Where is the Section for NA ITB Tuning

Hi Folks,

Do any members have ITB set up on their car.

Is it time to have a new subsection for NA Information.

I have had MP62 charged Mx5 in the past.

I am now building ITB Eunos Roadster for fast road and Hillclimbs. I want the throttle response and about 180 BHP.

ITB? Translation please.

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Individual Throttle Bodies made by Jenvey and others.

Not that common a mod in the UK - try looking up Miata ITB and you will get to some useful threads on the Miata.net forum.

I guess you are asking for somebody to add information for your use?

Jenvey Throttle Body Kit as now fitted to my 1989 1600. Running Megasquirt ECU tuned at Bailey Performance.




Possible ‘pain in the derrier’ I suspect.

Hi, For anyone following this.

I have now found a Map For ITB which I have downloaded into my ME221 Ecu and the car now starts very well both cold and hot.

I have to open the throttle a little bit on starting cold.

Tickover is not lumpy at 1100 RPM which is pretty good with Piper 285 cams / 60 Thou head skim and a few other Mods.

As this is a slowtime build do not expect power figures for a while as the car is still a way off being finished.


HI DickieRltd

Can you tell me where i can get this map from. As i have an itb set up on a 1.6 na which i need to get going as the base map is no good.(y)



Hi Folks,
Update on my ITB Mk1 Eunos. Its locked down at the rolling road due to the Virus.
They have told me its 172 BHP so its at my target power area, It will have less torque than a blown car but more response.
It still needs an MOT and registration number.
The Rolling Road will be back in operation first week of June.

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Hi Folks,
My ITB Eunos has been released from prison early. I can get it back this week, I will have to book it in for its first ever MOT Then I can legally drive it from the rolling road to the MOT testing station.
I am making a cold feed airbox with remote filter for it at the moment to replace the pipercross foam sausage filter currently fitted,
The new arrangement should quieten down the induction roar and keep the inlet air temp down a bit.

Hi Folks,
I finally got to drive the car to the MOT Test, unfortunately it is close to home so I did not get out of the 30 mph speed zone.
On the positive side the car drove well, and the brakes pulled up in a straight line, the engine is very responsive once its over 2500 rpm.
The car now has its first ever MOT at 26 years old, its been in the UK for nine years and been stripped down and re built in this time. ( The Tester described it as a Minter )
I will now have to wait for DVLA to give it a V5 before I can drive it. ( Hopefully early July )


Any update on the road experience? I am keen to know more. :grinning:

Hi Enjoyabull,
As this car is an unregistered import I can not drive it until the DVLA have sorted out all the documents and issued the V5. I have asked for the Tax to start on July 1st.
I suspect that I will be in for a long wait due to the Covid 19 thing.
I will have had the car insured for four months or more before I can legally drive it.
There are still a few finishing of jobs to keep me amused. I am making up an airbox witha cold air feed for the throttle bodies so that I can dispense with the foam filter and hopefully make it a bit quieter when I give it some !!!

I can understand your excitement and can’t wait to hear more from you about this conversion.

For anyone following this I now have a fully road legal car, The DVLA came through with all the paperwork, I have not driven the car yet. I have only just had four new Michelin Pilot Sports fitted to its wheels today, I have had the car stood on some old tyres on slave wheels while it has been worked on.
The cold airbox and inlet duct with filter is now in place taking cold air from the vented lamp cover and turn signal indicator air vent, the exhaust manifold has been wrapped painted then a heat blanket fitted as well which will help keep the air filter cool.
I am looking forward to having a drive to settle things in at the weekend.
The rolling road tuning went through 3/4 of a tank of fuel !!!
It will be interesting to compare the 169 BHP with the 130 BHP car.
I have an airfield sprint lined up in a couple of weeks so I should be able to give it a good exercise.

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That sounds amazing, Do you have a picture of your air box solution? Will you be at Gaydon with the car?

Hi iam trying to fit a supercharger to my na can anyone let me know if I need a wideband sencor and if yes which type or will any lamba wideband sencor do
Anyone know and what ecu module can I get

I have made a grp airbox which feeds air over my throttle cable set up a flexible tube crosses in front of the engine, the filter box sits just behind the power steering reservoir with an silicone elbow to collect cool air from the vented headlamp cover and vented turn signal indicator duct.
I will try and post a picture of it.
At the moment I am running with the Pipercross foam filter, It is civilised at small throttle openings and in traffic, If you nail it it becomes very LOUD !!!. ( Over 100 Decibels inside the car according to my Lidl noise meter )
I can do a swap to the remote filter box in 15 to 20 Mins.
I will use the quiet filter for normal use and the foam noise maker for sprints and hillclimbs,
They only noise test the exhaust which is nice and civilised for a straight through system.
I will not be going to Gaydon as I have been to the last two events there.
Thank you for your continued interest.

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Hi Nicknock,
You will need a wideband sensor and controller.
There are various options as far as ECUs go, the best way forward is to find your local rolling road that tunes competition cars and ask which unit is the best for him to set up and tune.
Piggy back ECU boxs used to be common but they are not as good as a full plug and play replacement. Megasquirt is popular and you can self build them or buy ready to use,The ME221 is another option Omex is more popular with competition cars.
Have a look at other Mx5 forums in the UK and USA and do a bit more reasearch before you jump in.


Thanks for that
Are all wideband sencor the same ,
Thread size and number of wires,
I am well into the build but it’s all DIY