I've got an 88 iroc with an L98. The motor is stock for now and the only mods that I have done are a new cat, 3inch cat back and some headers. Now I want to open up the intake on the car. Who makes good intakes and runners that make good power? What do the siamiezed intake runners do?

 

Do a search and you'll find at least 30 topics on this.

 

AS&M are probably the best but are pricey. Use the links to the right and youll find what your looking for. Also try fasttoys.net along w/ Jegs and Summit.

 

I like edelbrocks.............because I have them on my car lol.

 

My understanding is that the port runners of the TPI are a low rpm power adder due to the ram effect of the design. The siamese runners eliminate this effect while increasing air flow at higher rpms. Not sure this is a worthwhile addon for a stock engine for the money.

 

regaurdless of what runner you pick the TPIS base is the best (bar-nun). what kind of power are you looking for out of this car? 1/4 times and so on.

 

I'm looking for good all around power. I don't go to the drag strip that much so I don't need a lot of power on the top end. I want some more low end and midrange power and torque.

 

I have a '91 L98 and i recently put on the stealth ram kit by holley. It will run a total cost of about $600 for the satin kit. It resembles a dual quad intake setup (for carb motors), but has a large plenum on top. The kit was pretty easy to install, easier than putting the stock tpi unit back on at least. The kit is rated from i think 1500 rpm up to like 6500 rpm and is supposed to boost your h.p. by up to 30hp. I did notice an increase in power, and a lot on the top end, the car pulls hard all the way through the rpm range. The intake and runner part number is HLY-7540, you also have to buy some fuel hose, some fittings, and a holley fuel rail kit in which i can't remember the part number, but get the one with the adj. regulator. they sell both items out of summit. you can get polished too if you so desire.

 

I was thinking about getting TPIS intake runners and manifold. I don't need the steath ram intake. From what I understand that intake make a lot more power where the stock tpi starts to run out of breath.

 

if thats all you want i say a cam swap and some porting.
63-08-304-8 Comp Cams 266 Hydraulic Roller Camshaft, 210 / 220, .500 / .510 114 LSA, For factory roller cam engines with modified TPI and computer.
thats a perfect cam for what your looking for. comp sales a (CK) that comes with all the things you will need. check out the site for more info. the intake will flow good enough for the power you're looking for.

the cam in stock tpi cars holds them back a lot more than people think. its actually cheaper to do a cam swap and some hand porting than it is to get the TPIS setup(witch is the only one i would spend my money on).

 

Will that cam let me pass an emissions test. I live in california so I have to be able to pass the test.

 

yes, or so it says it is. it really comes down to how you get it tuned.
and if you not happy with just the cam swap, then you can get the TPIS setup. all of that with that cam would be mint.

 

I had went from the stock unit to the tpis unit and then upgraded again to the stealth ram kit. The tpis kit is good, if your looking to gain a power in the same powerband as your stock unit (but i only gained 15hp off of the tpis kit), but if your looking to pull hp all the way through the rpm band, the stealth kit does pull harder, and it pulls the same from about 2000rpm all the way up and doesn't die off like the factory system does. as far as cams go i agree with the other guy, cams in the tpi motors stock are really small, and there is so much you can do with cams, i am running a crane cam 'xtreme fuel' series, which really made a huge difference, but you'll have to go to 1.6 rockers to run this cam plus a modified chip. don't forget the stupid stuff that people don't think about, like running msd ignition, underdriver pullies, power chip, adj. fuel pressure regulator, K&N filters,and so on. my girls car went from 15 flat out at the track to around 14.4 ,14.3 with just simple bolt ons and it was pretty cheap.

 

Thanks for all the replys guys. I'll probably get the tpis intake or edlebrock intake. Has anybody used the ZZ9 cam or the GM hot cam? I heard those are good cams but only good for non-stock tpi intakes.