ITR Throttle
Still here... sorta...
Joined: Sep 2000
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From: CO
The throttle cable connections are completely different, I know that for sure. The GSR cable comes around the passenger's side of the TB, while the ITR TB shares the same design as the B16s where the cable comes from the driver's side accross the runners into the TB.
You might be able to use the sprocket off of the GSR TB to get it to work though.
You might be able to use the sprocket off of the GSR TB to get it to work though.
Wannabe yuppie
Joined: Dec 2000
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From: Madison, WI
There's no real significance to the 2 mm difference in diameter. It's the kind of incremental change that an OEM makes when trying to find the most "balanced" way to add power. Honda does't have to start with a GSR throttle and replace it with an ITR one, they just equip the ITR with a different throttle from the start.
If you want to upgrade the throttle on a GSR you're going to have to buy an entire replacement unit so you might as well get something with a wider throat, say around 70 mm. Erick's Racing makes a really nice 70 mm piece.
But really, the throttle is not much of a restriction and I can think of a whole lot of other things I'd bother to replace first.
If you want to upgrade the throttle on a GSR you're going to have to buy an entire replacement unit so you might as well get something with a wider throat, say around 70 mm. Erick's Racing makes a really nice 70 mm piece.
But really, the throttle is not much of a restriction and I can think of a whole lot of other things I'd bother to replace first.
Thread Starter
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Joined: Feb 2004
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Would you kindly share me your thoughts on what to do first...i was leaning towards changing the JDM GSR head to JDM ITR or change the cams to CTR or JUN III plus a cam pulley...any advice here...my block is a B20B P&P, Manifold P&P, main pulley Aluminium, valve springs Type R, lighten flywheel, LSD, Racing clutch, 4.40 tranny...thanks...
Future Jedi
Joined: Feb 2004
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From: Coruscant, Galactic Republic
Originally Posted by Avictar
Would you kindly share me your thoughts on what to do first...i was leaning towards changing the JDM GSR head to JDM ITR or change the cams to CTR or JUN III plus a cam pulley...any advice here...my block is a B20B P&P, Manifold P&P, main pulley Aluminium, valve springs Type R, lighten flywheel, LSD, Racing clutch, 4.40 tranny...thanks...
Wannabe yuppie
Joined: Dec 2000
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From: Madison, WI
No point really in switching heads. The ITR head is essentially a B16A head with a minor port/polish job done to it and of course the assorted valvetrain upgrades.
The hottest cams I've sen are the JUN III, or copies thereof (for example skunk2 Stage 2). I'd go with those cams, but you'll need stiffer valvesprings than plain ITR ones. You can use ITR inner springs with Portflow outer springs and that will be sufficient. You also want adjustable cam gears to tune the cam timing.
From there, you definitely want to make sure the exhaust is nice and uncorked. At the minimum for this kind of setup you want a header with a 2.5" collector, a 2.5" high flow cat, and a custom exhaust made with 2.5" pipes going back to a muffler with a 2.5" inlet. The key here if you didn't notice, is 2.5".
As far as what header to go with, they run the entire gamut of price and performance. At the low end of things you can go with a 98-up JDM ITR header or a DC Sports 4-1 header designed to bolt onto a '98-up JDM ITR. These both run under $500. From there, you can go for any number of exotic headers which sell for $800 on up and will gain you another 6 to 10 hp at the wheels on a highly built motor compared to the JDM ITR or DC header.
The hottest cams I've sen are the JUN III, or copies thereof (for example skunk2 Stage 2). I'd go with those cams, but you'll need stiffer valvesprings than plain ITR ones. You can use ITR inner springs with Portflow outer springs and that will be sufficient. You also want adjustable cam gears to tune the cam timing.
From there, you definitely want to make sure the exhaust is nice and uncorked. At the minimum for this kind of setup you want a header with a 2.5" collector, a 2.5" high flow cat, and a custom exhaust made with 2.5" pipes going back to a muffler with a 2.5" inlet. The key here if you didn't notice, is 2.5".
As far as what header to go with, they run the entire gamut of price and performance. At the low end of things you can go with a 98-up JDM ITR header or a DC Sports 4-1 header designed to bolt onto a '98-up JDM ITR. These both run under $500. From there, you can go for any number of exotic headers which sell for $800 on up and will gain you another 6 to 10 hp at the wheels on a highly built motor compared to the JDM ITR or DC header.
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Joined: Dec 2000
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From: Madison, WI
Your plan sounds good, I would definitely go with JUN III over CTR cams. As for the exhaust your header is more than sufficient but if the exhaust is designed to bolt up to the stock catalytic converter it might be a restriction on that much of a highly built motor. Which model 5Zigen exhaust do you have?