3500 swap questions

[PCGUY112887]

The only gauges I have are spedo, tach, fuel, coolant temp, and a light that can say "low oil" if it can't detect any oil in the bottom of the pan.

That's about it.

[berettafreak22]

looking into putting one of these in my '88 retta minus the already mentioned issues(crank trigger, fuel rail, fpr,vacuum lines, power sterring pump, tuning) what else might pose a problem? people are saying the mounts definetly, but others are saying no. anyone have any idea about this and a remedy for it?

[IsaacHayes]

Buy 3500. See what you need. Then make it work

[berettafreak22]

easy to say, but im not a welder or a fabricator, and if i spend my money on a 3500 i want it to work, so if i buy one and i cant make it work cause im not a welder//fabricator, then i just wasted alot of har dearned money... lol

[PCGUY112887]

Are the stock 3100 injectors at the stock pressure going to be enough to feed this modified 3500?

Thanks for the sticky btw.

[Superdave]

Are the stock 3100 injectors at the stock pressure going to be enough to feed this modified 3500?

no, you should run atleast #24's with the 43.5 PSI FPR (for a stock 3500)

I'm running #32 typhoon injectors @ 43.5 PSI

[PCGUY112887]

I guess there is no easy way to modify the 3500 injectors to work on a 96 fuel rail?

[Superdave]

I guess there is no easy way to modify the 3500 injectors to work on a 96 fuel rail?

not even close..


here is a standard Multech 1 VS a 3500 injector

[PCGUY112887]

Oh wow! I've never had any other injector out of a car so I didn't know.

Any suggestions on an easy car to find to yank it's injectors? Or anyone happen to be selling any injectors?

[Superdave]

Oh wow! I've never had any other injector out of a car so I didn't know.

Any suggestions on an easy car to find to yank it's injectors? Or anyone happen to be selling any injectors?

Injectors from a 3.4 DOHC would work well, they're #24 @ 43.5 PSI.

[PCGUY112887]

Well I hope someone here knows anything about tuning this. Main issue right now is just to get it to run as a stock 3500 vs my 3100. I considered trying to take all of the important tables from a 3500 BIN file and put them into my 3100 BIN file, but I don't know how effective that would be.

Over on the DHP forums everyone seems to think I need a whole new computer system for it to work.

[Superdave]

Well I hope someone here knows anything about tuning this. Main issue right now is just to get it to run as a stock 3500 vs my 3100. I considered trying to take all of the important tables from a 3500 BIN file and put them into my 3100 BIN file, but I don't know how effective that would be.

Over on the DHP forums everyone seems to think I need a whole new computer system for it to work.

i'm running a 3500 on the stock 91 3.1 computer...

If you get the right sized injectors in it and start scanning you may be suprised...

[bszopi]

Since it won't be a "true" 3500, you can basically make any computer run it. I've said this time and time again - the engine could care less what is controlling it. Its the computer that is requiring specific inputs for proper operation. You could run a 3900 on a 1980s ECM and it would run. Would it run as good as a 3900 in a G6? Probably not, but it would run.

With that said, focus on satisfying the needs of your PCM (hence the external crank trigger, the non-electric TB, etc) and go from there. And I wouldn't ditch your 3100 BIN, as I'm sure there are parameters in the 3500 BIN that may not function properly on a 3100 PCM. The main things you will be wanting to take from the 3500 BIN is base spark and fueling. Incorporate that into the base 3100 BIN and tune from there.

[PCGUY112887]

Right sized as in say the 3.4 injectors?

I want to ensure I am not maxing the injectors I put in it out, I want plenty of headroom so that is why I am kind of unsure of the 3.4 injectors seeing since I'm not far behind you in mods, but your injectors are much bigger.

[SappySE107]

You can increase the fuel pressure as well if you need more fuel. At 65psi, 3400 injectors become 26.7#. 4.2 trailblazer injectors are 28#. For NA, you can generalize 280 hp for 28# injectors and 225hp with 22.5# injectors. That isn't the end all be all of injector matching for power but I use that scale.