Guys I'm looking to turn my e46 into a track car. I've got all the typical e46 BMW problems, and not really interested in spending thousands to keep it on the street. I'd rather spend thousands on tracking it and have fun with my kid.

so. Ive read a lot about ls engines and I really want an ls3. But 7k , meh... I'm thinking I should go 5.3 route with a cam, heads, etc. I do want an aluminum block, and I'm thinking right around 500hp, but I don't know if 5.3 can get there. I'd like to just go cheap to start, get the engine bolted in, make good power, do so racing, have some fun, and then if I decide to move up to more power I can cross that bridge when I get there. I'm thinking maybe the lh6 is a good one to start with? Is there an ls3 block that gm released with less cubes? (Giving the option to overbore later) also thinking of keeping it carb'd.

or maybe I should just get an aftermarket short block so I don't buy heads and other parts twice.

interested in hearing your thoughts. I'm trying to think in terms of replacement/repair cost later down the line as well.

thanks!

 

Been road racing for over 20 years, no insult or anything intended just trying to save someone some pain...

1. READ THE RULEBOOK!!!! (BEST INVESTMENT YOU CAN MAKE)
2. A E46 with a Chevy V8 is an SPO claass or GT class car.. Count on dropping 50G to see tail-lights of the front runners..
3. Count on 2000 a weekend or more to race a V8 car.
4.A 500HP car is about 5 seconds faster than a 4 Cylinder Acura... Power doesn't always mean the speed..
5. I have as much fun road racing in a small car as a big one...

Cheapest way to get there is get rid of the e46 and go buy a roller/running race car. I promise,, I've helped many rescue projects well started but not finished because building a track car from scratch is EXPENSIVE, way more expensive than anybody ever counts on.. And the E46 is the nicest driving car, but not 1 item on it is track cheap to replace. (I own a 330X1... ) The suspension is fragile, the tub is fragile, a light get-off will damage the car beyond repair if you don't strip reinforce and cage the chassis.

Then there is running a 500HP track car, you'll need a set of tires every weekend at 1200 bucks a throw, and 250 dollar an end for brake pads... Race gas because road race sessions on pump fuel eat engines,,, Rework of the rear suspension on the E46 is going to cost you 3500+ to handle a 500HP motor on track(And that's if your a talented fab guy) The list goes on..

There is a Pro-46 class in SCCA and I believe NASA these days, look on line at the cost of the cars, they are typically half what it cost to build them. And they are pretty much the bare minimum to have on track at speed. a 5.3 with some light mods will push a lightened car north of 150 on a long straight, crash,, without a 8 point cage and your road kill. Heck you'll be over a hundred between turns.

FWIW: A roller NASCAR road race chassis can be had for < 5K. And it will protect your *** at any speed you get to at a track, drop the 5.3 in with a top-loader and your on track in a couple weeks, Parts for the NASCAR chassis are cheap, at least compared to any BMW, heck, you can probably wrap the body as an E46.. call it a 353XM just to dick with people.. (Sorry I enjoy messing with fans..) You still wont take anybody's lunch money in GT1 but you will have an E-ticket ride.

Above all good luck and have fun.. That's what its about..

A 500HP car is about 5 seconds faster than a 4 Cylinder Acura... Power doesn't always mean the speed..

 

I'm not interested in competitive class racing. Just open track days. The car is going to get caged/tubbed next spring. I'm not buying another car because I have this one and I can't do anything with it. It would cost thousands to fix and sell it and I wouldn't break even. I'll sell the engine, trans, and whatever else I can when I strip it.

anyways back to the engine. Still looking for a good candidate for a hobby car that's easy to find and cheap to replace when I blow it up . I'm not interested in spending 50k to Compete with front runners, just making laps

 

PDXMotorheads advice is on point.

A 5.3L isn't going to get you 500ph without significant mods and spinning to 7500...If you want 500hp, get a LS3/525...

Andrew

 

430 is good enough for now.

 

430HP = Totally stock LS3
500HP = Above engine with GOOD cam

 

Again, I'm looking for an engine that's much more readily availible and cheaper so I can beat on it, break it and replace it quickly. I've seen a few 5.3s that I could buy 3 or 4 of floor the price of one ls3. I'm just not sure which is the right one to get here.

 

But how much are you going to have to invest in that 5.3 to be as fast as you want it to be?? AND as dependable as a stock LS3?

 

The goal isn't to be as fast as possible right now. I'd much rather have a couple cheap engines in reserve with a cam in them, than a single ls3 that goes down and kills our whole weekeND or plans. Like I said, if I get more involved or decide to go faster or compete later, I will...but for now I just want to do some laps and have some fun. I want 500 hp, but I don't need it to go that

 

Gotcha. I get your point of view.

 

Aluminum 5.3 with 799 heads, TBSS intake, and 222/225 cam made 425 HP on a buddy's engine dyno. If its flywheel HP you want 450 of, Then that same engine with milled heads and more cam would have more 455 or so no problem.

 

Roger that. Now the question is, of. The aluminum 5.3....which one? Lh6? L99 (I think) or is there really no difference and just get what's cheap? (I do know lh 6 needs dod delete)

 

LH6, LH8, and LC9 are the Gen IV all-aluminum 5.3's. Gen III's were L33 and LM4. The LC9, I believe is most common of all these.
The L99 is the 6.2L engine used in 2010-up automatic Camaros.

 

The Gen 4s will come with the better intake manifold, and its more common to find an aluminum one. L33s are worth their weight in gold anymore and the LM4 isn't that good of an engine.

You should be able to pick up a Gen 4 aluminum 5.3 long block for $1200-1500. They will already have good heads, a good intake manifold, stout rotating assembly. You might not be able to fit the intake under your hood, though, but can sell it for $300+ complete. The LC9 is flex fuel and might fetch a little more for the bigger injectors.

Howard's 232/236 112 LSA with a FAST 102 and 1 7/8" long tubes should make 450 at the flywheel without killing torque, and the cam has relatively mild lobes so it won't beat the valvetrain to death on anything longer than a drag strip.

 

As horsepower goes, 500 is a lot in an E46. They never left the factory that powerful.

The good old M3 had 343 horses and was ridiculously fast. And is mostly a different car than a regular 3-series. They only look slightly the same...

Any stock 5.3 with all that extra torque is going to be a handful. If you are not all that familiar with track driving, a stock 330i with sticky tires and stiff suspension is going to feel fast, too.

I'd go for an all-aluminium LS, keep it stock. And spend the time and money upgrading brakes, safety equipment and suspension to cope with that power level to begin with. (that sounded a lot of fun, I want one too)

 

I won't swear that this is a definitive list, but I put the attached spreadsheet together to help me in searching for an aluminum block LS motor (to go into an eventual track car). I got all the info from good ol' Wikipedia and some searching here, so there may be (probably are) some errors, and there are certainly gaps in the information. Hopefully you'll find it useful.

 

Thanks guys, this was the info I was looking for. I think just one more question, in regards to mounting and tuning. If I start with an lh6, and mid season need to change to an lc9, is there going to be a substantial difference or would it just be an ecm swap? (Assuming the horsepower and tune are different)


It does sound fun, that's why I'm doing it
Get one and let's go racing

 

You shouldn't have to change anything. You can use the same PCM for both of them.

 

Same pcm but slightly different tune correct?