late model racecraft
One of the biggest LSx performance shops in the world. DUH!
I have a set for you , on a car…
nick, ive told you my opinion on the best turbo for your setup.
the precision GT42-76. its Billet, with a ceramic ball bearing center section. supras make 1250rwhp on them, so just imagine what 2x the displacement could do spool wise.
a 76mm + a 370cu/in engine screams RESPONSE. no nitrous needed for spool. perfect.
do the math its not that hard…get the equations and good info from Corky Bell’s “Maximum Boost”/
You are fucking killing me!:Idiots
I run a BW S372r, billet wheel. I have no complaints.
Nick is trying to beat audijay’s goal 1600rwhp @19,632 rpms
Great turbo.
But yea, it all depends on your power goals. You have to start much bigger if you plan on making 1200+whp compared to 900whp.
Why so much HPz, put the power down to the ground first. Suspension + Tires>HPzzz
He’s already quite setup, 11.6@11x is great for the weight/power.
HP comes from air and fuel
more HP comes from more air and fuel
more air comes from more CFM getting slammed into the motor
turbos make more CFM
bigger turbos make much more CFM
Compressor maps for each turbo tell you how much and when that CFM will come into the motor. Read and understand the maps.
I split the massive amount of turbo choices in 4 based on motor’s powering them.
Tiny displacement (1.0L - 2.2L) Small displacement (2.2L to 3.6 liters) VS medium displacement (3.7 liters - 4.6L) Large displacement (4.6L +)
A 33MM turbo (stock VW size) on a 1.8T starts to make boost neutral reving it! Makes stock boost level (8-10psi) around 1100rpm, and can max out around 24psi around 2200rpm.
A 50MM on a 1.8l journal bearing spools around 3100rpm. Add a ball bearing and maybe 2800rpm.
A 57MM on a 1.8l journal bearing spools around 4300rpm. Add a ball bearing and maybe 4000rpm.
A 62MM on a 1.8l journal bearing spools around 5100rpm. Add a ball bearing and maybe 4900rpm.
A 33MM turbo on a 5.3l would probably make 20psi at idle!
A 50MM on a 5.3l journal bearing spools around 1200rpm. Add a ball bearing and maybe 1150rpm.
A 57MM on a 5.3l journal bearing spools around 2200rpm. Add a ball bearing and maybe 2150rpm.
A 62MM on a 5.3l journal bearing spools around 3000rpm. Add a ball bearing and maybe 2900rpm.
A 76MM T4 on a 5.3l journal bearing spools around 3400rpm. Add a ball bearing and maybe 3300rpm.
A 76MM T6 on a 5.3l journal bearing spools around 3800rpm. Add a ball bearing and maybe 3700rpm.
A 88MM T4 on a 5.3l journal bearing spools around 4400rpm. Add a ball bearing and maybe 3300rpm.
A 88MM T6 on a 5.3l journal bearing spools around 4700rpm. Add a ball bearing and maybe 4600rpm.
More or less, the larger the displacement, the less the NEED for a ball bearing and a billet wheel in regards to spool time. There is so much exhaust passing over the wheel, it doesnt really matter. UNLESS you run wicked boost. Then the ballbearing and billet wheels are NEEDED for longevity, alignment and balance, etc. keeping it in one piece for a while. Wicked boost vs normal boost on a big motor is like a 500-2000hp difference.
2 smaller frame turbos will spool quicker than one large one, yet flow the same if not more air overall. generally.
thats like the nitty gritty, piss into the wind turbo 101. you could spend a life time on this. there are SO MANY variables its not worth the effort. Work your way backwards. Cars weight with driver track ready, target ET, HP needed, Motor configuration, turbo needed to flow XX CFM to the motor in question, in this operating range to make the necessary HP to hit the target ET in the cars whose weight with driver track ready is XXXX.
Dont just start in the middle and work around it. IMO.
Can’t wait to see twins on 12.5:1 compression…killing me.
Also a great choice!
A little high, yes, but I’d run it 11/1 on E85, no questions!
11:1 yes…I am looking for 12 psi on 11:1 for my own car. 12.5 on a Hemi with boost? no way. Blow the heads right off it and the overlap needed in the cam to manage it would make for a waste of time trying to push boost through, might as well have the intake tube plumbed straight to the exhaust.
why not? compression is only half the battle, GI-JOE!!!
less boost, more flow (bigger turbo(s)) + higher flash point fuel divided by high compression = OK
MOAR boost, more flow (bigger turbo(s)) - higher flash point fuel divided by high compression = :ohnoes
and there is allways timing to consider of course.
many guys in the vw world are going higher compression with race fuel/e85 on the same frame turbos and making more power than before, and safely.
Because with enough boost to make it worth while you will lift a head. Timing would be almost non existent, maybe 10*, the internal parts in his motor aren’t up to the task of boost…lets see…what else.
I agree with the more compression, less boost argument…but on a Gen III it’s not a good thing over 11:1…and 11:1 is pushing it.
Just to add…with the current tuning available on the GenIII stuff 12.5:1 N/A is tricky. We are learning every day and gaining access to more tables all the time but it’s still not close to being 100% control.
whats worthwhile? 1000HP? if so nope not worth it, should have built it from the ground up with that figure in mind FI. 700Hp, large single, 7-10psi should put him close to that right?
and yeah I agree, compression is just a number, each motor and their designs are completely different so its irrelevant until those design specs come into play.
food for thought:
LM7 5.3L with stock heads and stock HG is 9.5:1
LM7 5.3L with 243 heads and stock HG is 11.0:1
LQ4 6.0L (stock dished pistons) with stock heads and stock HG is 9.5:1
LQ9 6.0L (stock flat top pistons) with stock heads and stock HG is 10:1
LQ9 6.0L (stock flat top pistons) with 243 heads 11.5:1
8-10 psi (76MM) on the lm7 will get you 500hp with a junkyard block.
8-10 psi (76MM) on the lq4 will get you a bit more with a junkyard block.
8-10 psi (76MM) on the lq9 will get you a bit more but you better have good head studs.
8-10 psi (76MM) on the lm7 & 243’s will get you 600hp+ with a junkyard block but dont go nuts with the boost.
yeah you see the trend. and are right. I wouldn’t be pushing it past 11.5:1 compression FI. unless you run like 5psi or something. and most large frame turbos like to spool up to be in their efficiency range.
Ignition timing doesn’t matter if the octane cant cool the chamber off long enough for the spark plug to fire.
i say crank the compression way up to say 17:1 and throw some real fuel at it and 40-60lbs of boost.
throw your spark plugs in the trash so you don’t have to worry about spark blowout too.
:rofl
+rep