this topic sucks with you dyno graph and freaking videos!!!!

 

ok, first of all the only way a single turbo is more efficient is in terms of cost. two smaller turbos like a pair of 3082R's or perhaps a pair of 35r's would spool faster than a large single, and you'd still have great top end. if you wanted to run a larger single, a T78 or an sp74, or a gt47R would still spool fairly fast. not as fast as the twins, but still pretty quick with 8 liters of displacement. either way, with all that displacement, i'd reccomend a pair of 50mm wastegates, and a pair of 50mm bov's. the sheer mass of air concerned with all that displacement warrants it. have fun though. looking forward to pics.

 

good post want a supra, BUT the 8.1L only revves to 4800 rpms
So if you go to big your lag vs rpm comeinto play. Also these motors make 455lbtq right off idel, so if you boost to low in the rpm range the just snoke tires for ever...

P.S. i got a supra ill sale ya

 

I will be putting twins on my 8.1 powered scsb 04 silverado

 

I love turbos. They are fun, sound awesome and twins are cool but if I was building something for your application, I go straight for a Roots or Whipple. 48' 13k pound trailer doesnpt need 500wrhp at 6000 rpms. You need 600lbs torque at 2500 rpm to put that beast up a grade.

Rick

 

Couldn't be more true. Most of the high end OEM's have gone to twin turbos versus singles to give the big cubic feel down low and still pull good on the top. Look at BMW's 3.0l straight 6 with two itty-bitty turbos. 300 ft lbs of torqe at 1800 rpm and still pulls 300 HP on the top. Compare that to a Subruru WRX 2.5l with a single that hits 300hp on top but only has 175 lbs of torque at 2000rpms.

If you do go the turbo route, the displacement will be part of the equation to determine A/R ratios but is irrelevent when deciding the size of the wastegates and BOV's. A kit builder will recomend the proper size componemts to compliment your turbo(s). If the turbo(s) will efficiently move enough air to produce say 600hp, it will be at 35lbs on a 2l and 12 lbs on a 8l. The BOV and wastegate is based off the volume of air the turbo(s) produce. I've seen plenty of kits that break 800 WRHP with only a pair of 30mm wastegates and a single 50mm BOV for a twin kit or single kits with a 40mm wastegate and 50mm BOV.

Rick