C4 Modified

[hemivette]

Hello everyone, I am building a 86 Corvette and have been trying to figure the best route to tune an obd1 car. Everyone keeps saying mail order is a waist of time. I also have been told different ideas about injectors, and throttle body. From stock to wild, so I would like to hear more on that. Basically the need to know stuff is, HSR, AFR Enforcer heads, and a 280 XFI cam {about 550 lift} with 1.6rr. Exhaust, as of now is, shorty headers, hi flow cats, and no mufflers. Trans is 700r4 with a mid build, and a 2400 stall. Rearend is new, and has 3,54s. I use the car as a cruiser, auto cross, and feeling hurter.
My plan is to get the Moates 2.0 emulator, and learn as I go. Like I said before, this is all new to me so any help here is also appreciated. Ive read guys are just using the emulator, and not burning chips. Is that a good idea? This is the only obd1 car I have. Does it also work on obd2 cars? What else do I need to know? Still a little skeptical my ability to learn this, but I sure want to! TIA. h

[dave w]

The 1986 has ECM 1227165, using Definition $32

Gearhead-efi link for 1986 Corvette computer information: http://www.gearhead-efi.com/Fuel-Injection/showthread.php?367-1227165-ECM-Information-32

The link has TunerPro files specific to the 1986 Corvette. TunerPro RT is used to data log engine information, to be used for tuning.

OBD1 tuning is somewhat cumbersome compared to OBD2 tuning. MAF tuning does not have as much tuning support like the TPI Speed Density (MAP) systems.

dave w

[space387]

With what Dave pointed out if you decide to go with a speed density setup your options are the 1227730 and 1227727 ecu. Both work the same but the 7730 is not weatherproof so it has to go inside your cabin. The upsides for it are they are more plentiful coming from an F-body and all the write-ups are on that ecu making it easier to chase pin-outs and the such. The 7727 is in the 90-91 L98 corvettes only (to me knowledge) and are usually harder to source for cheap with a memcal. FWIW a good MAF system is more forgiving to variations in the engine like cam timing or replacing parts as they directly measure the airflow coming in but the speed density systems tend to be easier to setup initially to my understanding. Best of luck

[dave w]

.FWIW a good MAF system is more forgiving to variations in the engine like cam timing or replacing parts as they directly measure the airflow coming in but the speed density systems tend to be easier to setup initially to my understanding. Best of luck

I wish "Myth Busters" would have tested MAF tuning vs MAP tuning.

dave w

[space387]

I wish "Myth Busters" would have tested MAF tuning vs MAP tuning.

dave w

me too, sadly there are too many other factors that make it almost impossible to properly test.

[dave w]

me too, sadly there are too many other factors that make it almost impossible to properly test.

Grant Imahara (R.I.P) would have figured it. He had many skills with electronics and computers.

[stew86MCSS396]

With what Dave pointed out if you decide to go with a speed density setup your options are the 1227730 and 1227727 ecu. Both work the same but the 7730 is not weatherproof so it has to go inside your cabin. The upsides for it are they are more plentiful coming from an F-body and all the write-ups are on that ecu making it easier to chase pin-outs and the such. The 7727 is in the 90-91 L98 corvettes only (to me knowledge) and are usually harder to source for cheap with a memcal. FWIW a good MAF system is more forgiving to variations in the engine like cam timing or replacing parts as they directly measure the airflow coming in but the speed density systems tend to be easier to setup initially to my understanding. Best of luck

Original '165 is behind the passenger dash so if it were mine, I would keep it there with a '7730. Out of curiosity, have you addressed the HSR clearance with the C4 hood? I actually own one myself but not willing to cut it up to fit. Supposedly a angled spacer that tilts the throttle body down suppose to work but I haven't seen any proof of that.

[space387]

its not a HSR but an actual LT1 intake so it sits lower than the Dizzy. If I go back to a set of Gen 1 heads I will go for a stealth ram and shave the lower by about 1/4-1/2 based on clearance.

[stew86MCSS396]

I know I quoted you but sorry space387...that question was meant for the OP. Bought HSR before I was a C4 owner. Also considered doing what you did with LT1 intake but like everything else I've done...backwards! Jumped on an LT1 intake for cheap only to find out '93 is the wrong year to use. :rolleye: Here's one guy that wasn't afraid to cut up his HSR (https://www.s10forum.com/threads/my-weiand-stealth-ram-intake-project-stage-4-n-a-engine.522913/)