I just got the new Summitt catalog in the mail today and they are selling the LT4 conversion now. They claim a proven 425 HP!! How can the make that claim? Wasn't an LT4 rated at 330HP? I know the hot cam is a little bigger than the factory LT4 cam, but its not worth 95 more horses! Any input would be appreciated. If i can get that much power for that kind of money I think more people would be doing this conversion.

 

you add a 30' sail to the back... it collects wind and gives you about 60hp/80lbFt

 

its probably a typo and meant to be 325+ hp instead of 425+.

 

That is FLYWHEEL HP.And it is possible.

 

no typo, thats what it says in the yearone catalog as well as on the website. who knows?

 

doubtfull........thats about 375 rwhp..............i havent seen any LT4 conversions making those numbers here.

 

it may be worked over a little. see what type of cam it comes with. any port work? what about exhaust? yea 425 hp is easy to reach. vette fever i think did an article on the LT4 conversion and with some mods to it at the same time they got 380 at the wheels. which is about 425hp at the flywheel. trey

 

On www.lt4.com there is a link to an article that shows how just slapping on the lt4 conversion gets you 425 flywheel hp. I would post the exact link but I'm too lazy, anyway it's on the website, check it out.

 

The 425 hp is at the flywheel. This would translate to about 360 at the wheels.

 

Speakin of insane hp, my freind has just bought a 96 trans am with 4.11's, and a borla cat back...and doesnt know what mods he has yet because it is a **** can and has been in the shop for a new tranny and clutch...but the previous owner claimed 383 hp...no blower...lt-1 engine...what in the hell could he have done to make that much power? i am thinking a cc306 cam?

 

Isn't an LT4 engine also a 4 Bolt main?

So I guess it ain't a true LT4 conversion

on a STOCK LT1, with no bolt-ons or anything, i seriously doubt it can produce even 425 flywheel HSP.

 

jpaugh, a CamaroZ28.com and Central Florida F-body club member, has a 96 Z28 with the LT4 conversion, LT4 hotcam, Hooker LTs, CAI, and PCM tuning and he has pulled 380+rwhp on more than one dyno. Up until recently I lived in Orlando and I've seen him dyno; those #'s are for real. Here's a link to his website with the dyno charts, as everyone has called him a liar in the past...http://www.imaliar.net

 

well thats pretty damn good...........i guess most people who get the conversion just dont tune it as well as they should.

 

Staying focused on what the kit is supposed to do and not that it's got LT4 all over it will likely lead you down a different path for that kind of $$.

I'm talking about heads that flow much better and a cam to take advantage of them. Moving towards that end, you can get your stockers ported and polished, larger valves, etc with a good aftermarket cam and valvetrain will net you even more power than the kit and likely cost less.

If you're hell bent on the LT4 thing, that's another story. Nothing wrong with that, it's your car and you should set it up the way you want it.

 

Wheelman,

The test on Lt4.com wasn't done without any other mods...obviously with a freer breathing cam and heads you need to open up the engine a bit with headers etc, but the test at least showed that the lt4 conversion had the potential to make that power.