4.0 Turbo Sizing

[AlaskanRider]

Ive been crunching numbers trying to ballpark a turbo for my 4.0 OHV, 200-250 HP range. 5-6 psi of boost.

Seems like the only thread I can find with explicit information is copykat's, and he recommended a T3 .45 trim. I love how cheap they are.

Im afraid that they are a little too small though. My math puts me around 27 lb/min air at 1.6 pressure ratio at redline, and that is well off of any map for a t3 I can find.

Garett has a cool little turbo sizing app, and it thinks I only need 22 lb/min for 250 HP, which seems a little optimistic, but is still off the map for a t3.

Do you think copykat is able to control himself in order to not overspool the turbo? If you look at it that way, it will bump the torque to 270 ft lb at 2200 RPM. But I think i would be overspooling the turbo on a regular basis due to my lack of control.

Any input appreciated. I have zero experience with this stuff, and am enjoying learning about it.

 

[Hahnsb2]

Holset HX35?

 

[AlaskanRider]

That map looks awesome. I was lookin at a gt2860, but theres alot more HX35's around.

Did you use that on your dakota?

 

[Hahnsb2]

Sort of, I use a WH1C which is the same 8 blade compressor as the HX35, but it uses a V-band on the compressor housing with a removable backplate and I'm using a 21cm housing from an H1C on it as well, but I'm going with a 6 blade 60mm HX40 soon as it's just too small for my motor but should work awesome on a 4.0. Also consider the HY35 which has a 9cm turbine housing, should spool pretty well on a 4.0.

 

[LameDuck]

Seems like the only thread I can find with explicit information is copykat's, and he recommended a T3 .45 trim. I love how cheap they are.

I read somewhere on RPS it was a .63 trim T3/T4. Rumor has it he is working on it again.

 

[AlaskanRider]

Bought a turbo!

Holset hy35, some guy wanted 200$ for it locally, brand new. Should provide all I need and plenty more.

Probably not going to do anything with it for while though. I really want to get megasquirt working WELL before boosting anything.

 

[AlaskanRider]

I read somewhere on RPS it was a .63 trim T3/T4. Rumor has it he is working on it again.

Yeah I've found a couple more threads of his recently. He does some neat budget exhaust work.

Im hoping to avoid cracking heads like he does though, seems like all the threads end with him cracking his cylinder heads. He never does any work with his engine management though.

Im hoping ms1 with a good tune, mild to moderate timing and low boost at higher RPMs only should survive a little longer.

 

[Davis]

Sounds like a solid plan. I've always wanted to see a Holset on a 4.0. I'd like to see what a properly tuned 4.0 can do at a decent boost level (10+ psi).

 

[AlaskanRider]

Sounds like a solid plan. I've always wanted to see a Holset on a 4.0. I'd like to see what a properly tuned 4.0 can do at a decent boost level (10+ psi).

Me too! Too bad I don't have a dyno.

Hand calculations tell me that 10+ psi should ballpark 300-350 hp at 4400 rpm. Considerably more if I rev higher. Lots of rough estimations involved there though.


Friend of mine did ~400 HP on a 4.2l f150 at 15 psi. Was awesome for a couple years, but now runs poorly and is thirsty for coolant...

 

[Hahnsb2]

The HY should spool nicely.

 

[AlaskanRider]

The HY should spool nicely.

Thats my hope, I was pretty excited when I found out about the auto cummins turbo having a smaller exhaust housing.

Thanks for the suggestion, I would probably not have jumped on it if it weren't for your pointer.

 

[LameDuck]

Yeah I've found a couple more threads of his recently. He does some neat budget exhaust work.

Im hoping to avoid cracking heads like he does though, seems like all the threads end with him cracking his cylinder heads. He never does any work with his engine management though.

Im hoping ms1 with a good tune, mild to moderate timing and low boost at higher RPMs only should survive a little longer.

Sounds like you might get a chance to see it again. This popped up on my subscribed list recently.

http://www.rangerpowersports.com/forum/showthread.php?t=243860

 

[AlaskanRider]

Sounds like you might get a chance to see it again. This popped up on my subscribed list recently.

http://www.rangerpowersports.com/forum/showthread.php?t=243860

Cool thanks, I really like his layout on that one. I think I saw these pics in another thread he did on a different forum, good to see that hes given it another shot.