Another M20 throttle body upgrade

[davvik]

Hey r3v, I spoke with someone near where I live about his E30's and he gave me a tip but wasn't very clear on it. I see lots of guys fitting bored out throttle bodies on the M20's but I'm looking for a different option. The idea of boring out a throttle body doesn't seem like a good option for me. The big downsides are the thin walls and the current health of the great Canadian Peso. Having someone bore it out for me is a pretty penny.

So this guy I spoke with, who I can't seem to find again, told me that certain Ford V8 throttle bodies will bolt up to the M20 manifolds and you just have to bore the manifold the match. I have been meaning to drop by a wrecker and pick one up but I don't know what model to ask for.

The guy didn't tell me and when I brought my throttle body to a nearby wrecker and asked to see some throttle bodies he didn't want to waste his time helping me. So I don't really have a way to figure out which throttle body will actually bolt up.

Let me know if you guys have this info or any ideas for other throttle body upgrades.

Thanks

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[dnguyen1963]

Why? You are not gaining much in term of performance.

[digger]

i dont think a BBTB is worth much, when i did a BBTB i noticed a difference in throttle response but that's all.

when you think about a 5" long round tube 60mm diameter isnt a restriction compared to other things so its going to have a pretty small effect. id save money and time for something else

[davvik]

Why? You are not gaining much in term of performance.

It's not about performance, it's about throttle response. Also it will make a bigger difference when I build an engine and swap this throttle body over

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[davvik]

Thanks for the replies but the question wasn't about if it will make a difference, the question which one will fit

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[Kershaw]

In terms of throttle response, switching to megasquirt was a crazy difference. No more lag where the engine seems to dip or suck in air and then the rpms climb. It's instantaneous.

I would look into that.

[davvik]

In terms of throttle response, switching to megasquirt was a crazy difference. No more lag where the engine seems to dip or suck in air and then the rpms climb. It's instantaneous.

I would look into that.

A standalone ECU is what I plan when I build another engine to put in here. For the M20 I have in there right now I'm just playing with it. It's mostly about learning to tune engines and learning what types of things make good improvements. Money is not the issue. I have cheap rent, cheap insurance, both my girlfriend and I make enough to live on no problem so I have plenty of funds to put into my car.

Also, that lag you describe sounds like a bad throttle position sensor. My car used to do that, it kind of would gasp for air if you hit the throttle.

When your TPS is bad, your ECU doesn't know that you just stomped on the gas so it doesn't know that it needs more fuel at that moment in time.

[Kershaw]

Lol. No. I have tested at least a half dozen oem TPS' in my e30. That's just a symptom of an AFM. All stock e30s do this.

Good luck ignoring everyone's advice.

[digger]

A standalone ECU is what I plan when I build another engine to put in here. For the M20 I have in there right now I'm just playing with it. It's mostly about learning to tune engines and learning what types of things make good improvements. Money is not the issue. I have cheap rent, cheap insurance, both my girlfriend and I make enough to live on no problem so I have plenty of funds to put into my car.

Also, that lag you describe sounds like a bad throttle position sensor. My car used to do that, it kind of would gasp for air if you hit the throttle.

When your TPS is bad, your ECU doesn't know that you just stomped on the gas so it doesn't know that it needs more fuel at that moment in time.

stock m20 has throttle switch TS so you're either idling, part throttle or WOT it doesnt sense rate of change of throttle etc the only way the ECU knows you have stapped the throttle is when the "air signal" gets to the barn door thats why you need a standalone with a true TPS there is less "lag". making the throttle too big just makes the engine be effectively at WOT (100kpa manifoild pressure) at a lower throttle % so you lose resolution

[davvik]

stock m20 has throttle switch TS so you're either idling, part throttle or WOT it doesnt sense rate of change of throttle etc the only way the ECU knows you have stapped the throttle is when the "air signal" gets to the barn door thats why you need a standalone with a true TPS there is less "lag". making the throttle too big just makes the engine be effectively at WOT (100lpa manifoild pressure) at a lower throttle % so you lose resolution

I know the TPS is only 2 switches on the M20 but I believe the ETA engines never actually get the barn door to open all the way. The AFM is the same part as the M30 engine I believe.

When I was saying "stomp the throttle" I meant going from idle to not partial or idle to full. That's when you'll experience the lag. Not 25% to 75% throttle.

However, you do bring up a good point. I can't debate it one way or the other because I don't know enough about it. I'd have to do more research.

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[digger]

I know the TPS is only 2 switches on the M20 but I believe the ETA engines never actually get the barn door to open all the way. The AFM is the same part as the M30 engine I believe.

When I was saying "stomp the throttle" I meant going from idle to not partial or idle to full. That's when you'll experience the lag. Not 25% to 75% throttle.

However, you do bring up a good point. I can't debate it one way or the other because I don't know enough about it. I'd have to do more research.

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people "up grade" to the m30 AFM as its bigger, and bigger must be better.... ;)

there is more lag anytime you move the throttle as there isnt a proper way to to have acceleration enrichment with the stock motronic

[davvik]

I found a thread a while ago on r3v where someone debunked the M30 AFM "upgrade"

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[digger]

I found a thread a while ago on r3v where someone debunked the M30 AFM "upgrade"

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i've been here a while and not seen anything debunked but i think any gains are small and outdone by the need to "retune" so it runs as well as a proper tune.

custom tune on bone stock engine runs better than half A$$ed m30 AFM swap, tried that a decade or so ago.

[davvik]

It may not have been on r3v. Alcohol is a large portion of my life.

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[TobyB]

Alcohol is a large portion of my life.

Admission is the first step towards... the liquor cabinet.

You need what we call pull-a-parts, where you go crawl around
someone else's disgusting, unmaintained failure of a vehicle
in the vain hope of finding 'upgrade' parts...

That's where I find most of my unrealized horsepower. And friends, recently...

t