Well I got the car dyno tuned today and ended up with 418rwhp and 408rwtp. I was hoping for at least 475rwhp if not 500rwhp. So where is my 75hp?!?!

I have a 3.6" pulley on there using the standard 6-rib set-up. On the first run there was some audible belt slip and it made 3lbs of boost. After tightening up the belt some more and a few more runs it peaked at 5lbs. Is that right for that size pulley? The boost was climing with the RPM's until redline so I think it had stopped slipping.

On the graph, the blue shows a run with the cutouts open, and the red shows it with the cutouts closed. I gained almost 20rwtq but only 2rwhp which seems very odd to me. I have cats AND Flowmaster cat-back. I am not sure why bypassing that restrictive **** would only gain me 2rwhp. I would of guessed at least 20rwhp gain from open cutouts.

I think 418rwhp is great, but not for the money that was shelled out for a Procharger kit. I know a 2001 with identical mods, same size pulley and boost, and made 501rwhp. I am honestly considering selling this kit and just going with a stroker kit. All of my mods are on my website in sig.

Thanks for looking.

 

Well from my understanding, a D-1SC with the original pulley should make around 8lbs of boost on a stock engine. I'm not sure how much your better cam affects the boost reading. Since boost is just a measure of restriction.

You might need an 8 rib setup, just because it isn't audible doesn't mean it still isn't slipping. But there's something you need to fix. You're right, you should be making 475-500rwhp...

 

couple of questions

1. Where are the cutouts before or after the cats?
2. Do you still have the screen on the maf.
3. What intake do you have
4. How many pounds of boost are u trying to run and how many are u seeing.
5. What kinda timing are u running.

 

1) Before the cats, pretty much right off the headers.
2) No
3) Stock LS1
4) I am not sure how much I am supposed to see, but I only say 5psi max. I was expecting a little more to be honest.
5) 18 degrees... in case I want to get a smaller pulley in the future.

 

You need to find out if your belt is slipping. Most likly this is your problem or loss of boost somewhere

 

Well, I'm not sure how much of an issue belt slip is right now. I saw on your car domain you have a bracket by Force Fed Performance. I thought you were on the bone stock setup, but who knows. That's one thing to look at. How does the run look using a scan utility... any KR? Anything out of the ordinary? Did you check for leaks ie. EGR, hoses, bypass, whatever ?

 

zero knock about 18 degrees total up top.

I just realized thats a uncorrected graph too! weird? it was a cooler day too so that means SAE number are gonna be lower, I will take a look tommorrow.

 

With that size pulley , on my car, with headers = 8 PSI at 6200 ish.

Now running a 3.4 making about 10 lbs and 507 RWHP on an unlocked automatic.

IMHO, sounds like you are having an issue with belt slip!

 

BELT SLIP

SDCE

But really belt slip is a major issue with the 6 rib ATI set up. Try a goodyear gatorback for now, cheapest option....tighten the crap out it and see where your boost sits at then.
J

 

I will all so say belt slip. Might want to think about the ATI Superdampner and 8 rib set up. Works great for me seeing 8-9 psi on a 3.7 D1SC. Made just over 500rwhp, stock block & 1.85 arms. Headers and cat back

Have seen tire slip on the dyno as well, did they push down on the back of the car during the runs? Might want to think of that next time as well.

 

your wasting your time with the 6rib.
but still at least to dyno you should be able to crank it down enough to not slip for a run or two.
either find a MMS crank pulley or do what every buyer of an ATI should do from the start and buy the SDCE spring tensioned setup.
you should be making ~500 rwhp.
don't discount valve float either if you have not changed out your valve springs. see how your power stops at 5k. it should definetly keep climbing.

 

There aren't any boost leaks. The bracket has two idlers instead of one which is supposed to make it "slipless." The belt was VERY tight. I didn't want to tighten it down anymore because I was afraid it would snap. I also don't think it is valve float. This graph is identical to my N/A graph of 365rwhp and the power peaks at about the same about the same RPM. The cam has 4 degrees advance ground in so it would peak a little lower. It has Comp 918 springs also.

 

Your about right for 5 lbs of boost..................


Off the top of there head most people know the ATI kit does about 10HP-15HP per lb of boost usually........... some more some less......
You picked up 53HP.......
Way back............. when i had my ATI kit.... the first time out i had a D1-SC with a 4" blower pulley and was told it would do 8lbs... Thats what ATI told me when i told them my mods and how much boost i wanted to see.....
I had LT's, no cats, Hooker catback, LS6 intake, and a baby 212/218 cam.....
I saw 4 psi at 6200 rpm's... this was with the 6 rib setup.....
The end result was 384rwhp and 417rwtq.... kinda low huh.....
she dynoed 323rwhp with all those above mods before the blower....
I then swapped to 3.2" blower pulley and only saw 7 psi and had belt slip so bad i could smell the belt all the time and belt dust was everywere.....
I then swapped to a Morgan Motorsports 7.875" crank pulley and went back to the 4" blower pulley and saw 11 psi......... and still had belt slip...
Ran 11.50's that way and blew up the stock motor........
I then switched to the forged motor i have now and a SDCE spring tensioned 8 rib setup..... 3.4" pulley..........no belt slip and 11 psi with my forged 370ci motor and FMIC setup......

Sold the kit to go turbo and the guy that bought it installed it on his SS and all he had was a LS6 intake, LT's no cats, B&B catback and spec stage 3 clutch and he dynoed 497rwhp on a 87 degree day.......

so like everyone else said..... you are seeing blet slip......... drive the car around today and put about 5 miles on it around town with some vigorous street driving and come back and put your hand on your headunit..... if theres belt dust.......... then bingo.... belt slip...... FWIW.. no belt slip and no belt dust with the SDCE kit....
And that was using a Napa belt.
Kyle

 

Mike.. if you switch to a 8 rib setup with that new procharger bracket you wont have any belt slip issues. Theres no need to spend a grip on a new tensioning system.. just swap to a 8 rib, ie just get the new pulleys.

Mike.. did you pin your crank?

 

hmm ok good to hear you have the springs.

like kyle said look for belt dust. it must be slip.

i made those kind of numbers on my stock motor with 5.5psi from my non intercooled powerdyne.

you seeing 5 with headers and cam you should be making more

 

Sounds like belt slippage, or that is what that pulley combo puts out.

 

Do you think pinning the crank is a necessary step at this stage? Also I cannot get a Gatorback belt because they dont make the size that I need, 960mm. 955mm is too short while 965mm is too long.

 

Looking at your dyno graph, there is no sign of belt slippage. No dips in the curve. I have not had any issues with belt slippage with my 6 rib. I saw 7.5lbs with a 3.5 pulley.

I think the cam is hurting you a bit. That is real low #'s for a M6 and a dynojet.

Good luck.

 

The dyno he ran on has "smoothings"... basically it makes the graph "pretty". Where there will be dips or spikes will be smoothed out by the software... one of the reasons I think smoothings is a bad idea for any dyno.

Personally I would pin any crank if I was going S/C.. never know when you want to step up to higher boost.

 

My 02 WS-6 dynoed at 540rwhp and 523tq with my D1SC and the only other mods are 55lbs injectors,racetronix in tank, and a ati super dampener(8 pounds of boost 8 rib). Everything else is still stock and my car and it is not tuned. Rich off the chart down on the bottom and goes lean around 5300rmps.Hoping to see if it will make 560 to 580 once it gets tuned. Looking for a good tuner in the charlotte area any one has any suggestions.