boosted TBI GM 2.hate

im currntly working on a 2.8 TBI motor in an S10. 87 to be exact, backed by an automatic. im building this truck to compete in next years GRM challenge, and dont have the money in the budget to do a v-8 swap or anything ilike that. so im looking at boosting the 2.8 with a rear-ish mounted turbo. probably be right after the y-pipe comes together where the cat used to be.

now, all the plumbing doesnt scare me a bit. its really nothing that me and my tubing bender cant take care of. and i found a pump at tractor supply that solved the fluid pump problem for me. all thats left is making the TBI work under boost, and what to source the turbo from.

first things first. what should i source the turbo from? im hoping to hold up to 6-8 pound of boost, with minimal lag being acceptable. haveing the turbo start to spool up around 2000 would be ideal, as any lower than that and ill just blow the tires abay with no rear weight. the key for the turbo is cheap. like pull-a-part sourced, as thats the kind of budget im working with here. if i can take two junkyard turbos, mix and match the housings, and make a good hybrid, thats perfectly acceptable too. i was personally thinking something off a volvo, saab, or mopar turbo2.2, as those would be small enough for quick spool, and easy enough to find. what's your take?

next up is the management side of things. i know from my research that ill need a boost referenced fuel pressure regulator, but cant find one to save my life. at least not one listed for a GM TBI. also, i think ill need a 2-bar map sensor, and some computer work to make it do ok. someone had mentioned that i can get away without it by running a boost referenced ignition retard, but that just doesnt sound right. so what are you guys doing?

again, the name of the game is cheap. im pnly looking for about 75 more horse out of this thing, and dont mind cutting, welding, or grinding. but i dont have the capability to burn my own chips or anything, and computers baffle me.

so please, help me out here. the motor will have a stock cam, ported and polished heads, port matched and slightly ported intake, port matched and slightly ported exhaust manifolds, 5.7 TBI, whatever injectors im toild to get, and 3 inch exhaust after the turbo.

thanks in advance Michael

you can pick up an fpr from an efi turbo dodge from a pick n pull for very cheap. then either run it stock pressure or i have a link saved on another computer that details how to make one of the dodge ones into an adjustable fpr.

for management, obvious answer is megasquirt.

for what it's worth, couldn't you pick up a running v8 from a junkyard for what it would take monetarily to build up a boosted and efi'd v6? i don't know gm motors well, but is that the supercharged v6?

i can show you how to make a TBI AFPR or make you one or i might even have an extra one i made to send to the cause.

there is so much room under the hood of a 2.8 s10 that i would keep the turbo up front, you should be able to run front wheel drive iron head 2.8 cavalier/celebrity/etc... manifolds and crossover and just plumb off the downpipe exit to a turbo on the passenger side above the inner fender - almost free and no enginnering to figure out. might need to clearance the firewall for the exhaust crossover but that's easy.

there are guys running turbos on blow through tbi setups but megasquirt should be relatively easy with TBI. i can hook you up with 305 injectors and a bigger 1 5/8" bore throttle body from a 4.3/305/350 and you could bore out the TB holes in the intake for more flow.

thanks, patgizz. id love to learn how to nake my own, but is it boost referenced?

i like the idea on the FWD setup, and ill look into trying that. may work, may require more surgery than i want to put into it.

as far as the dodge FPR, will it work with the GM TBI? any suggestions on how to plumb it, etc? also, any pictures so i know what im looking at? and the turbo from the 2.2 dodge as well, right?

reason im not small blocking it is that id have to do new radiator,mounts,hoses,driveshaft,transmission,engine,wiring,brackets,and accessories. i figure i can be into boosting the 2.8 for under 300 with the proper sourcing.

and please, patgizz, shoot me a PM on the TBI stuff. im definately interested.

how would the megasquirt work with the TBI, Auto with lockup torque converter, boost, and daily driving? any major sensor/wiring/motor mods to consider when coverting to MS?

thanls Michael

alternately, skip boost and find yourself a 3.4 block out of an impala or something. If all you were going to do is blow 6-8lbs anyway....

trying to be helpful, don't want to be a stick in the mud.

As a side note I absolutely love the sounds of GMs 608 V6.

http://protourings10.makeforum.org/project-drivabeater-t185.html

link to my build thread so you can see what im doing.

Michael

the 2.8 uses a map sensor type of system right?... for fuel you could do what some honda boys did... extra injectors and a valve to keep the stock MAP from knowing it's in positive pressure... so control the extra injector and spark with the MS (or could go with a BTM type box to retard spark) if you wanted to go real ghetto you could do the old school turbo dodge trick of using a cold start injector and a pressure switch... with the BTM box... also the possiblity of flashing the chip... as i understand it GM ECU's are pretty well hacked... that would likely be the cheapest route

for the TBi you'll need carb hat type thing or an entire box... look around and see what the turbo carbie guys are doing... i know somone sold a centrifugal SC kit for the 2.8L... just can't recall who it was...

i was considering a turbo setup like this a while back... but like most things it never happend... lots of options...

belteshazzar wrote: alternately, skip boost and find yourself a 3.4 block out of an impala or something. If all you were going to do is blow 6-8lbs anyway.... trying to be helpful, don't want to be a stick in the mud.

the 3.4 swap was going to be after the challenge, or after i window the block in the 2.hate. i figured that 6-8 was all the stock internals would hold anyway. well, at least with any longevity as im going to be driving it to the event.

Michael

wouldn't the 3.4 make nearly the same power with stock driveability/reliability AND be less work?

though I'll admit, way less interesting.

honestly, i have no idea how much the 2,hate makes, ket alone the 3.4. so it may make another 75 on top of the 2.8 N/A, just dropped in with a set of headers. anyone know?

Michael

Were in in your shoes. It'd be a 3.5L fwd top end running on a cavalier wiring harness repinned for a turbo grand prix eeprom. That would require a crank trigger though

Turbo dodge turbos have a weird flange, which you wont be able to buy easily. To do a turbo and get it working right probably wont be any cheaper than a v8 swap really. At the pick and pull yards here. just a turbo costs 1/3 what a complete engine does.

one COULD swap in a late model 3500 and build a sheetmetal intake for the TBI or a carb, i'm thinking they still have the oil pump drive where the distributor was and distributors from older stuff goes right in.

or the newfangled 3900 from a G6 GTP has 240hp. there are 3500's on ebay from LKQ for sub $300

Ya the 3500's use the same oil pump drive style as older ones. But you're forgetting that fwd's have the starter on the other side of the bellhousing as rwd so he'd need a newer style s-10 bellhousing that has holes on both sides for starters in order to use a fwd block. Poop. I forgot that the 3500 combustion chamber is too wide for the 2.8L poor. Stick to 3400

I would look at the stock turbo from a 951. Those were for a 2.5 motor so they will spool up fast enough and with your bigger displacement it should keep the boost down to something reasonable. Although your static comp ratio may equalize the difference in motor size. Best of all they can be had for reasonably short $$$ as many are replaced / upgraded.

thanks for all the tips on different motors and such. ill actuyally be going with the turbo idea, as i just can get it out of my head. im picking up a 350 TBI form a fellow GRM'er, porting it a bit, installing an adjustable FPR for right now, and porting the intake while its off to fix the leaks in the front and rear gaskets. im seriously leaning toward the megasquirt setup, jsut need to do a LOT more reading. but the way i understand it is that it will work with all my stock sensors, etc, accept a 2-bar map sensor, amd be able to run boost with a minimal of hacking to the factory harness, etc. just a whole lot less screwing around than it woudl be with an FMU, 3rd injector, etc. and a lot safer.

thanks for all the help, and feel free to learn me some stuff on megasquirt.

Michael