boosted 3.1??

[1996Monte_Carlo]

what is the cheaper way of going about boosting a 3.1? i have a 96 monte ls, i was looking swapping in a 3.4 sohc motor and changing the cam, pushrods, and the injectors out, and mounting the t3/t4 turbo in the rear. This came out of a cavalier owners mouth. He had the exact setup. I wanted to run it by you guys to see what you thing? Btw im new here

[bob442]

there is no SOHC motor but there is a single cam motor, swapping to a 3400 and rear mounting a turbo is not unheard of here, but i think on a w body you have enough room to mount a turbo under the hood. its a easy task if you have access to fabrication tools and such.... then theres tuning to do.

[1996Monte_Carlo]

i can do the tuning, but how would i run the turbo?

[bob442]

Make headers and put the turbo where the air box is. Be creative.

[1996Monte_Carlo]

thats what i was thinking, what lb of jets should i run, cuz im only lookin at running 7lbs. I think the stock one are 19lb, im not sure idr, but i think 20 to 21lb should be about right

[bob442]

You will need bigger for that, someone might chime in for more info on that

[Joseph Upson]

thats what i was thinking, what lb of jets should i run, cuz im only lookin at running 7lbs. I think the stock one are 19lb, im not sure idr, but i think 20 to 21lb should be about right

With a 7 psi limit you should be able to get by on 19s, the Turbo Grand Prix ran ~23 but it hit and has been pushed to higher boost levels on the same injectors and it had some dirty rich areas in the code. The stockers always have some reserve above their intended use. Run and watch whatcha got and change only if you see a need as larger injectors can cause idle problems that can be difficult to tune given the number of parameters involved.

[RedZMonte]

I would run bigger. im running 42.5lb injectors on my 7psi setup on my DOHC. find them on ZZPerformance or any other verious site for 3800's, they are a direct swap into the car. you should be able to find tons of pics on this site to show how to run it under the hood. should be simmilar to my DOHC setup in my photo albums.

S

[RedZMonte]

This might help show you the setup: (this is a MPFI motor but basically the same thing.

http://60degreev6.com/forum/showthread.php/39956-so...highest-HP-from-a-3.1-MPFI

[Joseph Upson]

I would run bigger. im running 42.5lb injectors on my 7psi setup on my DOHC. find them on ZZPerformance or any other verious site for 3800's, they are a direct swap into the car. you should be able to find tons of pics on this site to show how to run it under the hood. should be simmilar to my DOHC setup in my photo albums.
S

He want's to keep it cheap and if that means no tuning equipment involved or minimal, 42s will make it run terrible at idle or not at all from personal experience, not to mention a 3.1 doesn't have near the efficiency that your DOHC does to require that kind of flow.

When it comes to daily driving, you need a steady idle and larger injectors will mess that up without a time consuming tuning effort unless you run openloop continuously.

[1996Monte_Carlo]

He want's to keep it cheap and if that means no tuning equipment involved or minimal, 42s will make it run terrible at idle or not at all from personal experience, not to mention a 3.1 doesn't have near the efficiency that your DOHC does to require that kind of flow.

When it comes to daily driving, you need a steady idle and larger injectors will mess that up without a time consuming tuning effort unless you run openloop continuously.

your seeing exactly what i want, i got the gist of the setup underneath the hood, im thinking about but not sure yet, but do i need to run 3in exhaust after the turbo? or can i leave it 2 1/2 in.???

[RedZMonte]

2.5" is fine. if you have crush bends in there you may want to replace any bad bend with a mandrel but im running 2.5" on my DOHC turbo setup. and for what its worth, my 42lb injectors idle like stock... 1 simple flash and it was good to go. if you don't want to tune then stockers or close to stockers and a FMU will get your fueling good for low boost. I ran stock injectors, walbro 255 HP pump and a 12:1 Vortec FMU for a couple years without problems.

[TGP37]

36 lb injectors from the supercharged 3800v6 work great. I have hit up to 12 psi and injector duty was below 85% iirc.

If you want cheap, weld the downpipe shut at the flange and mount the turbo right onto the crossover. Use 12 gauge steel sheet to cut out a box that mounts the T3 Flange to the crossover, and cut the crossover open inside the box. Weld it up real tight. Dont want a leaky manifold jetting hot pressurized gasses. If you do not plan to boost any higher then 8psi, using an internal wastegated turbo will make things a lot easier for you. Otherwise you need to fit in an external wastegate.

You can also get a battery trunk relocation kit for under $100 and that will give you more room to work with. I removed the AC and cruise control for yet more space.

Keep in mind the turbo oil return MUST have a steady downward flow into the oil pan (entering above the oil level) or you will blow out the seal and smoke like crazy.

Stock camshafts for the OHV work surprisingly well with turbochargers.

Be sure to use a turbo that works well so learning how to read compressor maps is a plus. I can say the T3/T04E-50 Trim (not super 50) is a good all around match for our engines. Turbo efficiency is important to avoid excessive heat and surge.

Use a spark plug that is 1 degree cooler.

A quality transmission ATF cooler can do a lot to prevent most trans damage.

Resourcing a method to tune your PCM for larger injectors is the best option. Though FMU's, etc can work.

A Wideband is a MUST for inexperienced boosting. So is a boost gauge.

[Joseph Upson]

36 lb injectors from the supercharged 3800v6 work great. I have hit up to 12 psi and injector duty was below 85% iirc.

If you want cheap, weld the downpipe shut at the flange and mount the turbo right onto the crossover. Use 12 gauge steel sheet to cut out a box that mounts the T3 Flange to the crossover, and cut the crossover open inside the box. Weld it up real tight. Dont want a leaky manifold jetting hot pressurized gasses. If you do not plan to boost any higher then 8psi, using an internal wastegated turbo will make things a lot easier for you. Otherwise you need to fit in an external wastegate.

You can also get a battery trunk relocation kit for under $100 and that will give you more room to work with. I removed the AC and cruise control for yet more space.

Keep in mind the turbo oil return MUST have a steady downward flow into the oil pan (entering above the oil level) or you will blow out the seal and smoke like crazy.

Stock camshafts for the OHV work surprisingly well with turbochargers.

Be sure to use a turbo that works well so learning how to read compressor maps is a plus. I can say the T3/T04E-50 Trim (not super 50) is a good all around match for our engines. Turbo efficiency is important to avoid excessive heat and surge.

Use a spark plug that is 1 degree cooler.

A quality transmission ATF cooler can do a lot to prevent most trans damage.

Resourcing a method to tune your PCM for larger injectors is the best option. Though FMU's, etc can work.

A Wideband is a MUST for inexperienced boosting. So is a boost gauge.

Definately for the most part. I had a discussion with NGK about plug heat range and even with my 11.5:1 they were not enthusiastic about suggesting I reduce my heat range from stock for 7psi & I didn't have a problem running stock plugs.

Although compressor maps are great for efficiency info, I've noted the trend is moving towards buying a turbo rated for the horsepower you're trying to achieve. As long as you're within its limits an intercooler will take care of the heated air. A turbo that puts your efficiency in the center of the map at max boost level will likely spool up slower than one that is reasonably to the right of the center island because the compressor wheel is usually bigger with compressors that focus your intended boost pressure in the center island. The efficiency difference might not be worth it at all if you have a good intercooler in place. You want to go when you hit the pedal, not spool up and then go. Look into liquid/air intercoolers also.

A wideband O2 sensor is very important as stated, but TunerproRT5 is even better provided you set the history table up to display boosted AFR. Had I known I could easily change the AFR history table I probably wouldn't have burned the rings in my motor,
not sure why the ADX table for AFR wasn't scaled for boost in the first place for Turbo Grand Prix 8F code. I have an AFR gauge but when your car is accelerating as hard as mine was at 8 psi you can't take your eyes off the road to look at the
gauge so I never saw the lean spot until I scaled the history table weeks later after discovering I could to find my AFR was as high as 18:1 in some areas under boost.

Nice to see constructive input in support of a budget oriented effort to improve performance instead of remarks about "the right way" to build a project by someone who's not contributing financially.

[TGP37]

I melted the ceramic loose on stock plugs at 8 psi. Could be a fluke though.

I agree but bad efficiency can bend the turbine blades. I had a T04e-50 "knock off" spool up really quick on the crossover design. Was hitting 5psi at 3200 rpm. Started boost at 2800. The compressor and turbine inducers and exducers were proper sizes too.

But that was a knock off CXRacing turbo. Will be installing an authentic turbonetics soon.

The maps are for a 3100v6. The Super 50 is inefficient entering boost and redline. The 40 trim should spool up fantastic.





Whats your advise concerning Joseph?