salemetro

iTrader: (5)

I know that this is just another in a LONG line of cam-related questions on this site, but "search" did not reveal any answers to me.....so here goes.

I have an L33/T56 that I'm going to be swapping into a 2001 Miata. In current factory 4cyl trim, the vehicle gets about 30mpg...but is pretty-much gutless. I drive this vehicle about 150 miles/day, so fuel mileage IS a bit of a concern on this next build....as is longevity.

I saw somewhere online that a comp "thumper" cam yielded a bolt-in 90hp gain with no other mods on a 5.3, but I'm not so sure that it is the way that I want to go. I'm thinking that the rough idle would get annoying in stop/go traffic, even though the conservative lift looks somewhat appealing. On the other hand, I'm pretty sure that a mega-lift cam would probably NOT be all that great for engine longevity (ie; guides,springs).

I'm really wanting to get to as close to 400 rwhp (with a 5.3) as possible with this car. I know what I'm asking for is not ALL going to be acheivable, but I'm wanting to see what y'all think might be a good compromise.

So now to the question:

What are my best options given the above desire for;
-normal aspiration
-30mpg
-400rwhp
-longevity
-a smooth an idle as possible.

ScorpioV8

I'd be interested in this too, I have UK Ford Scorpio Cosworth that had a 2.9 Litre V6 and A4LD automatic, did a best of 31 mpg (UK gallons). Putting in a stock 5.3 L33 and 4L60E. Hoping the technology will give me more smiles per miles - gas over here is now £1.30 a litre - nearly $2!!

Gareth

joe77

might want to take a look at eps lobes people are making good power on smaller cams

Pocket

iTrader: (22)

LS6 cam and intake, some form of headers with the T56 should net you very good power retaining street manners. The efficient LSx engine with the double overdrive from the T56 and featherlight Miata should be well over 30mpg

I may not hit your 400rwhp mark, but it wont be far off

salemetro

iTrader: (5)

I'm thinking that combo would probably net me closer to 300-325 rwhp. It would definitely have great street manners, but I'm hoping for at least 350 at the wheels.

Any other cam ideas?

Pocket

iTrader: (22)

L33's had 310hp stock. A better flowing cam, intake and headers are quite a boost, plus the T56 wont eat up as much as an auto would

It should be easily past 350

nastychevelle

iTrader: (7)

talk to Geoff at EPS im sure he can help you out on cam choice...

salemetro

iTrader: (5)

I just did....Helluva nice guy, and full of great info! I'll be ordering soon.

hammertime

iTrader: (1)

Don't confuse HP at the flywheel (310) with the OP's desire to get 400rwhp. That roughly translates to somewhere between 460 - 475 at the flywheel.

I have a hard time believing that at all. Most vendors claim 40-60rwhp from moderate sized cams, and that's on a 5.7L engine. That kind of gain on a 5.3 would require a cam that definitely idles rough and lacks low end punch.
Glad to see that you bolded the reality check here. You are definitely going to struggle to hit all the goals. The least expensive choice would be to let go of the RWHP goal. If you really want 30mpg, 400rwhp reliablility and a smooth idle, the best way to get there is to move more air.

A mild 6.0L would have a better shot at your goal, and should only cost a little more than the 5.3 if you can tolerate an iron block. Starting with an LS2 would be much more costly.

The other alternative is to drop your N/A requirement. This way you keep the longevity and smooth idle of a stock engine, and retain fuel economy when you are not under boost. Again, you are talking about more money, but you don't have to go boosted right off the bat.