Light weight 500hp driveable motor for Miata/S2000/Z4

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Re: Light weight 500hp driveable motor for Miata/S2000/Z4

Post by ptuomov »

This is 2017. Well engineered turbo systems don’t have any lag worth speaking off when the rpms are up. Especially if we’re talking about low boost setups like 500 hp from a 2.2 liter engine.

In true street cars, maybe there’s a little bit of lag still. You’re cruising in traffic at 1500 rpm and have to fill a hole on the other lane, then maybe there’s a lag. Although in my brand new e63s wagon with small turbo V8 the engine is never the problem, the lag is always caused by the god damn 9-speed transmission trying to save fuel to meet some government regulation.
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Re: Light weight 500hp driveable motor for Miata/S2000/Z4

Post by mk e »

ptuomov wrote: Sat Oct 21, 2017 9:27 pm This is 2017. Well engineered turbo systems don’t have any lag worth speaking off when the rpms are up. Especially if we’re talking about low boost setups like 500 hp from a 2.2 liter engine.
The key part us "when rpms are up".

I used to think no-low boost at low rpm was BAD but I'm not so sure any more. Less boost down lie encourages you to rev the engine and I'm thinking that helps keeps the sports car "feel". If I do another street boost project it will probably be a centrifugal blower, I've never had one of those and avoided them thinking they are the worst of both worlds between blower and turbo....but if like to try one.

Lag is bad and very turbo I've driven has very noticeable lag at low rpm...how much is the turbo and how much is the way not opening the throttle quickly I don't know, but I hated my 2010 2.0 VW, and am dreading the day I need to part with the 6cyl NA car I replaced it with as that engine is now gone and a 4 cyl turbo replaced it....and I thought it sucked when I test drove it and decided to keep the na car until it dies.
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Re: Light weight 500hp driveable motor for Miata/S2000/Z4

Post by mekilljoydammit »

If it were my Miata looking for 500hp... I think peejay is on the right track but personally, man, all the stuff to make the chassis cope with more torque seems like a pain in the ass. You're basically getting rid of everything in the driveline though at least there's off the shelf solutions. No real solution to "not enough tire" without doing huge amounts of unibody surgery though. I mean sure you can make the little iron block I4 make 500hp but it won't be happy about it.

S2000... basically the same boat except you can more easily get there by boosting the stock engine. But it literally uses the same 7" ring and pinion as the Miata and from everything I can tell, the rear suspension is much more optimized to kill you.

The BMW is going to have the worst suspension of the 3 (though how much that matters is up to you) but I think that you can partsbin swap to a driveline that will hold the power you're talking about. I'd be amazed if there wasn't an LS swap kit, or turbo the stock I6, whatever.
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Re: Light weight 500hp driveable motor for Miata/S2000/Z4

Post by Newold1 »

My sort of out of box thinking takes a Nissan VR30DTT V-6 all aluminum turbo stock engine out of a wrecked Q50 sedan and with a little stripping and re-tuning , a nice after turbo exhaust would really make a little Miata fly! Easy 450HP, 350lb/ft. of torque from 1500 to 5500rpms and the lighter weight will serve the handling of a nicely set up Miata. I've seen these used in Sand cars and they really perform without hardly any tweaking. Sort of an unconventional idea but workable in my opinion.
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Re: Light weight 500hp driveable motor for Miata/S2000/Z4

Post by 340king »

I would be inclined to use a 302 Ford with alloy heads. Put some money into the bottom end to allow it to rev to the 8,500 range to make your 500 hp goal without creating so much torque that you kill the "Sports Car" feel. Some IMCA dirt track racers used the 302 to great effect when there weren't any weight rules. They set them up to turn 8,300 rpm and used the mechanical advantage of deeper gears to help make up for the smaller displacement. On dry slick tracks they were killer. They didn't blow the tires off like the larger displacement engines. I would bet a high revving 400 hp 302 would be a serious ride keeping the best of both worlds. The deeper gears would make it feel like it had 500 hp when you really got after it. That would be an easy target hp to reach. Good luck with your project.
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Re: Light weight 500hp driveable motor for Miata/S2000/Z4

Post by Kenova »

peejay wrote: Fri Oct 20, 2017 7:34 pm The idea that is rolling around in my head is a cheap early aluminum 5.3 (the ones with the "worthless" heads, so available cheap cheap cheap) and drop in a 4.8 rotating assembly, to make an aluminum 4.8. Maybe drop the 5.3 internals in the 4.8 block and sell it to someone else to recoup some funds. Then add a big honkin' cam to kill off as much low end torque as possible, since low end torque is bad if you want a drivable engine. If it accidentally makes more power at the top end, that's fine too, but the real goal is to keep it from blowing the tires away so easily at the low end since we're at the bottom end of what is available displacement wise. Use a worthless takeoff LS1 intake manifold, use the Corvette drive by wire throttle and PCM controls. The smallest torque converter possible that has an acceptable stall speed, to minimize rotating weight. That's the expensive part.
This combo gets my vote.
I've had two 4.8s in pickups and the little buggers do like to rev. A hot aluminum 4.8 with a manual trans behind it would be a blast to drive without turning it into a death trap ( But I guess that depends on driver talent :lol: ).

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Re: Light weight 500hp driveable motor for Miata/S2000/Z4

Post by Ron E »

mk e wrote: Fri Oct 20, 2017 10:02 am Pretty much every car project I've done involves more hp in a sports car.....and it really changes the driving experience. The car is certainly faster but that's not what I'm talking about, it feels different, it drives different, its a different car.

Maybe a little off topic but if you love the feel of a little sports car adding gobs of low end power will probably make it not feel that way any more.
This is so true. If you want the same "feel" I.E. the same car with twice the power, you may not like any of the V8 swaps. If a V8, the above 302 SBF will make a great combination with its light weight, serviceability, low CG. It is the shortest V8. The 350 Nissan motor will be tight on the sides and will raise your CG. But, it will haul ass.
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Re: Light weight 500hp driveable motor for Miata/S2000/Z4

Post by Newold1 »

The 3.0 liter 2016 Nissan V-6 turbo engine I suggested is not that wide as it has the exhaust manifold to the small turbo's integrated into the heads and the stock water to air inter coolers can easily be removed and a nice front mounted air to air inter cooler used instead. This engine is way lighter than an iron block 302 SBF V-8 and is shorter and the balance on the car should be much easier to set up and control. CG should not be a problem. The huge flat torque curve this engine can deliver would make a nicely set up Miata a winning car on a track for one big reason-"IT WILL BE QUICK EVERYWHERE"! Track cars that are quick "everywhere" win more races! JMHO
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Re: Light weight 500hp driveable motor for Miata/S2000/Z4

Post by autogear »

Its been talked about a lot, but Ive never seen one in the wild; what about a 3800 supercharged 3.8L V6? Has anyone ever gotten that to work in a North-South configuration? With an upgraded W/C T5 (Gforce gearset and case) is a pretty compact package and should be extremely durable.
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Re: Light weight 500hp driveable motor for Miata/S2000/Z4

Post by rfoll »

The aluminum Buick/Olds 215 V8 is one of the lightest packages out there. They weigh just over 300 lb.
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Re: Light weight 500hp driveable motor for Miata/S2000/Z4

Post by Ron E »

Newold1 wrote: Fri Oct 27, 2017 9:56 am The 3.0 liter 2016 Nissan V-6 turbo engine I suggested is not that wide as it has the exhaust manifold to the small turbo's integrated into the heads and the stock water to air inter coolers can easily be removed and a nice front mounted air to air inter cooler used instead. This engine is way lighter than an iron block 302 SBF V-8 and is shorter and the balance on the car should be much easier to set up and control. CG should not be a problem. The huge flat torque curve this engine can deliver would make a nicely set up Miata a winning car on a track for one big reason-"IT WILL BE QUICK EVERYWHERE"! Track cars that are quick "everywhere" win more races! JMHO
I didn't know about that engine specifically. I'm driving a 300zx tt and I researched (for the hell of it) a LS swap. Turns out the LS is lighter than the Nissan engine and access is improved a huge amount. (You can actually see the frame rails with a LS.) Also, the 3.0 carries more of it's weight up high than the LS. I "assumed" it was similar to the 3.5 in bulk


I did see a swap and the LS has a ton of room under that hood. As you probably know, the 3.0 has just enough room for you to injure yourself trying to work on it.
I read about the TT vs. LS weigh on the internet. So, it has to be true...right?
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Re: Light weight 500hp driveable motor for Miata/S2000/Z4

Post by steve316 »

I blame the enter net & global warming.
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Re: Light weight 500hp driveable motor for Miata/S2000/Z4

Post by Newold1 »

The 2016 - 3.0 DDTT V6 engine is when stripped of all the factory gobble d gook one does not need or want in the Miata and the inter coolers are removed for a front mount air to air inter cooler this little engine will weigh about 75 lbs lighter than the similar power LS engine variant. Because of the special design of the exhaust manifolds in the heads design the small turbo assemblies this DOHC V6 engine is not more than about an inch wider than an LS and the fact it can ultimately stripped down its overall length will be shorter than the LS and allow when installed fore-aft it would help keep the front/rear weigh bias of the Miata in a better place for track handling. This was my reasoning and thoughts about using an "out of the box" power plant.

There are obviously a few other small light weight engines that will fit in a Miata but the ability of these aluminum engines like the Buick 215, Rover and
most others is that they can not easily be built up or equipped to operate in the 400-500HP range the OP was asking for.
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Re: Light weight 500hp driveable motor for Miata/S2000/Z4

Post by Ron E »

Neworld1, That sounds like a great platform. I'll familiarize myself as soon as possible. Probably pricy for a "drop-out" with the supporting parts, but nice always rhymes with price.
Earlier mention of turbo lag I doubt would be a problem. Even on my ancient version lag is never a bother. On a good dry surface, if I stab it in 1st from about 2K RPM, it's responsive. About 1 to 1-1/2 seconds later it just breaks the tires loose. Does that through 1st. Any other time you have control over starting RPM, so it's a non-factor. If my drivetrain was in a 1K lb. lighter car, like a Miata, with suspension/tires to match it would be quick. Based on that alone this newer, evolved, more powerful Q50 deal at that weight will require some serious suspension upgrades ( and driver finesse ) to utilize all of it.
A wrecked donor Q50 would be the way to go...And, I'd make a effort to include the traction control too.
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Re: Light weight 500hp driveable motor for Miata/S2000/Z4

Post by engineguyBill »

If I recall correctly, the reason that you see so many small block Ford V-8's in Miata is simply starter clearance. If the starter is on the left side of the engine, it interferes with the steering. A 289/302 Ford can be built for a very reasonable cost and they are reliable. (The 351W has slightly taller deck and may result in some clearance issues.)
It should be very easy to modify the chassis/suspension/frame to handle the torque/horsepower output of the Ford V-8. Nothing spells "bad-ass" any better than the sound of a hopped up American V-8 in an import car . . . . :D
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