NA MX5 Fuel pumps.

12a MX5 · Post by **12a MX5** » Thu Jan 17, 2008 5:46 pm

As you mite have guessed by the user name, I am Doing a rotary conversion on a mx5 and was wanting to know the flow rate of a standard fuel pump to see if they are suffiecent for my rotary?

Thanks for any help.

Keith Jones · Post by **Keith Jones** » Thu Jan 17, 2008 10:31 pm

The flow rate of the standard pump might not tell you whether it will be suitable for your 12A.
The MX5 pump is a high pressure unit intended for injectors. Unless your 12A is the turbo injected model you'll have to use a separate pressure regulator to get the pressure down to the 2psi needed for the Nikki (or Weber). This regulator might drop the flow rate too much for the rotary.

Good luck with the conversion.

Keith

Post by **jif** » Thu Jan 17, 2008 10:53 pm

it flows enough for ~300hp at the standard pressure of 43psi. I'd guess that shouldn't be adversely impacted by lower pressure..?

Habanero666 · Post by **Habanero666** » Thu Jan 17, 2008 11:31 pm

I would have thought the 13b 6 port was a better option myself, I have worked with rotaries in the past and the 12a seems to produce more noise than actual get up and go.
DONT get me wrong, I am by no means being disrespectful to your project, its just that here in Palmerston north I see too many good willed customers blow lots of $$ on 12a's bridge, extend, J and p portin' brap- brap- toss and gettn 'moked by bog-standard series 5 sevs!
The 13b with 6 port has a usable torque value to work with for starters.
Injected 13b fuel pressure and flow requirements would be quite similar to that of the out put of the mx pump. MX pumps from Bosch are rated at 4 bar and around 190 lph and are almost identical... save the shape to fit in the tank with that of an fc sev.

12a injection with a touch over 7 degrees overlap and v'd inlet ports mmmmm...
Drrrrrrrrrrr! not brapitty brap brap! now thats smoooooth!

I recall Alan Moffat had some awesome battles with Peter Brock in an injected12a sev back in the 80's......pretty good considering Brock was in an XU1 torana!!

Anyway good luck and it will be awesome to hear your success story soon!

SLYDIT · Post by **SLYDIT** » Fri Jan 18, 2008 6:56 am

ring Don at autoway services..he has put a rotary into his MX5 he should be able to tell you how he hooked it all up

12a MX5 · Post by **12a MX5** » Fri Jan 18, 2008 6:29 pm

Yes a 13b would have been a better choice to go with But the project started with the engine THEN the choice of car to put it in. Im still workin out the kinks as I go. I wasnt really after a speed racer just a nice rotary crusier that could out handle any s1 rx7, have a drop top and no rust!! But I could go 13b later on if I an not happy with the 12a.

Thanks for any input

Psycho_Dad · Post by **Psycho_Dad** » Sat Jan 19, 2008 11:53 am

well i have a series 7 13b with 60000 kms on the clock and a 12a front housing so shell drop right in if youd be interested

PEace
Psycho_Dad

Habanero666 · Post by **Habanero666** » Sat Jan 19, 2008 5:57 pm

Psycho_Dad wrote:well i have a series 7 13b with 60000 kms on the clock and a 12a front housing so shell drop right in if youd be interested

Whooo hooo what an upgrade that would make to an mx7... I mean mx5!!

Go on- into it!! 12a mx5, sounds like your heart is in the right place! I absolutely agree with you, a nice rotary transplant into the right vehicle will give you lots of grin strecthing driving. Besides there is always time to tweek things up later on

MN · Post by MN » Sat Jan 19, 2008 8:54 pm

Wandering a bit off topic but there was a rotary MX5 and a V8 MX5 at a MR2 Taupo track day early last year. Both were very very nice, especially the sound!

Habanero666 · Post by **Habanero666** » Sat Jan 19, 2008 9:25 pm

MN wrote:Wandering a bit off topic but there was a rotary MX5 and a V8 MX5 at a MR2 Taupo track day early last year. Both were very very nice, especially the sound!

You know that sound......alright!

12a MX5 · Post by **12a MX5** » Sun Jan 20, 2008 9:41 am

Oh while were all here.... Does any one have a manual steering rack for sale or to sawp for my power steer item? I have no need for a power steering in my project and it also gets in the way of a few things.

SLYDIT · Post by **SLYDIT** » Sun Jan 20, 2008 9:58 am

you can convert the power rack to manual fairly easily..the power rack has less turns lock to lock than the manual rack for a bit more direct feel..i'll try and dig up the article on how to de power the rack for you.

The mx5 pump will have plenty of flow for your rotary youll just need to hook up a low pressure regulator to the line then into the carb...there are PLENTY of after market low pressure regs about form the usual V8 parts places.

Post by **jif** » Sun Jan 20, 2008 10:44 am

as Glenn said, the PS rack is quicker than a manual one. :]

http://www.flyinmiata.com/tech/depower.php

12a MX5 · Post by **12a MX5** » Mon Jan 21, 2008 5:57 pm

Very help full. thank you

NA MX5 Fuel pumps.

NA MX5 Fuel pumps.

NA MX5 Fuel pumps.

NA MX5 Fuel pumps.

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