Engine/Transmission (1994 - 1998) Which Turbo to get?

[Tom C]

I've been trying to figure out what to do with my turbo. I've finally figured out what power options I want. The stock HX35 just won't be able to keep up once I have all the power upgrades are installed. Here what I've have and/or soon to be installed/altered:



#10 (custom - a little taken off the top for more high rpm power) full forward

3GSK

DDP stage 3

Snow water/meth stage 2 w/220psi pump (using both 625ml nozzles)

16° timing

AFC housing full forward w/light spring (no tension)

ARP head studs

Lost muffler & gutted cat

60Lbs exhaust springs

planning on 45psi boost



Piers has mention that a twin setup with my stock HX35 on top and a HT3B on the bottom would work nice for me.



Any suggestion/Comments would be appreciated.



Also any idea on what HP this will give me?



Edit: I may have to tinker with the plate position once I have the injectors installed to control EGT's. Currently hitting 1350 max with stock exhaust still intact.

 

[bmoeller]

How do you use the truck? Towing, daily driver, competition, ... ... ..... ?



Shouldn't need 45psi to control the EGTs, depending on use. It really isn't the number of psi you need, it's airflow.



I have all of my engine fueling mods in the sig. The PDR 40 that I had before was fine empty on the road, but couldn't take care of the EGTs towing. Haven't towed with the new HTT 64 turbo yet.



Was making 38# (45# before bumping the timing) with the 40, and so far, I've seen 35# with the new one.



Since you have water, assuming it will handle the juice, a 62/14 might work just fine. A Phat Shaft would probably be better.

 

[Tom C]

Bmoeller,



Thanks for the input.



If I can get the power without the boost then all the better for low boost but I don't want my boost above 45lbs.



The truck is used mainly as a daily driver. Accationally I tow a 6K lb trailer and sometimes I may race someone off the line at a stop light The kid in me just wont go away



Are you running a 14CM on the B2-64?



I don't want to go to a 16cm housing if possible. I had poor experience in the past with slow spool up. The 14cm I think would be a good compromise.



How do you think my stock turbo would do with a 14cm housing on it?



The Phat shaft 62 looks interesting.



Any single turbo should be alot cheaper than twins. And I would still be able to change my oil filter easily.



Anyone know which spools up quicker, the HTT64 or Phat shaft 62?

 

[zstroken]

Given same turbine sections a 62 will spool faster than a 64. Comparing a phat shaft 62 to a htb2 62 the spool will be almost identical. Pretty much the same charger.

 

[Tom C]

Bmoeller, sorry. I couldn't see your sig while posting a reply. Guess you do have the 14CM housing. Why did you go withe the 64?



Thanks for the reply Zstroken

 

[zstroken]

Mgarland on here has a 62/12 on his 97 5 speed 12V. It is my old charger, PM him and he can tell you about it.

 

[bmoeller]

Bmoeller,



Thanks for the input.



You're welcome.



The truck is used mainly as a daily driver. Accationally I tow a 6K lb trailer and sometimes I may race someone off the line at a stop light The kid in me just wont go away



The 62/12 should be just fine.



I don't want to go to a 16cm housing if possible. I had poor experience in the past with slow spool up. The 14cm I think would be a good compromise.



How do you think my stock turbo would do with a 14cm housing on it?



It will help, but probably not enough to justifiy the cost. Would probably be better to do the 14 housing, and installing a bigger compressor wheel. Bumping the timing to 16 will lower the EGTs by about 100-150*, and help with the spool up a bit.



Anyone know which spools up quicker, the HTT64 or Phat shaft 62?

The 62 spools like stock, with enough fuel. The 64/14 spools like a PDR HX40/16. Slight tad more lag than the 40, but not much.

Guess you do have the 14CM housing. Why did you go with the 64?

Yep, got the 14. Plans for more fuel. I'm actually a bit under fueled for it, but, so far it is working quite nicely. Very streetable for me. I also have 4. 10 gears, so my RPMs are higher than the 3. 55s would be. The real test for it will be when I hook a trailer.

 

[Cooker]

That fact that you will not have real heavy fueling I would go with the 62. I tried a 62/12 at one time and it spooled really well. If I were to buy another 62 it would probably be a 62/14 for the better breating up top.

 

[Tom C]

With the bigger compressor (say 62) and more fuel I'll get more air volume, but will the 12cm housing take the extra volume? What effect on cylinder pressure?



Will a different air filter or modified stock filter housing help with the air flow. Or do I need to worry about that with my HP (I'm guessing 375-425).



Wonder if I should Dyno it before getting the turbo to be sure of the HP rating?

 

[bmoeller]

Doubt a 62 compressor would be available for a HX35. A stock 12 is REALLY a choke point with 4. 10 gears at higher RPMs, with additional fuel. But the HTT 62/12 has dual wastegates (as does my 64/14), so drive pressure shouldn't be any issue at all.



http://www.htturbo.com/cu.htm



IIRC, their 60mm comp wheel is the same size as what the one on a HX40 is. I would want a minimum of a 14 turbine housing.



I wouldn't bother with a modded stock air box. I just get a BHAF (Wix 42790, which is just a rebadged Donellson air filter). Depending on the source, probably looking at ~$40-50. A straight thru muffler (or straightpipe) will help the engine breath better.



With your current mods "to do list", you are probably closer to 325hpl. A HTT 62/12 will work just fine. Can always upgrade their turbos without to much trouble. They are great to work with.

 

[Cooker]

At 40 psi an HTT 62/12 is around 53 psi of drive. Sure it is greater than 1:1 but most run stock HX35's to 40 psi and the drive pressure is well above 53 psi. My point is drive pressure is a consideration but I think some over value it's importance. The 62/14 would have less drive pressure but I am not sure how much less.



Since you do not have huge injectors and substantial pump fueling mods I think the 62/12 would work well for you. If you are sensitive to spool up (if you have 3. 55 gears, tall tires, and a tight convertor) you might prefer the 12 housing over the 14. If you have 4. 10 gears I would not hesitate to go with the 14 housing regardless.

 

[Tom C]

bmoeller,



Is that RWHP?

 

[zstroken]

At 40 psi an HTT 62/12 is around 53 psi of drive. Sure it is greater than 1:1 but most run stock HX35's to 40 psi and the drive pressure is well above 53 psi. My point is drive pressure is a consideration but I think some over value it's importance. The 62/14 would have less drive pressure but I am not sure how much less.



Since you do not have huge injectors and substantial pump fueling mods I think the 62/12 would work well for you. If you are sensitive to spool up (if you have 3. 55 gears, tall tires, and a tight convertor) you might prefer the 12 housing over the 14. If you have 4. 10 gears I would not hesitate to go with the 14 housing regardless.

What was the wastegate set on that?? That seems out of wack. Was the wastegate open or closed?



A 12 cm turbine housing off of a s300 flows more than a 12cm holset.

 

[zstroken]

At 40 psi an HTT 62/12 is around 53 psi of drive. Sure it is greater than 1:1 but most run stock HX35's to 40 psi and the drive pressure is well above 53 psi. My point is drive pressure is a consideration but I think some over value it's importance. The 62/14 would have less drive pressure but I am not sure how much less.



Since you do not have huge injectors and substantial pump fueling mods I think the 62/12 would work well for you. If you are sensitive to spool up (if you have 3. 55 gears, tall tires, and a tight convertor) you might prefer the 12 housing over the 14. If you have 4. 10 gears I would not hesitate to go with the 14 housing regardless.

What was the wastegate set on that?? That seems out of wack. Was the wastegate open or closed? The 4. 10s I could see the 14 working out ok. I thought the 3. 55 and the 12 cm was a little slow in the top gear at low rpm, but once it got up there it would pull very well



For other clarification a 12 cm turbine housing off of a s300 flows more than a 12cm holset.

 

[bmoeller]

bmoeller,



Is that RWHP?

Ya. Actually, you might be a bit lower than that on #2 only, but should maybe have more with the water, once it's dialed in. Don't know if they actually give the amount they claim in ads.