is there anyone who has done the LT4 conversion to a OBDII car that lives in california?

im hoping to find out if the heads will pass smog or not.

im thinking about selling the SC and just finishing off the LT4 conversion. i like the cam kit and ive heard some good things about the conversion.

thanks guys,
jeremy

 

I would stay away from the lt4 con kit. The heads have good "potential" but at expensive. I would keep you lt4 hot cam and just have llyod elliot or advanced induction port you stock heads.

 

I live in Palm Springs California, and I have the LT1 to LT4 conversion kit from Summit installed on my '97 Camaro Z28. The kit came with the LT4 heads, GM Hot Cam, LT4 Intake, and all the small parts needed. Its passed Smog twice now. Just make sure you send your computer out to be re-programed. The original programming for the LT1 will run the engine, but sluggish at times. Once I got my PCM reprogramed, it ran flawlessly.I had mine programed by Combination Motorsports in Las Vegas. www.cmotorsports.com

 

thanks. so you didnt have it dyno tuned? what did they charge you? id probably have MadZ28 do it again. its only 50 bucks for changes.

if youve had it dynoed, what did you see HP wise? im not looking for the most power possible. i just dont want the blower to harm my motor so im thinking of getting the heads and intake and calling it good.

i can get the heads for $650. i could have the stockers ported but i think the higher CR the LT4s have will give me more power over a port job. and if im taking them off to port em....then id rather just swap em out.

 

oh yeah, onebad97.....the smog guys didnt give you any crap about the cam lope?

im nervous about it. i have the single chamber flowmaster, which makes the lope very obvious. especially after its warmed up good.

thanks again for the info.

 

The Hotcam is not wild enough to elicit any issues with the smog test equipment. I passed with the CC305 on a stock tune. The smog test technician even noticed the lope and only smiled.

 

yeah i know the cam will pass. i was just wondering if the heads would cause an issue.

onebad97, do you run regular 91 pump gas?

also, is there any difference in the LT1 intake from the LT4 intake besides the port alignment? does the LT4 intake except the egr valve? the original LT4s didnt use an egr valve due to the cam design i believe.....

jeremy

 

Lol the higher comp ratio wont do alot. Just have your stock heads ported and milled and you will achive the same as the lt4 or higher than it. Or just waste your money and dont make much power its up to you. The kit from summit is very overrated and will not make the 425 hp that is mentioned, well maybe on a 383.

 

No, I didnt have it Dyno Tuned. I simply stopped in, told them what I had done to the car, and gave them the PCM. As far as I remember it was 199. As for gas, I run regular 91 pump gas. I cant run anything below that or the SES light comes on and the car misses.
As for the Smog, the guy didnt care. He was more interested in talking about cars than the Smog, and even said he loved the sound.
As far as CR, Ive heard that blowers are best with lower CRs. Check that one out though to be sure.

 

yeah, the blower is comming off. thats why im planning on doing something with the heads.

the LT4 heads i found on GMpartsdirect.com that where $650. yeah well thats 650 for each head!!! what a joke. i think im getting mine ported.

 

I have the LT4 hotcam kit and some bolt on and got it tune and dynoed mine at 348 to the wheels. I now workin on my 383 LT4 so should be a monster. oh yea did I mention it gonna be on nitrous aswell. But the LT4 hotcam to me is a good daily driver and performance cam.

 

Smog is no problem. I just got the kit because I failed to realize I could send my stuff to LE.
At this point, I would have Lloyd do the work. for less.... oh well.
Car runs good, passes smog and has a nice idle. CR is high but thats what you get when you go NA...
I was thinking of putting on a 4.5psi powerdyne for the hell of it and addind a 255lph pump. Just for 100+ hp and no detonation.

--Troy

 

with those LT4 heads i think youll have some problems with any amount of boost. especially not intercooled. you may get away with it for a while if you get an aftercooler or intercooler and also run some Meth/water injection.

 

Just do nitrous instead and call it good!