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Can anyone give me some good tips on gaining performance on my 89 mx5. It has a stainless steel exhaust system. Im getting headers for it. However whats better. 4-1 or 4-2-1. Whats better? And intake. Whats the best kit? Best position? Please I only want Professional tips and advice. Send me text, pics and links. The whole package. Cheers mx5 mates!

What is your budget?
What are your goals?
To be honest there are very minimal gains to be made without going to the time and expense of a built motor and programmable ECU.
That still doesn't stop many people (myself included) but it is always better to know where you want to do with your car rather than just aimlessly buy parts.

I dont want to massive increase the hp because i know it will cost big bucks. But something thats affordable, DIY Style and noticable.

MX5's are a difficult one to get power out of cheaply.

Basically, as a rule of thumb, unless you have some way of changing the tune (standalone ECU, piggyback ECU, etc) don't expect more than a couple of kw total.

So any tips on headers and intake. Because for mx5 thats like the biggest restriction

Headers I;ve heard good things about the ones made by Hurricane.
Again, don't expect a night and day difference, but maybe a mild bit more grunt.

Intake, the MX5 mania style ones are loud and sound ok, but don;t expect much power increase either.


From memory, on the NA6 the biggest restriction is the airflow meter, which you can't really fix (car wont run without it unless you have standalone ECU)
From memory you can use an RX7 AFM for a bit more flow, but again, not a huge gain.

By all means do intake and exhaust for the sound, but if you jump into them expecting a noticable power gain you'll probably be disappointed.


I'm on my 3rd intake setup for my NB and I can honestly say, sound aside, there has been minimal (if any) difference in power from all the setups (Stock - Open pod - MX5 Mania - coldside shorty)

Currently i've got a coldside shorty intake on, purely because it looks neat and I wanted a bit of intake noise since I had to remove my exhaust setup.

For an NA, without changing the computer, I think the best power/dollar ratio is to put in a pair of mild cams, from memory there's a few companies that make straight dropin cams that work with the stock ECU, from memory they quote about 10hp gain. (I think I remember seeing a dyno plot from an aussie owner, and the 10hp gain was about right in real life)

I can't remember the price.

Ok cool cheers for the tips. Ill look into it.

http://www.autospeed.com/cms/article.html?&A=110680

An ancient article,but gives some ideas.

Note, while the cowl intake works, if you park near trees you'll be cleaning it out every few weeks to get the leaves out (otherwise it clogs and becomes more restrictive than a stock system with a sh*t caked filter)

Cool thanks man

Before I started modding my NA8 it dynoed at 48rwkw. I chucked out a blocked exhaust and put in a used a 2 1/4" exhaust, 4-2-1 headers and an old but good cold air intake to take it to 66rwkw. Playing with a Jaycar digital fuel adjuster to lean out the fuel a bit got it to 77rwkw. A better exhaust and some DIY head work to fix really bad manifold/port alignment and replacing the DFA with a remapped OEM ECU got me to 84rwkw and it has run reliably like that (except for valve spring failures) for years.

It's mostly a track car and to be honest most of the gains in the car have come from seat time and fine tuning suspension and brakes. Better power feels nice but it's only a minor factor.