ok guys I got 89 iroc z with a mild 355. Still need to change cam and heads since there stock, but for now its ok...I was just wondering how much would i benefit from a Lt1 intake...im just sick of TPI dying out so early plus i like the way a Lt1 looks. also how much would it be if I bought a intake from john and had him do it. Also I have a edelbrock high flow base then stock runners and ported plenium I want to sell. If anyone is interested.

 

Your best bet would be to e-mail John (me) for cost info.

Do please post here and ask others opinions on the swap though.

 

yeah I just e-mailed ya a lil while ago..

 

So what does everything else thing about the Lt1 intake? DO you feel its worth it? I figured I'd put it on cause very soon I will be swapping out the stock l98 heads and cam and the lt1 intake would do nicely with those.

 

I'd do it at the same time you do the heads and cam. On my car, it's a drastic difference in where the power band is. I really wish I felt comfortable reving it to 6500 now, because it's still going strong at 6000. I don't know if you would see a big gain with the stock heads and valve lift, but you definately have to be prepared to rev it to 6000 to see any gains. What gear are you running? I'm getting 3.73's installed this weekend, because I'm barely getting going in 3rd (5000rpm) at the end of the 1/4 with the 3.27's. I think this setup needs at least 3.73's and a 3000 stall. So next up is a Vigilante. It's just a vicious cycle to try and acheive a balanced setup. The other big thing is that I'm leaving a ton on the table with this MAF setup. I even burn my own chips, but things don't behave like they used now that the engine load range and airflow is so different. Guess what, a 730 ECM swap is next on the list also. One of the big gains is how uncluttered the engine bay is now. Geez, it used to be a pain just to adjust fuel pressure with the tpi. It looks tons better too.

 

Hey Steve10,
Do you have any time or dyno #'s of before and after. Your setup looks a lot like mine. Just wondering how its running.

 

ive got the lt1 intake on my 383 last year i had a 355 with all aftermarket tpi best i got was a 13.0 this 383 has the same cam my 355 had i ran a 12.4@111 on my last run but my trans came apart i know i can hit a 12 flat my chip is still the one i had in my 355 and im running a maf set up still i love the intake i got mine from john later
383 with lt1:hail:

 

Is this a daily driven 383?

Have you had any problems with leaks/cracks/etc ?

What heads are you running?

 

yep i drive this every day its my only car ive had no leaks or any kind of probs at all im running afr 195cc heads

 

Free Bird, I've got some tuning issues, but it still runs pretty good. G-tech before swap was 13.3@107.5 and after swap 13.1@109. I'm not real happy with the numbers, but the thing is that I took so long to complete the swap, it was ~45 deg on the before, and now 90 deg and humid on the after number. Anybody know how much temp/humidity affects hp?

Steve

 

I have been very interested in modding an lt1 intake for my 88 IROC. I bought the intake, fuel rails and all. Then my friend started telling me about all these horror stories about lt1 intakes and coolant leaks and cam gears grinding etc. Has anyone had these problems with their lt1 intakes? It seems that I don't hear any problems here with the intakes, but the lt1 intake has taken a backseat to the stealthram. BTW...on the passenger side fuel rail, is there a way to disconnect the rail from the steel fuel line coming out the back. It doesn't seem like it can disconnect but mine doesn't seem like it is held very good in there and I was wondering if there was an o-ring inside that I could change so fuel does not leak out of the back of the passenger side fuel rail.

 

I'm not sure I follow the piece you're trying to disconnect? The fuel cross over??


As far as the horror stories have you heard these first hand from anybody who HAS one? Or is it a friend of a friend of a guy whos ralated to a dood that heard about it?

The distributor angle is held in place by the block, not the intake, the only thing you need to get correct is the depth, and there are tollerances that differe from stock to aftermarket intakes anyways, get it as close as possible and your distrib gear should be absolutely fine.

And coolant leaks? what intake doesn't get coolant leaks? the mounting angles are the same, thats all you can ask for, you want to talk about coolant leaks run a felpro 1205/1206 on a stock TPI base, then you fight leaks.


The LT1 intake is a hybrid, Its not perfect, and wasn't designed for a GEN1, but there's no reason to fear it like the black plague, the people running them can vouche for the gains, and the worth of running one.

$200 for an Intake that keeps pulling passed what hydraulic lifters could dream of taking, sounds good to me.

 

No leaks, no problems. If you plan to keep modding the car...stroke it, wild cam, whatever...this is the last intake you will ever buy. My 3.73's will be installed by this afternoon and I can't wait to make better use of the LT1 rev range.

 

Well said Roc!

 

John, do you have a correction established to seal the center EGR ports on the older (pre 80) heads to the flange on the LT1 intake mods?

 

Just out of curiosity, wuold a person be able to hook up an external egr so that i can fool the smog police? (pass a shady visual.....) and pass the dyno type test..........

 

Not yet, got any suggestions besides welding? I am not set up to TIG yet and it may be a while before I can afford too.

Right now there is no fix for the EGR leak on stock type heads. Aftermarket heads either don't have an EGR port or it's a small circle that is easily covered by the flange of the LT1 intake. My TF G2's are that way, that's why I never noticed the problem.

 

Hey CUSTOMX, there was a posting here a couple of weeks ago where someone was saying they were trying to use a small distributor and modifing the EGR to mount for "visual" inspection. Maybe some of these guys can remember who it was and post the thread here.