3500 swap questions

[Superdave]

hundreds of people are running the FFP pullies w/o problems. Sure in theroy it's bad.. so is drinking beer

[PCGUY112887]

I hope to be able to hit 250WHP, it's kind of a long shot but I think I will be able to get close after exhaust, custom ram air, and a damn good tune.

I would go with an under drive pulley to try to pick up some extra HP but I still don't like the whole idea of it not being an insulated pulley or whatever people talk about who say it's bad for the engine in the long run (something about it transmitting vibrations to the crank).

[Superdave]

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.

my goal was 300 WHP, that's why i'm running such big injectors.. i swapped out the FPR to the lower PSI one for now.. i'm going a little lean in the top end but i've still got plenty of injector to handle it.

[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.

[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.

[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.

[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...

[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]

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]

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]

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]

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

[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]

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

Thanks for the sticky btw.

[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