MPFI conversion planning thread

[135sohc]

So I've taken the plunge and my new 2 piece intake is on its way.

swapping over parts isnt a problem. Between all the wiring scraps & pigtails I imagine getting the wiring installed to run all the injectors and adding in the 2nd connector pickup for the HEP wont be a problem.

But what will be a problem (for me anyways), no stock computer exists for the configuration that the car is.

94 (SBEC 2 ?) 2.2 & 5speed. Now pardon the stupid questions that are about to be asked. (The whole socketing, chipping and custom calibration thing is still foreign language to me)

Could a flex fuel computer (2.5L only) be recalibrated to the fueling requirements of a 2.2L ? since its got the drivers for 4 injectors. That I would assume are not present in a TBI computer.

[jl93sundance]

you can use any 90/91/92 computer with minor pinout changes, though I think you will need at least a turbo computer to compensate for the extra injector driver even if your going to socket it. Pm Wvrampage he did a rampage once, but I think he just used a whole turbo harness and a turbo computer.

[Murphy]

doing this with a 94 is going to be quite a challenge. A FFV computer is more trouble than its worth since it has extra sensors to measure gas / m85 concentration and fuel adjustment for it, tho htat might be your only option. to make up for the 2.2/2.5 difference you could jsut lower your fuel pressure. I dont think D-Cal is really setup to be used with SBEC2.

[jl93sundance]

doing this with a 94 is going to be quite a challenge. A FFV computer is more trouble than its worth since it has extra sensors to measure gas / m85 concentration and fuel adjustment for it, tho htat might be your only option. to make up for the 2.2/2.5 difference you could jsut lower your fuel pressure. I dont think D-Cal is really setup to be used with SBEC2.

Really I see no difference in sbec 1+2 my 94 sundance which I just converted to 2.5 turbo with 90/91 electronics will run on both sbec computers so really I see there is not too much of a difference, except for maybe a few pinout changes IMO.

[turbovanman²]

Your going to need a harness anyhow, so I would grab an earlier harness, 90's and matching computer, it will make it alot easier I think.

What car?

[chilort]

I've got a '93 FFV computer from a 2.5L auto. I was hoping to do something with it that isn't going to happen. I paid $30 for it. If you want it, it is yours for $30 plus shipping. Just send a PM.

[135sohc]

Your going to need a harness anyhow, so I would grab an earlier harness, 90's and matching computer, it will make it alot easier I think.

What car?

I dont know. I think it would much easier to add on the additional wiring for the extra injectors, HEP pickup. And relocate the wiring connectors for the TPS and idle speed motor to the other side of the engine.

everything else is (according to the FSM) the same layout as a regular TBI engine. The Map sensor & purge solenoid are the same between the two as well.

car is a 94 P-body

[turbovanman²]

I dont know. I think it would much easier to add on the additional wiring for the extra injectors, HEP pickup. And relocate the wiring connectors for the TPS and idle speed motor to the other side of the engine.

everything else is (according to the FSM) the same layout as a regular TBI engine. The Map sensor & purge solenoid are the same between the two as well.

car is a 94 P-body

I think its alot more work than you think. If you picked up an earlier P body, say 90/91, then it should be mostly plug and play and you have a computer you can easily mod.

[135sohc]

I think its alot more work than you think. If you picked up an earlier P body, say 90/91, then it should be mostly plug and play and you have a computer you can easily mod.

That would be ideal but those parts dont exactly fall out of the sky around here nor online here or elsewhere.


Guess I'll be keeping it for a conversation piece after all.

[jl93sundance]

I think its alot more work than you think. If you picked up an earlier P body, say 90/91, then it should be mostly plug and play and you have a computer you can easily mod.

I completely agree, Use a 90/91 turbo harness+computer, there will be some minor pinout changes for headlights turnsignals. but at that point your halfway there you should just turbo it lol

[Murphy]

you could jsut wire the injectors in parallel. that way you dont need to change the wiring or computer. you do need specific injectors tho and i dont remember what kind. I htink i saw it done before over on TD

edit: LINKY! http://www.turbododge.com/forums/f11...-w-pics-d.html

[135sohc]

I completely agree, Use a 90/91 turbo harness+computer, there will be some minor pinout changes for headlights turnsignals. but at that point your halfway there you should just turbo it lol

I do not want the hassle, expense and reliability issues of a turbocharger right now. I'd just like 4 injectors vs 1


Eventually (read as: if I ever stop procrastinating ) I'd like to pickup a solid CB core and rebuild it into a nice T2. forged crank, carrillo rods, wiseco's, 4 bolt mains, ect but thats a long ways off.

[turbovanman²]

I do not want the hassle, expense and reliability issues of a turbocharger right now. I'd just like 4 injectors vs 1


Eventually (read as: if I ever stop procrastinating ) I'd like to pickup a solid CB core and rebuild it into a nice T2. forged crank, carrillo rods, wiseco's, 4 bolt mains, ect but thats a long ways off.

Reliability issues,

Anyhow, if your not in a panic, just keep looking.

[135sohc]

Reliability issues,

Far less overall to go wrong on a N/A engine. Now I'm not saying you cant have a reliable turbocharged engine. if its stock and meticulously maintained. But mile for mile a TBI engine will go farther and longer than its turbo cousin.

[jl93sundance]

Far less overall to go wrong on a N/A engine. Now I'm not saying you cant have a reliable turbocharged engine. if its stock and meticulously maintained. But mile for mile a TBI engine will go farther and longer than its turbo cousin.

That may be true to a point, but which motor will you have 10x more fun with?

[Aries_Turbo]

ive had 0 issues with my turbo engine. i did trash 1 clutch (cheapo replacement) and a 140k input shaft bearing on the trans but that was cause i was hammering it with 20psi all the time.

you dont need all those fancy parts in your list for a turbo engine either. stock everything and a set of pistons is good for more than the stock head can flow.

id swap in a turbo harness and ecu on the now MPFI motor and then tune the Vacuum part of the maps to get good power and mileage from your NA engine. youll have full control of timing and fuel so you should be able to tweak it alot without much hassle.

Brian

[GLHNSLHT2]

+1 you don't need a turbo to run the turbo ECU. The ECU will just never see boost.

[135sohc]

you dont need all those fancy parts in your list for a turbo engine either. stock everything and a set of pistons is good for more than the stock head can flow.

I have no intentions of building a stock factory T2. Would rather overbuild it and not have to touch it again. and make future power upgrades easier.

[Aries_Turbo]

its already overbuilt stock. i can see the 4 bolt mains as the 2 bolt are seeming to shift a little at ~500hp. id do the k1 rods over the full on carrillo for the huge price difference vs insanely small difference in quality.

i see your point though.

Brian

[Vigo]

Reliability issues,

haha from the man who has one of the more impressive collection of broken stuff on the forums.

turbos are WAY less reliable and more likely to break then the tbi's, but that doesnt mean the turbo engines are unreliable at all.. it just means tbi's are insanely reliable. in my experience.