whitess

What effect does rear end gearing have with the chip? I want to put TPI on a car that has an automatic w/3.73 rear gears but the best stock chip I find is one for an auto w/3.27 gears. Obviously there must be something different (timing, fuel, firing of the injectors) because there are different ones for different ratios, so I would assume that there would be a performance loss, maybe even emmisions, using a chip for higher gears (3.27 or 3.08 or..). The TPI is an '88 setup with MAF and the stock analog speedometer. Since the rear gears are spinning faster the parameters I would think would be different. Any ideas, custom chip maybe?
Thanks, Larry.

Grumpy

The only way to get the correct will be with you learning how to do your own.

The gearing has alot to do with how you decay out the timing, and the Accleration Enrichment functions. And those areas are typically not even touched by the aftermarket chip guys.

whitess

Grumpy,
Thanks, that's kind of what I was figuring.
I looked through the proms for the SD systems and they don't list any gear ratios, just auto or manual transmissions. Is the rear gear ratio not a factor in the SD system PROM's?

MonteCarSlow

whitess: for what it's worth, if you are putting the MAF based TPI on a stock L69, I think you will find the stock 305 TPI calibration to be close enough, if close enough is good enough for you. Been there done that.

The base calibration for SD 305 is so-so in the Monte, I found the MAF base calibration to be better purely from a bolt-it-on and drive it experience.

Auto and Manual SD 305 bins have the same VE table, even though the cam shafts are different grinds. (Food for thought) To the best of my knowledge, the L69 cam is the same as the 1985 TPI 305 cam... so if your L69 is stock now, and all you are doing is bolting on TPI, it's close enough to stock for the stock cal to be reasonable forgiving.

HTH's.

whitess

Thanks for the information, every little bit helps.
Larry.

MonteCarSlow

Here's what it looks like when you are done your swap.

I hope I didn't spoil it for you.

Good luck!

whitess

Oh sure make me want it more!
Looks great. And white too! I'll save the pics for inspiration.
I'm getting anxious to do the swap, right after I get some more "suspension goodies" from Marcus.
Thanks,
Larry.

DENN_SHAH

iTrader: (1)

MonteCarSlow, it took me a few minutes to figure out why your a/c compressor is on the left side & mine is on the right side, you stayed with v-belts, i went with the serp belt. where did you get your air box from & what is it off of?
mine doesn't look no where near as clean as yours does, nice job

MonteCarSlow

The intake plumbing is from a MAF Firebird, the aircleaner assembly is from a FWD V6 car. I don't remember what the car was (scrap yard item). I installed the aircleaner assembly upside down, and made some other modifications to it. You can't really see it in those pictures, but if you want I can take pics of it to show you.


Thanks. Got pictures of your Monte's TPI?

Sometimes at cruise nights I get the odd person who thinks my TPI install is factory "Yup, special collectors edition... rare..." wink wink, nudge nudge. I even put the "tuned port injection" badge on the trunk lid like they did on Camaro's. TPI Camaro owners notice it....

JP86SS

iTrader: (1)

I do like how you did the intake, turned out nice.
I'm still running the v-belts and air as well but with belt driven clutch fan.
I need to go to the electric because I can't put anything but the K&N right on the throttle body. Its real tight there and with everything on the front there's not even room for an elbow (or anywhere to run to if I could cget the el on there)
I still hate the A/C lines running across and want to do something about them on mine.

As far as the chip goes, I'm using the AUJP on a 350 in mine and its working out good. I'm able to burn changes with the AutoProm and I'm happy with the money it cost to get the flexibility of doing the changes myself.
JP

JP86SS

iTrader: (1)

WhiteSS,
Grab the schematic from this post:
https://www.thirdgen.org/techbb2/sho...hreadid=242358

I don't know how long I can leave it on the site and it has alot of info for you on the swap.
JP

whitess

JP,
Thanks.
Larry.

JP86SS

iTrader: (1)

This give you a good idea of what this took for me to do.
You'll have some better info to start with so good luck!

JP86SS

iTrader: (1)

This was taken out as well.

JP86SS

iTrader: (1)

(picture shows almost done.

whitess

That first picture looks like you needed a comb.
I'm gonna cheat and get a harness from Howell. (I know, I'm a wus )