Boring out the throttle body on a 7th gen.

[Galanttuner]

Has anyone here done this on their 7th gen??

I *think* that our stock Tb is 54mm...correct?

Should I have it bored out to 60mm or more?I don't want to swap my tb to a 1g clip, but would rather keep my stock one and bore it. Or would it be more beneficial to just get the 1g one? How much do you think that boring the galant tb costs and how much downtime?

I had this done on my prelude a while back, but mitsus are so much different than hondas.
Please help me guys or point me in the direction of someone who knows.
Thanks.

[pinoyesv6]

pro flow design has bored out 2g eclipse TB's both the NA and Turbo versions. you might wanna see if they can do ur galant's tb. it runs about 140 for the boring and like 150 core charge. and u get that core charge back when u return the core. http://www.proflowdesign.com/throttlebodies.html

[JiP]

Why dont you just swap to 60mm tb and save yourself a shitload of cash. Check my website.

You can port that one to like 64mm if you really into porting things.

Rob

[seth98esT]

stock is 52mm, so ive been told...

[Galanttuner]

How far can you bore the galant tb SAFELY?
Probably like 63 or 64mm right?

I need more air flow desperately. JIP, did you notice a larger gain in throttle response or through the powerband?

[JiP]

Ye there is a lil more "umph" in the throttle. If you go to my website you can actually see the graphs from my datalogger there is a lot more air being sucked in.

But why would you bother porting to 64mm for 150 bucks when you couldjust buy a 64MM off ebay or junkyard for 30 bucks and slap it on.

Also don't theink the stock galant TB could be ported as high as 64mm before you hit the air and coolant passeges. But I dont know for sure.

[Kain]

<div class='quotetop'>QUOTE(Galanttuner)</div><div class='quotemain'>How far can you bore the galant tb SAFELY?
Probably like 63 or 64mm right?</div>

Well, looking at the stocker...I'd have to say maybe 56mm? There's too many vaccum ports on the back side to go much bigger. Your best bet is to get a '93 2.0L N/T Eclipse throttle body, and use that. It's already 60 mm, it can be bored out probably another 6mm if you were really obsessed, but you probably won't need it. The TB is not the Achillies heal of the '64 head, it's the intake manifold that's the problem. It's just plain tiny down on the runner end.

[JiP]

Omg KAIN, seriously. The intake manifold runners are horrible. If your seriously looking for performance yet staying naturally aspirated heres a few suggestions:

cai
60mm tb
sheet metal intake from rpw (i think) and ported head
oversized valves
upgraded exhuast system, header- piping
get rid of ur air conditioning system gets some ponies and drops weight

best bet is to do the DOHC headswap, youll get nice big intake and another 20hp

cant think of anything else rightnow...could always add nos for quick hp.

[Galanttuner]

Does anyone offer aftermarket intake manifolds for our cars?? Or is our only choice to take it to a machine shop?

[JiP]

<div class='quotetop'>QUOTE(Galanttuner)</div><div class='quotemain'>Does anyone offer aftermarket intake manifolds for our cars?? Or is our only choice to take it to a machine shop?</div>

Like I said above, I think RPW makes a sheet metal intake but you still have to get your head ported to match the new larger intakes.

[spyderdude24]

Expensive possible option:

You may be able to bolt on a BBK 2G Turbo throttle body (have these at SUmmit) that is already 62mm. According to my manual, we have the same IAC as the 2G turbo's- but not positive.. You would then need to add a TB elbow (Road Race has a nice one). I may go this route with my Spyder, but not sure since I have a 92 1G 60mm TB in my garage too.
Unfortunately, the 1G uses the ISC and you have to do some tweaking to get this to work. Anyway, I would definately have the intake ported to match whatever route you choose.

[JiP]

I am not to sure about the 2g Turbo TB having the same IAC. But that would be another way to go if you want to spend the cash. You should also realize that the opening on the intake manifold is only 63mm. Wich means using a 64mm TB, you'll have to port the opening of the intake larger so that the plate can swing open, as well as have the openings for the vaccume ports. The 60mm tb itself just makes it.

Also if you gonna grab a 1g TB, another member Kain brought to my attention that there are different types that were produced. Some ofthe 1g NA models have the IAC casted with the TB, so its impossible to remove it to swap with your 4g64 one. Other then that TB is only like 30 bucks used and the swap takes, (after some rtv dries), less then 20 minutes.

[spyderdude24]

Rob,
any concern with leaks since only 3 of the 5 screws on one side holding the 2G IAC to the 1G TB? :shock: I've already got a 92 TB that I got for $50, but
I may get the BBK TB just to see if it works. If it doesn't, then I'll send it
back. If it works, then it should be a nice improvement with a port matched intake..

[JiP]

Well so far its been about 2 months no leaks no problems. You have to make sure you plug that extra hole, just some simple rtv shot down the shaft of the hole will hold. The rest of the IAC is tight enough and has a lil gasket in there that the seal is good so nothing leaks out the side, lil rtv on the mating surfaces is a good idea also.

I mean if you got the cash and you dont want to worry about things go with BBK but you may have to get the intake opening widened a little bit for 64mm.

[spyderdude24]

thanks Rob for the insight and paving the way for us 4G64 guys to
swap with a 1G TB. I will try the BBK just to see if it is a perfect fit on our
IAC. If interested, I'll post my results. If it doesn't, I'll be using your instructions to install my 1G TB! 8)

[JiP]

Defintly post the results, or atleast PM me with them cause im interested

Out of curiosity how much is the BBK?

[g96nt]

to be honest.. guys.. you *REALLY* need to think about getting a custom intake manifold...

have you ever seen the intake runners of the 4g64 intake!?

it's the size of your Thumb..(well... it was the Size of mine..)

doesn't Really matter HOW much of a throttle body you get on This thing... if you can't suck the air through the intake planum.. it's worthless....(and you lose a ton of low-end)

[JiP]

I didnt lose any low end at all. You are correct about the runners sucking balls, but the larger TB still lets more air flow faster. My datalogger never lies to me! :laughing:

Well hopfully i'll figure out this ignition bs and I'll be DOHC with nice big 1g runners

[spyderdude24]

Rob,
they want about $250-300 for the 62mm BBK TB. Not that bad if you look at what they want for a mildly ported TB for $250-$300 to only 58mm. May be able to find it cheaper if you search. If it just bolts on, I'm throwing on a 1G HKS elbow and dremelling it out to match. Dude, I wish I could swap on a 1G intake but unless I go DOHC that probably won't be a reality. :cry:

[JiP]

Screw bbk extra 2mm gonna cost 300 bucks. Use your 1g 60mm put the other money into getting a new intake and head ported.

My elbow is a tomato soup can.