Tune, Pulley, Long Tube Headers

[ChocoTaco369]

I would much rather have an LSA than an LT1, but that's just me. The motors are nothing alike. Which would you rather work on?

[hognutz]

Originally Posted by Blackdevil77

What's the difference between doing an upper pulley and lower pulley? Is there an added benefit of doing one over the other? Would a smaller upper pulley cause any belt slip at all?

Also, is it safe to rev this engine to 6500 rpm or so with a pulley swap? I've seen dynographs go past the stock 6200 rpm redline once the car was tuned.

my engine is set for 6500 rpm right now but I an not at real high boost.

google the boost charts. larger lower give you more rpm, smaller upper give you more rpm.

lower intalls quicker but costs more. depending on your reline though you have a blower RPM. I read the reconened blower RPM was 23,000 so the combination of the lower and upper get you the closest to this. some will say you can go more like 26000 rpm.

some will say the upper can cause belt slip but many say this is BS.

I did 10% lower to start with you don't have to change out any brackets or idlers to do this. I was not changing injectos at the time so it made sense to me.

there is alot of information out ther from lingenfeltor or weapon x etc.

if you jumpoing in right from the start the upper 2.4" pulley is the cheapest solution but would most likely require injectors right out the gate so you have to budget for that.

it will all make sense after you read it for a wile.

look over this thread

http://www.camaro5.com/forums/showthread.php?t=270334

I only had som much coin to start with some my mods are kind of coming in stages.

[ChocoTaco369]

Originally Posted by Blackdevil77

This might be a stupid question, but why not set the car to shift at 6500 rpm? Power doesn't drop off, looking at the dynographs that I've seen. Wouldn't it be beneficial to wind out the gears a little longer since it continues making power up top?

If you set the shift points to the limiter, you'd be bouncing off the rev limiter all the time. The trans doesn't shift exactly at 6100. I've seen variances of 100 rpm's. It's set that way to give a buffer. If you want to set your shift points to 6500 rpms, you'd have to up to limiter to probably something like 6800 and now you're really going to be taxing the stock parts.

[Blackdevil77]

Originally Posted by ChocoTaco369

If you set the shift points to the limiter, you'd be bouncing off the rev limiter all the time. The trans doesn't shift exactly at 6100. I've seen variances of 100 rpm's. It's set that way to give a buffer. If you want to set your shift points to 6500 rpms, you'd have to up to limiter to probably something like 6800 and now you're really going to be taxing the stock parts.

But in a manual car lets say, you'd be able to rev it out closer to 6500 rpms? I remember seeing a spec sheet that stated the rev limiter on the LSA crate engine was 6600 rpms. I can't remember where I found it.

[Blackdevil77]

Originally Posted by ChocoTaco369

I would much rather have an LSA than an LT1, but that's just me. The motors are nothing alike. Which would you rather work on?

Yeah, there's more potential in the LSA without having to go into the engine. It already comes for a blower, and the engine is already set up for boost. I'd rather add a little boost to a car that is already set up for boost, then boost an engine that wasn't designed for boost and has a compression ratio of 11:5:1

[wirebender]

Originally Posted by wirebender

Perhaps this chart from LPE will help.
This past Saturday I ran an 11.6 @ 124.6 on stock tires. probably ~13-14 lbs. boost. When I add lower pulley the supercharger will be just about maxed out.

AUTO...tuned by Ryan @ RPM. He also set rev limit at 6800 I think but tranny shifts way before that so I never get that high.

[Blackdevil77]

Originally Posted by wirebender

AUTO...tuned by Ryan @ RPM. He also set rev limit at 6800 I think but tranny shifts way before that so I never get that high.

I'm feeling very strongly about the ZL1. Good chance I'll be joining you fellas soon If I can reliably trap 125 in the quarter mile with bolt ons without issue or having to constantly bring my car into the shop like I had to with my G8, I'll be quite happy

[jessrayo]

Originally Posted by Blackdevil77

I'm feeling very strongly about the ZL1. Good chance I'll be joining you fellas soon If I can reliably trap 125 in the quarter mile with bolt ons without issue or having to constantly bring my car into the shop like I had to with my G8, I'll be quite happy

The ZL1 is very stout in the stock form. The stock clutch won't make it with drag racing when you add a lot of power, everything else is pretty good. You can always use more cooling.

[Blackdevil77]

Originally Posted by jessrayo

The ZL1 is very stout in the stock form. The stock clutch won't make it with drag racing when you add a lot of power, everything else is pretty good. You can always use more cooling.

If I had to pick one thing to be the weak link, I'd rather have it be the clutch then anything that has to do with the engine or transmission. From what I've been reading, the LSA engine is tough as all hell. It should be able to handle 14 pounds of boost for a long time reliably (I hope).

[jessrayo]

Originally Posted by Blackdevil77

If I had to pick one thing to be the weak link, I'd rather have it be the clutch then anything that has to do with the engine or transmission. From what I've been reading, the LSA engine is tough as all hell. It should be able to handle 14 pounds of boost for a long time reliably (I hope).

As long as you can deal with the heat generated with 14 pounds of boost the rest of the motor and drivetrain should be fine. And, if you start to get too much intake heat the car just reduces timing and power until you cool back down.

[Blackdevil77]

Originally Posted by jessrayo

As long as you can deal with the heat generated with 14 pounds of boost the rest of the motor and drivetrain should be fine. And, if you start to get too much intake heat the car just reduces timing and power until you cool back down.

What can I do to offset or at least reduce the effects of this? Any recommendations?

[jessrayo]

Originally Posted by Blackdevil77

What can I do to offset or at least reduce the effects of this? Any recommendations?

Reservoir (bigger is better), heat exchanger (bigger is not necessarily better), bigger pump. If you are primarily drag racing I would consider a chiller.

The stock pump is very good but there is one pump that is much better...be prepared for sticker shock though.

[Blackdevil77]

Originally Posted by jessrayo

Reservoir (bigger is better), heat exchanger (bigger is not necessarily better), bigger pump. If you are primarily drag racing I would consider a chiller.

The stock pump is very good but there is one pump that is much better...be prepared for sticker shock though.

Yes, mostly drag racing but also spirited driving. Not really lap after lap at Laguna Seca type stuff.

I'm sorry if I sound stupid, but I'm very new to FI, and never modified a car with a supercharger. Bigger reservoir for what exactly? The supercharger is liquid cooled?

I'm bracing myself for the sticker shock, hit me!

[jessrayo]

Originally Posted by Blackdevil77

Bigger reservoir for what exactly? The supercharger is liquid cooled?

I'm bracing myself for the sticker shock, hit me!

The supercharger system is liquid cooled but the stock system has no reservoir, it just circulates the water between the heat exchangers in the airflow under the supercharger and in the grill of the car. Adding a reservoir gives an increased capacity to store and dissipate heat.

Here is a link to the pump. Most people replace the heat exchanger in the grill of the car first but my personal experience has lead me to believe that you may get more cooling gains from the pump.

http://www.lingenfelter.com/mm5/merc...=#.Uxim6oVfTJM