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Advice for turbo size


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I just got a southbend dual disk installed in my truck with southbend hydraulics. After talking to some guys about injectors and reading on here and various other forums I decided to go with a set of DAP new bosch 125hp SACs. I would like to know which turbo size would be better to run for this amount of fuel. I was going to go with small twins but after my other truck got totalled, the clutch job, and buying a 1998 jeep to replace the totalled truck, I'm getting short on cash so I'm sticking with a single. Budgeting around 1,500 for turbo and downpipe. I've decided on a borg warner SX-E 57/65/12or14   61/65/14 or a 62/68/12or14. I know that I could probably go bigger with the amount of fuel I have but I'm think about driveability. Not really after a power numbers just enough air for my fuel. Any advice would be very appreciated.

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How much power do you want?  

 

You can tune 125's to be happy at 400 hp or right around 500 hp.  You will be air limited with the 57,  but you might like how it drives better.   The 62 is a good turbo as well that you wont be air limited, but it wont spool as fast.    

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Yep I run the 62 68 14 I like it for what I do lights hard spools good keeps the egys down low with my high gearing only thing is it's laggy under 1500 rpms not a big deal in my life the 12cm would gain u 150 rpms quicker spool but egts would climb faster then the 14cm I wouldn't even consider a 65 over a 68 exaust wheel 

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Thanks for the quicl responses.  I'm gonna go with a 62/68/12or14. So the question then is 12cm vs 14cm. Quicker spool vs cooler egts. This is a video of a .70 vs .83 vs .91 housing. It doesn't show each individual dyno run or egts but it does bring them all on the same graph I think 1/3 through the video. I think I'll go with a 12.

 

Edited by Steven cash
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Like the guys with big tires are struggling with EGT control because the final ratio to the ground is too low. I'm the reverse of this I've got high final ratio to the ground and zero EGT's issues at all. I can tow my RV up 7% grade with the Quadzilla on Level 3 (Wiretap disabled) and hold it to the floor and never reach 1,200*F. Even empty truck running with full wiretap it takes quite a bit for EGT's to rise for me. My Average 55 MPH EGT is 475*F and then 550*F for 65 MPH

 

Trying to fix high EGT problems caused by an excessive low final ratio with upgrading turbos is not the right way. If you want to run large tire then re-gear the axle properly so your final ratio is back to 3.55 realm. This is why my final ratio 3.69:1 is screaming fast acceleration and EGT's are not even a problem, still can outrun a factory 4th Gen no problem. 12cm2 is perfect sized housing. Yes, tires do impact what turbo to get. 

 

+75HP injectors (7x0.0085)

HX35/40 hybrid (60/60/12)

Quadzilla Adrenaline

3.55 gears with 245/75 R16 tires (30-inch)

Edited by Mopar1973Man
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the thing that i see being the benefit of the 12, is the shorter time to totally lite.

 

pulling, entering traffic, or even play....where is most of your time spent....down lower, once going how much room do you normally have, not much, so a quicker lighting turbo will edge you out and have them chasing you

 

my little 2 gen outruns most newer trucks up to 3rd gear, by the time they start pulling....we are coming off throttle ( or i am art least), then it is all talk.

Edited by Stormin08
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I've considered a he351cw but with the 125s I got I'm gonna go with the 62/68/12 sxe turbo. May as well use all the fuel I got. Again, thanks for the advice. While I have your attention, while I had the trans out I decided to install a fleece coolant bypass. After that my coolant temps stay at about 150-170. The colder weather probably doesn't help. Seems to be working too well. I did put the thermostat back in with a new Oring and made sure everything was perfectly clean. Is there a higher temp thermostat I can get to bring it back up to 190?

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  • Owner
22 hours ago, Steven cash said:

After that my coolant temps stay at about 150-170. The colder weather probably doesn't help. Seems to be working too well. I did put the thermostat back in with a new Oring and made sure everything was perfectly clean. Is there a higher temp thermostat I can get to bring it back up to 190?

 

Might try a Quadzilla Adrenaline and crank up some timing. I'm running a 180*F thermostat rolling down the road at 60-65 MPH I hover at about 185-190*F. When I come to a stop and allow the Quadzilla to cool down everything to 275 EGT's the coolant drops to a mere 175*F. The 180*F thermostat gave me room to run the high timing. On the 190*F thermostat, I was pushing over the top of 202*F too much for me.

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23 hours ago, Steven cash said:

I've considered a he351cw but with the 125s I got I'm gonna go with the 62/68/12 sxe turbo. May as well use all the fuel I got. Again, thanks for the advice. While I have your attention, while I had the trans out I decided to install a fleece coolant bypass. After that my coolant temps stay at about 150-170. The colder weather probably doesn't help. Seems to be working too well. I did put the thermostat back in with a new Oring and made sure everything was perfectly clean. Is there a higher temp thermostat I can get to bring it back up to 190?

 

What temp are you using now? Can you put a shut off valve in the bypass for the winter? You can add a winter front or a piece of cardboard. I think the t-stats to fit your truck are 180, 190 or 200. 

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