Hi everyone. I am in the process of building a 355 sbc with aluminum trick flow heads, a comp xr276 cam (.503/.510 lift, 112 centerline), 1.5 roller rockers, and probably a holley stealth ram or mini ram setup up top. It also has shorty headers and a borla catback. I was wondering if I can get the car running pretty decently without a custom tune? It's an 86 and it had the 305 TPI in it before.

Also, do I have to have a chip from a 350 car, or will the 305 chip work? Motor will most likely have 30 lbs injectors.

Last, If I go with a 350 chip from an 89 car, can I remove my cold start injector safely, or is this too good to be true, haha?

I know a lot of you have pretty serious motors in your cars, and I just want to know what I'm gonna need to get it all running good, until I get the money and equipment for a custom tune. Thanks guys!

 

I'd say that you'll need a custom PROM burned. The cam, LSA, and injectors will go beyond a stock PROM;even for a 350.

 

I ran a 350 no CSI prom (bin, actually) in my 86 TPI 350 with the XE268 cam, and it ran decently. But what you're proposing probably won't work. The prom may have the VATS enabled.... I forget. I know I had to disable VATS in the bin file I ran. Plus you are running a bigger cam than I had, and I feel that mine was about the limit of what the stock prom could take (occasionally had a little up and down idle). Plus if you put a HSR on it, you'll need to lose (and disable in the prom) the EGR valve.

 

Sorry, but I am drawing a blank....what is the VATS? Also, is there some type of aftermarket engine management system I can replace the factory computer with that will run the engine better and not spend an arm and a leg? I thought accel had made something for the TPI motors that made then easier to tune?

 

vats is that small chip you see in some of the gm keys that require a special resistor signal to fire the injectors.

I would not go through all the trouble you are going through to have a dope ride just to half step on the chip. You do not need a engine management system because you will not get enough power to justify the expense.

Have someone else burn your first chip and then get the equipment, which is getting cheaper by the day, and when you start to get board burn baby burn!

 

Wow, that was the best advice I have ever gotten, lol. Your right, I do not want to spend all this money on a mean street motor, and half-*** the chip. I've always wanted to burn my own, but I have never "tuned" a car before other than mess with fuel pressure and timing through the distributer. I read up a little about chip burning on this forum, and would love to get into it, but I'd love for someone to burn me a chip just to get the car running for now.......With the down time that it will take for me to learn how to do it and then get it right, the car will probably sit until next summer. As long as I can get it running, then get the equipment to burn my own, and learn from there, I'll be set. Anyone who'd like to lend a helping hand for the chip part, I will GLADLY appreciate it. Thanks everyone, and this site has always answered every question I have ever had!

 

VATS was not avaliable for the T/As until 1988. Only vettes had it prior.

You are running MAF, so for the most part, it should run fairly well. They are more forgiving than SD. The problem is, your system will think its still firing 19lb injector, while its actually firing 30s. You will be real rich. Probably so it makes your eyes water. The injector constant should be changed to match yours. Alot of other tuning can be done also, like the scalar tables, but, its up to you, if you want to get involved with it.

Aftermarket DFI systems are expensive.

 

Brutal, I think he mentioned he'd be running the 89 chip, which would still be the MAF with the VATS, is that correct? But the best bin to run would be the 89 since it was the last MAF one that GM had, but it is still gonna need some mods. I will confirm that the my car would not run on the stock 86 TPI prom, but did fairlly well with the stock 89 prom (VATS disabled, of course). Personally, I am running the Prominator, but those are hard to come by these days.... How about Moates' Ostrich??? www.Moates.net The Prominator allows me to easily hook my laptop up to my PROM and adjust any values I want to through TunerPro. TUNERPRO I just disabled VATS and changed the injector constant through tunerpro, although timing, fuel tables and much more can be changed.
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The Prominator can be found here......PROMINATOR I don't know if they're currently manufacturing them anymore though.

 

no 350 was offered in 1986 . But .....


time to either decide for ....DYI prom tuneing or get an aftermarket ECM. I also have the Prominater PRO( 8 bin files at the flick of a switch ) . Better than burning chips every time . SO I'd at least go with some sort of emulator ( or if you can get a prominator ...)then burn a chip when you think you are close.

 

white devil what city do u live in, maybe i can swing by and give you some pointers, i did a similiar swap on my 86

 

Transbird86, I am in Suffield. I have seen your car before......one of my friends is friends with you I believe. I think he has a mustang, and posts on purewheelhp.com. Can't remember his name though(kind of one of those friends you see once in a blue moon). But I would love any pointers you can give me. If your close to me, maybe we can get in contact and figure something out. Thanks a lot!

And yes, If it came to it and I could not get a custom chip, I would use the 89 chip because I would like to retain the MAF if possible.

 

i sent my chip to tpi chips and he deleted my cold start injector and just enrichened my main injectors for cold starts and it works great and still uses the 86 chip so theres no vats problems.he can also custom tune anything you got done to the car. i've worked with him before and every chip has been great.

 

Thanks iceman. you are correct. After re-reading the post, I see where he did mention the 89 chip. I think I need some glasses.

 

Yo D,
Obviously I replaced the 305 in my 86 Iroc with a 350. No, I'm not claiming I had one of the few stock 350s they made for testing that year.

White Devil,
Street and Performance sells a cold start injector plug kit for about $20, I think. LINK