elesjuan

iTrader: (11)

I have a local friend who just bought a 96 Miata and wants more power. First he was all about building a DIY turbo setup -- He can weld pretty well and has a ton of metal working tools at his disposal. After talking to him for a while it was decided he'd probably be better off with a monster kit and a 5.0... Now hes obsessed with how much a v8 would affect the weight bal and handeling of the car, even though I've assured him, even found results of FTD's set in auto-x with 5.0/LSx powered miatas.. Hes still not convinced.


Basically what I need help with is trying to talk him out of "building" a 1.8 N/A motor. No matter what I tell him or what links I send him he seems to think he bought another Honda or something. I've yet to find an N/A build that even hit 200whp but he seems really convinced a high comp motor with a ported head, ported intake, cai, header, and good flowing exhaust will get him more than enough power.

Other thing he seems fixated on, if he was to do a swap is use the KL-ZE motor from 626/Probe then turbo it later.. Granted those have a _LOT_ Of potential, it seems if hes going to go through the hassle of a foreign motor swap (foreign to the miata chassis) its really stupid not to just use a damn V8..

Ideas? Help? Or should I just let him fail?

18psi

iTrader: (76)

Let him build his n/a 1.8 and be disappointed. If you've provided all the info/arguments detailing how inferior his plan is to whats available for him If he's still dead set on having 150ish whp with no torque let him fail.

I love my close friends to death and help them any way I could, but sometimes you have to let em learn from their own mistakes. If they're that dead set on making them.
Just my .02

gaius49

It depends on how much effort he is willing to put into his N/A build. With rods, high comp pistons, porting, relieving, IRTBs, more aggressive cams, new bearings, stronger oil and water pumps, ATI damper, no A/C or P/S, oversize valves, solid lifters, 4-1 Header, free flow cat, properly sized cat back. It might be possible to make 200whp out of an N/A 1.8, if it spins north of 8 grand...

But yes, it seems like he is bound for trouble with such a build. What does he want to do with the car? top end speed, throttle response, wide power band...

SKMetalworks

iTrader: (7)

Fully built car for all that costs like what. 8 grand? atleast.

Turbo kit there was a deal last week 600$ for turbo mani DP and external WG. All you would need is intercooler lines and intake piping. And of course some way of controlling fuel. But thats a 1000-1400 build for 200rwhp. After being on these forums i figured that N/A is definetly not the way to go with these "bulletproof" engines. I hope you slap him once he says at the dyno, " 172 rwhp wtf i just dropped 9 grand " Then you get on the dyno and its like BAZAAM 250. and you tell him the number of moneys you spent and hell himself to death

gaius49

Yeah, cost per hp clearly favors FI, no question about it. But if your friend really wants to go N/A it can be done, for an arm a leg and a first born... Not exactly worth it for any but the most insane N/A fanatics. And it won't go as fast as a cheap turbo set up.

I spec'ed out such a build one time, all said and done, with clutch, flywheel, timing belt, valve springs, adjustable cam gears... it came to around 12-15 depending on just how far out you're willing to go.

18psi

iTrader: (76)

If he really wants to stay n/a and make decent power I think swapping in a f20 or 22 from an s2000 would be easier/cheaper. At least then he'll have some high rpm and a well flowing head/valvetrain. Miata motors are just not made to be great n/a motors.

fmowry

iTrader: (8)

The biggest costs of a swap are everything else. If he uses a KL-ZE, what's he going to use for a trans? Being a good welder and being good at fabricating a K-member, modifying an oil pan, fabbing up motor mounts and a trans diff are two different things. Not to mention dealing with an ECU and wiring after the fact. But if he can do the fab work for everything and can get a good deal on his engine/trans/wiring/ECU combo, then his power goals should be the determining factor.

An LSX swap is less than 200 lbs more than a stroked turbo according to FM's scale:

Flyin' Miata : Projects: The V8 Miata Project
Flyin' Miata : Projects: The V8 Miata Project

Check out FMs comments under the weight pics.

Frank