infamous

Hello. I purchased a 1994 Corvette over the summer that had already been built up by the previous owner.

Here is some of the ad from the previous owner:

This 1994 Corvette LT-1 runs beautifully and is very fast, recently running 12.06 @ 113MPH in the 1/4 mile. Fully built 383 Stroker with a Stage 3 Redline Transmission, both with less that 1,500 miles. The vehicle has a modified MAF sensor, 58mm throttle body, CNC ported LT-1 manifold and heads, Comp Cams 1-piece pushrods, roller lifters, and 1.6 roller rockers, and an LT-4 Hot Cam. The shortblock consists of an Eagle 3.75 in crankshaft, 10.9:1 forged flatop TRW pistons, and forged H-beam 5.7in rods all in a fully relieved LT-1 block. All suspension components, brake components, accessories, and stainless exhaust pieces are also new. The interior has been fully restored with all new dash panels, carpet, seat covers, and door panels as well. The rear end contains a 3.54 ratio gear...
...pulls 1.6 sec 60-foot times as well with ease. Over $15,000 has been invested into this streetable road racer and that's not even including the original purchase price of the car!...


I do not have all of the documentation for everything that was used in the engine/trans. build, but I do have documentation showing:

-383 Eagle Stroker Crankshaft/Speed Pro Stroker Kit
-Eagle 5.7 Inch Forged Steel Rods
-10.6:1 Hypereutectic Pistons (either the CR here is wrong, the ad was wrong, or the heads bumped it up a bit)
-350 4-Bolt Main Block, Bored 0.030" Over
-LT1 CNC Ported/Polished Aluminum Heads, 195CC, Comp. Valve Job and CNC Ported/Polished LT1 Intake Manifold (Straightline Performance, but I can't find any other info on this)
-Comp Cams 1.6 Steel Roller Rockers (Magnum?)
-Comp Cams 1-Piece Forged Pushrods
-Cometic Viton Head Gaskets
-ARP Hardened Head Bolts
-ARP Hardened Main Bolts
-LT4 Hot Cam (214/228 duration, 0.530/0.530 lift w/1.6 rockers, 112 degree separation)...this seems a bit different than the specs I've found online for this cam as 218/228 and 0.525/0.525 w/1.6 rockers, but is probably just a mistake (it was hand-written on a receipt)
-58mm Billet Aluminum Throttle Body
-Melrose Ceramic-Coated Full-Length Headers, 1-3/4" Primaries, 3" Collectors
-Accel 30 lb/hr Injectors and Adjustable Fuel Pressure Regulator
-Yank Super Stock 3200 Torque Converter
...the transmission was built with parts from Red-Line, but I haven't been able to find much info on that. A receipt I have shows:
-Master Kit (Red-Line Clutches)
-HD Pump Bushing
-Kevlar Band
-Internal Wire Harness
-Valve Body Kit
-HD (this is illegible, looks like sun shell or seen shield)
...the engine was tuned locally, though it has a PCM4Less computer under the hood.

The most recent dyno plot is here:

http://forums.corvetteforum.com/memb...vette-dyno.jpg

For some reason I can't add an attachment. I have an older dyno plot that looks like it had more low-end torque and less top-end power (I didn't put this anywhere, but I can add it). The one in the link shows more top-end torque and power (peak power and peak torque are 200 RPM higher than the older run) than that run. I edited out some of the last owner's info.

This dyno run had peak power at 320 HP at 5800 RPM and peak torque at 320 lb*ft at 4600 RPM at the wheels. I've seen a lot of 383's on this website that seem to be posting high 300 to low 400 HP and a similar range for lb*ft of torque. Does this combo of parts listed above seem like it should be making higher numbers? As stated earlier, the car ran a very low 12 in the quarter mile and had a 1.6 second 60' time...so it's definitely no slouch. I'm really happy with it overall, just seeing some of the other posts on here makes me think it should have some more power in it. I wish I had more info on the heads.

What do you guys think?

Also, I was considering getting a ProCharger next winter...but looking at the compression ratio of 10.6-10.9 and the hypereutectic pistons I'm leaning a bit away from it. Any thoughts on this?

Thanks, any feedback is appreciated.

Zix

Well, a couple things...first the Mustang Dyno is known as a "heart-breaker" because it usually reads low compared to Dynojet dynos. If you really want to see better numbers you can try to find a Dynojet and see what it says.

Onto the engine, do you have any idea on the flow numbers for the heads? Does the company that ported then have any flow sheets for similar heads? Also the HotCam is a pretty small cam for a 383, there are much better cams out there for power, but the HotCam is a nice cam for emissions and decent power.

It sounds like its running pretty well though!

infamous

No, I don't have much info on the heads. I Googled Straightline Performance, but couldn't find any relevant info on the heads. All I found was an address and phone number:

Straightline Performance Parts
23 Phoenix Crescent
ERSKINE PARK NSW 2759
Ph: (02) 96706300

...but I'd rather have an email or website to check out than try to give Australia a call. The website I found that on didn't even say what kind of work they did. There was another company with the same name I found in Montana, but they do work for small engines (snowmobiles).

I've read on here that there are better cams for a 383 than the Hot Cam. I figured I'd keep the Hot Cam in there for now. Michigan doesn't run emissions tests, so that isn't a reason for me to keep that cam in there.

Matatk

Do you really think your heads and intake were ported in Australia and then sent to the US?

Straightline Performance is a shop in the Chicago suburbs and they work on performance cars, installs, tuning, etc. Good reputation. They are a supporting vendor on here if you do a search.

Matthew

infamous

Thanks, I'm shooting them an email...and yeah, why couldn't they be in Australia? Australia makes lots of performance parts for GM and Ford vehicles. I have Australian suppliers at my job, and we're based in Michigan, Japan, Germany, California, etc. This is a global business world. Just off the top of my head Pro-Race dampers, http://www.pro-race.com/, is based there and they make dampers for GM V8's that I've bought in the states.

Zix

It's just unlikely really, especially considering the potential shipping costs for a set of standard LT1 heads. Certainly not impossible that they were done in Australia, but it's just more likely that they were done someone within the US.

BrianCunningham

How well is it running?

A lot of car that are built up and sold, are done either because the build was messed up, or the owner beat it to death.

infamous

The car runs great. I drove it all summer. I wasn't even looking at C4's or automatics at the time, but I came across this one and decided to buy it. The engine, trans, rear end, suspension, and a good amount of the interior are less than two years old. The previous owner got a C6, and did not need two Corvettes. I'm really happy with it. There's always the chance it was beat on a bit, but the car runs smoothly and I've only had to replace a radiator hose so far...and that didn't need to be replaced, I just wanted to get rid of the union that was used for the throttle body byass in the coolant loop.

cv67

Youre running low 12s, I wouldnt worry about a dyno number at this point

infamous

Ha, I know...I'm definitely not complaining. It would be nice to break into the 11's though. Maybe some slicks will do the trick if I ever get a chance to go to the track. The suspension is stock, so I was going to take a look into my options there as well.

I was hoping for some responses like Zix had saying that the Hot Cam is pretty small for a 383 or other responses where maybe a bad combination was set up. Hopefully I'll get a response about the heads from the email I sent out. The last owner set the car up well for driveability, as it has a smooth idle (though it is at 1000 RPM) and pulls hard no matter what RPM I'm at.

Thanks for the responses.

Zix

You can easily drop the idle to 825 or so as long as the tune is decent, a 1000 RPM idle with a 383 HotCam is a bit high, but it won't be a problem at all. My 383 with a MUCH larger cam idles at about 950

reoch999

I'll trade you for my basically stock 92, and you can build a dyno queen out of it if you want.

320 sounds a bit low, even on a mustang dyno, for a full weight car that runs 12.0. I'd run it on the track and on the dyno a couple times, just to make sure both sets of numbers are true. But if it's my car, I'd take the 12.0 on the track and who gives a rat's rear end what the dyno says.

STL94LT1

A good ET, but a so-so mph. The Hot Cam and heads may be holding it back. It looks like it is running out of steam by the end of the 1/4 mile.

infamous

Yeah, it hooks up well off the line. I'll check tonight to see if I got a response back regarding the heads.

Thanks for the feedback so far. I haven't done any intensive search here, but what cam/cam specs. are other people running on here with their 383's?

95wht6spd

Great time for the power and cam, must be a good total package.
Get a bigger cam and bump the CR up to 11.x if you want more HP.