motodog

has anyone installed a lt1 intake on there l98? what gains did they get? and is there a differance on the lt4 intake ?

RandyJ75

I don't think an LT4 intake will fit on a L98 head, as the LT4's have raised runners. Do a search on this, you'll find that the engine will pull to about 5500 rpm, but that you will need a reprogrammed chip to make it work.

redrose

nope.

having actually DONE several lt1 intake conversions (including my vette) and talked with at least a half dozen others who have DONE the swap, a stock L98 chip runs just fine with the lt1 24 lb stock injectors, pulls hard till the lifters pump up (6000+ rpm for most)...car runs like it got A-rods breakfast goodies.

gixxr

Is the swap easy, are there any alterations, whats the hp tq boosted to and how does this mod compare to a stock LT1

jeffp1167

from california, I can tell you a gain you will get! a faster emmision failure LOL

Demonic85

From all the threads i've seen comparing different intakes, the LT1 conversion seems to be the cheapest and best if your looking for an intake that will pull well past 6K rpms. I'm sure there are better intakes but you can get one for around $400 compared to $1000+ for a miniram.

billvh

Redrose,

Did you have any sealing problems with the L98 heads? I have heard about port mismatches, etc.
I have a modded intake, and am thinking about installing it, but first I would like to fix a lean exhaust code I am getting (it is actually running rich though) I can't find any vacuum leaks, so after I change my collector gaskets, I may need to replace intake gaskets anyway. I don't want to install the manifold if there is another problem.

neat

While the stock chip will work, the car will run MUCH better and make MUCH more power if you spend the time/money and tune the computer; especially if you are converting a speed density car.

I did the swap, and by the time I was done, I spent more than the mini ram would have cost.

Fuel lines, rails, fittings, hose, clamps, small cap HEI, external coil, external fuel pressure regulator, my time, tweaking things here and there, etc... None of that stuff is free. By the time it was finally on the car, didn't look like ****, tuned, and ready to roll; I had about $1100 in it. The really ****ty thing was that I also had 40+ hours into it.

In the end, I pulled it off and bought a used mini ram for $750.

If you are on a shoestring budget and don't really care what it looks like, the conversion would probably be the way to go; but if you can at all afford it, there are better options.

Demonic85

What about this...

http://www.lt1intake.com/services.htm

geogolf

heres a Lt1 on my 90, I am not much into how the motor looks but I do like how it goes to 6K also did 1.6 rr and pcm chip and 24# injs. used stock distr.

"swamp rat"

I have a question !! PM ME I have a L98 !

redrose

my pile, topside egr added since this pic.

Is the swap easy, are there any alterations, whats the hp tq boosted to and how does this mod compare to a stock LT1
swap is less hassle than some back/day tunnel rams that we did, beware 'some assembly required'...future total restoration to oem was maintained, no alterations to oem pieces...difficult to compare with stock lt1 as this engine has other mods to its advantage.

Did you have any sealing problems with the L98 heads? I have heard about port mismatches, etc.
no sealing problems, everything lines up IF IF the new cyl head/manifold mounting holes in the lt1 manifold are set from head ports (not from end of manifold casting)...NO welding should be done to the manifold, it will warp and need to be 'refaced'...some alum L98 cyl heads have a raised edge just below the rocker arm cover that will require slight 'trim' of the lt1 manifold to allow the manifold to drop between the heads and compress the intake gaskets...ports on my cyl heads are abt 1/16" smaller top/bottom than the lt1 manifold, but were left 'till next teardown' (still waiting, performance gain not yet needed)

86GoldProject

as far as I know that guy hasn't been actually doing them for a year or better now, from what I heard he no longer answers e-mails or anything..

DrEvil11417

i have one off my car if anyone needs it.. john millican converted it

pologreen1

which one do you run now?

motodog

this is my 1st motor build in a car, so i am loaded with stupid questions. i have a 350 4bolt block with a 396ci rotating assy. going with afr 195 the latest ones. my builder will match the cam when a intake is chosen. at first i was going with the tpis mini ram as it fits under hood and will support 500 hp, 500hp is the goal. i was interested in the lt1 or lt4 because i was thinking i would try to pass a CA smog. if not i have a way. the car is an auto but i am heavly looking at the zf6. in fact a forum member is selling one and i am trying to work my books for it rite now. but back to the intake it looks like it may still be the tpis, i havent seen a dyno # for lt1.

Rogue1

CA smog law is very specific. It is not legal to install parts on your engine that is not OEM replacement or equivalent, or not C.A.R.B. approved (50-state legal). So technically, the only thing you can do to an L98 TPI is replace the runners with bigger tubes then port and polish the upper and lower plenums for better flow. That's technically of course.

In reality, your smog inspection results will vary from inspector to inspector. These cars are approaching 20 years old so most inspectors won't even remember what is stock and what is not, let alone which years are suppose to have the TPI and which do not. The important thing is the APPEARANCE of stock and retaining all smog related equipment, in addition to passing the sniff test.

So once you get all your parts sorted and the motor running cleanly, your next challenge is to find a "friendly" smog inspection station/inspector. Usually, you will find one of these if you find and get to know a local speed shop who "sends" most of their clients there. wink-wink

An alternative is to go to the TPIS website and get their Big Mouth Lower plenum plus the Big Tube Runners, then have the upper Plenum ported to match, then the throttle body replaced with a bigger 52 mm. TPIS also sells preprogrammed Computer "Chips" in differing levels of engine tune. You can also have a chip custom made by TPIS by sending them your engine's specs and $$. You get the look of stock that won't attract all kinds of scrutiny. BTW, TPIS also sells a 50-state legal cam for the L98 that can take full advantage of opened up intake and exhaust for the L98. From what I gather, it is possible to get 350 bhp from an L98 with simple bolt on parts while using the stock bottom end while still passing the CA smog test with flying colors.

96lt4c4

I have been working on a similar project for a while but it has since been put on hold. I plan on running a complete LT1 top end including the heads. I did this so i would not have to mess with the bolt pattern in the intake. I plan on running water out of the ends of the heads. I drilled and tapped the factory crossover holes to 1/2 npt. I planed on just using the rear holes but I thought I might have a problem with air getting trapped at the front of the heads, so I may use all 4 holes. I don't have anything to put in yet either other than my truck.















Accessory brackets are out of a TPI f-body, I have about $300.00 in it so far.

RandyJ75

RR, I posted my response because I remember reading the problems George had getting his car to run right after the swap. Perhaps the reason is that his car (like mine) is speed density, and does not have a MAF?

Sinister87

For those looking to buy!

http://www.thirdgen.org/techboard/en...-s-lt-1-a.html