Hey guys,

I've got a 90 Gta with a 350 tpi, auto trans with a tci 2500 rpm stall converter and 3.23? gears. I'm getting together some goodies to put on her this winter and I'm having trouble deciding on a cam. I've got a set of trick flow 23* heads, lt1 intake, hypertech stage 2 chip( I know they suck but it was in the car when I bought it) slp single inlet cold air intake, gutted cats and a flowmaster 80 series muffer. I'd like to get a set of slp 1 3/4 coated headers without air but I can't afford them at the moment. Given this combo which cam would you go for and why? Also what kind of computer mods am I looking at? I know I'll have to get into prom buring to get the most out of my combo but I'd appreciate any tips or suggestions.

 

With the heads and LT1 intake the HOT cam would make the most power.You really need some headers or you wont get the full effect.The prom tuning isnt really that hard to do.It looks like alot of stuff to change but over half of the settings you dont have to mess with to get the engine running real good.And by then the other half is just a bonus for better fuel mileage-driveably.

 

With this intake...Hot Cam and more gear. It will rev past 6000 easy, and you need to, to make it work. I wish I had more stall, so keep that in mind.

 

I forgot I'm going to try to go to 3.73 gears so I think I'll be okay in the gear department. How do you guys like your setups around town? I do have a set of flowtech headers but I think they are only 1 1/2 tubes and I don't think they would be the best for my setup. I noticed steve10 has 1.6 rockers, what do you have e-man? I'd like to use a set of 1.5 crane gold rollers since I've got a good set. I just wonder how much of a power difference there is between them. what kind of stall speed would go to if you had the chance?

 

All I can say is HOTCAM!!!! I have it already and will be doing the LT1 intake and heads soon... at least hopefully.

 

The LT4 HOT cam will definitely require a custom chip. I got away with the stock chip when I used a ZZ4 cam. Power was 282 RWHP with the ZZ4, and in my sig with the LT4 HOT.

 

How is the LT4 Hotcam with this combo:

'89 L98
-AS&M large runners
-52mm t/b
-fully ported and matched plenum
-Edelbrock base
-stock heads

 

Formulate that basically is Kevin L's Combo, except he has the Corvette heads.

And Impecabble tuning, and SD

 

Hey kevin,

With 1.5 rockers the hot cams lift is .492 on both intake and exhaust which isn't much more than the stock cam. how bad does the stock chip run? I have a hypertech stage 2 chip which I know isn't great but it came with the car. How did the zz4 cam run in comparison?

 

Slayer, go with 1.6's for the total .525" lift. This is what I did. You'll be surprised how good it will run like this on a stock chip. I'm running mine on a 305 SD chip and its running pretty decent for a starting point. You have SD as well, and a 350 chip so I'd say it will do ok. NOT 100% efficient, but it WILL be driveable. Later You will still need a custom chip to take the motor and car where it is possible of!

 

I have 1.52 rockers which is .498" lift. The stock cam is .413"/.428" lift. .498" is way more than stock. What are you saying?

The stock chip was absolutely horrible with the LT4 cam. The car was dead rich at idle, it was burning our eyes out. It was undriveable.
The ZZ4 cam was excellent and had no problems working with the stock chip. However I wasnt doing chip burning then so I have no idea how good it really was.

 

Kevin, I guess the stock chip is somewhat horrible... definately too rich at idle. You do your own chips?? What did you change so much to lean it out/??? Thanks!

 

My bad. I thought that was the 305 "peanut" cam. I thought 350 got along the lines of .450 lift. What kind of changes did you have to make to the hotcam run well?

 

My KPa values with the stock engine were in the high 20's to low 30's. Now they're in the low 40's. That's a lot less vacuum, so the ECM is using the fuel tables from the higher KPa values at the same idle RPM. Those values have larger numbers in them, so the computer is adding more fuel. Hopefully that makes sense.

I just lowered the numbers from 30-50 KPa and 600-1000 RPMs until the car idled the best it could. Its slightly easier with a stick shift than an automatic.

http://www.tunercat.com/tnr_desc/main_spk.jpg

The above is the spark table in TunerCat, but it looks really similar to the fuel table for speed density. Hopefully that will help you figure it out.

 

Will having a mass air setup help with going to a bigger cam? I have just started modding my 87; but I know a lot of people switch to mass air on Mustangs.
Jon

 

Its really a toss-up. Having a MAF does not let you go hog wild on mods. I've seen some MAF cars run great with large cams, and I've seen MAF cars run crappy with smaller cams. I would suggest doing your own custom chips anytime you change the engine size, or add a cam and heads.

 

By "getting the idle better" do you mean more smooth? Leaning it out at idle? etc... just curious. I've just messed with my idle screw and IAC... thats about it. Its way too rich overall though with this 19# constant in the chip, and even richer at idle most the time?!?! WTF?