M42 turbo build, tech help needed

[bossco477]

Hi,

I am working on a turbo M42 project and need some tech help

So far I have:
1. A newer motor with new to be installed main bearing set (rods/thrust)
2. OBX exhaust manifold (planning to reinforce)
3. A Garrett turbo (freshly rebuilt...compressor is a .48 with a 44mm diameter impeller and turbo is a .63),
4. 3 in downpipe
5. BOV
6. 44mm wastegate
7. Med case 4.10 LSD
8. A one semester away Mechanical engineering degree with a motorsports concentration (lots of theory, not a whole lot hands on)

Still to get:
a. Exhaust
b. Engine management
c. Intercooler + piping  
d. Injectors
e. Fuel pump
f. Wideband O2

Target HP is as close to 300hp as possible but I could settle for anything over 250hp. This is my first time turbo ever but not my first time turning wrenches.

I am debating weather to upgrade internals due to the high cost of machining and parts (I refuse).

I have some questions for the turbo M42 crowd or the experienced in turbo tuners.
1.What engine management is the best for this application? so far best candidate is megasquirt, which one though and from what source?
2. What products and source do you suggest from list a-f
3. How much HP and boost will stock internals handle with the 10:1 compression?
4. How about lowering the compression?


I will appreciate any tech help you may provide. Please paste links to useful information. I have done my research but I have no concrete answers.

Cheers

[rob_e30]

Good luck with the build:

1. Choose something with a MAP and knock sensor.  Not sure if MS does that, but I think so.  This is critical to being able to tune accurately and for longevity.
2. A - Custom 3" with straight through muffler
    B - See above, but I don't know MS if that's what you want.
    C - Pick a core but the plumbing will be custom
    D - We run RC, but you need to select properly for your HP expectations
    E - Walbro
    F - PLX
3 - Plenty:  we've made well over 45psi (by accident), physically blew the HG from between the block and head and simply replaced the HG and raced that afternoon.
4 - Custom pistons, stock BMW head gasket

[gearheadE30]

going off that-
1. MS does have knock capability, from MS2e up. I don't have a knock sensor, but I have everything tuned very conservatively. If you are running more than maybe 8 psi on 10:1 compression, you probly want to find some knock solution.
A. I have a 2.5" exhaust. 3" is better. Basically, the turbo will muffle sound a bit, and you want the least amount of restriction possible. The turbo will tend to spool more quickly and operate a bit more efficiently due to reduced manifold turbulence.
D. I use ford racing 42 lb/hr injectors. Sounds like you want a tad more boost than these can support though.
4. I have an MLS head gasket. This is probably not the right way to do it, and I would definitely just run a stocker and low-comp pistons. That said, I think ACS318is on r3v is running 14 psi on a stock motor.

word of note-my HG is currently (I think) starting to go; getting tested for combustion gas in coolant soon, as the car keeps overheating. This was at 7.5 psi, but with a 250k mile engine that's never been touched inside.

[bossco477]

Thank you guy for the info, it is all very useful.

rob_e30 the info on the stock internals will save me a bunch of money. I had planned to build a motor but, I have two, and I will be learning forced induction as I go so keeping it low budget will be ideal.

I will find out about Megasquirt options and reference numbers

I have some questions regarding the intercooler...I was looking at the space and it is all very limited in front of the condenser. I am keeping my ice cold AC, I noticed the condenser fan is not working anymore so i was planning to delete it if I put my intercooler in front of it which would be ideal.
I have also considered moving the radiator closer to the motor using an electric fan and trying to put intercooler in front of it. Not an ideal setup but definitely easier to install.

Where have you put your intercooler? any options on other manufacturers intercoolers (volvo)? can you please share some photos?

This is the radiator fan I am considering:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=190524564745&viewitem=&sspagename=STRK%3AMEWAX%3AIT#ht_3438wt_1156

Ideas on how can I keep a fan on my condenser for cold traffic a/c with an intercooler?

As fas as the exhaust I will buy ss 3" piping and get a high performance cat for environmental reasons and if its too loud I will consider a muffler. I like my car stealthy

As far as injectors go, which injectors from other vehicles are interchangable and what #/hr raiting do they have ?
rob_e30 which RC did you get and from what source?
gearheadE30 where do those 42# ford racing injectors come from?

As far as the fuel pump I had read Walbro is the way to go. Now which one ? does it drop right in the tank like the stock one? any mods necessary? fuel pressure regulator required?

As far as the wideband I had considered innovate, what are the views on it? how does it compare to PLX, can you data log with PLX? where do you get the PLX?

As far as dropping compression. Is it absolutely necessary when using 92 octane? what are the boost limitations (what psi starts being an issue)? now I had considered dropping the compression by getting a cometic gasket, anyone done this before? if I go the piston route, which pistons are ideal? dished? what brand, source, and reference number? Keeping it stock 10:1 would be the cheapest

Another question arrises on keeping the stock head as it is. what is the max safe RPM,  that the stock head will turn?

Please post some photos on your build setup and comment on your engine management and how you have targeted all these points.

[BlueAppleSoda]

Using a thick gasket is not usually recommended to drop compression, but for "honda" guys it works. fucks with your squish area; large gasket area means easier to blow the gasket. But hey, if you are limited in budget this can be one way to do it.

10:1 comp with turbo...your gonna be running into detonation issues past 10psi on pump gas, for sure. Custom pistons from wiseco, cp, je....all are good manufacturers, and comp ratio should be roughly 8.5:1, adjust accordingly.

If you run megasquirt (which is the best option for the money imho ), your stock fuel pump will work fine as long as you keep the stock fuel pressure regulator. If i can flow 320whp on a stock e30 in-tank pump, so can you.

You can fit ev1 style and ev6 style injectors. you can find them used on ebay, or you can buy em new from me or the internets. do some searching.

You can fit a small electric fan on top of medium sized intercooler (IC: 24x9x2.5", fan size 12" i think) mounted to the condenser. If you dump the factory aux fan all together and just get a nice fatty radiator fan, you could fit a large 3" intercooler in the space between the a/c condenser and the valence.

colder spark plugs too. 1 step colder should be fine. if you are keeping a/c and you are gonna be in traffic...you don't really need 3 steps colder. just makes your car run like ass.

Derek
DedericMS