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Old 10-23-2000, 05:26 PM   #1
slide
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Post Bored throttle body

I finally found the phone number to where i got mine done. TAD motorsports.. 847-550-8116.
About 160 bucks But HP aint cheap.
Sorry for the long wait
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Old 10-23-2000, 05:39 PM   #2
kid22
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what size did you bore it to?
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Old 10-23-2000, 09:15 PM   #3
slide
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Ooh don't quote me... but I belive it came back at 78mm. I will check and post tomorrow.
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Old 10-23-2000, 09:28 PM   #4
kid22
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wow, cool, not a bad price too
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Old 10-23-2000, 10:31 PM   #5
JaiMak
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78mm sounds like a lot, a shop affiliated with the TO club had 63mm throttle bodies, and the cylinder wall on the body looked pretty thin, I'm pretty sure you'd only be able to bore it out to about 65mm without the walls being paper thin.

Stock size I believe is 60mm.
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Old 10-24-2000, 05:58 AM   #6
Kevin Thomas
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Question

Was there a reason you overlooked the Cobb Tuning Throttle Body (http://www.cobbtuning.com/impreza/engine-throttlebody.html) even though it's about $90.00 more *not including the core charge*?

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Old 10-24-2000, 08:43 AM   #7
stimpy
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...and the results?
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Old 10-24-2000, 02:30 PM   #8
JC
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The Cobb throttle body is 64mm.
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Old 10-24-2000, 02:56 PM   #9
8Complex

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The OD of the stock throttle body is 2.75" so even if you wanted to keep a 1/8" wall, the bore could only go to 2.5" (63.5mm).

BTW, I'm fairly sure TAD sent it out to be bored... they're more of a garage with lots and lots of cool stuff in it. Some day I'll get up there and take a few pics for those who want to see EVO's and WRX's and stuff apart and all over the place. Last time I was up there we were walking along and I kicked a pallet and looked down. There sat a WRX motor in full splendor.
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Old 10-24-2000, 05:00 PM   #10
Pipercub
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The operative question is how large is the intake manifold at the point it mates to the TB? If it is larger then it makes sense to open the Tb up but if the opening is the same size as the TB is stock then it seems like you would end up with a turbulence inducing step.
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Old 10-25-2000, 01:40 AM   #11
slide
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Uh the reason the cobb unit was overlooked was that I had it done in 1996 on my 95 2.2l. I am going to get an official measurement today to post.
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Old 10-27-2000, 10:55 PM   #12
slide
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I had the manifold port matched to the throttle body by extrudehone. Sorry about the delay. I have been at work and will be untill sunday. around 11 am sunday my car will be apaart and Ill have answers.
sorry
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Old 10-27-2000, 11:23 PM   #13
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When you say that you had the intake manifold "port matched", are you just referring to the opening of the intake manifold or do you mean taking some metal out of the entire intake runners?

I was thinking of extrudehoning my intake manifold until they quoted me almost $300 for the process. ouch.
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Old 10-28-2000, 09:38 AM   #14
Necromancer
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Yeah, that's about right.

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Throttle? We don' need no steenking throttle! Pop it off and run wide open baby!
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Old 10-30-2000, 04:59 PM   #15
Buckbomb
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Sorry to butt in, but would you happen to have a ball park figure on HP gains/ Pick up? It sounds like a good deal if gains are significant.
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Old 10-30-2000, 05:06 PM   #16
slide
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All I have is abunch of g-tech stuff from a while ago. I never had any baseline tests.
My butt dyno was happy.
Ill do some more runs and plant some numbers. Remember i only have a 2.2l
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Old 10-30-2000, 07:13 PM   #17
Kevin Thomas
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Question

I'm a little confused about all of this. 8Complex says that the stock throttle body is 2.75" (69.85mm). Slide says that the diameter of the intake port on the manifold is 70mm (2.76") and that he had the throttle body 'port matched' to the intake port. This would mean he had his throttle body was ported from 69.85mm to 70mm (or 2.75" to 2.76").

Is this saying that a .01" (or .15mm) ported throttle body is a significant amount to make more horsepower or torque? Is there an faq somewhere that says how much hp/torque you can expect with each inch or mm the throttle body is ported until it's matched with the intake port?

[This message has been edited by Kevin Thomas (edited October 30, 2000).]
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Old 10-30-2000, 07:48 PM   #18
slide
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You have to remember that mine is a 95 2,2 l and whether or not that resembles your 2.5 stuff. I had to spend a couple minutes trimming the gaskets. The next time I am at a dealership, ill measure a stock one.
Maybe there is nothing you can do to the 2.5l recent TB's. But if there is... getting more air through that bottleneck can't hurt. It's just up to you on if it is cost effective for you. I liked it.
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Old 10-30-2000, 11:13 PM   #19
Aspen
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Remember when you use the butt dyno on items like lightened flywheels or underdrive pulleys or even bored throttle bodies, not to confuse increased throttle response with horsepower. I see so many people making this mistake.

It is true that increased throttle response can get you a better time at either track and can make your car faster without gaining any extra horses.

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Old 10-31-2000, 12:53 AM   #20
slide
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Oh I agree 100%, but my butt dyno is responsive to how much throttle I have to put into going up certain hills and keeping consistant speeds on my hour long commute to and from work.
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Old 10-31-2000, 01:15 AM   #21
slide
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Hey sorry for the delay.... Its 70 mm on the dot. Could probably have gone to 72mm but oh well.
Aspen port matched means the diameter of the throttle body is matched to the diameter of the intake port on the manifold. And they also rmoved material on all the runners Its like glass in there now.
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Old 10-31-2000, 01:29 AM   #22
Imprezer
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Aspen, you can be making horses without increasing the max HP. That TB can increase the HP at the lower RPMs making the the HP/torque curve fatter and improving throttle response.
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Old 11-01-2000, 01:14 AM   #23
Aspen
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yup yup on that Imprezer also. I realize that certain mods can broaden the torque/hp curve or change it at certain rpm ranges.

I was just merely stating that increased throttle response can easily be mixed up with hp.
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