Looking for some help.
I recently blew holes in a couple of my pistons on a stock1988 L98 long block tpi motor running a procharger 600b, tpis big mouth intake ported and matched (by another third gen member) to slp simiesed runners, 28lb?? accel injectors, stock tb, custom prom (agian by another third gen member) 373 gears. The car ran consistant 12.8 on street tires as above.
I was thinking of upgrading to a 383 with forged pistons, good rods and crank along with a s/c friendly cam. I will probably (do to budget) keep the stock heads for now.
I am concerned that if i make these mods i will have to upgrade to an aftermarket computer for big bucks.
Please help.

 

No problems......

I'm running 415cui and a procharger F1 on a GM computer........

Learn to do your own PROMS now over the winter......

What ECM do you have now or what year are your car?

/N.

 

The car is a 1988 Formula 350 with factory computer, custom prom to the 350 and a grinelli Mass Air Sensor. I have been told by a couple of people that the maf will be over saturated by the s/c.

 

You could get away with a modified PROM and a FMU, but the best would be to convert to a 730 ECM and the $58 code and bigger injectors. Read about it in DIY-PROM section.

But anyway I think you should download Tunerpro and start getting familiar with prom burning even if you are staying with the MAF setup, you are going to need th change the timing or you will probably burn your new pistons......

I would start with buying PROM/data logging tooling and start learning with your current setup and then decide to swap to SD or not.........


/N.

 

Thanks for taking the time to respond to the post. I will go ahead and check out the prom burning forum.
I am going to move forward with the 383 build.

 

Good luck.............

 

Terry, I just did the exact thing you're talking about (doing the swap I mean...not destroying pistons). Switch to big injectors *I bought (8) 60lb'ers from Lingenfelter for 398 last December and switched to the $58 code (in process of tuning). That way you can ditch the FMU (need a H.O. intank fuel pump and I'd recommend keeping the inline ATI pump) and you should be set. Good luck.

 

K ,so whats the difference in swapping to the 730 ECM with the $58 code ......vs going right to a 749 ECM.

 

D, the difference is you can use a '730 ECM (Speed Density Car) and simply pull a couple of pins in the harness that connects to the ECM and you can then run the $58 code (bin) instead of the '730's normal $8d. Very, Very simple really.
With a true blue 749 ECM you would still have to swap wires/pins in your harness...and purchase...no wait....FIND a 749 ECm.

 

...adn run a 2 bar MAP ...and it's will be all good ? Sounds better than the 749 swap ???

 

D, oh yeah...forgot about the MAPs...BTW I never knew but Summit sells MSD MAP sensors. Search their site for 2 bar and 3bar....nice price. I bought my 2 bar from them. What I'm describing kinda is a 749 swap in a way, we're just not physically swapping ECM's but running the corresponding ECM mask (code) and repinning a few harness wires so the right input/outputs are routed.

 

The only reason for using a 749 is if you are going to need P/H injectors. The 749 can be modified to handle 8P/H the 730 can NOT.

Otherwise its the code that decides the pinouts not the ECM itself

8D code 1bar map + 730 ECM you need orginal 8d 730 pinout
58 code 2bar map + 730 ECM swap some pins
58 code 2bar map + 749 ECM swap same pins.............

And yes its easier to find a 730 than a 749.............cheaper too.

And you will need a new memcal and bypass the ESC and put a resistor on the KS signal if you are going for the 8D/58 route, but its all in the DIYprom board.........