I need to purchase a turbo for my 20b project and am having trouble deciding on a hot side. I am shooting for 600rwhp at ~15psi and near immediate response at 3500rpms -the lower the better.



I am more or less set on using a TEC Turbo HT-400 II compressor. The HT400 II generates about 85lbs a minute at 2.02 and has a very wide sweet spot. For a hot side they recommended a Q trim wheel with a 1.10 A/R. That seems small to me because I am using a 1.0A/R on my 2 rotor with a 35R compressor. However, the 35R has a P-trim wheel instead of a Q, so I’m not sure it is a good reference.



1. Aside from trial and error, how can I determine what the ideal specs are for a hot side (wheel and A/R)?

2. For those of you with a 20b single turbo please share your specs

 

T88 34D. You'll get 600rwhp @ 1 bar of boost. Very responsive. With a little more tuning and some 1600's i'll be at 600rwhp pretty easily at 1 bar. Click on the link in my signature.



-Destin

 

[quote name='sillbeer' date='May 25 2005, 07:58 AM']T88 34D. You'll get 600rwhp @ 1 bar of boost. Very responsive. With a little more tuning and some 1600's i'll be at 600rwhp pretty easily at 1 bar. Click on the link in my signature.



-Destin


[/quote]



He's asking for hot side specs, so what size exhaust housing are you running on that T88?



Stock motor T76 Qtrim, AR .96 will get you 15psi at ~3000 and 1.30 will get you 15psi at ~4500. Ported motor you should see boost a little earlier and be able to rev the motor a little higher, so depending on the porting the 1.15 could possibly be what you are looking for.

 

[quote name='IGY' date='May 24 2005, 06:58 PM']He's asking for hot side specs, so what size exhaust housing are you running on that T88?



Stock motor T76 Qtrim, AR .96 will get you 15psi at ~3000 and 1.30 will get you 15psi at ~4500. Ported motor you should see boost a little earlier and be able to rev the motor a little higher, so depending on the porting the 1.15 could possibly be what you are looking for.


[/quote]





Iggy is pretty spot on for a good all around size 1.15, what size footprint is on it makes a difference as well.

 

Q trim .96 all good. 1.15 ok. Any bigger no good , seen bigger on T76 20b pp drag car, gets into sweet spot at about 8500rpm cars a joke because of it.

 

[quote name='ccarlisi' date='May 24 2005, 09:40 AM']I need to purchase a turbo for my 20b project and am having trouble deciding on a hot side. I am shooting for 600rwhp at ~15psi and near immediate response at 3500rpms -the lower the better.



I am more or less set on using a TEC Turbo HT-400 II compressor. The HT400 II generates about 85lbs a minute at 2.02 and has a very wide sweet spot. For a hot side they recommended a Q trim wheel with a 1.10 A/R. That seems small to me because I am using a 1.0A/R on my 2 rotor with a 35R compressor. However, the 35R has a P-trim wheel instead of a Q, so I’m not sure it is a good reference.



1. Aside from trial and error, how can I determine what the ideal specs are for a hot side (wheel and A/R)?

2. For those of you with a 20b single turbo please share your specs


[/quote]



Your 35r 1.0 on the 2 rotor is a T3 footprint. A 1.1 on a T4 footprint should be a good bit bigger

 

Thanks to everybody for their input.



Sillbeer, that's a hell of a car.



[quote name='IGY' date='May 24 2005, 04:58 PM']Stock motor T76 Qtrim, AR .96 will get you 15psi at ~3000 and 1.30 will get you 15psi at ~4500. Ported motor you should see boost a little earlier and be able to rev the motor a little higher, so depending on the porting the 1.15 could possibly be what you are looking for.


[/quote]



The motor has a large streetport. Based on what you guys have said I am leaning toward a Q-trim 1.15, unless I can hit the top end numbers I'm looking for (600rwhp at less than 16psi) on the .95 -in which case I definitely want the .95.



I have decided on a GT42 compressor (the large one). The hot side and center section are still up in the air. The GT42 and T76 have very similar maps, so I assume Igy's experience with the T76 is somwhat representative of how a plain bearing GT42 would perform. If Igy is correct about the .95 and 1.3 on a stock motor I assume a 1.15 will hit 15 at ~3750.



Now, how much should I lower that number based on the following factors (seperately)



+street port (I have no experience going from a stock port to street port with a single. It didn't seem to make a difference with the stock twins in sequential mode-but the amount of airflow required is of course much different).



+ball bearing center section (I believe garrett claims it reduces spool up by 800rpms. I find that hard to believe).



[quote name='Zero R' date='May 30 2005, 03:20 PM']Iggy is pretty spot on for a good all around size 1.15, what size footprint is on it makes a difference as well.


[/quote]



Sean,



Don't you have a street ported 20b with a GT42R? If so give me the hard numbers





[quote name='93 R1' date='Jun 1 2005, 11:58 AM']Your 35r 1.0 on the 2 rotor is a T3 footprint. A 1.1 on a T4 footprint should be a good bit bigger


[/quote]



Actually I have a T4 footprint. It's a 35R compressor, but the rest of the turbo is basically a T04S.

 

ErnieT is selling a 2 rotor t88 34d kit for cheap

 

I will be running a Garrett T76 with a 1.32 on a large streetport'd motor, but I also have a 1.15 just incase the 1.32 in to laggy.

 

We curenly have a GT42R kit availible for the 20B 2g body this is a special made to order item 4 weeks $5200.



Chris..







[quote name='20b 3rd gen' date='Aug 7 2005, 02:14 PM']I will be running a Garrett T76 with a 1.32 on a large streetport'd motor, but I also have a 1.15 just incase the 1.32 in to laggy.


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