WickedVetteLT4

Just as the title says... I'm mid swap on my car and need to know which blower pulley and belt I need. Its an 08 LS3 (STOCK BLOCK) auto car with blower cam, flip drive, meth, A&A fuel system, 70# injectors, etc. I was running a T-trim with a 2.90 pulley which was making 13lbs of boost. Car went 9.55 @ 144 with that setup. I have now decided to do the YSi upgrade so it'll be ready to go big once I get my block forged. Ultimately shooting for between 950-1000rwhp. I ordered the 8-rib upgrade, IW +10% 8-rib balancer, etc for the swap. The car has a circle D built 6L80E with 3600 FTI converter than can be foot braked to 3800.

So... With the +10% crank balancer, what size blower pulley do I need to keep the car around 13lbs boost??

I plan to crank up the boost later but for now I'd like to keep it safe so it'll last until im ready to do the motor.

Thanks in advance fellas!

Unreal

Pretty big. 3.1-3.2 I would say and even then that maybe 15ish.

breecher_7

Probably 16ish with a 3.125". To stay 13ish you will need a big pulley...

WickedVetteLT4

Ok. I was initially thinking a 3.25" would be about the size id need but if that'll put me over 13, I'll go a little bigger than that. I don't want to push this motor too hard being the stock bottom end. It was making 13 lbs and would tap 14 lbs for a split second at the top of the band.

Good news is the motor is still running strong as ever. Hasn't skipped a beat. So... I'd like to stay at 13 lbs.

What do you guys suggest I run pulley wise? 3.25 or a little larger than that? I plan to have it tuned again as well once installed.

yur2slo

My suggestion would be to pulley down the YSi and use a restrictor plate until the built motor. It's a different beast than the T-trim.

Mike Farris

How many psi will a restrictor plate knock off of a deal like this?

WickedVetteLT4

I'm not too familiar with the restrictor plate idea. I was told I could just pulley it to lower boost while I'm on the stock block and then swap the pulley when I build the motor.

Is that not a wise idea?

ShaneFap

The restrictor plate is used so you can run whatever pulley you really want but limit peak boost with plate. In short lets say you run 3.xx pulley and that gives you 16lbs of boost at 6,500 RPMs. With the plate you throw on a 2.x pulley and would hit 20psi at the same 6,500 rpms but it limits it to where you hit 16 at 6,500rpms but makes ALOT more power down low due to the smaller pulley.

WickedVetteLT4

Ahh I see. Makes sense. Where can I order one of those?

I suppose that's better too since it will allow me to get the pulley I'll need later now and just turn it down temporarily with the plate. I like that idea.

ShaneFap

Pm sent

Guard dog

^^^This^^^

Slo-Poc

In for results, sick build

turbotuner20v

9.55@144... sometimes I wish I got an auto. Very curious what it will lay down with the ysi. Restricting it will probably bump up torque quite a bit in case you need to plan for that with your trans setup

WickedVetteLT4

Thanks guys! Ready for it to be done completely but its a work in progress. Restrictor plate seems to be the best option. Trans is built to handle 1000rwhp (so circle D says). We will see. So far so good!

I was honestly looking for a 6-speed car when I bought mine but I'm glad I went auto. If it didnt have the paddles, I prob would have gone 6-spd but the option to do both is nice and there is nothing faster than an auto in the 1/4. It ran that pass with a 1.55 60 ft on some C5 wheels, Hoosiers and GTO spares for runners. I'm really curious to see how it runs with the YSi too! Ready for it!

BADZ

Good luck, I would go to the smallest pulley 2.75 lol