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DrBoost
DrBoost SuperDork
9/7/11 5:07 p.m.

I rode in my buddies LS3-equipped FD last week after helping him get the wiring sorted out. Man, what a car. Now, I just don't have the coinage for a LS powered FD, or an LS powered FC even. He's trying to get me to put a 5.3 in an FC.
I loved the miata I had and know I can't afford to do an LS in anything. So, for those that have done a 5.0 in a Miata, what can you tell me about it? How much did it end up costing, and what would you do differently? How about some driving impressions?

DavidinDurango
DavidinDurango Reader
9/7/11 7:56 p.m.

Have one. Bought it "mechanically sorted" according to the PO. What a joke!

Car needs everybit of stiffening you can put on it; fatcat suspension.

The car is fun but one can feel the wt. - which isn't much but % wise is a big gain due to low starting wt. Make sense?

I'm running a barely warm 302 (carb) and its "peppy" - also - drove it1800 miles round trip and two track days last spring. 28mpg average! YMMV.

the V8 is much easier to drive than a turbo car, but not quite as much BANG. LOve the handling, but then I like Miatas. rear tires wear quickly - its toooo much fun - - and I drive it relatively easy.

Put some motor in it - I only have traction problems in low gear. (althought I did get it sideways in 4th WOOOOHOOO at Fernely!) oh, and lots of tire for track days.

Greg Voth
Greg Voth HalfDork
9/7/11 11:53 p.m.

This is the $2010 car we built.

More pics and a couple videos.

https://picasaweb.google.com/111810921315920094000/GRM2010Challenge?authkey=Gv1sRgCKLH0aeRkszKEQ

http://www.youtube.com/watch?v=dDpfHx0Kt44

http://www.youtube.com/watch?v=Ic81M-TmQV4&feature=related

I liked it but it was not sorted. None of the stock gauges worked. No windows, or top. It had about one inch of ground clearance since we ran the exhaust under the front cross member rather than run the Monster Miata headers due to budget reasons. You can see the clearance in the photo above and the ones in the album. The clutch would not release at the event but we still managed 16th IIRC. Sold it for just under $4k after fixing the clutch which the current owner advised is slipping. We must have adjusted it out too far. Must have had the motor in and out half a dozen times in the year we owned it. We only ran it at the challenge. I was glad to see it go. To work on anything it was PITA. No room for anything.

Handled very well with Eibachs, KYB's and a FM front sway. Went like stink.

I would recommend the 5.0 swap in the FB RX-7 or a 5.0 or 5.3 in the FC. There is tons of room comparatively. We have a 5.0 FB Lemons car. Very easy to work on. Currently just starting a LS1 FB which should still have plenty of room.

DrBoost
DrBoost SuperDork
9/8/11 7:03 a.m.

I had a miata. bone stock and incredibly fun! I immagine putting thrice the hp would make it tons of fun.
Greg, would you mind sharing your budget papers with me? I'd like to see where the money went, and where I could spend my budget to make it a occasional driver.

Greg Voth
Greg Voth HalfDork
9/8/11 8:10 a.m.

If I can find them you could absolutely take a look but I am not the best record keeper. I can't find the actual sheet with receipts but do have my handwritten scrap paper I was putting numbers on. It is incomplete but gives you an idea.

Here is the basic break down of our build. It was a stalled project from another forum member. It was a rolling shell when we got it. It nickel and dimed us to death especially after the event. Needed an alternator, put in an oil pump. Trying to fix the clutch etc.

Car w/ motor, trans, suspension, T2 Rear end. - $1000 / Cage - Budget Exempt -$500

Tires and rims $120

Exhaust $300

Gauges - $40

Starter - $40

Steel/Metal - $120

Various Oil etc. - $50

E-Fan - $35

Belt - $20

Paint and supplies - $20

Master and Clutch - $150

Power Steering Silver Solder work - $15

Remote Filter - Free from Oldtin + 35 for hoses.

In the end it was rough car that was perfect for autocross and maybe track work. A cruise night would be ok but it had no HVAC, no windows, top etc. Probably $1500 more to make it a streetable car.

White_and_Nerdy
White_and_Nerdy HalfDork
9/8/11 10:18 a.m.

The LSx weighs quite a bit less than the Ford 5.0, especially if you go for one with an aluminum block. Keith's documented which versions to go for, and/or read the LSx article in GRM from a few months back. I've heard of the 5.0 Miatas' nose heavy tendancies, but haven't heard the same complaints about the LSx swaps.

DaveEstey
DaveEstey HalfDork
9/8/11 11:23 a.m.

There's a 5.0 swapped Miata that runs with us. I was chatting him up about the swap versus turbo (he has one of each) and he said for the money the V8 is just plain better.

With that said, his 5.0 does seem a tad nose heavy.

Sofa King
Sofa King Reader
9/8/11 2:46 p.m.

I have a 5.0 powered Miata and I am building a LS1 Powered Miata. I also have a 350 powered '88 RX-7. Saying that you can feel the additional weight in the Miata is like saying that you can feel the weight of your passenger. I think that the V8 powered Miata still feels like a Miata, it just now has more punch. I only added about 150 lbs and about 50 of those came from the roll bar and the 8.8 rear end. The balance of the car changed about a half a percent. On the other hand, putting the 350 in the RX made it feel nose heavy. It still handles well, and the weight balance probably didn't change all that much (I have not had the RX on corner scales) but you seem more aware of the location of the weight than you do in the Miata.

I think that the initial reaction is that it is cheaper to build a Ford powered Miata, but the stock F 5.0 will give you around 225 horses. The LS1 will cost more to buy but will have a minimum of 345 horses. To get the Ford to that level you will end up spending at least as much as the cost of the LS1 and it will still be heavier. This is why I have a Ford but am building an LS1! Even after adding a Trick Flow top end kit to the Ford, I am still below the stock horsepower of an LS1.

nderwater
nderwater Dork
9/8/11 3:22 p.m.

MUST KNOW MORE

Where did you source your subframe? Did you use the traditional Ford transmissions? What are you using for engine management? How hard was it to sort out integration with the Miata's electrical system?

That is a thing of beauty.

Alan Cesar
Alan Cesar Associate Editor
9/8/11 3:29 p.m.

My friend and LeMons driver built himself an LS1 Miata. He overspent on a number of things, he says, but he did a complete build -- including seats, big brakes, wheels, tires, roll bar, SFI bellhousing, limited slip diff, coil-overs, new front bumper, camshaft, tuning and so on. He used the Flyin' Miata kit.

All told, he said he spent close to 30 grand. Maybe slightly more than that, my memory's fuzzy. Did all the work (except the tuning) himself. Skilled guy, too. Top-notch, show-quality work; he's won a few trophies already.

He said if I wanted him to build me a similar car, he'd charge a bit over 20 grand. Maybe 24k? Again, fuzzy memory. No doubt you could build one for quite a bit less if you forgo a lot of the upgrades.

He's been surprised that it's not an oversteering, unwieldy drift machine; it's got plenty of traction. He has details on his blog, and he'll be at Holley LSx Fest this weekend.

Dyno http://www.johnnycichowski.com/2011/03/dyno-time.html

Scales http://www.johnnycichowski.com/2011/03/ls1-miatatale-of-scales.html

Autocross http://www.johnnycichowski.com/2011/05/we-got-ourselves-race-car-wcmc-auto-x.html

pres589
pres589 Dork
9/8/11 3:40 p.m.

I'm wondering what weight could be saved if an aluminum 5.3 were used in conjunction with a non-T56 manual trans. Which, I don't know, the 4 speed out of a mid-80's GM pickup perhaps... those have been talked about here, are cheap, and are plenty strong for a near-stock 5.3 truck LS. I think a serious change in rear gearing would be required after that though.

Sofa King
Sofa King Reader
9/8/11 3:51 p.m.

In reply to nderwater:

Thanks, I am proud of the way both cars turned out and I expect the LS1 Version will be better than either of these.

We did the subframe ourselves. It doesn't really require that much cutting and welding. We copied photos of subframe modifications that others had done. It really boils down to cutting a notch large enough to give room for the starter. The subframe for the LS1 is much more radically altered, but will make for a much better solution for the exhaust routing. The transmission is a Ford T-5. I ran the stock rear for a year and converted to a Ford 8.8 from a 2002 Explorer. The wiring was very easy. I used a Painless harness. The stock Miata wires go to the Ford starter, then follow the detailed instructions that came with the harness. From starting to install the harness to hearing the car run took about 45 minutes!

Duke
Duke SuperDork
9/8/11 4:00 p.m.

I've never driven one, but I'm familiar with two. One is an injected 5.0 with a T56 and a T-bird rear. It's the hobby car of an engineer and he seems to be doing a very thorough job on it, with lots of chassis reinforcement and suspension development. The other is a pretty much stock carbed 302 out of an Explorer. Dunno about the transmission, but I believe that one has a stock Miata rear (not certain).

The 302 has way more space under the hood than my ubercharged 1.8 does. WAY more space to poke around.

If it was me, I think I'd do an Ellis-powered FC instead of a Miata. More room underhood, and I would think the somewhat longer wheelbase would suit the extra power better.

DrBoost
DrBoost SuperDork
9/8/11 5:57 p.m.
pres589 wrote: I'm wondering what weight could be saved if an aluminum 5.3 were used in conjunction with a non-T56 manual trans. Which, I don't know, the 4 speed out of a mid-80's GM pickup perhaps... those have been talked about here, are cheap, and are plenty strong for a near-stock 5.3 truck LS. I think a serious change in rear gearing would be required after that though.

I thought the only manual trans that would bolt to the L-series engines was the T-56. Is that true?

Greg Voth
Greg Voth HalfDork
9/8/11 6:01 p.m.

From my understanding a T-5 can be made to work as well as the old Chevy 4 speeds. I believe there are also manual trans Chevy trucks with the 4.8 and 5.3.

ProDarwin
ProDarwin UltraDork
9/8/11 6:22 p.m.
Alan Cesar wrote: Scales http://www.johnnycichowski.com/2011/03/ls1-miatatale-of-scales.html

Ooof. That's way heavier than I was thinking. Is there still room in that car for weight reduction?

unk577
unk577 Reader
9/8/11 6:26 p.m.

Check v8roadsters for making the T5 work. They sell the bell housing for the V8RSpec. I've driven they're old shop car(NB LS6) and it had all the characteristics of a miata only with lots of torque and hp. Felt very docile but was a rocket when on the gas. I'm almost finished building a L33 NB and I'm at the $15k mark including the car.

Zomby woof
Zomby woof SuperDork
9/8/11 6:37 p.m.

My buddies built a twin turbo 5.3 Miata.

This was during the build

It's pretty fast.

MitchellC
MitchellC Dork
9/8/11 6:47 p.m.

That seems like a bit of an understatement.

Zomby woof
Zomby woof SuperDork
9/8/11 6:50 p.m.

It is. The car is INSANE

Alan Cesar
Alan Cesar Associate Editor
9/9/11 6:29 a.m.
ProDarwin wrote:
Alan Cesar wrote: Scales http://www.johnnycichowski.com/2011/03/ls1-miatatale-of-scales.html
Ooof. That's way heavier than I was thinking. Is there still room in that car for weight reduction?

Under 2500 lbs for an NB with a V8 is more than you expected? Flyin' Miata says the car gains about 300 lbs, so I think he's done slightly better than that.

Miatas are pretty simple; I don't know that there's much to remove at this point. The biggest single thing he could still do is probably strip the interior. Other than that, the car is basically shell, engine, driveline, suspension and brakes right now.

ProDarwin
ProDarwin Dork
9/9/11 8:56 a.m.

I'm not saying he did a bad job... I just didn't realize the swap added so much weight. Was hoping it would still be 2200-2300

edit:

Flying Miata said: Overall, the car gains less than 200 lbs with 1/3 of that on the rear wheels. In other words, the car does not become a nose-heavy beast. To put things in perspective, one of our SuperFour Challenge turbo Miatas came in at almost exactly the same weight and distribution. From the outside, the car looks completely stock. The ground clearance is unchanged and nothing needs to be altered on the body.

I guess that's not terrible. With ST miatas weighing as low as 2100lbs, you make a V8 around 2300 then. Less if you wanted to strip it.

Hmmm. Anyone want to trade me a V8 miata for an S2000?

Alan Cesar
Alan Cesar Associate Editor
9/9/11 9:41 a.m.
ProDarwin wrote: I'm not saying he did a bad job... I just didn't realize the swap added so much weight. Was hoping it would still be 2200-2300 edit:
Flying Miata said: Overall, the car gains less than 200 lbs with 1/3 of that on the rear wheels. In other words, the car does not become a nose-heavy beast. To put things in perspective, one of our SuperFour Challenge turbo Miatas came in at almost exactly the same weight and distribution. From the outside, the car looks completely stock. The ground clearance is unchanged and nothing needs to be altered on the body.
I guess that's not terrible. With ST miatas weighing as low as 2100lbs, you make a V8 around 2300 then. Less if you wanted to strip it. Hmmm. Anyone want to trade me a V8 miata for an S2000?

Yeah, the weight advantage is probably better if you start with an NA. Curb weight for an NB is ~2350. Still, it'll haul balls.

nderwater
nderwater Dork
9/9/11 9:51 a.m.

Curb weight for the lightest NB is ~2350. Later and fully-optioned cars edge up toward 2500 with a full tank of fuel.

ProDarwin
ProDarwin Dork
9/9/11 10:06 a.m.
nderwater wrote: Curb weight for *the lightest* NB is ~2350. Later and fully-optioned cars edge up toward 2500 with a full tank of fuel.

Eh. There are C Stock '99 Sports under 2200lbs. I've read you can get an '03 Club Sport within 50lbs of that with the big brakes.

The NA -> NB weight difference isn't that big. If I did a V8 it wouldn't be a fully optioned car. It would be basically STR prep (even lighter than above) except with a V8.

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