How big are your pulleys?

[TTTAPOUT]

I have been seeing some great numbers out there, and I am wondering about going up on pulley size and making a couple minor changes. Currently, I am running the 2.55 press on and a 9.17 lower, I have a Rotofab intake, Speed Engineering headers, 1050x injectors, 160 thermostat and a set of colder plugs. I'm making 662/692 on an E50 mix with flex fuel sensor.

So I am thinking about going up to a 10" lower, and doing a ported blower snout, 102mm TB, and a 5" intake. Of course, at this point we are going to have to do a real fuel pump system and I am working towards a BTR stage 3 cam.

Any suggestions? My end goal will be to reach the 9.90's but this sounds like a good step in that direction without breaking the bank too bad. Am I going too big with the pulleys? I know heat exchangers are also in my future along with coolant reservoirs and some other misc supporting mods.

[jrhagen]

2.55 and 9.5

[Can'tHave2MuchHP]

Way too much boost for no cam/heads. First off, 2.5 + 9.1 is the max "safe" supercharger RPM but a good amount of people do spin it past that point. Knowing full well that they're going to be generating ludicrous IATs and their car will be pulling timing by the end of a 1/2 mile pull. Not worth the 10-20 HP in my book BUT if you want to do it, you'll need as much cooling upgrades as you can get. Definitely need bigger heat exchanger and you might also want to look into an Interchiller. Besides that, you'll need that cam NOW to support more pulley. In fact at your current point, you're past the end of what boost only is going to do. Probably also seriously in need of Meth injection.

5" intake
Cam
Heads
Heat exchanger or interchiller, coolant expansion tanks, and possibly a water/ice box
Ported snout
102mm TB
BAP (Boost a pump) or entirely different fuel pump
Meth injection
9.5" lower pulley or 10". Note that 10" + 2.5" is off the charts in supercharger RPM. And even a 9.5" is pushing the hell out of the blower. You might be best off to just get a real blower on there.

That my friend is a max effort, maxed out, LSA. Short of a shot of boom juice.

And I'd maybe even go for a slightly larger cam than a BTR 3 if you really just want to turn it into a 1/4 mile one and done car.

An A6 car will need 720+ RWHP (Probably closer to 750+ to do it consistently) and slicks and skinnies to do a 9.90 pass, if not more.

[leemozoid]

9.17 and 2.85. 13ish lbs of boost and safe blower RPM.

[Crash76]

Stock Upper and 23% Lower, 12-13lb boost

E85
Cam and LTs

[2013 ZL1 #7860]

2.5/10.0

[DrkPhx]

Originally Posted by 2013 ZL1 #7860

2.5/10.0

Dayum. That's a lot of pulley. What's your boost and hp? I run a 2.75/10 and see 15 psi on a hot day.

[TTTAPOUT]

Lots of pulley and hopefully lots of power. What else is done?

[Can'tHave2MuchHP]

Originally Posted by TTTAPOUT

Lots of pulley and hopefully lots of power. What else is done?

He's completely built. See his post history. Big Cam, E85, Porting etc.

[2013 ZL1 #7860]

Originally Posted by Can'tHave2MuchHP

He's completely built. See his post history. Big Cam, E85, Porting etc.

OK... (why do you always reference my posts and information incorrectly?)

Stock Bottom End, Stock Heads (never off the block), Ported Blower and 102mm Throttle Body, BTR 3PD Cam (mild), E85 and a Chiller.

Pretty tame to drive to be honest.

I would describe "built" as a forged bottom end with larger displacement and better heads...

[jrhagen]

Originally Posted by 2013 ZL1 #7860

OK...

Stock Bottom End, Stock Heads (never off the block), Ported Blower and 102mm Throttle Body, BTR 3PD Cam (mild), E85 and a Chiller.

Pretty tame to drive to be honest.

I would describe "built" as a forged bottom end with larger displacement and better heads...

Why is larger displacement and better heads a requirement for "built"? Crate motor isn't good enough?

[2013 ZL1 #7860]

Originally Posted by jrhagen

Why is larger displacement and better heads a requirement for "built"? Crate motor isn't good enough?

Did I say anything about a crate motor?
An LSX B-8 is a Built LS3 you can buy assembled. That would be built!
I would describe your setup as "more built" than mine.

A stock engine with a cam and a ported blower like mine is not built... (Especially not "Completely Built" like he wrongly stated)

It made 763 to the wheels (E70, A6) on the DMS dyno and the only person to touch the car besides me is DSX (tune).

[jrhagen]

Originally Posted by 2013 ZL1 #7860

Did I say anything about a crate motor?
An LSX B-8 is a Built LS3 you can buy assembled. That would be built!
I would describe your setup as "more built" than mine.

A stock engine with a cam and a ported blower like mine is not built... (Especially not "Completely Built" like he wrongly stated)

It made 763 to the wheels (E70) on the DMS dyno and the only person to touch the car besides me is DSX.

"I would describe "built" as a forged bottom end with larger displacement and better heads..."

A LSX B-8 is stock 376 displacement and stock LS3 heads. So, it isn't "built" per your comment.

Just sayin.

[Smittty]

I am running 2.55 upper and 10 lower with cam and heads.