Hey Guys. I scanned through all the threads on here and didnt really see what I need to know. I am thinking about purchasing a 90 or 91 Miata. i have a 02 LS1 motor. I am wondering about the rear end issues, tranny, radiator, traction, etc. I am not gonna do the road racing thing, I want a fast, lightweight, nitrous miata.

 

And I also need to know about the wiring harness and computer

 

you best bet would be to contact the company http://www.monstermiata.com/ IIRC their conversion uses the small block ford

 

http://www.racingconcepts.net/

 

theres like 3 of them running around jacksonville here

 

You won't need nitrous in an LSX powered Miata. Rear end, Ford 8.8 is preffered, T-56 transmission. Traction can be improved by opening the wheel wells & installing fender flares. Otherwise 24.6" diameter tires is the limit. This ends up w/ a max. 245 wide tire. My T-56 w/3.55 rear end on 245 tires provides decent traction. Although, tires can be spun in 4 gears if one chose to. Big radiator w/ dual fans works well. My car runs 165-180 F coolant temp. & 200-210 F oil temp w/ a 160 F stat & fans on @ 180 F, regardless of ambient temps..

Suspension, sub-frame bracing, k-frame & big front brakes are the keys to a properly set-up LSX powered Miata. Without all of these, you're waisting your time because the car will not handle as well. Be prepared to spend twice the money & 5 times the time you think you might spend on the build.
Good-luck.

 

LS1-450, do you happen to have any pics of your build? Nice setup!

 

I think i can do this bulid for 10k. The motor has Patriot Ls6 heads and a 224/226 cam. I looked at the racing concepts page, but I dont really like there set up. Theres a company in North Alabama called Hinson SuperCars that I am gonna try to deal with. They doe alot of LS1 RX7's and 240's. Why not the nitrous though? I know the car will have a great power to weight ratio, but its not gonna be a road racer.

 

Hinson stuff is garbage, i'll tell you that first off. Their mounts sit way too high, their headers are overpriced, and i've yet to see anyone truly satisfied with their products (in the Nissan 240 market).

 

I don't have a web page & do have various pics taken to from time to time. Here's a few that may be of interest. Can provide pics of particular areas that can help those in the process of a build.

 

Well i would like to take back something I said. I didnt like the racing concepts kit because I thought it was a $$8500 dollar kit. I was confused with another company. I would like the info that anyone has done on making their own kit because that is the road I would like to travel. thanks for any info guys.

 

Perhaps you can build it for 10K. I can tell you that IMO, the best k-frame, LCA's, & sub-frame bracing can be aquired from Diamondmotorsports if they still sell to those do it yourselfers. These parts alone will run you 7 to 8k from Diamond. If you are a handy fabricator/mechanic, then it is possible to fab everything yourself & save money, just don't skimp on the important areas or you'll be driving an over powered POS that won't handle well.

Big front brakes = 1K
LSX motor & trans = 3 to 4K
good rear end = 0.5 to 0.7K w/ gear & detroit locker true trac
K-frame, trans mount drive shaft w/ mod's., & diff. mount = 1.5K
sub-frame bracing = 0.5K
Coilovers = 1K
front & rear antisway bars & mounts = 0.3K
front & rear strut tower braces 0.15K
wheels & tires = 1.5K
tune = 0.55K
added gauges & wiring = 0.2K
PCM & combination wiring to Miata = 1K & a huge PITA
after market clutch master & hydraulic lines= 0.1K
Radiator & fans = 0.4K
clutch, flywheel, slave cylinder = 0.7K
headers & exhaust = 1K
Rear brake bias control (proportioning vavle) & lines = 0.1K
Misc. = 2K
Donor Miata = 2.2K min.

Around 17.7K ish

My point about nitrous is that those of us whom have built from the ground up Miatas have found that the 400/400 mark is around the limit of a driveable car; anymore is unuseable power. There are exceptions; if you are building a dragster, then nitrous could be added after the launch to assist the run. I would only suggest using nitrous if the rear wheel wells are tubbed & you are able to mount a 295/315 tire or a similar width slick. Although, if a dragster is your prefference, there are far better platforms to build on. I mean cars w/ a much longer wheel base like an F-body or Mustang. IMO, a high powered, short wheel based, rear wheel drive car is a disaster waiting to happen on the drag strip.

Good-luck, all modified cars a cool. I hope you build it. BTW, there are a few guys in the conversion section of Miata.net who have links to their web pages containing plenty of build pics.

 

Nice build. Curious as to why you have the air filter in that location. Was there no room to bring it down in front of the motor and over to the side? Seems you're sucking in some pretty hot air in that spot.

 

There is no room or need to put the intake elsewhere. Inlet temps. are ambient. The ugly black duct running to the left front of the motor cools the intake & brings ambient air under the hood. I don't always use it & it looks like ****. Also, the heat from the headers is isolated by heat shields, not seen. There is a second un-seen duct that dumps ambient air directly into the filter (same as in the nose or wheel well area). Some would call the set-up "Hillbilly" stile, but, I opted to do this in leu of a cowl or louvered hood. When the duct on the left is removed, onlookers can't see the second duct that directs ambient air into the filter. So, the set-up looks descent.

 

I have the motor, and trans already. I purchased a 91 Miata this morning for 500 dollars. I want to build a car that will hang somewhat with my friends that have 408 T-88 cars and heads and cam nitroused camaros. From what I have seen the Miata will be the best platform for me to do what I want to do. As for computer i have the fast XFI set up that i will run.

 

Glad to hear that you've got some of the more expensive stuff @ a good price. I'm all for anyone willing go through the work of building their ultimate car. Good-luck

 

ls1450, do u have any high speed problems??? i am afraid of some front end lift off. and did you put GM brakes on??? I noticed the ZR1 wheels. And where can I find an 8.8???

 

Ford 8.8 rear differentials can be found @ just about every junk yard. The problem you'll have is machining &/or welding 7.5 CV's to work w/ the 8.8. Wheels in the pics are Rota & are only used for mild street driving. Brakes are from a C4 Corvette w/ the rears dampened w/a proportion valve. Only high speed issues you'll have is if you over power the car & lose high speed traction under acceleration. Otherwise, there are no issues. Spring rates are as important as the sub-frame bracing.

 

i would go with a 9 in 31 spline many differnent gear combos and one from a bronco will be narrow