Has Any One Ever Ran A Cam With 112 Lobe Sep. I Have A 91z28 L98 Tpi. I Want To Put A Very Lopey Cam In, But The Map Will Go Nuts And The Car Won't Idle. Can I Get A Custon Program That Will Let The Fuel Curve Change Enough To Run.

 

eh, i got a 112 and my car wont run period. Wont hold idle and drives like garbage. Got a chip burned...no help so Im going to carb. Just get a computer compatible cam and get 1.6 rockers if you dont want to get too far into the tuning aspect of it.

 

you dont want anything less than a 112 LSA cam with injection. i have a 480/480, 210/220, 112 cam with 10.41 comp and it runs like mad. BUT iv had some chip work done. my cam is a comp 08-302-8 and reqs tuning. a 08-300-8 will be just enough to make the car pep up but you wont need tuning. my car is a MAF car so im speaking from that angle.
as for SD cars, they make better use of a cam but arent as forgiving as a MAF car.
also gotta be careful on going with 1.6 rockers and a cam, ya might hafta do some clearancing for the pushrods. Lespaul, did ya set your timing and your IAC? also how big is your cam and how and who did your chip? did you mail order it or what?
if your cam is too big i can see why your having issues or if you got a mail order chip your mostlikely never gonna get it right as the guy on the other end cant fully see whats going on as your car runs. he can only "guestamate" what its doing and what it will do.
i sugguest ya dont give up just yet, find someone local or within a reasonable distance to do your chip work. its worth it in the end. it took me a while before i found someone that can do the chip right and within a few sessions hes gotten the car running the best its ever ran since it was stock.
you will LOVE the gas milage you get with injection vs a carb.
after the F body ebent in bowling green KY i filled up and headed home to memphis, i made it all the way there on that 1 fill up and FINALLY hadta get gas when i was 15 mins from home. i live just south of memphis in MS. anothe thing about injection, ya dont hafta re jet or adj when the weather changes. the ECM does this for ya.

 

I have a 112 lobe seperation cam. The car ran with a stock chip but it didnt have enough start up fuel so it took to long time to start(if it would start). I had lsracingchips burn me chip so I could start the car then he dyno tuned it and now it runs flawlessly.
I am also running a MAF system so that my be difference.

 

The ZZ4 cam is a common upgrade in earlier TPI roller cam engines. It's got 208/221* duration and a 112* LSA. Lots of guys have gotten it to run good in their TPIs.

 

Right, I know lots of guys running 112 lobe seperation including myself. However the further you get away from it the harder it is to tune.

 

I'm running a 107 lsa in a 383 with map. Drives just like the 110,112, and 114 lsa cams I've had in the car before this one.

If you tune it, then it will run fine.

If you don't want to spend time tuning it, then get something like suggested above.

 

I had a 110LSA cam in my 305tpi.
I did not burn another chip for it to idle.

I turned up my idle speed to fix it, that's it.

This cam
http://store.summitracing.com/partde...5&autoview=sku

 

The problem lies with the air metering system of your car, not the cam or the fuel injection type. I've seen several TPI cars run fine on LSAs as tight as 110 with no advance, but they were all MAF cars. You have a speed density system, which is much less forgiving of modifications like a larger camshaft. Off-the-shelf type mail order chips won't cut it. You need to either have the car professionally tuned (or a VERY GOOD custom chip burnt, try www.fastchip.com ), convert to MAF, or look into some other form of induction such as a carb.

 

A Very Lopey Camshaft Is Not The Best Setup For A TPI Engine, Especially One With A Stock Intake And Runners. If You Have The Stock Heads, The Largest Camshaft You Can Safely Run Is The Compucam 2032, Which Is 214/220 Duration And .450/.460" Lift On 112 LSA, With 1.5 Rockers. You Should Also Change The Valvesprings, As They Are Worn Out With 15 Years On Them And Who Knows How Much Mileage.

Carbs Are For People Not Smart Enough To Figure Out Fuel Injection.

 

Or,they are for people who want to save money and put it elsewhere into the car and make it faster than the moron spending butt loads of money to keep his F.I. b/c he wants to get another 2-3 MPG .

 

Kevin and Marc have it right. The reason you want to keep a 112 degree to 114 degree lobe separation is in order to preserve a vacuum signal for the speed density system.

 

im running a 210/220 480/480 112 in my 305 with no sweat and its @10.41 comp.

 

I always forget to quantify that. For a drag car, you cant beat the simplicity of a carb. But for a street car, fuel injection is better. You're going to spend just as much time, money, and effort buying and swapping to a carb as you are upgrading your EFI intake.

If you have 10.41:1 compression ratio, then I dont think your heads are stock. Max lift on stock heads is about .470". If you're running .480", then you're lucky.

 

VERY bold (and ignorant) statement coming from someone with TPI, which happens to be one of the more expensive fuel injection systems to modify, that also returns very little...

Yeah, small cams are the way to go for performance, and carbs are for idiots. Oh wait, you're from CA