Can it be done? (rx8/ls/challenge budget)

I've been thinking about this waaay too much to be healthy lately. The question is, can it be done? I know the budget will be tight, but I think it might be possible.

Here's what I am thinking:

• rx8 shell (can even start with an auto for the 'taller' diff ratio, steel driveshaft, and the interior effects)
• ls1 + 4L60e (I think the aluminum block, extra displacement, shallow pan and intake make the ls1 a more desirable choice here over the common truck motors)
• keep interior (think a fast road car that could be used as a daily - not all out race spec)

Can it be done? Assume you can get an RX8 shell (may need a little work) for $800. I know the truck motor + auto could be done (I see those motor/trans combos for less than $1k frequently), but unless there is turbo involved in that route I am less interested. Get as creative as needed - like selling the gauge cluster and replacing with some used gauges - IDK. Post some details to your solution, like notably how you will source your LS1 and for what price.

If you are looking at using a it for a road car you might want to get good with vehicle electrics of OBD2, everything else will be easy enough so long as you've done extreme swaps before.

Can it be done? Not if the EPA has anything to say about it.

I think it could be done but it's worth pointing out that the skills/experience needed to pull it off under $2k are much harder to acquire than a pile of under-budget parts with ALL assembly required. Some of the people who've won the challenge before could probably pull it off, and some larger group of people could probably do it for less than like $5k, but i dont think this idea + challenge money limitations is something a typical gearhead could pull off.

NickD wrote: Can it be done? Not if the EPA has anything to say about it.

Ha. The EPA should love the fact that you are replacing a dirty old rotary with a nice, clean, GM engineered V8....

In reply to Vigo:

So you are saying that you think the parts could be acquired for challenge budget or less?

What's your formula?

Let's assume that the building is done by someone with 1%er gearhead skills and therefore they can pull it off.

Robbie wrote:

NickD wrote: Can it be done? Not if the EPA has anything to say about it.

Ha. The EPA should love the fact that you are replacing a dirty old rotary with a nice, clean, GM engineered V8....

That would imply logic. I always thought that about some of California's emissions laws and how you can't mod post-'75 cars. You would think that a '76 Camaro with a modern cleaner-burning EFI engine and modern catalytic converters would be an improvement

The parts shouldn't be an issue to pull off. I've seen a few $500-1000 RX8s pop up, may need some rust repair. Best bet in getting an ls1 would be finding a disassembled engine or a used truck motor and swap in a different camshaft.

Really just need to just keep an eye out on a broad Craigslist search. Parts shouldn't be an issue, making them all work together will be the hard part.

If you build a pure stripped down hot rod solely for the challenge and skip the turbo, yeah it can be done.

Buy the shell and a donor truck. Sell as much un-needed stuff as you are allowed, to reduce budget. If you can get it to run with the truck wiring, the car will be fast enough to be fun at the challenge.

A good set of tires in this case would be a better asset than any power adders.

NickD wrote:

Robbie wrote:

NickD wrote: Can it be done? Not if the EPA has anything to say about it.

Ha. The EPA should love the fact that you are replacing a dirty old rotary with a nice, clean, GM engineered V8....

That would imply logic. I always thought that about some of California's emissions laws and how you can't mod post-'75 cars. You would think that a '76 Camaro with a modern cleaner-burning EFI engine and modern catalytic converters would be an improvement

Is this really the way it works in Cali? I've always heard that engine swaps were allowed as long as the engine going in was the same age or newer than the vehicle it was going into, and it retained all of it's emissions equipment. So you'd be able to put that EFI engine in the older Camaro as long as the EFI engine had the emissions equipment for it's year of production.

Why does the truck motor turn you off? You know with the same cam and intake ls1 and 5.3 are only 10hp difference and the torque range is shifted a bit. And with less than 100lb weight difference it's not too much to make it worth the extra $1000. To me at least...

STM317 wrote:

NickD wrote:

Robbie wrote:

NickD wrote: Can it be done? Not if the EPA has anything to say about it.

Ha. The EPA should love the fact that you are replacing a dirty old rotary with a nice, clean, GM engineered V8....

That would imply logic. I always thought that about some of California's emissions laws and how you can't mod post-'75 cars. You would think that a '76 Camaro with a modern cleaner-burning EFI engine and modern catalytic converters would be an improvement

Is this really the way it works in Cali? I've always heard that engine swaps were allowed as long as the engine going in was the same age or newer than the vehicle it was going into, and it retained all of it's emissions equipment. So you'd be able to put that EFI engine in the older Camaro as long as the EFI engine had the emissions equipment for it's year of production.

Well, I guess "can't mod" was poorly worded. "Can't mod without a lot of hassle and CARB approval" would be a better phrasing.

If you're not worried about functional factory gauges, it seems possible.

Brett_Murphy wrote: If you're not worried about functional factory gauges, it seems possible.

Apparently the CANBUS is a gigantic PITA, along with routing the factory steering column

Yes, it can be done. But Vigo was right about the Challenge build experience.

I am currently in the planning stage of an LS Challenge car. It CAN be done, but I have been playing the Challenge game for 12 years. I could not have done it 12 years ago (Not only because I didn't have the mechanical skills, but because I didn't have the budgeting skills).

The best formula (IMHO) is for the engine to come from a complete wrecked donor car with enough good high value parts left to play deep inside the recoup budget. In other words, not just an engine, but an entire car. This car will be more than 50% of the expenses. YMMV.

My theory on budget is $1000 for the Challenge car, $1000 for the engine donor (complete car as stated above) recoup $1000 from those two. That leaves $1000 for incidentals, nitrous, and turbos.

chiodos wrote: Why does the truck motor turn you off? You know with the same cam and intake ls1 and 5.3 are only 10hp difference and the torque range is shifted a bit. And with less than 100lb weight difference it's not too much to make it worth the extra $1000. To me at least...

I like the truck motor just fine. I figured though if you go the truck motor route then you need the f-body pan and intake, and by then, you might as well have started with the ls1. Is that not the case? Is there still a price advantage to go with the 4.8 + other accessories?

Robbie wrote:

chiodos wrote: Why does the truck motor turn you off? You know with the same cam and intake ls1 and 5.3 are only 10hp difference and the torque range is shifted a bit. And with less than 100lb weight difference it's not too much to make it worth the extra $1000. To me at least...

I like the truck motor just fine. I figured though if you go the truck motor route then you need the f-body pan and intake, and by then, you might as well have started with the ls1. Is that not the case? Is there still a price advantage to go with the 4.8 + other accessories?

Oh, definite price advantage. Aluminum block LS engines command a premium, even the LS1, which honestly isn't that great. The biggest power bottleneck on the truck motors though is that they come with the world's tiniest camshaft. I don't think they even broke 200* of duration, seriously.

Even a 4.8 WITH a wicked cam would make way more power for the same price or less than a stock aluminum block engine. Considering you would pretty much have to buy the cheapest thing available to you.

Even the worst possible LS is going to make more power and torque than Mustang GTs had up until 2010 or so, and in a lighter car. Don't let the perfect be the enemy of the good! Iron block is fine!

In reply to Robbie:

Well an oil pan is cheap and you don't even need a car manifold unless clearance is an issue. Usually swapping from the truck to car manifold looses torque but gains only a couple (seriously MAYBE 10hp) so all your looking at is an oil pan. Not worth the extra $500-1000 and as others said some of the ls1s sucked. Iirc the ones before 2000 (the cheaper ones) had the crappier heads and the intake wasn't as good as the later ls1 design (changed to more ls6 style I believe)

Short of the short, the 4.8 and 5.3 can make just as much (usually more) hp dollar for dollar than the aluminum based motors. Main thing is the power band is shifted up, big whoop cause who doesn't like to rev stuff out?

There are some decent forums for RX8 V8's that I've been lurking lately. Check out. RX8 with LS3 RX8 with LS

The mechanicals scare me much less than the electronics. I'm super anal and want all the accoutrements functioning including gages and ac... I was shooting under 10k for a sleeperish OEM+ style beast.