Turbo D

iTrader: (3)

My goal is to make as much power as I can on a $180 69mm Gt45 turbo. This will be going in my 2600lb pinto, 4.8, 862's, glide, 3.55's 28" tire, pumpgas and meth.
Thinking about a JFR 218/218 cam or a 220/224 sloppy 1.5 or even a lil john stage 1 (222/227), I really only need the least amount duration to carry the rpm to 7000 or so, without choking out the turbo. The car is light so it doesn't need alot of cam to get moving but there has to be a point where exhaust duration and timing will have ill effects. Any ideas?

JoeNova

Less camshaft will go a long way with a GT45.

JFR Triple 12 or the 218 would work best IMO. Maybe that Elgin 220/224 wouldn't be so bad, or the Howard's 222/222.

Turbo D

iTrader: (3)

Yes for sure, One of the cams I was looking at is the Howards 218/218 113 .604. The only reason I'm using a 4.8 is to squeeze out as much as I can out of this GT45.

svslow

That Howard cam would be a good choice.

Forcefed86

iTrader: (4)

I’d think the VE on a 4.8 would go up with RPM… So the higher you can take it, the better. That’s assuming you have the supporting parts to make power at higher RPM.

If you are or aren't limited RPM wise, you’d be able to max that turbo out either way. Once the air pumps done pumping, the end result will be pretty similar won’t it? So would the cheapest cam the gets you in your desired rev range with minimal overlap be the best option?

Hell if I know… but I’m in for results.

FWIW I really like the 220/220 @111 .510” lift cam on the 4.8 I ran. It pulled to 7k and made it really snappy 4.8. If you only plan on 7k, tighten up the LSA to bump the midrange up I’d think. As long as the overlap is under control with lowish duration the tighter you can go on the LSA the better on small cube stuff IMO.

Rated to 6500ish on an LS1.
http://www.jegs.com/i/Edelbrock/350/2215/10002/-1

For a roughly that price, you could get a custom cam that has similar specs and more lift. I’d think a 215/215 with .600” lift on a 110lsa would be a mean sucker and still have -5* overlap at .050.

Turbo D

iTrader: (3)

I'm not going to limit myself to a certain rpm, I'll shift this thing at 8000 if it's still making power. The one you posted is pretty close in events to the Howards 218, but it has almost .100 more lift. I feel like I'm splitting hairs with this, there is probably 10 shelf cams with IVC and EVO withing a degree of each of other, the only difference I've noticed is that some cams (like the elgin's) will have a super soft lobe with the advertised duration. The elgin 220@.050 lobe's advertised duration is 286* where the howard's is 270* which I think would matter when the back pressure starts to get out of control.

truckdoug

iTrader: (26)

my take on it after using the OG 69mm is that the compressor is the restriction. while boost is only a measurement of restriction to airflow, both the 5.3 and 6.0 I had it on would see IAT's shoot from 110* at 14psi to 170* at 18psi. At 18psi it was just putting out more heat than my ebay intercooler could manage.

IIRC the turbine is ~77mm with a rather large A/R . backpressure was never a problem for me with that turbo.

Turbo D

iTrader: (3)

Ya, that thought had crossed my mind also, since alot of guys are using the 78/75's on 6.0l's (me included) which has a smaller exhaust side then the gt45. I have no idea what you would pick then (longer or shorter duration) it would really depend on the compressor map.

truckdoug

iTrader: (26)

well if it were me, i'd go with a little longer duration and try to keep the overlap low.

but i'm a serial dad-cam guy. i'll put a "three quarter race cam" in a ******* lawnmower

Turbo D

iTrader: (3)

Ya I've been using this 240 from a few years ago for comparison, he did it with a LS6 cam so going from a 204 intake duration to a 218 would be a big jump. https://ls1tech.com/forums/forced-in...-18-146-a.html

turbocamaro125

iTrader: (3)

I built a buddies car a few years ago. Sbe ls1 with ls6 intake dual springs and a tqer 3 cam with a gt45 t56 4.10's in a 9". 3750lb 4th gen Camaro ran 10.40@136mph. 16psi
shift rpm 7K cam specs Texas Speed Torquer V3 231/234 .643/598 Camshaft

JakeFusion

iTrader: (7)

LJMS Stage 1 222/227 113+3. It's probably as big as I'd do on a 4.8.

But, I came across this today when looking for some info on 4.8s... has that cam in it and a GT45 style turbo. Seems to pull cleanly to at least 6700 here. I think that cam and anything in the 7875 range will pull to 7k and make good power at 18-20psi.

http://www.powerperformancenews.com/...urbo-cam-test/

Turbo D

iTrader: (3)

Dam I missed that test, awesome data. I really wish Richard would do his tests at 14.7 psi vs 7psi, would make it alittle more real world.

JakeFusion

iTrader: (7)

Yeah, agreed. But that's a big jump with that cam. I think it'd pull away even harder with more boost.

I imagine it would drive pretty well and sound awesome in the 4.8. And LJMS uses LXL/HUC lobe combinations... which are pretty easy to control.

293LSX

Sloppy stage 2 or triple 12. Both proven time and time again. Look at Matt right now with his 4.8 in the Colorado.