Ok, the engine project is starting sooner than I originally thought it would, theres just a few little details I'd like to put in front of you guys. First things first, the planned setup is basically an L98 motor (L98 heads and shortblock) with an LT1 cam and an edelbrok TBI intake. Nothing crazy, because I want the setup good for everyday use as my only car with halfway simple installation.

Now I know the stock chip isn't gonna work so good, so I figure a good starting point would be a Caprice PROM and 350 injectors on the stock TBI unti. I'd eventually want to upgrade to the Holley 670 but I'll get to that later. My first question is, on a mild engine like this, do you think the Caprice chip would run this alright until I get into custom ones? I mean its not much different than the cop motor other than a slightly better cam and intake.

My second question is, rather than wait till later, should I just mount a Holley 670 with the 350 Injectors in the first place before even putting the motor in? (Bore the intake of course to fit it) I'm on a really really tight budget, but would that just be better in the long run? Also, even though it has the 350 injectors would the larger TBI unit throw the chip off too bad? I mean, custom is always the best, but I'm talking for the time being until I get something better.

Geez thats long. Sorry.

 

Is the caprice chip a stock chip cause those chips used a different ecm, already been through that, got an old cop car chip and not the same ecm, we cant even read the whole thing. We burnt a chip from the 9C1 and it runs great, see sig.

 

The ANLU eprom from a caprice will pop right inplace of the ANTT or whatever other eprom you have in the 8746 ecm, they're the same exact ecm. Infact the 8746 was only used in the TBI vin e (305 TBI) f-body and the 350 TBI caprice models.
One other factor is that the caprice is a heavier vehicle so the timing is going to be a big off BUT much better if you've got a mild 350. You could probably get the motor to run very smooth with the stock ANLU eprom, 350 injectors (a MUST), and playing around with the base timing WHILE watching the spark/knock counts.
So long as the heads are stock and it's a mild cam, it should be cake. Different heads and larger cam...time for a carb or get somebody to burn you a chip or start burning your own.
Stick with the stock TB, just get the 350 injectors that color match from the link/article on www.diy-efi.org and go to the gm_ecm link, the link is somewhere in there about the color of the injectors to double check flow rates.

 

Think the stock TBI will move air ok? Hey I'll take your word for it man, you know your shiznit. It'll save me some money thats for sure. Good thing I have an 8746 ECM sitting around that came out of Mike's 89 RS beacuse the 88 uses some weird one dosen't it? The one 8746 outa the 89 should be a straight plug in last I heard. I did check the #s on it and thats what it is, at least I remember it being so. Lucky for me there are 2 or 3 TBI Cop Caprices down at Darst Parts (Great local yard if you're in my area btw) so I should be able to snag the chip probably for darn near free if the ECM is still intact. Heck I could just take the whole thing, ECM chip and all. I'd rather buy new injectors though instead of ones that have been sitting for months if not years in a car with the hood off exposed to the elements. Thanks guys!

BTW you wouldn't happen to know 1. If some of the cop cars came with 305s or they were all 350s and 2. Where the RPO codes are on the cars so I can make sure it has the right stuff in it. If I remember right theres a couple of guys on here who have worked with these cars before. It'd suck to just pull the PROM out of another 305 car thinking it was a 350 and have it run crappy and not know why.

 

The 89-93 TBI Caprice police package (i.e. the 9C1 option) had a 4.3 v6, a 5.0 v8, or a 5.7 v8. All were TBI. Larger cities often bought the 5.0 version (LO3) for fuel economy reasons, because they didn't need the bigger engine. The v6 versions were usually used as unmarked nonpursuit admin and detective cars. Everyone else bought the 5.7 (LO5) for obvious reasons. Most of the cars you'll find will be 5.7 models, but check the trunk SPID sticker or the emissions decals under the hood to be sure.

One ThirdGen reader has a 93 TBI Caprice 9C1 police package that has run 15.70 @ 85.2 mph with exhaust, air filter, fuel pressure and timing mods. He has the stock cam and stock ECM. That timeslip suggests that he's in the 230 fwhp area as-is, which is an increase over the stock 205 fwhp rating.

So you should be able to, at the very least, match his torque and power output. In an Fcar weighing 600-800 lbs less than a Bcar, tha would mean 0.6 to 0.8 seconds, or close to 15.0. You cam is hotter than the stock LO5 cam so you should make a lot more power than 230, but you will be limited above 4000 rpm by the stock fuel delivery ECM, so you will need to do something more. That means raising the fuel pressure, and I really think you'll need the vFPR mod to do it in a load-dependent sense. Read the vFPR thread for more info.

A custom ECM will be needed to optimize the mods, but smart tuning with FP and the vFPR should work well. HTH, FYI. - Ken

 

You guys are very helpful thankz bigtime. If I can even hit 14.9 with the motor I'd be thrilled. I'm not obsessed with running numbers or anything, but at least I'd be able to run with the majority of my freinds cars without being left in the dust and be able to put cocky import guys in their place.