I know that the lt4 in the corvette was rated at 330 hp. What i dont know is the pure differences between the lt4 that summit offers, and the lt4 that came in the corvette. I dont think the hot cam is the same one in the lt4 vett is it? I know its probably a lame question, but if anyone knows what is actually different about any of it please let me know. It just seems a bit odd to me, that the lt4 in the vett had 330, and summit says a proven 425 hp. Thanks!!

 

The LT4 kit comes with a better cam than the stock LT4 had. The Hotcam. Same heads and intake though. Although I think summit is being optimistic with its numbers. However LT4 heads and intake are a great design or start for a awesome H/C pacakage, it all depends on how much you have to spend and where you want to be.

-Dustin-

 

There are a lot of choices besides the LT4 stuff, many of them arguably better, do not just jump on that stuff before you do a lot more reading. Also if you tersted your stock motor as that LT4 HOT package was tested you would end up over 360hp you have to consider it was rated on a dyno minimal accessories, maximized exhaust and intake and I believe aftermarket injection too so comapring that number to in car numbers is about pointless.
The true LT4 has a little different rotating assembly too but nothing I would call a signifigant upgrade.
Take a look at eportworks.com for just one of the many better options out there that will cost you less money and make more power.

 

I wonder if they are saying 425hp being at the flywheel. You'll most likely need all complimenting parts to go along with, were does the madness end!
I know... call Lloyd. I did . All I can say now is... WOW!

Dwayne, You ever go to the real street drags @ WIR. The car should be in the 11's and I don't want to run a cage in my car. I also need to get my Spohn Torque arm with the Driveshaft loop so that realy rules out the street class.I hope to get up there the first Friday of July. If your out there I'll look for you or look for a loud Green 94 z with a SS spoiler and a mean *** lopey idle!

 

Just FYI, I know Injuneer has posted this before, but that 425HP rating given for the LT4 "conversion" kit was flywheel rating, at More Performance with (IIRC) no accessories hooked up, long tube headers, and extensive DFI tuning among other things.

 

Honistly, i would be happy if i could bolt that package on and get that much hp at the flywheel. Because im sure with all of my bolt ons, an electric water pump and so on...it would be a bit more then that. I was also wondering what other packages are out there that put out more then this? That are around the same price range or less. Also i have seen Gonzos videos, he has the LT4 kit and he is running some really good times.

 

Honestly, you'll probably only see around 390-400 tops at the flywheel (in the area of 330-345 at the rear wheels).

 

there is also the elelbrock kit, i remember a magazine article comparing it to the lt4 kit and it put out slightly less power but is less expencive, but i think the best bang for the buck is probably one of the loyd elliot packages.

 

Got his website, i want to make sure i get something really sweet before i do any 2k spending you know. Its tough being a poore colledge kid so Honistly, i kinda want to just experiment with my stock heads and stuff, but i the fact that the lt4 gives you a true 11:1 compression ratio. Im not sure i can do this with stock heads, maybe i can? ;]

 

The Edelbrock heads have the same intake port volume (or maybe slightly less) than the STOCK LT1 HEADS. They have the same size intake valves as the STOCK LT1 HEADS. Only the exhuast valve is larger than a STOCK LT1 HEAD (1.55" vs. 1.50). Even Edelbrock only claims 26HP for those heads. They are not in any way comparable to a STOCK LT4 HEAD.

You may be thinking of the Twisted Flow heads... they have 195cc intake ports like the LT4 heads, and larger intake and exhaust valves, and the quoted flows are very similar to the LT4 heads. Unfortunately, the TFS heads have an oversize 62cc combustion chamber, meaning they are going to reduce the compression ratio about a point.

 

yeah i think the real power is in the edelbrock cam, although i dont see it being better then at lt4 cam so yeah.