HighMileage

I am looking to pull the trigger soon on a bracket upgrade to increase boost from 7-8 pounds to hopefully somewhere near 12 pounds.

I have been looking at old threads and noticed that the ATI intercooler may limit this.

Trying to see if anyone made 500RWHP with the ATI air to air intercooler on LT1 cars.

Want to avoid alky injection, its a daily driver, not weekend warrior.

AKS Racing

While the ATI intercooler can support that level of HP, it would be better to upgrade. At that level, the psi drop is excessive and you are loosing a lot of power to the IC.

Why are you opposed to xxOH?

What level of power are you producing at 7-8 psi? What do you have done to the engine?

qwiketz

my car was a daily driver and alky injection is not a hinderence at all. I only had to fill the tank every other tank of gas and I would stomp on it all the time. If you're worried about it, install a dummy light on the windshield wiper tank so that when it's low, the light illuminates.

Alky injection alone can be worth 50-75 hp.

HighMileage

AKS/Qwiketz,

Thanks for the replies.
Current setup is forged rods and 21cc dished blower pistons somewhere in the 9 to 9.5 range.

ATI procharger with LT1 air to air intercooler, currently making 7 to 7.5 pounds of boost.

Shorty headsets, flowmaster force 2 catback.

Car was tuned with FMU, so tune is good, it just needs the FMU to allow stock injectors to work( I will be ditching this for 60lb injectors in the near future when I lock down on my upgrade path)

I think/hope I should be near 400RWHP right now and am looking to bump boost top 11-12 pounds and try to get close to 500RWHP. I may be optimistic on this, but the car has taken a viper and crotch rocket on the freeway, so it runs strong.....

I realize that alky may make more power, just would rather keep it simpler with air to air and not have to work about a pump going or tank running low.

I have also been told that alky is better for stop light to stoplight and avoids heat soak and air to air is better for highway. For my driving, I spend a lot of time on highway and since my fans and water temps stay at about 195 (even hot weather) heatsoak has not been an issue around town.

So main thing to figure out is I calculated the the new boost level based on the new impeller speed assuming that the pressure drop across the intercooler remains the same with 11-12 pounds output as it did with 7 to 7.5 pounds output. So I need to know if the intercooler losses will drop more and I won't actually see the 11-12 pounds.

Path to get there is to go from stock 7' balancer and 3.6 pulley to a 7.5'' balancer and 3" blower pulley.

Appreciate any advice you guys have. There is a path that says dump the intercooler, pick up a few pounds, and redirect money to the alky setup.

PS if you use the windhield wiper resevoir for alky, what do you clean your windows with?

Kyle Lemish

My 95 makes 540 very conservativly tuned on pump gas....i run an s trim vortech with only six rib belt setup i get 9 lbs after the procharger intercooler.....an easy way to get more boost on an lt1 is to cut the radiator shroud and build a better inlet tube from 90 deg 3 inch exhaust tubes.....i gained 2 to 3 lbs at the manifold by this mod alone.

HighMileage

Can you let me know what your whole setup is?

Also curious about the details of the intercooler, if you have any pics.
PS, why a vortech head and then ATI intercooler? Is the intercooler a modified LT1 unit or is is a more generic one with tubing mods?

AKS Racing

Are you saying that the extent of the mods are the lower compression forged pistons and shorty headers with Flowmaster cat back? If so, based on your mods, I calculate a healthy 350LT1 with lower compression to be ~325FWHP NA. With 7.5 psi boost added, this yields 491FWHP and 367WHP (MD) or 417WHP (DJ).

If you increase the boost to 11 psi, the power increases to 568FWHP and 425WHP (MD) or 483WHP (DJ). At 12 psi the numbers are increased to 590FWHP and 441WHP (MD) or 501 (DJ). Remember these are calculated numbers, and real numbers may (and probably will) differ from calculated.

So... your estimates seem to be fairly accurate (based on DynoJet numbers). Now your comments of maintaining low temps in the car will be tested shortly. It seems that any car that begins to make decent power starts to have issues with temperature due to the location of the IC in front of the radiator.

0EPP

I would not use an fmu with anything other than stock boost levels. When you add more boost you need to be able to pull some timing out of the engine above 5000 rpm.

We've tried cranking up the boost with the intercooler you have, and it didn't work for us either. I'd seriously consider ditching the intercooler and going with a good methanol kit for the boost levels you are looking for. Bob

HighMileage

Bob,
I asked this in a different thread (I was off topic so maybe you missed it)
I noticed you guys installed a procharger on a 96 CE LT1 car.

Do you have the before and after dyno numbers?
I noticed in the pics it still had the FMU - was it dyno tuned for the FMU?

I searched all over past threads and have yet to see what a stock LT1 procharger setup does.

Also, curious as to what you saw when you started increasing boost levels.

BTW, I agree on dumping the FMU, I am at 80 pounds at redline, so if I increase it will probably put me past danger zone. I am not even sure I like it spiking to 80 pounds, which is why I will increase injector size when I step up to a higher power level.

HighMileage

Aaron,
Thanks for the reply.
By the way, I think I am the guy that bought a 3.07 rear from you a few years back.

Also, On the LT1 cars the intercooler sits on top the shroud rather than in front of the "scoop". I would not think that airflow idiverted out the top would not impact flow through radiator.

Having said that I do run hot with AC on and NOT moving. BUT, I noticed a lot of crud in the condenser (My fans run at 200, so I think they are on more than off and more prone to picking up junk). When I cleaned the front of condenser, the temp rise with AC has not been as fast, which makes me think that I have additional crud between radiator and condenser and I need to get in there to look.
Runs no higher than 190 moving with the AC, which is making me think there is dirt and crud that is impacting the non-moving situation..

My main question is it looks like you are figuring a 25% loss for an automatic and 15% loss for manual. I thought the automatics were closer to 20%, and even a little better (I know not as good as manual)

0EPP

We made 413 rwhp on that Corvette. We used the FMU and dialed it in on our Mustang Chassis Dyno. We didn't do any before dyno runs but most of these cars tend to make around 200 to 220 rwhp stock on our dyno.

We have customer with a rather rare '94 Corvette. He bought this car new and he ended up with an LT5 chassis with an LT1 engine. For example the brakes are larger than LT1 chassis brakes. We installed a D-1SC on it five or six years ago. This was his only car until last Winter, and we built the engine for him four years ago using a stroker crankshaft. The engine now has 50,000 miles on it, and the car has 245,000 miles on it. We experimented several years ago with cranking up the boost on this car, and only got higher inlet air temperatures as a result. He ran the Gumball Rally this year with the car, it's back at our shop now as the Hooker Headers rusted through that we installed when we first put the ProCharger on it. Bob

AKS Racing

Straight up 15% loss for auto, with 12% for manual. The different values are (DJ) DynoJet and (MD) Mustang Load Bearing Dyno.

I have run numerous cars on the same dyno at the same shop back to back on the DJ and MD and they all seem to average ~12% lower. That is the difference between the DJ and the MD.

I hope this helps.
Aaron

AKS Racing

Weird???

HighMileage

Actually the bigger brakes may not be that wierd if I understand correctly.

My 96 CE has corvette scripted balck calipers on 13" rotors. A friend I work with has a 95 with 13" rotors.
His calipers are the stock finned looking Girling/PBR.
I also believe the 13" and 12" front calipers actually take the same pads.

So somewhere around 95 the LT1 cars started coming with ZR1 style breaks. I am not sure if the ZR1's had beefed up rear brakes. On earlier LT1 cars I think the Z07 suspension package had the ZR1 style brakes but do believe they became standard on the last of the C4 models.

AKS Racing

The HD suspension packages came with 13" front rotors 1988 and up. Even my car has that set-up straight from a take-apart GS. The 13" rotor is not exclusive to the ZR-1.

0EPP

Yes, this car has LT5 emblems on it. I'll get some pic's of it when I get a chance. Bob

95wht6spd

Does it also have the wider rear and the 8K tach? All of this can be modified, emblems added, etc. Possible they swaped engines, but more likely they changed the other parts.
VIN will tell for sure, but it wasn't from the factory this way.

AKS Racing

I agree, a standard coupe did not come from GM with LT5 emblems. I think the original owner needs to come clean.

And as an aside, I had a neighbor when I lived in Victoria, TX (I believe he stayed at home and wifey was a lawyer) that had a 91 black vette coupe with ZR-1 emblems on the rear bumper. He always bragged about how that car was so expensive, rare, and fast. One day I stopped by and he was cleaning the vette with the hood up, and low and behold, stock TPI. I questioned him, and he said the "other engine" was having work done. Yeaaaahhhhh.....

Again, the original owner of the car mentioned above should come clean. Emblems are cheap through Mid America...

HighMileage

Bob,
One clarification if you don't mind. If the LT1 car made 413RWHP, it is the same power listed as the LT4 car on your website. Since the LT4 has better heads and cam lift, how can they make the same power?

I have been trying to figure out if the LT1 cars can make upto the 480 crank power that ATI says. Their C5 kits seem to make the power claimed.

Also, the Moroso oil resevoirs on your site peaked my interest. I dont like the ATI LT1 PCV setup and all of the tubes run to the air filter. I am thinking of using something like that. Would I need an air pump also for the PCV system and this resvoir? Referenceing an LT1 application.

0EPP

I was actually referring to the '96 LT4 that is on my website. I don't recall what kind of horsepower we made with Harry Bowers '96 Corvette. We did the install on Harry's car back in late '02 if I remember correctly.

My brother's '95 Formula might be a good example to use, as he bought this car new as a leftover back in '96. LT1 bone stock internally with just 5,000 miles on it. It has Hooker headers and exhaust, with a ProCharger P-1SC on it. The suspension is all done for dragstrip use, and it has run a 10.92 in the 1/4 mileat almost 122 mph. RWHP on my Mustang chassis dyno is under 400 with this car, due to the turbo 400 and the 4000 stall converter. Bob