Twin 42mm turbos

[Ajbonert]

hello all,
I am brand new to this forum but not new to the auto world. A little background, I live on a farm have done all mechanical work to all tractors implements trucks so on so forth. Graduated auto school three years ago and went right into ford. Am certified through ford, Volkswagen, and ase so I am somewhat inclined.

Now to the question. I have a little over 22k in my 96 4.6 gt and am currently hiding wire/welding in panels. The engine is being dropped in soon. I do a lot of side jobs so I have 2 02 Subaru wrx turbos that id like to fabricate onto the mustang. I see kits everywhere with 76mm turbo or two 60mm turbos but I wanted to know if the two (I believe 42mm) turbos would add much to the car? I initially built it to 5.1 heads cams etc. the whole nine yards and actually took the motor out and sold it to a close friend and in return he gave me his 02 gt pi block that runs perfect. I do not want to stick really any more money in the car so that is why im using the Subaru turbos. If anyone has any insight on the twin 42mm turbos like how much boost I can make how many lbs of air they could produce before I waste my time mounting everything and tuning the dam thing. Any help is greatly appreciated just don't tell me to buy a kit or to buy a bigger turbo I have a lot of other stuff to spend that money on and don't want to keep adding to the cost of the car at this point in time.

 

[Thomas_W]

If you dont want to spend anymore money on the car, dont put turbos on it.

And

"42mm turbos" doesnt tell anything about the turbos. We'd need to know the turbine wheel trim, turbine housing flange and A/R, compressor wheel trim, compressor housing A/R, etc etc.

the stock PI block would only be good for 8-10psi max, which should get you in the 350-400rwhl range, but your also going to need a fuel pump, injectors, MAF, turbo hotside, turbo cold side, rails, fuel pressure regulator (if 96-98), oil feed lines, oil drain lines. Coolant lines (if liquid cooled). I could keep going.

 

[mcglsr2]

Not sure what year the WRX turbos are from, but supposedly they are TD04-13T's and supposedly flow something like ~385 CFM. I honestly don't know the specs on these guys. Will they work for you? Sure, I guess. While maybe a tad small, I don't know how well they spool, so perhaps it's an okay thing for them to be small-ish (I'm sure they aren't ball bearing turbos). I also have no idea where the efficiency is, though people generally run them around 15 psi up to ~20 psi, there-abouts. Probably too much boost for your application.

That's probably why the dual turbos you see have a larger exhaust A/R - the car wants less boost so you can get away with better flowing turbos that don't need to spool up to high boost. I'm sure you can make the WRX turbos work though, but they probably aren't "ideal" for the engine.

Edit: and if you don't want to spend too much more money, then supercharge it instead. You get the performance you want (or close to it) in a simpler-to-install package, for probably a touch cheaper. Unless you want the challenge of installing the turbos. In which case have at it

 

[ttocs]

I am curious how he plans to tune it all as a great mechanic can make anything but he probably can't tune our computers.

 

[Ajbonert]

Yes those are the correct Subaru turbos. If I was looking for people to tell me not to do it is go else wear if I was looking for someone to tell me I supposedly don't know how to tune I'd go talk to a carbureted 350 guy so thanks for the lack of help this forum really let me down.

 

[Thomas_W]

Yes those are the correct Subaru turbos. If I was looking for people to tell me not to do it is go else wear if I was looking for someone to tell me I supposedly don't know how to tune I'd go talk to a carbureted 350 guy so thanks for the lack of help this forum really let me down.

Chill with the attitude man, you asked for opinions from other people snd you got them. Just because you dont like them isnt our problem.

Twin turbo's arent cheap and if you dont want to add to the cost of the car bc of other things to spend money on, then you should probably revisit what the priorities are bc fabbing up a twin turbo kit will cost you atleast $1000 in tubular front suspension parts alone. Another $500+ in hot section (not including wastegates) $500 in cold section, $500 in external wastegates, $175-400 in blow off valves, $350 in injectors, $150 fuel pump, $150 regulator, $150 fuel rails, $200 in silicon connectors and T bolt clamps, $150 for a MAF, $100 in a Maf extender, $400 for a tuner, $400 for a proracers tuning package.

Im speaking from experience on building a turbo setup (currently collecting and planning my own twin build). If you want to go cheap on a forced induction build, you likely will be doing it twice

 

[Ajbonert]

I understand that but I do have full cool overs, tubular k member, a arms, battery relocation, just finished my built t45, just finished the rear end with gears locker and axels, have all the bolt ons (they don't help much but I have them, cobra brakes, hot and cold side parts, turbos, maf, tuners I mean I have everything needed but the fuel system I'm just wondering if the turbos will world alright or if I'm better off getting a set of t3s or some other oem turbos. I hate superchargers I've had them before and would like a turbo setup now. Plus I have at least 2 grand in parts I can sell to so I can stick that back in the car I just don't want anymore coming out of my pocket into this build.

 

[Ajbonert]

My auto correct is ****ing with everything I type sorry about that

 

[mcglsr2]

Yes those are the correct Subaru turbos. If I was looking for people to tell me not to do it is go else wear if I was looking for someone to tell me I supposedly don't know how to tune I'd go talk to a carbureted 350 guy so thanks for the lack of help this forum really let me down.

Like I said - have at it.

You have a statement in your post ("...and don't want to keep adding to the cost of the car at this point in time") that is very misleading and will cause a lot of people to respond a certain way. Obviously this stuff costs money, and if you have already budgeted the WRX turbos and supplemental stuffs needed to make them work, then super. Just understand that's not how what you said comes across though. It makes it sound like you want to set up to WRX turbos and don't won't spend money doing it. Regardless of whether that's the case or not, have at it.

Also, tuning will be a serious concern - and while perhaps what ttocs said did not come across well to you - you also didn't mention anything about it in your original post. So how are we to know what you have accounted for and what you have not?

Lastly, cliffs notes for this forum: the vast majority of us here (like 99.99%) are NOT pretentious know-it-all pricks. Everyone here is pretty damn cool and glad to help out however they can, and certainly do not bash people for: whatever other cars they have/love/work on, not knowing things (we all have to start somewhere), sharing knowledge/lessons learned/information on things they have done, doing builds that are non-standard, etc. So: all around good guys. Honest. And while I totally get your intro and the need to lay the foundation of where you are in your mechanical/automotive life so as to avoid flames from hateful/spiteful/childish members - let me just say there's no need for that here.

So, let us start over as I believe we all got off on the wrong foot. Welcome to forum! Dual 42mm WRX turbos you say? Hmm. Well, I'm sure it can be done, but be prepared for a challenge. We will be glad to help you with whatever knowledge/info/guidance/brainstorming we can offer. I don't believe anyone here has done a dual turbo setup with the TD04-13T's - so make sure you create a build thread and show us how it goes! I know for a fact you will get peeps interested in how it turns out. We'll support to the best of our collective abilities (which is not unsubstantial).

 

[Thomas_W]

I understand that but I do have full cool overs, tubular k member, a arms, battery relocation, just finished my built t45, just finished the rear end with gears locker and axels, have all the bolt ons (they don't help much but I have them, cobra brakes, hot and cold side parts, turbos, maf, tuners I mean I have everything needed but the fuel system I'm just wondering if the turbos will world alright or if I'm better off getting a set of t3s or some other oem turbos. I hate superchargers I've had them before and would like a turbo setup now. Plus I have at least 2 grand in parts I can sell to so I can stick that back in the car I just don't want anymore coming out of my pocket into this build.

Well when yoi say you have all that, it changes things.

Would the turbos work, yes, but how well is unknow. Properly sizing a turbo is gery important for the best performance and is best suited for those who know alot more about your setup than the average garage guy. Garret has a turbo sizing app that is pretty decent, download that and see what they recommend and then compare those turbos to what you have.

 

[96blak54]

This is going to be a sweet build! This guy gots talent! Ive contemplated rear twin turbo with around the size turbo this guy speaks of. Im not turbo savy, but im watching. Keep us informed mang!

 

[mcglsr2]

This is going to be a sweet build! This guy gots talent! Ive contemplated rear twin turbo with around the size turbo this guy speaks of. Im not turbo savy, but im watching. Keep us informed mang!

Guess I missed that in reading - the plan is to mount these turbos not in the engine bay?

 

[ttocs]

I guess I am not sure why you are here then. Your first question is will it add weight? Yes it will. Now asking a mustang forum the specifics of a subaru turbo your not going to get much info there. It sounds like you have everything you need and know everything you need too have at it and tell us how it goes. Welcome to the forum.

 

[neverenuff]

Those Subie turbos sound like they are too small. On3 has a decently priced kit and might be worthwhile if you upgrade their turbo. More than likely the 42's will build boost down low and taper off after 5-6k, unfortunately this is where the modular motor makes the most power...at the top end. Keep us posted as it sounds like you are breaking new ground with modulars. Welcome to the forum.

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[rz5.0]

You should try it.. They might be small but they will spool up quick.. Worse thing can happen you will eventually need a lil bigger turbo. Twin set up always use smaller than single turbo kits..

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