OBD 1 3.4L DOHC Running Boost?

[grandprixgtp_91]

Ok, now that ive been buying parts for my 91 GTP to turbo it i need to know what i need as far as electronics go, i know that at least one person has done this on obd 1 , i forget his name though, so maybe other people remeber.

do i need a TGP computer? and will it plug right into my stock harness without modifying it?

or do i need just the prom?

i have a 5 speed so i dont care about the transmisison shift controls.

also i know i need a 2 bar map sensor,
will i need to run more wires to the computer for this or will it plug right into my harness?

also once i get that all set up will there me anything else i need ?
will the computer detect boost properly?

how can i import the dohc timing and fuel delivery table into the prom and adjust it for proper boost? i have a programmer so thats all covered. i am planning on running 9 psi on a turbonetics 62-1 turbo which ive already bought.

i already bought 42 lb/hr injectors so thats what im using there.

basically, any help, any knowledge of doing this is greatly appreciated,
thanks for any replies.

Jake

[grandprixgtp_91]

or better yet, does anyone know what brian89gp did? his website doesnt work anymore , does anyone know his email? from what i remeber he used a dohc chip just moddifyed. thanks

Jake

[grandprixgtp_91]

Ok last night i purchased an apu1 emulator from moates.net so i can do real time programming, but i still dont know what to do, lol any help please!!!

Jake

[Mr_Efficiency]

I'm not 3.4 expert but i can help you out on a few things here, the 2 bar map sensor uses the same ammount of wires, and will plug into your stock connector with minor modification, or just wire the 2 bar plug into your harness, they both use three wires.

I'm no tuning expert either but if the TGP chip did work with your ecm then you would need to let it know its now controling a bigger engine so it will add more fuel, you also need to let it know the heads flow better, again so it adds more fuel, and tell it the size of the new injectors.

I dunno if it would be easier or not but what about just programing your 3.4 chip to use a 2 bar map?

like i said I'm no tuning expert I have a guy do it all for me i just tell him what i want and he hands me the chip, lol

good luck with it tho, sorry i couldnt be much help.

[grandprixgtp_91]

Yeah, im thinking of trashing the idea of using the tgp chip, i just want to moddify the 3.4 dohc to work with boost, question is how? how do i moddify the wiring for the 2 bar map? does the tgp use a 2 bar map so i can get one? thanks for the help, any more you could give would be awesome, its hard to find help on this topic. thanks

Jake

[Mr_Efficiency]

the 2 BAr map came on turbo sunbirds and the TGP, im sure theres lots more but those are two that come to mind.

you can plug a 2 bar map into your stock plug but theres a guide tab on your plug you have to remove with a dremel, or just cut your plug off and wire in the 2 bar map plug off one of the above listed cars, I think the wires are even the same colors.

[grandprixgtp_91]

so its the same wiring, just the connector doesnt fit, so i can just buy a new connector and sensor , wire it up the same and boom i have a 2 bar map sensor? also whats the point of the 2 bar map sensor? what does it do opposed to a 1 bar map sensor? thanks

Jake

[Mr_Efficiency]

yes but the computer wont know how to read it so you need a chip that can.

the reason you need a 2 bar map is the 1 bar only reads up to 14.7 psi (atmospheric pressure) so anything over atmospheric pressure (ie:boost) the 1 bar map cant read and your computer dosent know what to do, it dosnet have the fuel maps for that kind of thing and has no idea what to do with boost.

on teh other hand the 2 bar map reads double that of a 1 bar so you can it 14.7 OVER atmospheric pressure allowing you to run up to 14psi of boost and the computer will still know whats going on, but stay a few psi below 14 cause if you get a boost spike and peak over 14.7 the ecm will stop adding fuel and bad things can happen.

you could always go the other route and bleed off vacume to the map so it never sees boost and run a rising rate fuel pressure regulator (RRFPR) and add the fuel yourself, the RRFPR will add more fuel as boost increases but this requires a litle more tuning from you and you most definatly need an A/F gauge to keep an eye on things, which is always a good idea anyways.

but thats only if you cant get a chip done, the chip a way better way to go... much safer to IMO but theres really nothing wrong with the other way when tuned right, but some consider that a kind of a hack job way to do it.

[grandprixgtp_91]

ok cool, thanks for the info, is your guy good with boost? maybe he could just get me started on the chip, i.e set it up to dectect boost and adjust fuel, then i could fine tune it from there. thanks

Jake

[Mr_Efficiency]

I dont know, I just gave him the bin file for the TGP with a 5 speed that i found online and he said he could put it on a chip for me, I'm going to ask him about changing displacement and injectors tommorow night tho, cause i'm using a 2.8 not a 3.1 and i'm using gen 3 heads and 9psi so i may need more fuel than stock cause of the boost and heads but maybe not so much cause im less displacement, so I'll see what he says.

[grandprixgtp_91]

ok cool sounds good.