

[P10DET]

Originally posted by Anthony
Well, on a stock SR20DE you'll want about 17 degrees BTDC.

I'm not sure why you are removing the Unichip - last time I spoke to you, getting it tuned did increase power like it was supposed to, so I don't believe that is at fault. Removing it will almost certainly LOSE you power.

I'd get another dyno done at a different company before you go assuming that something is definately wrong and removing/fiddling/replacing bits.

You will lose power with that much advance with JWT S3 cams. They are extremely efficient at filling the cylinders and require less timing that stock. In no instance should you set base timing beyond 15 deg BTDC with S3 cams. The JWT ECU program for S3 cams actually gains additional power by removing advance from certain parts of the map.

I think you could try a few things.

One, I would try dynoing the car without the Unichip and timing at 15 deg BTDC. I am not familiar with the Unichip, but if it can control spark advance, I'd play around with removing some advance around the middle rpm. I don't know exactly where in the rev range, and how much JWT takes out (that's propietary info), but I am 98% sure it's near the middle of the map and know they pull out timing. You might find more detailed info by searching the SE-R Mailing List archives and look for posts related to S3 cams by Rob Cadle.

Next, I think a different dyno shop might be in order. Dynos are relatively easy for an operator to manipulate, either on purpose or quite innocently. Some of the questions I've raised several times should be answered. The dyno operator should not only know the answers, but should know why they are being asked and should be forth coming.

[G-Forces]

Originally posted by P10DET
You will lose power with that much advance with JWT S3 cams.

Careful George his sig says he has Piper cams. I don't know why you think he has S3's? Maybe I missed something?

But yes what George said about the S3's will still apply to the Pipers. That's what dyno tuning is all about.

[P10DET]

Originally posted by G-Forces

Careful George his sig says he has Piper cams. I don't know why you think he has S3's? Maybe I missed something?

But yes what George said about the S3's will still apply to the Pipers. That's what dyno tuning is all about.

Stupid me.

For some reason I thought he had JWT S3s and I never bothered to look at the sig. Thanks for correcting me Jason.

Uh, do I ever feel stupid.

As for the Pipers reacting the same as the S3s, I'm not completely certain about that. But, the dyno chart and general lack of gains with a Hotshot header and a CAI would seem to indicate something is a bit buggered.

As I said before, most dynos have software that can smooth the plot. If there is any smoothing applied at all to those plots, I'd say there is definitely some detonation taking place.

[G-Forces]

Originally posted by P10DET
As for the Pipers reacting the same as the S3s, I'm not completely certain about that. But, the dyno chart and general lack of gains with a Hotshot header and a CAI would seem to indicate something is a bit buggered.

What I ment by that was on the dyno it might be benifical to play with the timing in different ranges. If the Unichip allows it. But I'll also have to assume whoever tuned his Unichip knows a thing or two about tuning an engine.

[T4 Primera]

Originally posted by G-Forces

What I ment by that was on the dyno it might be benifical to play with the timing in different ranges. If the Unichip allows it. But I'll also have to assume whoever tuned his Unichip knows a thing or two about tuning an engine.

Yes the Unichip can remap timing.

Tuning with the Unichip is as about as easy and fool proof as it gets. You have 2 pots (knobs) for fuel/air and ignition timing and you adjust them while on the dyno in real time to get the best hp and emmissions figures. There are something like thirteen throttle positions and map points every 400 rpm.

If your tuner is getting paid a fixed price for tuning or remapping then you may not be getting as many points checked/tuned as if you paid on a time basis. I agree with P10DET and G-Forces that timing should be looked at. You've spent too much on the hardware to get cheap on the software now

[pche059]

For Street cars, I highly recommend the C2 cams. The C2 cams looked much worse than they really are in the SCC tests, because they were tested last (when the header crack was the biggest--I can see daylight through it!). In my testing, C2 cams only lost about 5 ft-lbs of torque relative to the stock cams at 2500 RPM. I still made 158 whp with the C2 cams. The C2 cams can be lugged in bumper to bumper traffic 5th gear at 1200 RPM, something you can't do with the C3's. I highly recommend these for powerful street cars.

Would anyone here know that if these c2 cams are still available on the market? what kinda price do they go for?
and how would you rate them compare to the JWT S3/S4 cams

and also are they cams that can be fitted without changing other components of the engine?

[P11GT]

Originally posted by T4 Primera
Yes the Unichip can remap timing.

Tuning with the Unichip is as about as easy and fool proof as it gets. You have 2 pots (knobs) for fuel/air and ignition timing and you adjust them while on the dyno in real time to get the best hp and emmissions figures. There are something like thirteen throttle positions and map points every 400 rpm.

If your tuner is getting paid a fixed price for tuning or remapping then you may not be getting as many points checked/tuned as if you paid on a time basis. I agree with P10DET and G-Forces that timing should be looked at. You've spent too much on the hardware to get cheap on the software now

Thats correct, ive seen this little box thing with two knobs that goes between the unichip and the computer, and he basically turns them to alter fuel and timing. Hes checked them and says its running good, so i guess theres not much more the unichip can do at this stage. However, i will go down and see him personally, cos its hard to get him to the phone. I know theres a few thing you guys wanted to know, what shall i ask him?? ...............it was something to do with the calculation method and atmospheric something or other................Let me know and i'll ask him for yous.

[P10DET]

Originally posted by pche059
Would anyone here know that if these c2 cams are still available on the market? what kinda price do they go for?
and how would you rate them compare to the JWT S3/S4 cams

and also are they cams that can be fitted without changing other components of the engine?

The C series cams are just now hitting the market.

According to Rob, the C2 cams are similar in performance to the S3 but I think the C2 will breath better at the top end.

With the C series cams you much use the JWT valve springs and ti valve spring retainers.

[P10DET]

Originally posted by P11GT
Hes checked them and says its running good, so i guess theres not much more the unichip can do at this stage.

You might try taking some advance out of the midrange and see how it runs.

Originally posted by P11GT
However, i will go down and see him personally, cos its hard to get him to the phone. I know theres a few thing you guys wanted to know, what shall i ask him?? ...............it was something to do with the calculation method and atmospheric something or other................Let me know and i'll ask him for yous.

1) How is flywheel hp calculated? It must be calculated since torque (and thus hp) is being measured at the wheels. There must be some conversion and it would be important to know what that conversion is.

2) Are corrections being made for atmospheric conditions, i.e. barometric pressure, humidity, temperature, etc.

[pche059]

According to Rob, the C2 cams are similar in performance to the S3 but I think the C2 will breath better at the top end. With the C series cams you much use the JWT valve springs and ti valve spring retainers.

What about the S4 cams then? are they more aggressive then the S3?
and would they be alright on a AT Primera? as in....would there be enough low end power and torque to even move the car?
or/and too much high end power that it could possibly kill the gear box at high rev?

and would the power gain from changing cams more significant then changing the header?

[P10DET]

Originally posted by pche059


What about the S4 cams then? are they more aggressive then the S3?
and would they be alright on a AT Primera? as in....would there be enough low end power and torque to even move the car?
or/and too much high end power that it could possibly kill the gear box at high rev?

and would the power gain from changing cams more significant then changing the header?

The S4 cams are definitely more aggressive than the S3. As I understand it, they have a pretty lopey idle. I don't know much more about the S4s. It seems that nobody really goes for them.

I'm not sure how they would relate to an AT. A pure guess would be that they give up low end torque for high end power. I'd stay with S3s.

The S3 cams are similar to the Hotshot header in terms of gains.