ITB setup

red devil · Postby **red devil** » Fri Jul 16, 2010 7:19 pm

Hi all just wondering if anyone has dealt with or come across any info on the installation of ITB's on an mx5. I have found a set of 4age throttle bodies and a conversion plate, my major issue with the install is the throttle position sensor. I have no idea as to how to wire the new TB's up :cry:

am i able to simply install a corolla TPS? or am i able to use the original mx5 TPS without any modifications?

any help would be really appreciated

Postby **mx52nv** » Fri Jul 16, 2010 8:32 pm

To the OP,
Use the search function - it truly is your friend. :mrgreen:

Here are Si.G's threads on his AE101 ITB set up on his NA6 using a MSPNP.
1) Si.G's NA6 Build Thread
2) ITBs - Not Enough Vacum Thread

Hope this helps.
Les

clubman7 · Postby **clubman7** » Fri Jul 16, 2010 11:42 pm

Had fitted the Mazda TPS onto the 4AGE throttle bodies.
Tuner had trouble getting decent signal tune in low rpm as the Mazda TPS is not a variable type like the original Toyota.
Ended up refitting Toyota TPS to make it easier to tune.

Si.G · Postby **Si.G** » Sat Jul 17, 2010 12:56 am

clubman7 wrote:Had fitted the Mazda TPS onto the 4AGE throttle bodies.
Tuner had trouble getting decent signal tune in low rpm as the Mazda TPS is not a variable type like the original Toyota.
Ended up refitting Toyota TPS to make it easier to tune.

What ECU are you running? The toyota tps has 4 pins but you don't need to use them all, only 3. The outer pins are +ve and ground for the feed from the ecu (5 volts) and one of the inner pins is the signal. Best way to tell which is the signal, is to get multi meter and measure the resistance between the +ve and each inner pin and see what happens when you move the throttle plates. If you are hooked up to the signal pin, the resistance will change in a consistant way as you move the throttle. If you get no resistance or change, you might be using the ground outer pin, so try the other outer pin - if that makes sense.

There are plenty of wiring diagrams out there for the toyota.

The Mazda connector is basically feed, ground and signal, I am not sure which pins are what on the mazda connector yet because I have to do some wiring in my Megasquirt PNP to hook up the feed and signal to the loom.

I will be going to TPS real soon - keep tabs on my garage (link above) and I will document my progress and any issues.

Si

clubman7 · Postby **clubman7** » Sat Jul 17, 2010 9:58 am

Have a Microtech MT8 but tuner is having diffulculties tuning low rpm due to lack of computer power.
Going to Autronic SMC now for better control.

red devil · Postby **red devil** » Sat Jul 17, 2010 11:01 am

thanks for all the comments guys, thought id ask before i went ahead and started pulling my car apart

clubman7 how much is the Autronic SMC costing you if you dont mind me asking? i might even head on down to mx5mania and have a chat with those guys as their green car is running ITB's, too much knowledge is never a bad thing :wink:

clubman7 · Postby **clubman7** » Sat Jul 17, 2010 5:25 pm

Got one off Ebay yesterday for $720, but still needs programming ($300-$400) and wiring in (Do it myself).
They look to be $2500-$2700 new.
Was going to go Microtech LT10S but thought this one may of been better.

red devil · Postby **red devil** » Sat Jul 17, 2010 8:30 pm

also am i going to need to run an uprated fuel pump? or will the pump i have in the car be sufficient as im not going to increasing power output tremendously nor am i putting bigger cams in (for now)?

clubman7 · Postby **clubman7** » Sat Jul 17, 2010 9:33 pm

No expert on fuel pumps , but would of thought there would be enough there to keep pressure at WOT.
Guess you would have check fuel pressure while tuning on the dyno.

Jeo · Postby **Jeo** » Sat Jul 17, 2010 10:33 pm

I doubt ITB's alone would need increased fuel pressure.

Si.G · Postby **Si.G** » Sun Jul 18, 2010 8:38 pm

FYI - I picked up my MegaSquirt PNP second hand from the states for $500 delivered and that was when the exchange rate was not so good.

One thing with the MS PNP - there are two types for the NA6, one has TPS wired up and one does not. If you end up with one with out TPS, it is not a problem, you just have to remove two resistors and add two wires. The instructions are on the web site. The current MS PNP is either MAP (Manifold Air Pressure) or TPS (Throttle Position Sensor) against RPM for mapping - however the new Megasquirt 3 has be ability to use MAP and TPS, not sure if there is PNP version yet.

Basically, as the name suggests, you just remove the stock ECU, plug in the MS PNP, hook up vacuum to the on board MAP sensor, load up the base map and the car starts. It is really that simple. Obviously getting it all set up and mapped is a bit more involved, but there is good support and if you are prepared to do the reading you can take on the learning challenge. I know there are better ECUs out there, but I have had no issues at all with mine. I don't use my car as a daily driver, but when I am going to and from events, it works really well.

NOTE - I would recommend getting a wide bank o2 sensor - the innovate motorsport one is popular and is what I have. Getting a gauge for inside the car is a good idea, just so you can keep an eye on things!

I guess this post would not be complete without the normal warning - As with any programable ECU, just remember it is quite easy to break of your engine if you get things wrong.

FYI - I am running a stock fuel pump, stock fuel rail, regulator and injectors. I am not having any issues and the duty cycle on the injectors is less than 80%, so still safe. I expect I will have to go to bigger injectors if/when I get cams etc.

Si.