Im going to start building a rear mounted turbo setup for my 96 z28 M6, Its currently bone stock. Ive just got a few questions, and was wondering if I could get some input.

The plan is to run with the stock exhaust setup into a Master Power T70 P-Trim .68 A/R Turbo unit, with a 48mm Wastegate. Im going run some stainless lines to oil the turbo and use a Mocal Differential Oil Cooler Pump http://www.racerpartswholesale.com/mocal1.htm) and -6AN line to return the oil back to the pan.

Im only going to run 7psi boost, at least until I can forge my engine up. Also going to make a meth/water injection setup, to help with detonation control.

What Im curious about is the fuel system, will it be able to support this level of boost, with a tune?

If not, I plan to upgrade with the Racetronix LT1 Fuel pump with Series II wiring harness. Would 42# Injectiors be a good choice for this setup?

Also, any other input would be much appriciated, thanks in advance.

 

I strongly suggest the pump, injecotrs and a good tune...even for 7psi. You should be up in the 400rwhp range. When I was making 383rwhp/353rwtq my stock injectors had a duty cycle of 113%@ 6k rpm.

 

Alrighty, Ill plan to upgrade the injectors and fuel pump.
Are the 42# injectors a good choice? I do plan on doing more with the setup when I can rebuild the engine, so would the injectors support more power, and if so, where would they max out at?

Another question is about the ignition system... Would upgrading to the 6AL be a good idea, or is there a better system out there for it?
Im on somewhat of a budget, so I dont have unlimited money to throw into this setup.

 

42's should be fine uo tp 500rwhp
55-60's would be good to 600rwhp

I am selling Siemen dieka 55lb/hr injectors if your interested. Email me if so ( jrbellas95z28@yahoo.com )

As far as ignition system, I think there are 3 ways to go about it. Remember, the stock MAP sensor doesnt "see" boost. It knows vacuum to atmospheric pressure (14.7psi). The boost gauge will read "0psi" at atmospheric pressure. So it doesnt read positive boost.

1. Dont run a timing retard at all. This is the cheapest way, but wont produce as much hp as with a timing retard. You would have to be conservative on the tune and set the timing as low as possible for max boost because you dont want detonation at full boost (lets say you will run 7psi) . This sacrifices power at the boost levels from 0-6psi though.

2. You could use a timing retard and have the retard unit retard the timing per pound of boost. This will work well and wont hurt the low boost #'s.

3. The most accurate way is to use a 2 bar map sensor (so it reads 14.7psi of boost) and rescale some of the table in your program. I have not done this, but would like to try it when my car is together.

 

I like the idea of a 2 bar map, would you know where to find the info on rescaling the tables for the 2 bar sensor?

 

Theres a guy who did a DIY kit on thirdgen.org in a cavalier.. I think he had a cheaper solution for an oil pump

 

There was a post either edited or deleted that info on it. Its tough to find now. I would search the FI under "2 bar" or something along those lines.

 

Oh yeah..I think I recall reading about his setup. Ill have to go and find out what he used to pump the oil back, thanks for the reminder

 

Here is the thread that had the info about rescaling the pcm tables for a 2 bar map. You might give the guy an email as he was sending the pcm file to those who asked. If you cant get in touch with him LMK and I'll dig around and see if I still have the file he sent me.

-Tony

 

Thanks for the link Tony.
Now Ive just got to wait for the Tunercat software for the OBD2 setup...

 

A couple of questions- how are you going to mount the turbo? Any template for that pipe? How about the turbo- how did you calculate the size & AR ratios?

I've looked into this, and those are the two biggest issues I have. I need to do something different for the intake piping as I still have a FMIC leftover from my P600B install.

The oiling situation has been addressed in another thread. You run a pressure switch that turns on the pump when you have oil pressure (sometimes this is called a fuel pump safety switch to cut off the elecric fuel pump if the engine dies, like in a crash- you are wiring it to do this with the oil drain pump).

I've done quite a few fuel calcs. I ended up running 55# high ohm injectors with a Walbro in tank high pressure 255LPH pump, and this should support about 640 flywheel HP. Racetronix has the best fuel setup I've seen.

IF I get this together, I'm going to have a dyno tune.

 

lemme tell you 2 things....

a front mount turbo might look the same, but is not on the inside... so it wont spool right, and will take a while...

2. the oil pumps out there were not desiged for this, eventually 'if' they fail, you're screwed...

dont do a DIY....

 

The only difference is the smaller turbine housing. It's sized smaller for rear mount turbos to help with spooling.

 

ok...

i'm just telling you what I know, because I have one and there are things STS doesnt say to the public so that everyone doesnt go make one

 

There's nothing special about the turbo. It could be built by anyone.