Larger throttle body
 

If we run a bigger TB, can it be done with stock ECU or will you need a standalone? I've searched and found nothing on it. I'm curious as to what, if anything, needs to be done TPS wise. Basically, if you're making your own IM, you might as well run a bigger TB. What needs to happen to allow that? What works, what doesnt etc.

Are you just bolting on a big TB to a stock im? Or installing a completely custom im and also a bigger tb?

Either way I think you need some sort of engine management. Just my 2 pennies

Honestly I don't see the small increase in power being worth all the work... I'm sure you would notice a much bigger increase in power by going to a larger exhaust, one without cats/muffler etc.

I didn't even notice that he was stock. lol
If you're stock or just have bolt ons, your stock mani/tb is not even close to being a restriction

99% of the 1.6 manual cars dont use a tps. It would work but, for the gains wich would be minimal its worthless.

I wouldn't say I'm all stock. My motor is out and being torn down, head is ported and polished, doing a full valvetrain upgrade, and putting forged internals in. Then piecing together a turbo build when that's all done.


I have these brand new and never used in my shop at home.
Miller - TIG Welders - Dynasty® 350
Miller - MIG Welders - Millermatic® 350/350P

So, Just an excuse to play with toys.

So youre building youre engine, but youre ging to run a stock ECU? what are you going o do for fuel and ingition control when youre boosted?

No, I'll be running MS when boost comes along. I'm going to put miles on the motor before the turbo build goes in for 2 reasons. I'm a student, not made of money so to do the turbo part right, will take me a couple months after the motor is done. Also I don't like doing too much at once, too many things to go wrong and troubleshoot. That being said, the motor will run on a stock ECU for a short time. I want to know if putting a manifold on with a larger TB will be possible or not on stock ECU.

Unless you are going to get serious with the turbo 300+ ftlbs, I wouldnt worry about that TB..

Well in that case, why not?

As long as all the oem sensors/valves are hooked up and operational, the air going through the tb first goes through the intake/afm. All air flowing through is measured by the afm and the engine will operate normally IMHO.

I'm sure you could run well into 300hp with the stock TB. Honda guys have showed larger TBs to increase power on NA cars. Their TBs stock are about the same size as ours. It surely couldnt hurt. Like I said, this is mostly my excuse to go welder happy.

Miata doesn't equal Honda.


You're starting to sound like a guy on my local forum who just used to say "But my Honda friend's do this" or "my V-dub guy says I need to do this" and he totally ignores what Miata info was given to him.

Yah, I have some experience with hondas and they respond to mods in a completely different way. Our engines are on different ends of the power band spectrum.

Now it deffinatly would be cool if you build your own manifold with a larger TB and whatnot, and It would show gains if youre going for a pretty big power setup. But to answer youre question I think it will probably run like total crap on the stock ECU. Just wait until the MS in installed, then tune for it.

I'm not dismissing any advice given, or arguing any of it. I wouldn't ask here, if I wanted to build my car around what other cars do.

I'm only stating honda's results as they've been dyno tested with real evidence of gains.

If your running a different displacement on your motor than 1.6 your ecu will go insane i suggest you tune the megasquirt to NA(which will give you ample time to lean how to use it without tuning to much) and drive that for a month or two to break the motor in.

And we're telling you it doesn't mean anything. Bolting a Honda head onto a BP motor (if it were possible) would probably be worth 25-30whp by itself. If the TB is the restriction, then you see power gains with a larger TB. If the head sucks (and ours is about as bad as you can get), then you might not see gains. Honda gains and BMW gains and Audi gains mean pretty much nothing when you're talking about a complex system like the intake tract of a motor.

Keeping along the same lines, is there a replacement/rebuild kit for the stock TB?

I posted a thread recently where I pressure tested the intake tract and the TB shaft seals were leaking boost quite severely. No one replied with any real solution...

If you're taking the time to make an intake manifold, definitely go with a bigger throttle body. If you're keeping the stock manifold, then don't waste your time.