HighMileage

Anyone with experience on stock LT1 procharge installs?

I have forged bottom and Exhaust has been done w/ shorty header and flowmast cat back. Do you guys believe the ATI claim of up to 60% increase? That would put the car at 480 to the crank. Amybe more with the exhaust work. Anyone have a RWHP figure for a stock headed LT1?


Looks like its pushing about 7 pounds boost. It ramps smoothly to boost, does not jump around. No belt dust is visible on supercharger. Everything seems solid. Stock 7'' balancer and 3.6' blower pulley.

Couple of questions:

1. Where do these things start slipping? I am setup to reduce pulleys, maybe upgrade to a larger balancer to increase boost, but I don't want to upset the system. It appears to be working. Is there a blower pulley size that problems will start happening at?

2. My throttle body is stock. I think they flow only 700CFM and that is with an airfoil. Is it worth it to upgrade to a 52mm? I think those flow 900CFM. I dont want to pull manifold if I dont have to for a 58 (would have to port it) but will if it would make a diff. Seems a 52 for 15min of work would be the way to go.

Flame Red

I have had my Procharger setup for over 10 years now. Only good thing I can say about it is it is reliable. As far as horsepower claims, no, they are bogus and you won't get anywhere near what they claim. Last time I dynoed I was at just short of 320 at the wheels. I can barely get 5 lbs of boost out of it on a good day. The weak link is the belt. If they would had a cog belt system I think it would work better, but they don't.

Overall, my experience is that if I was to do it over again, I would not go with ATI. If I had to do it over, I would spend the money on the engine. There is no replacement for displacement. I have heard about a turbo charger setup that mounts most of the goodies under the rear of the car. But I have not looked into it at all.

yzfr1mike

Hi - I have had a procharger for 5 years an am very happy with it. As noted there is a problem with belt slip above about 8 #s of boost. I use an ATI 7.5 inch LT1 damper on the crank, a 3.4 inch blower pulley, and an extra helper spring on the tensioner. My car makes 10#s of boost and 496 HP at the rear wheels on the dyno through an automatic transmission.

Having said that, I also have 190 cc AFR heads with 74cc combustion chambers on a forged bottom end and a 0.030 overbore. I run a Comp Cams Hyd roller in my engine, also. (544 lift, 220/230 duration at a 114 degree lobe center)

I think a stock 1992 LT1 auto car would probably make from 230 - 240 HP at the rear wheels. If the procharger gave 60%, that would make about 385 HP to the rear wheels, and with a 20% loss on the auto drivetrain, the crank HP would be 480HP.

The actual HP will vary greatly depending on the tune of the engine, wear and tear, mileage on motor, etc. If the kit is installed and tuned properly, their numbers are not that far off.

If you are still running the manual fuel pressure unit, (FMU) you should look into a computer retune and time on the dyno to prevent a blown engine.

PCM For Less did my tune, and the car is a joy to drive. I still got 28 MPG on a trip last summer, and it really goes!

Mike

RVY

When you read some of these posts. just smile.

BlowerWorks

Hi Guys, any LT1/LT4 owner with a ProCharger can greatly benefit from my bracket & crank pulley set-up. It is a SuperDamper with a separate 8 rib belt for the blower.
Best regards,
greg

0EPP

Replacing the ProCharger supplied air filter with a larger one will also help with belt slippage when shooting for higher boost numbers. Bob

Flame Red

Greg,

Anything like that to help us L98 guys?

BlowerWorks

Yes - take a look at my slotted pulley - it really works!

Bruce

a lot of people under the impression that the belt slip is at the blower pulley. It does not matter what style pulleys you are using or how many ribs belt you are using. It just ain't going to cut it. The Procharger for LT1/4 vettes is simply **** designed on the belt routing it self. ALL your belt slipage happened at the bottom of the crank pulley due to the very little shadow belt wrap. Sure some people claimed they are getting 7-9psi of boost, that boost number may or may not be consistant and or unreliable. I personally have never seen a solid 5psi of boost. Some time it got up to 5psi and dropping down 1psi. The only way to get solid reliable boost for the LT1/4 vettes is to do a dedicate 8rib drive system. That mean the blower get it own belt driven by the 8rib crank pulley and the factory 6 ribs serpentine belt system remain the same. When you decided to do that conversion and when it done. You will have a big smile in your face when you stomp on the gas pedal.

AKS Racing

There are bracket mods to be done on L-98 cars that will improve driven pulley belt wrap. The larger blowers have less slip issues due to the larger SUR, and the same can be said for ProCharger over Vortech.

Search and you will find numerous postings on said topic.

HighMileage

Bruce,
Was your setup a P600B or P1SC?
Mine is a P1SC, it has a better step up gear ratio of 4.1:1 and can use a bigger pulley than then the P600 for a given impeller speed and boost level.

In my original question, I appear to be getting 7 to 7.5 lbs slip free (3.6"" blower pulley). Am trying to figure out where I will run into problems. Sounds like any size down on puley size my upset the system.

I wonder if a Blowerworks slotted pulley would keep this slip free witha a 3.25" pulley

Bruce

It was a D1SC.. Believe me the blower slotted pulley is not your answer. It is not the blower pulley that slip as I ve said above. I had try shorter belt still ain't cut it either. If your lucky and some how it can make a soild good 6psi and alway steady boost(not dropping boost) leave it alone. The more boost you are trying to apply to the motor and the more likely it will going to slip. Let say you are gotten good soild 6psi of boost and you decided go get more boost and change to a smaller pulley and the bottom crank balancer will start to slip because it take a lot more stress on the belt and with that little belt wrap on the bottom of the crank balancer it will guarrrentee to slip. Perhaps you take a closer look at the bottom of your crank balancer, you will know what I am talking about.

Over the years I have never seen any Procharger LT1/4 vette owners say they are happy with their Procharger setup long term. When they start changing pulley etc. Soon or later they will find themself saying belt slip like craps etc....need help.....
If your setup is working fine and you are fairly pleased with the hp. Leave it alone, don't change to a smaller pulley. I know the Procharger setup very well because I had tore down the setup countless times more than I can ever remember and I custom build new blower bracket to run a dedicate belt setup as mentioned above.

HighMileage

Bruce,
Did you use the Blowerworks 8 rib setup with the ATI balancer or did you fab your own? Wondering how you change the braketing to deal with the crank wrap, it would seem that the system more addresses the blower pulley side.

Like the rest of most on here, you get a taste of some good power and then you know there is maybe 100HP more with other mods, so I am happy with my current power level, but more would make me even happier. My pistons and rods can take it

Bruce

My was totally custom built have no relation to any of Blowerworks stuffs. I have never seen first hand how Blowerworks Procharger setup. Therefore I can not say anything about Blowerworks stuffs. The way I see it, if the blower is driven by it own deicate belt, it should be good to go. I know Blowerwork can modify the Vortech bracket serpentine kit to accept a 8rib dedicate drive system, so that the factory 6 rib serpentine setup is the same as factory. I did not know Blowerwork offer dedicate 8ribs drive for Procharger.

Vortech= can modify bracket to accept 8ribs drive 8rib + 6rib
Procharger= need totally new bracket to accept 8ribs drive 8rib + 6rib
Both of these ribs needs ATI 8+6 Balancer or you can modify your factory damper to 8+6 which ever you choose is works.

Good luck..

nbh83

The bigger the pulley the larger the contact patch for the belt.It also allows for more belt slap when the distance between pulleys is greater. I have had better luck running the D1 with the larger pulley.I also was not impressed was the numbers out of the P600B.(10.73 1/4 vs 11.07)The problem is the more power the more peices that seem to be coming out of my tranny when i rebuild it.

AKS Racing

This is true on the blower pulley if the belt wraps around it. In the case of the early LT1's crank pulley, the larger pulley will help slightly, but there is just minimal contact on the crank pulley.

I agree that the D1 is a far superior head unit to the P600B. Again the SUR comes into play.