Throttle body porting
 

I'm sure I have seen references on the forum to throttle body porting but I cannot find them again with the search.

Was I imagining it?

Have people done much in the way of porting the throttle body? Obviously there is a bit that can be done to clean up the flow through the standard one but I was thinking of enlarging the diameter and putting a larger butterfly in aswell as slimming the shaft.

Has anyone tried this before? If so how much can you take out before hitting any major channels (either air or water)?

Maybe I'm off to a bad start with this one, I'm also fairly sure that I have heard that the edge of the butterfly has a synthetic coating on it to seal perfectly on closed throttle and people who have fucked with it get terrible idles.

How much of this is fact and how much did I dream up while pissed?

If porting is not worth it with the standard TB what have people done in the way of swaps for larger TB. I was thinking of going for a ITB setup from a bike but its a bit JDM fanboi for me.

Thanks

I ported mine. The main thing was removing material on the shaft so more airflow can pass through, and i got rid of the lip just before the butterfly valve, then simply trying to port it out.

http://www.boostedmiata.com/projects..._notported.jpg

http://www.boostedmiata.com/projects..._ported004.jpg

http://www.boostedmiata.com/projects...ed_compare.jpg

I have a ported and polished TB from a Protege with a enlarged butterfly laying around somewhere. I think it will work on a NA Miata, but I am not 100% sure. I can get some pics and post, so you NA guys can take a look at it, if you are interested?

Torkel,

Yes please, all input greatly appreciated. Now what was that expression......errr.....

Pics or BAN!!!! :fawk:

Brain,

Thanks for the pics man, is there anything you havn't tried on a miata. Was I right in thinking there is a synthetic seal around the butterfly? If so how careful do I have to be around it?

Also I tried to PM you about ordering a MS harness, did you get it or is my post count too low to send PMs?


I was having another think about the ITB option. As I understand it, on our engines only one cylinders inlet valves are open at a time so each cylinder can breath through the stock 50mm TB. Most of the ITB setups have seen are made using bike TBs and most bike TBs are usually about 38-40mm I think (to get big ones I think you have to get the 45mm TBs off a ZX12) So while the ITB crowd are :jerkit: over their throttle response are they not restricting the overall airflow to each cylinder?

plenty! I didn't touch any material on the butterfly itself on the edge it seals against.
i probably got it, i tend to ignore a lot of the MS request. I'm not smart to simply copy and paste my typical I'm not building anythign anymore response.

Cool. Now I know. I really need some form of harness, actually I only need the 64pin male plug as I am going standalone. I cannot find a supplier in the UK who can get me the plug and onlinecomps want $100 minimum order for non US orders!!

Anyone have a 64 pin male plug that they might spare for a MS noob stuck in the United Kingdom of expensive and unavailable parts?

I never thought I would threadjack myself..ho hum :p

your ECU has a one in it :)

Yipes :eek5: butcher my poor little eunos' brain!! Last resort but you gotta do what you gotta do. My aim with this car is to make all of my mods reversible so that I can put her back to stock for sale time.

Maybe ebay will yield a spare ECU

My offer still stands though, if anyone has a plug lying around taking up space then I will take it off their hands free of charge!

Paul has done this and has a write up on his site on how he did it.

Before:
http://www.miatamx5.com/engine_rebui..._pics/tb_1.jpg

After:
http://www.miatamx5.com/engine_rebui..._pics/tb_4.jpg

and the link to the website is here: http://www.miatamx5.com/engine_rebuild/tb_a.html

Thanks for the replys guys, I will have a go at smoothing my TB for now and if I can find a spare TB then I will have a go at putting a larger butterfly in there.

Any one have any input on my ITB hypothesis^??

Not that its worth the money but I have seen dyno of ITB and exhaust and results of 170 odd whp.

I have seen ITB results of 105rwhp.

http://forum.miata.net/vb/attachment...chmentid=59310


stock everything, MSPNP.

So in that last example ITBs actually reduced power output or if its a 1.6 did very little to improve it. Interesting.

I suppose that could come down to the ITB throttle size issue. Bike TBs vs proper car ITBs eg Fuji or Jenvy.

I also expect that the 170 was largely due to a shit load of other mods. Hell if I thought I could get a 170whp car simply by bolting some ITBs onto it I'd be there like stink on cheese!!

How big do you reccon the diameter of the ITB has to be before it starts to actually offer some benefit?

i believe that car preivously dynoed at 97rwhp or something. I blame all the gains on the MSPNP and the spark table.

I got an extra TB...
 

Finally got those pics of the TB I promised. This is from a protege, but I do not know year or history. A buddy told me it would fit an early Miata. Can you guys confirm that? It is ported and has a larger butterfly installed. Diameter at the butterfly is 57mm.

Thanks Torkel,

Yep looks like it would fit a 1.6 NA. Im just guessing from the dashpot, I hava a 1.8 :P

And I'm guessing that blue shit is some sort of sillicone rubber paste to replace the seal from the edge of the original butterfly?

send it to me and ill find out for you :) non tps shaft ftl.

:doh:

I think he used the blue shit to check the contact between the butterfly and the TB. But I am not sure. Could be a sealant too. I got the TB from a buddy who moved and cleaned out his garage. He got it from a friend... and so on.