Quick spool turbo for 700 fwhp 5.3 on E85
02-23-2014, 05:51 PM
#1
Quick spool turbo for 700 fwhp 5.3 on E85 I am about a year away from adding a turbo to my LS4/F40 powered Fiero. It is daily driven in the summer and I want to build it for the street as it only sees the track 1 weekend per year (LS Fest).
Engine is 2007 LS4 (aluminum 5.3 w/ 799 heads, 10:1 compression) and the long block is stock with the exception of the camshaft (will be changed when I add the turbo - LS9 or custom turbo cam for the combo) and I don't plan on any upgrades to the rotating assembly. The engine only has 27K miles on it.
700 fwhp will be more than enough since the transverse manual transmission has about 15% driveline loss and the car will see 600+ whp and weigh 2950 lbs. Any more and it will just break more parts.
I would like to keep the LS7 exhaust manifolds (factory heat shields help keep the engine bay temps down) and just taper the collectors to a 2 or 2 1/4" crossover.
I would prefer a single turbo vs. twins for simplicity and space considerations.
Since this is a street car, I would like to see boost start building in the 2000 to 2500 range and have it peak in the 3500-4000 range and max rpm being 6500-6800. I can read the compressor maps to find the right compressor size, but my concern is on the exhaust side. I want something that spools quick but doesn't become a restriction until north of 750 hp.
Any suggestions on turbine size and A/R ratios would be very helpful as there isn't much info on the exhaust side. Most dyno graphs with the 5.3 don't start till 3-4K rpm so its hard to see how early it starts building boost.
Engine is 2007 LS4 (aluminum 5.3 w/ 799 heads, 10:1 compression) and the long block is stock with the exception of the camshaft (will be changed when I add the turbo - LS9 or custom turbo cam for the combo) and I don't plan on any upgrades to the rotating assembly. The engine only has 27K miles on it.
700 fwhp will be more than enough since the transverse manual transmission has about 15% driveline loss and the car will see 600+ whp and weigh 2950 lbs. Any more and it will just break more parts.
I would like to keep the LS7 exhaust manifolds (factory heat shields help keep the engine bay temps down) and just taper the collectors to a 2 or 2 1/4" crossover.
I would prefer a single turbo vs. twins for simplicity and space considerations.
Since this is a street car, I would like to see boost start building in the 2000 to 2500 range and have it peak in the 3500-4000 range and max rpm being 6500-6800. I can read the compressor maps to find the right compressor size, but my concern is on the exhaust side. I want something that spools quick but doesn't become a restriction until north of 750 hp.
Any suggestions on turbine size and A/R ratios would be very helpful as there isn't much info on the exhaust side. Most dyno graphs with the 5.3 don't start till 3-4K rpm so its hard to see how early it starts building boost.
02-24-2014, 01:48 PM
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I agree and I have a BB one for sale for the right price with the 3.5 inch down pipe discharge instead of 3 inch. PM me if interested. Mine has brought me to a 9.86@140 on only 15psi on a 6.0L and full exhaust and spools dang near instantly.
