gwarren007

iTrader: (1)

So I just bought this, and I'm thinking full exhaust 2.5", L31 with 94666492 camshaft, TPI fuel pump , 350 tune and police car 350 injectors in the L03 TBI unit.

Am i on the right track?

DynoDave43

iTrader: (11)

Congrats on the purchase. I love that color.

Schurkey

Does it actually HAVE a 350?

gwarren007

iTrader: (1)

It's a RS, so it has the 305

blacksunshine'91

iTrader: (10)

Why would you put a "350 tune" in a 305? What does that even mean? Before you start getting fancy, just start with the basics. A solid tune up (new plugs, wires, cap & rotor, oil change, tranny filter change, etc.) should be the first order of business.

blacksunshine'91

iTrader: (10)

Also, make sure it is electrically sound. That rat's nest up by the master cylinder looks awfully suspect.

Ty92Z

iTrader: (11)

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I believe he’s saying those are his plans for the car, not what it currently has.

ironwill

Before putting even one cent into that engine, in what condition is the rest of the car? The A-pillars and floorboards, in particular, would be a good place to begin an inspection.

ShiftyCapone

iTrader: (7)

To add onto what others are saying, fix the broken stuff first. That car needs some love but hopefully is rot free (Arizona car?). I wouldn't touch the engine until you have performed the necessary brake and chassis/suspension upgrades first. They aren't as sexy as a new motor but are just, if not more, important. Also, if you stay TBI you are going to need to learn how to DIY EPROM tune. There is no such thing as a "350 tune". There is a tune that is needed for any modified TBI system but it must come from you or someone who can tune the car in their hands.

Tuned Performance

iTrader: (92)

Atjp or anlu isn’t considered a 350 tbi tune ?

ShiftyCapone

iTrader: (7)

Any stock 350 TBI tune is only good for the application it was intended for. I doubt GM had the same tune in all platforms with the 350TBI, they likely had many. In the 3rd gen, the stock "350 TBI" tune would work, albeit not optimized for the lighter platform, if the engine remains stock (Not vortec, no cam, etc).

Tuned Performance

iTrader: (92)

The bcc mentioned were used in the caprice but with same 1228746. Would work for 89-92 f body as well.
a good starter tune but would be better is recalibrated for the cam and heads.
dynamic ebl would make custom tuning easier. Not sure why the 350 tbi tune isn’t considered a 350 tune.
it works

gwarren007

iTrader: (1)

Sorry guys/gals- I guess I needed to paint a picture

The 305/700r4 and i guess 2.73 (like my 1989 Formula), need some help with the 305 breathing.
1. Planning for 1 5/8" headers to 2.5" exhaust pipes with a Cat delete (not required here).
2. Buying a L31, and taking the stock camshaft out. I would rather run the 94666492 camshaft, then get a base tune from one of the "burners" to guesstimate what I need.
3. run data logs to get more info to dial it in better.
4. Replace the L03 fuel injectors with 350 "police" injectors in the TBI. Bore the TBI as close to 2" or use a 454 TBI unit with 2" bores to get more airflow
5. Have transmission rebuilt from Bowtie Overdrives
6. Go to 4th gen Brakes front and rear
7. Have 3.55 gears and Locker pit in a 9" or S60
8. Subframe connectors
9. (probably) 6 point roll bar.

dmccain

iTrader: (2)

A lot of $ to sink in a car. Id first make sure the car was sound and didn't have lots of rust or electrical gremlins. Probably cheaper to find a nicer car with some of these things already done..

ShiftyCapone

iTrader: (7)

I should have expanded, it is at the micro level. Just trying to explian to OP that a 350 TBI tune doesnt mean it works for any 350 TBI (modified). Any modifications from stock, such as his plans, will require tuning.

Fast355

iTrader: (2)

While I am all for tuning a TBI system for maximum power and driveability the stock cop car caprice tune would make the car driveable and make decent power, IMO. Would need to crank the initial timing up and run higher fuel pressure though.

I have setup a few no tune TBI and Vortec engines over the years that ran great. Just have to keep things close to stock in terms of engine vacuum and match the injector flow to the WOT HP. ECM does quite well at controlling the fuel at idle and part-throttle.

As for the stock TBI tunes....They are pretty similar across the board, B-Car, Truck, SUV and even van tunes are pretty close. All run about the same wOT timing and similar timing advance tables. I had a 1993 Caprice cop car ECM in my old G20 and it put down almost identical HP and TQ as the 92 G20 TBI ECM. At the time I had 601 heads and a 204/214 Mellings cam with headers. Factory TBI intake manifold bored to 2" and a 454 TBI unit with the high pressure regulator and 46 lb/hr high pressure injectors that flowed 74 lb/hr @ 30 psi. I had the marine regulator that most people called the VAFPR back in the day hooked to manifold vacuum. Cut the injector flow around idle to keep it from loading up and increased the flow at heavy throttle to keep up with the fueling. I ran the Caprice ECM with that setup because it had closer fuel trims datalogging the end result. With 8* initial timing (non swirl port heads) no knock counts either. The Caprice ECM was calibrated to work with higher compression and the larger L98 cam, both of which more closely matched my setup than the Van ECM. The caprice ECM also had a WOT A/C cutout relay and dropping that A6 compressor at WOT was like unhooking the parachute you were dragging when passing or accelerating at full throttle (easily a 20 hp drag). The Caprice ECM also locked the torque converter at a higher speeds at part-throttle and had WOT lockup at higher speeds (80-85 mph), my setup enjoyed both. Caprice cop car also had an IAT where the truck did not. Running an open element air cleaner on a TBI truck ECM will drive you nuts without the IAT compensation of both fuel and spark. In hot weather the truck ECM will tend to run rich and in cold weather it will run lean with an open element and often the hot air inlet without the IAT spark compensation will cause knock retard.

Also FWIW, the injector BPW is set higher on a stock 305 chip. If the engine runs lean on the 350 chip, the 305 chip will provide more fuel when used with larger than stock (for the 305) injectors. It can be done, crude and dirty way to do it, but it can run very well. A few years back a guy did not want to tune a HT383 swapped in his 95 305/Auto truck. Had the GMPP Vortec TBI manifold on it. A swap to early model 454 injectors is all it took to get it enough fuel at WOT and a timing bump to 10°BTDC had it running very well. You can shift the fueling by altering the timing on a TBI. Generally speaking the more timing, the more vacuum and the leaner it will run at part throttle. Less timing, less vacuum and it will run richer at part-throttle. My Vortec head 383 with TPI on it was actually very driveable with a stock 95 G20 van 350 TBI chip with the timing bumped to 10°. I had removed the memcal and chip years before during the vans slumber. Fuel pump relay had died. I shot it with some ether and it fired right up after sitting 4+ years and stayed running. Drove it nearly 2 miles down the road after letting it warm up a bit and checking the trans fluid. Then loaded it up on the trailer and brought it to my shop for an 8.1 swap. I matted it to the floor and it smoked the rear tires for atleast 100 feet. Was a little rich around 11:1 at WOT but it didn't bog, surge or anything. Was amazed at just how well it ran on the stock TBI 350 chip despite being a cammed 383 with TPI that had nearly double the injector flow rate of a stock TBI injector. Then again the TPI 383 had a little more than 2x the HP of a stock TBI 350. All about balance. Idle was perfectly stable and had excellent throttle response. TBI peak and hold drivers with TBI firing rate even running the port fuel injection. Double the firing rate of a batch fire TPI setup. Actually if anything it felt more responsive with the shorter double firing rate of the TBI injectors than it ever felt with the longer single firing TPI injector firing rate. I never checked the fuel trims but the wideband showed the part-throttle and idle air/fuel ratio was spot on. Idle was a touch rich on initial startup but went into closed loop very quickly and settled down right around 1.00 lambda with a closed loop swing of about +/- 0.03

Fast355

iTrader: (2)

FWIW, my experience with GM OBD1 EFI stuff is generally you can take a whole mismatch of stuff, put it together and it will usually start, run and drive well enough to be able to tune it.

Kinda like the end result of this 403 Olds EFI conversion. I helped setup a Cadillac 500 with TBI fuel injection off a 454 GM motorhome in a GMC motorhome ~10 or so years ago. The 500 Cadillac fired up and ran on the stock 90 TBI 454 computer and ran well enough to drive it around to datalog it. Later it was converted to PFI and the stock TPI ECM ran it well enough to get it going.

http://www.grimers.com/vehicles/olds/403efi/index.html

dmccain

iTrader: (2)

Do you think an L98 with a 66492 cam would run good on the L05 copcar tune or would you leave the stock L98 cam in it? Upgraded 46mm TBI and 15lb spring.