If anyone is thinking about doing the same swap, here is the perfect chassis (located in Gainesville). Not mine, but I did buy some parts from the guy after his turbo motor let go. I've see the chassis and it appears to be in great condition.
http://www.tampabaymiatas.net/forum/viewtopic.php?f=6&t=6446
Kieth. You suck. As well as all of your Flying Miata counterparts.
I know the guys with Vorshlag, all old Ags. So I have thought of this for awhile. Now with the possibility of moving into a position without a work vehicle, this is starting to look REALLY viable.
Dangit! This is something else I dont have time to get together! :)
Keith wrote: Well, we do have a lot of drivers here equipped with organic traction controlWe had one car here that had traction problems in 4th gear according to one driver, but I never noticed a problem. The big problem with trying to fit fat rubber to a Miata is diameter. If you want to go wider than 225, you're generally looking at a tire that's about 2" taller than original and that brings along some downsides. Yes, there's the oddball Hoosier, but that's an autocross-only tire.
with all the available torque, is going to a higher tire with more choices a viable option? Especially if you kept the diff ratio closer to that of a stock miata.
We've run 25" diameter tires on a Miata in the past - a 245/45-16. If we really have to go fatter than our 225/45-15, it can be done at the expense of higher CG and some very careful wheel specification. A bunch of problems start stacking up in a hurry, though.
The diff ratio is only part of the equation, we're using non-Miata gearbox ratios as well.
While looking for something else (Miata related), I found this picture and thought it relevant. Don't know anything about the car though...
(BACK FROM THE DEAD!)
So now I see the Martini Miata (I apologize, the TARGA MIATA) 
is getting a big hunk of GM under the hood? Keith! we want more information!
Kind of old hat.
A local business with a lot of experience building Cobra kits did this back in the 1990s and sold a bunch of converted Miatas using the even easier to fit Ford V8.
They found that the actual performance of the cars was a little disappointing because they could only fit so much rubber under there and then the tires would just sit and burn. The only alternative was to make them look like Cobra wannabes with wide flairs, which put paid to any idea a customer had about owning a sleeper.
Obviously with another 15 years of tire technology, the grip limits are now higher, but the same strictures will apply.
We've found that the very best swap for the SBC is into the Fieros as they have far superior traction as a result of the mid engine weight over the drive wheels.
I'm sure the LS1 Miatas would still be a lot of fun, though.
PS - there are a few very interesting (and expensive) LS7 swaps into the Solstice, but they have room for the rubber needed for this sort of delightful automotive idiocy!
Should I stop my LS7 into a Austin Mini project then?
An LS-powered Miata works just fine with 225/15s. Driving in town, driving on the highway, driving on the track, et al. The weight/balance of the LS-powered cars is very close to stock Miata specs anyway. I don't know about the Ford-powered Miatas, but I'd be very very happy with an LS-powered Miata of my own.
I'd love to try a V8 Solstice, though.
Tom Heath wrote: I'd love to try a V8 Solstice, though.
+1.41
That Mallet Solstice looked like a bag of fun
pinchvalve wrote: Should I stop my LS7 into a Austin Mini project then?
Yes, unless it's a twin-engine setup, or at least AWD.
Not much point in using the LS1 in a Solstice as you can better the power using the stock turbo engine quite easily ( sneak under 13 secs 1/4 with the stock turbo unit, and 0-60 in around 4.5 secs).
The LS3 is really where life begins for those and the LS7, although very expensive (~13K for crate engine) makes a very interesting swap. As well as under 4 sec. 0-60 and a 10.99 1/4. 
No way to get that sort of power down in a Miata without making them look like an Elan on steroids by hacking the fenders and grafting big bulges on (the Solstice runs 245 x 45 - 18 rubber stock and has lots of room for more).
Well, wspohn, we've now got two years of experience running these things on the track and the road, and we've delivered a number of LS3-powered Miatas to our customers. The cars have proven themselves to be quite effective. With the right rubber, you can put the power down nicely - don't underestimate the effectiveness of that Getrag LSD.
Actual experience: in 2008, the fastest Miata we'd ever had around our local track (small and tight kart track, definitely a handling track instead of a power track) was my Targa Miata with me driving. I brought Elvis, the LS1 car discussed in this thread, out to try it. Elvis was running the same suspension that was developed on the Targa car, but the car was in full street trim. Leather interior, CD player, carpet and spare tire vs stripped out caged rally car. The weight difference was on the lines of 400 lbs, 2100 vs 2500. Which, by the way, is healthily motivated by a 350 hp engine.
My first timed lap was 2 seconds faster than I'd ever gone in the Targa car. It became clear fairly quickly that the chassis was able to handle the power. Yes, wheelspin was possible in lower gears but that's the case with my Locost as well. It simply requires a driver with an analogue throttle. So far, nobody who's experienced one of these cars has used the term "disappointing". What really opens people's eyes is the way it accelerates above 100 mph, where aerodynamic drag is simply shrugged aside.
So I'm sorry if it's "old hat", but the small rwd sports car concept wasn't new when the Miata came out in 1990 - and people still liked that. The difference between the LS motors and the Ford is fairly large when it comes to ground clearance, packaging and weight distribution. We certainly weren't the first to put the LS engine in a Miata either, but I'd like to think we're the ones that made it a much more acceptable proposition. We now stock a full collection of parts, so that we can supply every single nut and bolt you need to install the LS376/480 crate engine in any 1990-05 Miata. The 376/480 is a far better value than the LS7.
http://www.flyinmiata.com/V8/ for details on parts and turn-key prices. In the last two years, the number of V8 Miatas has exploded.
Yes, the "Martini Miata" is indeed getting an LS engine in order to run in the Targa Newfoundland. It's interesting, I'd expected the Miata to excel in the tight twisty stuff and suffer on the fast open road. It turns out the opposite was true. Because you're dealing with unknown corners, tight rally stages end up being more of a "point and squirt" proposition. The Miata's good handling helped, but I just couldn't carry much speed through the corners and got punished on the straights.
The fast sections were different. I usually had better sight lines, and my small size allowed me to adjust my lines nicely. So I could run on momentum, and the car proved to be quite competitive there. Still could use some extra speed, of course, but when running between 80-100 mph the Miata was strong.
The goal with the V8 version is to make point-and-shoot much easier - I'll be able to teleport between the corners. I'll also be able to get up to speed faster on the fast stuff, and can actually leave more margin of error in the corners. The engine going in the car is actually the one that we originally put in Elvis, the car at the beginning of this thread. Elvis now has an LS376/480 crate motor. I don't know exactly what we're going to do to the LS1. The goal is a very wide powerband and anvil reliability instead of peak power, as flexibility is most important to us. We're also not planning on spending a bunch of money 
Our machine shop has turned up an LS2 crank and piston set sitting around, and we're talking to some other suppliers.
The Targa car is also going to get a T5 trans. Partly because it'll let us test this out, partly because it'll be lighter. If we can get this car to the start line at 2300 lbs with spares, I'll be very happy.
Keith wrote: The Targa car is also going to get a T5 trans. Partly because it'll let us test this out, partly because it'll be lighter. If we can get this car to the start line at 2300 lbs with spares, I'll be very happy.
No, no, no! You're supposed to be testing the "back half" diff upgrade development so I can get the rear end of my car back together in time for summer and do the V8 swap next winter! My stock rear is out and if I still have a job next month I'll be buying the diff and rear kit.
And I kinda hope the T5 doesn't work out since I already bought a T56 
Keith - wasn't saying the Ford was better than a Chev at all - I have a lot of respect for the GM LS series of engines, and it is certainly the best choice for these sorts of swaps. Just commenting that the wheelwells on the Miata aren't exactly made for the sort of rubber needed to get that power down. Nor was I trying to indicate that the fact that people had been doing this sort of swap for many years made your project any less interesting.
A little surprised that you are using a T5 as the torque capacity is limited to less than I figure you will have - do you have an uprated trans or do you figure you can get away with it considering the nice light weight?
I expect that your Miata will probably have a better top end than a converted Solstice as well. The GM Kappa platform was designed for beauty rather than speed and with stock engines they top out at only 143 mph (148 on the aerodynamically better coupes, like I have).
Not sure how the Miata will feel at high speed - you never know until you try it and once may be too many! I have avoided trying to find out the top speed of my Jamaican, given the shovel nose shark front styling, as I am afraid I might discover that the top speed is attained while in an inverted position....
Junkyard_Dog wrote: And I kinda hope the T5 doesn't work out since I already bought a T56
T56 is a hog as far as weight - around 40 lbs. more than the T5.
You could consider the Solstice Aisin 5-speed (from Chevy Colorado pickup and Hummer H3) as it happily accepts the LS series at anything under 500 BHP and IIRC, weighs closer to the T5 than the T56. It comes in at 107 lbs.
I have an Advance Adapters bell housing that will mate your LS motor up to a Toyota W-series transmission if you can get the input shafts and such all the right lengths. Would be smaller and most likely stronger than the T-5. I am easily bribed with shiny things....
Sorry, the "old hat" comment kinda rubbed me the wrong way. I don't think anyone's ever done such a good job of building V8 Miatas as we have, even though they have been around since 1989 in various forms. Just because it's been done doesn't mean it can't be done better...
I don't speak about the LSx Miatas in the future tense much. To me, they're a pretty well tested critter and I've got quite a bit of seat time in various ones. We've put together nearly a dozen of them so far, and customers have built a bunch more with our parts and help. Remember, this thread was started over two years ago!
The T5 is being used in the V8 Spec series with the 5.3 Vortec variants. It's not up to the punishment of the real LS monsters, but it should deal with the LS1 in the Targa car - of course, we'd be using an uprated part. The T56 we used is actually no longer available new other than the Magnum. For a street car, I'd take the T56 due to that nice tall 6th speed. The use of the T5 in the Targa Miata is partially due to the request of one of our sponsors.
A set of R-compounds in 225/45-15 on 15x9 wheels will go a long way towards putting down power. I'm not a drag racer, of course, I'm usually more interested in how the car comes off corners. And the LS Miatas are very competent there.
I've never personally had a Miata over about 140 or so, although coworkers have taken them north of 150 and our Track Dog racer used to hit over 140 at Willow Springs on a regular basis in 2002. That doesn't matter for the Targa, where the top speed is limited to 120. Of course, that's on an unknown, bumpy road with rocks on one side and trees on the other - fine with me 
Junkyard, you have a good point. As far as I'm concerned, getting the "back half" kit sorted should be the matter of days. I'll try to get it put on the front burner.
Keith wrote: The T5 is being used in the V8 Spec series with the 5.3 Vortec variants. It's not up to the punishment of the real LS monsters, but it should deal with the LS1 in the Targa car - of course, we'd be using an uprated part. The T56 we used is actually no longer available new other than the Magnum. For a street car, I'd take the T56 due to that nice tall 6th speed. The use of the T5 in the Targa Miata is partially due to the request of one of our sponsors.
Im curious, even ``BUILT`` t5s are pretty weak. Do you mean something like a tremec t5k0 or whatever they are called nowadays? Also curious why you don't just throw a 4 speed box in there with a tall 1st gear or a low numerical rear end?
Edit- And since I am bugging you wish questions, is there a specific year of Miata that FM thinks is the best for this type of swap? I could see myself in one of these next year...
I think Keith pretty much has this figured out, guys. Sorry, but the "not enough fender" stuff is silly. He just proved it to you with actual lap times. No better proof than that.
Keisler has recently announced a new 5 speed transmission, based on the Borg-Warner T45. They're marketing it for the muscle car guys, but it looks like it would maybe work well in this application as well. It's smaller and considerably less expensive than a Tremec, and is supposed to shift better. http://www.keislerauto.com/
Keith wrote: The T5 is being used in the V8 Spec series with the 5.3 Vortec variants.
Details? What is the V8 Spec series?
I have to admit I'm a bit concerned about the T5 as well. This has to be a bombproof application. Of course, it's in a much lighter car than usual. But it's something I still want to discuss. V8 Roadsters - one of our sponsors - is behind the V8 Spec series and that's what they use, so that's where the push to run a T5 comes from. I'm concerned that we're going to be making more power than them.
More on the V8R Spec series: http://www.v8rspec.com/forum/index.php. Basically, an L33 (aluminum 5.3 "Vortec" HO), T5 and standard V8Roadster install kit.
Best year for an LS swap? The NB. It's got about an extra inch of engine bay room, a big wiring grommet into the firewall and an electronic speedometer. Plus it's a stiffer chassis. We've built a bunch of NAs and it can certainly be done, but it's just a bit more work. So if you've got a Miata, go ahead and use it. If you don't have a Miata, buy an NB.
Keith, is Elvis the car I drove at the Mitty 2 years ago? That car was amazing in so many ways. My little girl will be out of the house in 13 years. Do you think the parts will still be available then? 
Keith wrote: I have to admit I'm a bit concerned about the T5 as well. This has to be a bombproof application.
Keith, you might give serious consideration to using an Aisan out of a Kappa. They are standing up beautifully to all fo the LS1 LS2 and LS3 swaps into the Solstice, while the T5 tends to fold when faced with considerably less torque. The Aisan would be a 25 lb. weight penalty, but it would get you a lot closer to being bullet proof. The Aisan also shares the correct bellhousing bolt pattern you need.
BTW, no reason you'd have known about Cardiac Cobras - John Bretoner, who made a bunch of early Ford - Miata swaps, as it was a local Vancouver firm. They were intially marketed here. He told me they had problems with chassis flex and had to do quite a bit to strengthen them up top take the V8 torque. Marketing moved to the US and they were sold as the Monster Miata. No idea how good or bad the product was.
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