MX6.0

I'm currently in the process of putting a LS2 with LS3 heads/intake into my 2001 Miata. I realize that my setup is somewhat uncommon so I'm looking for some suggestions on cam selection.

I知 looking for a cam that will produce good power with a sound that won稚 be mistaken for a stock engine. I知 not looking for something overly obnoxious or something that will stall constantly. This is a weekend/fair-weather car so I知 not concerned with fuel economy. The car is not a daily driver. I drive it on the weekends and the occasional autocross.

Here's my setup:

Weight: 2500-2600 lbs with driver
Engine: LS2
Heads and Intake: LS3
Exhaust: Shorty headers with 1.5" primaries, 2.5" collectors/catback and X-pipe (I realize the primaries are small and would be the choking point of the engine but it's all that's available for now. Will be upgraded in the future)
Transmission: Stock GTO T56
Rear: 3.23
Tire: 23" tire
Clutch: Lightweight clutch/flywheel (not sure which one yet)

I'd like to increase the compression using thinner head gaskets but I'm not sure how far I can go and still preserve piston clearance. What effect does timing have on cam selection if any?

From what I've read I should expect anywhere from 450-480+ RWHP with the LS3 top end, depending on cam selection.

Thoughts?

Tainted

iTrader: (9)

using the ls3 top end you wont need a large cam to make good power. if I was you I'd have pat G or someone custom spec me a cam...

SNLPerformance

iTrader: (15)

You can't run a huge cam with the LS3 heads large intake valve and a thinner head gasket would only make that worse. With that being said you don't have to worry about low end torque with the car being so light, but the small tube headers will limit your high end breathing. So I would recommend something with not a lot of overlap and with a healthy exhaust bias. My sleeper cam is a 218/230 116 and a very similar cam made 450rwhp in an LS3 with LS7 exhaust manifolds in a vette. Feel free to call me and I'll help you get in the right cam. Chris, 817-750-2000

XtraCajunSS

iTrader: (2)

A variant of our TRuTorq Level 1 with additional exhaust duration would be the ticket. PM me and I will give you the specifics. Rough specs are 219/230 115. Let me know if you need any help.

Thanks,
Shane

hookemdevils22

iTrader: (12)

see post 7 for dyno results

MX6.0

Yea, I've read that piston clearance could be an issue. I'm not looking to run a huge cam though. Just something with good power that sounds not-so-stock. Typically the exhaust note isn't that important to me but the only thing that distinguishes my car from the run of the mill Miata is the V8 under the hood. Do I need a huge cam to get a choppy sound?

I like the idea of having a cam that favors exhaust flow. I didn't realize they made cams specifically for cars with exhaust restrictions. I'm sure a better header will be available for me in the future but it's highly unlikely that it would be a full 1.875" long tube. The exhaust friendly cam would probably serve me well for a long time.

One other question about running a thinner head gasket. Maybe I misread this from a different thread but from what I understand, running unmilled LS3 heads and the stock .051 head gasket would yield a lower compression than the stock LS2. Any downsides to this? Or is it just a balance of cam lift vs. gasket thickness to preserve piston clearance?

Thanks again!

MX6.0

Thanks for the link. It's interesting to see such a wide spread of dyno numbers for such similar mods. Is it safe to say that all of these cars have headers of some sort? I'd be curious to see what one would make with a similar shorty header to the one I'm using.

SNLPerformance

iTrader: (15)

You can taylor a cam to suit different combinations of parts. You can still get a slight chop depending on the exhaust you run and your idle speed. The static compression would be a hair lower, but you're not going with a big cam so you will maintain good dynamic compression.

Ragtop 99

iTrader: (7)

with such a light weight car and small tires, it's like you will have 4.10s in the car compared to most of us. Assuming you're going to fix the exhaust side, I'd get a cam that you can spin to 6800. A 226/234 115 +2 on EPS lobes will have a nice controlled lope at a 750 rpm idle and get closer to the 480 HP estimate than the smaller cams suggested above. If you want off the shelf comp lobes, a 227/236 115 +2 would would be similar.