Turbine housing sizing + quickspool valve

[ForcedFirebird]

I have the worlds worst habit of over analyzing things. I cant stand taking guesses. Id rather have the benifit of a mathmatical equation. In most ways its my strongest trait, in others my worst flaw.

In any case, It should be fun at the end.

Oh! BTW. If you have any spare 3400/ 3.4l connecting rods, could you please mail one to Marc at TCE. Hes in the midst of machining my SBC con-rods and need one to use as a template for locating the proper spot for the bearing tangs. Call me when you get the time. I know that youre extreemly busy, so its no rush.

John,
Ben sent me a rod and I picked up a set of bearings to verify tang location.

Good deal. John, can you believe this is finally coming to a close? I know you should have a very fast/reliable setup this time (as long as another Ike flood doesn;t hit TX )

[CNCguy]

John,
Ben sent me a rod and I picked up a set of bearings to verify tang location.

[Driver_10]

See, John? Stop overthinking things I have had turbos in my hand efficient enough that they would turn over with a slight blast of air from the blow off tool on the low setting. One just about took the tip of my finger off when I wasn't paying attention and just being plain fascinated haha, 'twas a mere flesh wound...

I have the worlds worst habit of over analyzing things. I cant stand taking guesses. Id rather have the benifit of a mathmatical equation. In most ways its my strongest trait, in others my worst flaw.

In any case, It should be fun at the end.

Oh! BTW. If you have any spare 3400/ 3.4l connecting rods, could you please mail one to Marc at TCE. Hes in the midst of machining my SBC con-rods and need one to use as a template for locating the proper spot for the bearing tangs. Call me when you get the time. I know that youre extreemly busy, so its no rush.

[ForcedFirebird]

See, John? Stop overthinking things I have had turbos in my hand efficient enough that they would turn over with a slight blast of air from the blow off tool on the low setting. One just about took the tip of my finger off when I wasn't paying attention and just being plain fascinated haha, 'twas a mere flesh wound...

[Nick-G]

done and done. Talked with Marc at TCE and we were both thinking of dropping the "quick-spool" project entirely... Oh yeah. Im actually going to use one of the Comp Turbo "GT35r" knock-off with a T3 1.15 A.R. Its got a billet wheel ($200 option), a triple BB shaft and a water/oil cooled "cast aluminum" center section (My first time ever seeing one). The one demo-unit that they had at the turbochargers.com wherehouse spins so effortlessly that you can blow in it and damn near make the impellor move. Its a bad-assed turbo. Definitely one of my better purchases this year. I ordered mine custom, so Ill post pics of it when it arrives.

pics or it didn't happen... jk

This should be interesting.

[Driver_10]

Well I just typed a bunch of info and got the blue screen just before I hit "post" so I'll make this quick.

John, you are concerning yourself too much with keeping the small turbine. Mars is correct, the Holset turbos are the shiz. We used an hx35 on a 2.5l i6 in our BMW race car and thought for sure it would lag with it's large 10cm turbine (about a .83 A/R), but to our surprise we didn't need to add a quick spool device. We were seeing 15psi by 2k-2500rpm and 21psi by the shift point of 6300 using the divided pulses - we beat out an lsx-powered car identical to ours in the auto-x and ran a 12.3@117 on the circle-track Hoosier 275/45-15's and a 2.0 60' (stiff sidewalls, lousy launch for a rwd car).

Your motor has more modern (ported) heads and are a full liter larger. The hx35 is almost identical to the Garrett gt35 but without ball bearings (61mm instead of 65mm, but has the same exducer). Many many 3800's have small t4 turbines on them and spool just fine and I have ported thier heads like crazy just to meet up to a stock 3500 flow rate, and I feel you should be more worried about choke than spool time. I would go with the largest t3 you can find, and if it lags, only then add the quick spool, but i have a feeling it will work just fine.

EDIT: Your turbo is a Borg Warner, and you can find turbine flow maps for the GT series of turbos on the Garrett link above.

done and done. Talked with Marc at TCE and we were both thinking of dropping the "quick-spool" project entirely... Oh yeah. Im actually going to use one of the Comp Turbo "GT35r" knock-off with a T3 1.15 A.R. Its got a billet wheel ($200 option), a triple BB shaft and a water/oil cooled "cast aluminum" center section (My first time ever seeing one). The one demo-unit that they had at the turbochargers.com wherehouse spins so effortlessly that you can blow in it and damn near make the impellor move. Its a bad-assed turbo. Definitely one of my better purchases this year. I ordered mine custom, so Ill post pics of it when it arrives.

[ForcedFirebird]

Well I just typed a bunch of info and got the blue screen just before I hit "post" so I'll make this quick.

John, you are concerning yourself too much with keeping the small turbine. Mars is correct, the Holset turbos are the shiz. We used an hx35 on a 2.5l i6 in our BMW race car and thought for sure it would lag with it's large 10cm turbine (about a .83 A/R), but to our surprise we didn't need to add a quick spool device. We were seeing 15psi by 2k-2500rpm and 21psi by the shift point of 6300 using the divided pulses - we beat out an lsx-powered car identical to ours in the auto-x and ran a 12.3@117 on the circle-track Hoosier 275/45-15's and a 2.0 60' (stiff sidewalls, lousy launch for a rwd car).

Your motor has more modern (ported) heads and are a full liter larger. The hx35 is almost identical to the Garrett gt35 but without ball bearings (61mm instead of 65mm, but has the same exducer). Many many 3800's have small t4 turbines on them and spool just fine and I have ported thier heads like crazy just to meet up to a stock 3500 flow rate, and I feel you should be more worried about choke than spool time. I would go with the largest t3 you can find, and if it lags, only then add the quick spool, but i have a feeling it will work just fine.

EDIT: Your turbo is a Borg Warner, and you can find turbine flow maps for the GT series of turbos on the Garrett link above.

[Driver_10]

I was originally intending on spinning faster than 7500rpms. However, I never could find anyone willing to go through with the original "destroking" like I had originally planned. Im simply having the crank-pins re-machined. There will be no offset grind to speak of.

However, Since I am using 20,000 PSI ARP rod-bolts and knife-edging the crank, I think that I can hold extended output at 7200rpms without any worry. A few short burst to 8000 (aka mis-shift) shouldnt be an issue. (BTW Im setting the limiter at 7500. Thats more than enough "spin" to do the job)

Oh yeah... And please hurry with those vids. I cant get enough of the ones you already have floating on youtube. I love that proper engine note.

[MidnightriderZ24]

only a few pulls that high lol, mainly i didnt have the rev limiter set so it ran high burning through 2nd once..or twice. im trying to keep it to 7500. videos soon! im still using the 3400 crank, deburred/balanced.

[Driver_10]

honestly if your looking for high output turbos with relatively lower spool times you need to really look into the holset family! im using a hx40 with a 62mm compressor and 78mm exhaust side, and i have 15psi at 3500rpm on a builllt 3400/3500 hyrbid, and it pulls hard to 8500!

Yikes! You're pulling all the way to 8500rpms? I did the math on a stock stroke motor and came out to a safe 7250rpm. With a destroke and upgraded L-19 rod bolts, maybe a safe 8000rpms. But 8500?, wow. I presume that you're using a steel crank.

PS Id love to see a vid of a high rpm run if you ever feel like getting your camera out.

[MidnightriderZ24]

honestly if your looking for high output turbos with relatively lower spool times you need to really look into the holset family! im using a hx40 with a 62mm compressor and 78mm exhaust side, and i have 15psi at 3500rpm on a builllt 3400/3500 hyrbid, and it pulls hard to 8500!

[Driver_10]

Cool build, thanks for the pics. I look forewards to seeing your vids when you post em'.

Oh yeah. I actually found an even larger 1.15 divided t3 housing. Theres a company that makes a water/oil cooled turbo based off of the GT35r that Ill be using. (I really wish that I could remember the name of the manufacture) Thier version comes with a CNC, billet, alloy compressor wheel, triple ball-bearings and a cast aluminum center cartrige. It cost about $200 more than the GT3582, but is well worth the money.

Spool-up should be rediculously fast.

[ghrarhg]

If you dont mind, I love to see some pics of your set-up.

Here are some pics during the process, overall I didn't document this too well unfortunately.

Here's my crossover, starting with a TGP x-over and basically just hacking the ends off it:


It's clamped into the vise by the trans mount. The welds aren't as boogery as the pictures lead you to believe.

3" Downpipe w/6 bolt outlet flange


Here are some crappy pics of everything as of last night. I had an issue where my oil feel line failed on Sunday and sprayed oil all over my engine compartment, fixing that now.


Using a stock TGP intercooler with a 90 elbow welded onto it. It's not ideal but the fastest way to get up and running this season, and it seems to work alright for now.




More to follow, and hopefully a few vids once I get the new oil line in tonight.

[Driver_10]

Go with as much as you need, you can always upgrade. If it's top end all out performance you want go witht he 1.xx series but if you're looking for low end short burst performance the .82 maybe the best route.

Thanks for the list bro. I feel pretty sure about using the bigger 1.06 housing now. I could also use a manual boost control valve to set the opening and shutting pressure.

I bet that I could generate a pretty broad torque curve.

[Driver_10]

I finally got my gt3271 up and running on my 2800 hybrid. It has the 0.78AR twin scroll turbine housing, and I can have 4 psi in 5th gear at 2500 rpm (highway speed). I built a custom crossover to run the separate banks to each side of the turbine. Spool is not an issue at all. It almost spools as quickly as my old TGP T25. If you've dedicated yourself to the quick spool valve, I'd probably try the large 1.06 AR housing. You may find that with your extra displacement you don't even need the spool valve though.

If you dont mind, I love to see some pics of your set-up.