Procharger Dyno'd
 

I finally have the car tuned and making boost. Here is the list of mods and the dyno sheet itself:

'00 Trans Am
Procharger D1 - Max boost is at 5lbs (4'' pulley)
MTI B1 Cam (221/221 .558 114)
Long Tube Headers
Off Road Y-Pipe
Hooker Aero Muffler
Built 4l60e
TCI SS3500 2.5 (Now stalling to 4000)
Stock 10 bolt with 2.73's

Take note - The dyno numbers are with the converter unlocked

Dyno Sheet

Thanks for all your help guys...even if most of it was just browsing through your threads.

:cheers:

if thats 12.0 a/f on the dyno then your running lean on the street, be careful

:bomb:

Thats not what I want to hear. Should I take it back to the tuner?

Looks like the belt is slipping. Your power stays flat then dips downjust a bit and back were it was.

There is something wrong with that pic. YOu make great power at first and then it just drops to the floor. I know heads and cam car that are on the mild side like mine that make more power. Chech you belt. Also do the make an exstra belt tentioner SP so the belt raps around the pully more.

Should I be concerned?

Are u sure u are seeing 5psi on a mechanical gauge? That dyno sheet doesnt look right at all. Did u get any knock on the dyno? How much timing are u running? Your AF looks good. 12.0 is great and u dont have to worry about it. That is one weird looking graph.

No knock at all on the dyno. Not sure about the timing.

The 5psi is on a electronic gauge (Autometer Cobalt)

Try hooking a mechanical gauge and see how much boost u would get. Also what did the car dyno before the SC?

ummm 12.0 on the dyno is almost 13 on the street, its a known fact. Most say FI cars need to be 11.5 or so.

Car dyno's 299 316 stock. I have added a lot of mods along with the supercharger.

I looked at another dyno in the dyno section and found a similiar graph, but he has more HP, I am thinking I am running into belt slip.

:barf:

https://ls1tech.com/forums/showpost....1&postcount=12

I know for a fact that when i see 12.0 at the dyno i will see 12.3 at the most on the wideband gauge at the steets. I have tried the same thing with more than one car. I never saw an increase of 1 point AF between the dyno and the street. Its due to the fact that the street has more load on the car than the dyno and the tune tends to lean out a little bit. My car is tuned at 13.0 at the dyno and i see 13.3-13.4 at the streets... My can is N/A, but when i install my SC i will tune it between 12.3-11.7 at the redline on the dyno (that means i will see 12.7-12.0 at the wideband AF gauge). As u know SC'd cars gets boost by RPM so u need increase fuel by RPM too. So u want to see 12.5-12.0 at the redline for maximum power. Now if this car is a turbocharged things would have been change.... I would recommend running leaner just before the turbo spool, but really rich (11.7) at peak TQ and then hold it steady to 12.0 at redline. This is how i see the best tuners in my area tune their Twin Turbo or SC'd cars. Just thought i share what i saw done with 900rwhp+ cars.

Well thats some damn good info, thank you. Tuners around here are overly safe i guess ;)

Don't forget he is running a 35shot of NOS. Thats why he saw 475rwhp. Maybe u just need to get a smaller pulley and give it more boost. Im sure u would have seen the belt slippage problem on the gauge. Try a 3.4 pulley and see where that puts u. Make sure u have a fuel pump and injectors to support it though. I would also try to put it at the dyno and give it more timing, but watch your knock while you are doing that. See if she likes 1 or 2 degree or timing. If the car responded with power then give her more until u see knock and then just back it off a little bit. Good luck man.

Thanks guys.

The car feels great, I guess I will tighten the belt down and see if that helps.

with the cam your using your bleading off alot of boost. I bet your only making like 3lbs. Try swapping the pulleys. Or go with a good blower cam. something like a 218-224 on a 115. Also I would watch that A/F. On the dyno it should be around 11.5. you wont see more power but itll help to keep your motor together. good luck.

Thanks!

A/F also depends on timing too.I tune the cars for 11.5-1 on the street(11.0 on my dyno) with it toping out at 11-1 at the rev limiter and add 1 more degree of timing compared to a leaner 12.?? tune.The fuel helps to cool the cylinders.

your graph looks like the converter is slipping too much.I get that on unlocked Nitrous cars.

Slowhawk,

I am thinking its the converter too, its a TCI SS3500 2.5str. Not really a good choice for a supercharger.

That is a common dip in hp for a non-efficient auto-torque converter. His torque curve is pretty much flat which is also common for an auto car.