This place seems to be reasonably priced on bends. http://store.racing-solutions.org

 

i think im going to do the 3'' otherwise i cannot afford to do twins for a little while. i think the 3.5 and 4'' look better to the eye but i dont see why they need to be so big.

Now ot to the 5'' down pipe. what flange adapter and degrees of bends will i need? TIA

Casey

 

awesome prices! especially on flanges and whatnot but no 3.5.

 

Pat, what you guys doing with the wastegate? I curious to see how you guys tweaked the twins. I still don't know why you put a mid span joint on the air tube? Is it for easy of install or you using the base of the S300 as supporting the air tubes.

 

as much air as a HT3B or equiv will move I really doubt if a smaller pipe will make any difference those turbos fill a intercooler and a 855+ cubic inch engine to 20-25lbs of boost in seconds. Do you really think it takes very long for it to pressurize 2' of 3"pipe? I would bet the difference between 3 and 4" is in the millisecond range.

 

We are using the S300 with the dual volute waste gate with our heavy duty actuator on it. The R700 kit just uses a bigger primary than the towing twins. We use an S300 and S400 now for more air. They still have great throttle response so you can tow with them and they will support 700-775hp.

 

The smaller piping keeps the velocity of the flow up to keep the turbo supplied with enough air. There is definately a difference between the velocity of 3" to 4".

 

Isn't velocity a moot point at 20psi+ charge pressure? I would think turbulence would become a problem in the larger pipe making a 180deg bend but at the same time there are higher friction losses in a 3" pipe turning 180. I understand the velocity deal but if you are already possitive pressure at the secondary compressor it becomes a volume over velocity question doesn't it? I made a 3.5" pipe for simplicity because my primary had a 3.5" outlet and the secondary has a 4" inlet so it was easier for me to step up gradual from 3.5" to 4". Going from 3" to 4" would have taken more room to make a gradual step up.

 

Isn't velocity a moot point at 20psi+ charge pressure? I would think turbulence would become a problem in the larger pipe making a 180deg bend but at the same time there are higher friction losses in a 3" pipe turning 180. I understand the velocity deal but if you are already possitive pressure at the secondary compressor it becomes a volume over velocity question doesn't it? I made a 3.5" pipe for simplicity because my primary had a 3.5" outlet and the secondary has a 4" inlet so it was easier for me to step up gradual from 3.5" to 4". Going from 3" to 4" would have taken more room to make a gradual step up. All piping on heavy engines are 4" or larger even on little H2E turbo's.

 

Nice selection on the turbos Pat. I liked Chris old white ride, but you guys gave up on the old stuff abit quick. I look forward to see what you guys have put together on the new twins. Sounds good so far.