99NassauC5

I have 99 C5 with an aluminum 5.3 block and floating pin 4.8 rotating assembly, ls6 cam, ls7 clutch and 2003 C5 Z06 transmission and rear end.

I've searched for a while and have narrowed down to 2 choices the on3 ceramic ball bearing 67mm or the 2nd gen 76mm 7675 turbo.

My goal is a daily drive that makes something close to 600 or 700 max rwhp, smooth idle (ls6 cam) and not too much turbo lag but I also want to be able to spin it to 7k.

Which one would you recommend on a single front mount?

svslow

A friend of mine has a C5 with a 5.3 and a single S366 turbo. He made 650whp on 15psi. Very responsive set up.

ddnspider

iTrader: (26)

If you want to rev it to 7k I wouldn't go with the 67. The 7675 will have more legs when being revved. Better tuning will be needed to get it to spool but it's a better choice.

99NassauC5

Thanks guys, reason I asked is because I was afraid the 67 would not be enough higher rpms and the 76 would be too laggy.

slowride

iTrader: (3)

I believe that 67 only has a 65mm turbine so probably not ideal. Get a 7275 from turbonetics or pte if you want better spool. You can get a cast wheel pte for for cheap or the Borg's s366 or sxe's etc.

The BallSS

iTrader: (9)

My Turbonetics T7875 isn't too bad when it comes to lag.
Since I've started street racing it I've noticed it does have a little lag but nothing some light brake boosting doesn't fix lol.
It'll pull cleanly to 6,500 rpm on my H/C LS1, maybe higher but that's as high as I'll go currently.
My vote would be any variant of a 7675 turbo, T-netics, PTE maybe even VS Racing?

sbcgenII

iTrader: (1)

76/75 will spool fine.

99NassauC5

I guess I better copy and paste the turbo specs from their website. It looks like the 76mm is a good match for my build. But I will also look up the other turbos previously suggested. Thanks for all the feedback guys.

On3 2nd gen 76mm 76/75 turbo

• Anti Surge Compressor Cover
• 4″ Inlet
• 3.0″ Outlet
• CNC Machined Billet Compressor Wheel
• 1/8″npt Port For Boost Reference

Exhaust Side

• 75mm Turbine
• 3.0″ V-band Outlet
• T-4 Flange
• .96ar

On3 67mm ceramic ball bearing turbo 67/65

Cold Side

• Compressor Wheel 67mm
• .70 a/r
• 4” Inlet and 2.5” Compressor Outlet
• Inducer- 67.05mm
• Exducer- 84.10mm

Exhaust Side

• Exhaust Housing T-4 Flange
• .96 ar Exhaust Housing Standard, .68ar Housing Optional
• 3.0″ Vband outlet
• Inducer- 74.5mm
• Exducer- 65mm

gametech

iTrader: (1)

Since you have included a super mild cam and the words "daily driver" in your post, I would recommend the 67mm. Most of this forum skews much more toward racing than daily driving, so I doubt many others will share this opinion.

99NassauC5

I agree, I know 600hp is low to today's standard but enough for something I would like to enjoy driving every day without having to worry about breaking other drivetrain components.
I got in enough trouble with the stock LS1 by being accused by a cop for racing a bimmer I never saw.

sbcgenII

iTrader: (1)

76/75 isn't a racing turbo on a LS motor until you have 2 of them. A 76/75 will be in a good spot at 600-700. A 67/65 would not be. You will have no problem spooling a 76/75.

The BallSS

iTrader: (9)

I had a TC7868 in front of my H/C LS1 and it was kind of annoying.
The power came on like a light switch and was really difficult to modulate.
The T7875 is way more linear and makes more power at a lower boost level.
I don't think the S366 is comparable to the TC7868 but that's just my input.

99NassauC5

I got a little off topic, sorry it still pisses me off until this day. I see your point.