4.0 SOHC turbo

[gvfd29]

I've been browsing the forums for years but finally joined. I'm wondering if anyone has done a sohc turbo yet? I don't recall ever seeing it done. Anyway I've got an 04 with 60k miles and the only mods are royal purple and high flow air filter with exhaust. I was leaning towards a nitrous 50-75 shot but I found a box from years ago that had a hx35 in it......fresh from cleaning and rebuild over five years ago. I think I can do a budget build on this truck and still have it under 600-700$ since the holset was a freebie.

I've had three rangers in all, 2.3l splash, 98 3.0, and this 4.0 sohc is killer compared to the others.

 

[Dirmaid]

I was considering doing the same thing with mine, but I've heard the block can't take much more than 7 psi before ka-boom. Are you looking at a kit or buying individual parts?

 

[gvfd29]

Putting it together, I've got a holset hx35 just rebuilt and an aftermarket wastegate with 3-5-6-8-9 lb springs. Intercoolers on ebay are pretty cheap and possibly doing mid or rear mount without the intercooler.

 

[CHKNFKR]

Mid/rear mount may be convenient/easy, but you'll have terrible boost response and oiling will become more involved the further from the motor you are.

 

[gvfd29]

Yes, thats why I'm currently check out intercoolers. A friend did a romote mount on his fi chevy love and the pump went out, I'm sure you can guess what happened from there. I'll probably do the 3# spring and use a stock bosch bov I've got laying around somewhere. Does the 4.0 ohc maf tend to hate seeing positive pressure? I'm drawing the setup and under the truck everyday checking spaces for pipes etc, I'm hoping to get this done before Christmas at least but spare help is hard to find.

 

[Hahnsb2]

Mid/rear mount may be convenient/easy, but you'll have terrible boost response.

Not true.



If you go remote mount, nut up and spend the cash for the Turbowerx Exa-pump, trust me on this.

 

[RangerSVT]

Well, I do know that using two turbo's off of an 87-8 T-bird turbo coupe work really well with the 4.0L, and they are sized right so you will have both boost at low rpm as well as higher rpm boost. Your limiting factor will be your cast pistons, which will be about 5-7 psi non-intercooled, 7-9 psi intercooled...I have a few of these turbo's if you are interested in going that route...I was going to TT my 4.0L but went V8 due to the trans starting to slip...
SVT

 

[Surrey]

I would be questioning wether or not your tranny will last behind a TT 4.0.

 

[RangerSVT]

Well, a 2WD would have a better chance than a 4WD, especially with 37" tires and using it as a 1 ton truck pulling loads the truck the was never designed to do (which is how I use my truck)...Mine was an auto, and if you have a manual it would last as long as you don't drag race the truck every day and you don't speed shift the trans (M5's don't like that)...
SVT

 

[Surrey]

Yeah, from what I've read in the tech library and stuff, the strongest rebuilt a4dls are behind 300hp V6s, anything more than that and shit starts bending.

With a 5-speed I would be worried about trashing clutches in like 10k miles with TT power.

 

[Hahnsb2]

Are the 4.0 pistons cast or hyper? Hyper pistons will actually put up with good amount of boost with a proper tune. FWIW the stock hyper pistons in the Mopar Magnum V8s have been proven to 15+PSI and 600hp+ with a good tune.

 

[Surrey]

Your limiting factor will be your cast pistons, which will be about 5-7 psi non-intercooled, 7-9 psi intercooled...

SVT

Are the 4.0 pistons cast or hyper? Hyper pistons will actually put up with good amount of boost with a proper tune. FWIW the stock hyper pistons in the Mopar Magnum V8s have been proven to 15+PSI and 600hp+ with a good tune.

Cast it would seem.

 

[Hahnsb2]

Cast it would seem.

Cast and hyper are often confused, which is why I asked for further clarifiaction. Google searching hasn't turned up any answeres for me.

 

[RangerSVT]

I have not seen a hypereuteric piston in a for NA motor, not they don't have them, just not that I am aware of. But if upgrading, I'd go straight forged, its cheap insurance...
SVT

 

[RacinNdrummin]

Hypereutectecs are Cast, they just have a higher silicon content that limits expansion, so a tighter fit is possible. This also results in a more stable piston movement, which is good for NA applications.... However, detonation kills Hypers just as easy as it kills Regular cast, so your tune has to be on.

From what I have researched, the SOHC pistons are hypereutectic (pretty much any piston in any modern engine, is hyper) and hold up fairly well to boost. The problem with the SOHC is the swiss cheese deck, and the likelyhood of blowing a HG with the high compression ratio...What I have heard is around 7psi is a good safe number for a stock engine. Even at that, your looking at 300+ hp, which is plenty through a ranger tranny...