The right way of doing DIY ITB
Thread Starter
Joined: Dec 2002
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From: manchester, nh, us
The right way of doing DIY ITB
first of all i hate it when people dont spread their itb's apart. they end up with angled runners on every runner. that doesnt flow the same amount of air for every cylinder, but hey its your car not mine. second not spacing them doesnt allow for you to use your oem injectors and rail in the itb oem location. now ur stuck having to use your stock location wich will work but not as evective for better fuel mixture and mo power. so before you go shave your intake manifold down and try to make some half *** diy itb's, just giving you some insight on how it should be done
you start off by spacing the itb's, u can see the chrome spacers here
this is the cnc 1/2" 6061 flange that i make now
welded runners and steps to accept the large hayabusa itb's
this pic will show the fuel rail new mounting location where those 2 bolts are,i welded 2 threaded tabs, and it will show you how i milled down the itbs to accept b18 injectors. threw those babies on the milling machine and went to town.
more pix of the progess coming soon. the injector hole enlargement, tb cable bracket, and the honda tps trick
you start off by spacing the itb's, u can see the chrome spacers here
this is the cnc 1/2" 6061 flange that i make now
welded runners and steps to accept the large hayabusa itb's
this pic will show the fuel rail new mounting location where those 2 bolts are,i welded 2 threaded tabs, and it will show you how i milled down the itbs to accept b18 injectors. threw those babies on the milling machine and went to town.
more pix of the progess coming soon. the injector hole enlargement, tb cable bracket, and the honda tps trick
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Joined: Feb 2005
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From: Milford, CT, USA
Re: The right way of doing DIY ITB (Fook_me_honda)
Awesome job. 
I think alot of people dont separate them because most sets of tb's appear to be paired up or in one piece. I prefer to use Suzuki TB's for that very reason. Dont want to thread jack but here's a set Im working on for my E30 BMW 325i
Everything should have ITB's
I think alot of people dont separate them because most sets of tb's appear to be paired up or in one piece. I prefer to use Suzuki TB's for that very reason. Dont want to thread jack but here's a set Im working on for my E30 BMW 325i
Everything should have ITB's
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From: upskirtsville, NJ
Re: The right way of doing DIY ITB (H23vtecEG)
hmm, your using the stock injector ports from the itbs ?
i was reading for optimum spray patern at lower rpms that the injector is too far up with the stock port . . for real hig rpms ( >8) it works good though . . do you have any manifolds that utilize the stock ports for injectors?( i have a shitty gsr mani right now that i wil be using, no its not pretty but it will work)
i was reading for optimum spray patern at lower rpms that the injector is too far up with the stock port . . for real hig rpms ( >8) it works good though . . do you have any manifolds that utilize the stock ports for injectors?( i have a shitty gsr mani right now that i wil be using, no its not pretty but it will work)
Thread Starter
Joined: Dec 2002
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From: manchester, nh, us
Re: The right way of doing DIY ITB (Fook_me_honda)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Fook_me_honda »</TD></TR><TR><TD CLASS="quote">Looks real good to me! what is it going on if u don't mind me askin?</TD></TR></TABLE>
type-r
type-r
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From: TX, usa
Re: (xerox445)
depends on the size of the motor he is putting those on. a 2.0 b series would make better use of thse gsxr's then a 1.6 or 1.8 ever will. unless your reving to like 10 grand and actually making power
Thread Starter
Joined: Dec 2002
Posts: 1,506
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From: manchester, nh, us
Re: (xerox445)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xerox445 »</TD></TR><TR><TD CLASS="quote">Those ports are pretty big, arent you concerned with loosing some velocity?</TD></TR></TABLE>
the bigger tubes go inside quite a bit the smaller tube. they only stick out about an inch, then it was blended in with a deburing tool. it will create turbulance for a better fuel mixture, thats y i changed the angle of the injectors as well. the busa injectors are at an extreme angle and it points right down the side of the tube instead right down the port. by changing the anlgle of the injectors and creating a smoother transition from the itbs to the larger tube hence a better mixture and flow.
fiero 95.............
everyone here yaps about how power can only be made at 8k or above, but everyone here also knows that the size of the throttle body and the length of the runner is what determens your power band. good example is people that make diy itbs keep them very short, usually @9 to low 10 inches. and even twm or jenvys are around that length. they were never designed for daily driving. if you want a lower rpm power band make the damn things longers, and play around with them
https://honda-tech.com/zerothread?id=1182389
heres a setup someone dynoed made 7hp and power all across the rpm range
Modified by H23vtecEG at 10:17 AM 3/27/2005
the bigger tubes go inside quite a bit the smaller tube. they only stick out about an inch, then it was blended in with a deburing tool. it will create turbulance for a better fuel mixture, thats y i changed the angle of the injectors as well. the busa injectors are at an extreme angle and it points right down the side of the tube instead right down the port. by changing the anlgle of the injectors and creating a smoother transition from the itbs to the larger tube hence a better mixture and flow.
fiero 95.............
everyone here yaps about how power can only be made at 8k or above, but everyone here also knows that the size of the throttle body and the length of the runner is what determens your power band. good example is people that make diy itbs keep them very short, usually @9 to low 10 inches. and even twm or jenvys are around that length. they were never designed for daily driving. if you want a lower rpm power band make the damn things longers, and play around with them
https://honda-tech.com/zerothread?id=1182389
heres a setup someone dynoed made 7hp and power all across the rpm range
Modified by H23vtecEG at 10:17 AM 3/27/2005
Joined: Jul 2003
Posts: 875
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From: TX, usa
Re: (H23vtecEG)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by H23vtecEG »</TD></TR><TR><TD CLASS="quote">
fiero 95.............
everyone here yaps about how power can only be made at 8k or above, but everyone here also knows that the size of the throttle body and the length of the runner is what determens your power band. good example is people that make diy itbs keep them very short, usually @9 to low 10 inches. and even twm or jenvys are around that length. they were never designed for daily driving. if you want a lower rpm power band make the damn things longers, and play around with them
https://honda-tech.com/zerothread?id=1182389
heres a setup someone dynoed made 7hp and power all across the rpm range
Modified by H23vtecEG at 10:17 AM 3/27/2005</TD></TR></TABLE>
good info. ive actually been curious on how runner length affected the power band. im in the process of building some itbs with honda 954 carbs. only wish i could space them out like you have with the suzuki's
fiero 95.............
everyone here yaps about how power can only be made at 8k or above, but everyone here also knows that the size of the throttle body and the length of the runner is what determens your power band. good example is people that make diy itbs keep them very short, usually @9 to low 10 inches. and even twm or jenvys are around that length. they were never designed for daily driving. if you want a lower rpm power band make the damn things longers, and play around with them
https://honda-tech.com/zerothread?id=1182389
heres a setup someone dynoed made 7hp and power all across the rpm range
Modified by H23vtecEG at 10:17 AM 3/27/2005</TD></TR></TABLE>
good info. ive actually been curious on how runner length affected the power band. im in the process of building some itbs with honda 954 carbs. only wish i could space them out like you have with the suzuki's
Thread Starter
Joined: Dec 2002
Posts: 1,506
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From: manchester, nh, us
Re: (ferio 95)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ferio 95 »</TD></TR><TR><TD CLASS="quote">also do you have a site up yet where we can order these flanges and runners? cause i for one would be the first to pickup a set </TD></TR></TABLE>
you can order them at tdctuning.com email first or IM me
</TD></TR></TABLE>you can order them at tdctuning.com email first or IM me
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Joined: Feb 2005
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From: Heinola, Finland
Re: (H23vtecEG)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote"> good example is people that make diy itbs keep them very short, usually @9 to low 10 inches. and even twm or jenvys are around that length. they were never designed for daily driving. if you want a lower rpm power band make the damn things longers, and play around with them</TD></TR></TABLE>
Right, exactly, thats all because of the timing of the resonance pulses. Gives you an added kick if its timed correctly to a prefferred RPM level. Longer for low rpm, shorter for high rpm. I tried to make mine as long as possible, its VERY close to the firewall and I have about 12-13" of runners to the valve, which is ok, it gives me a pulse strength of about 4% between 5294 to 6413. I can calculate it further, this is just a gross estimate tho. Then again, thats already cutting it close to my redline on the toyota
Right, exactly, thats all because of the timing of the resonance pulses. Gives you an added kick if its timed correctly to a prefferred RPM level. Longer for low rpm, shorter for high rpm. I tried to make mine as long as possible, its VERY close to the firewall and I have about 12-13" of runners to the valve, which is ok, it gives me a pulse strength of about 4% between 5294 to 6413. I can calculate it further, this is just a gross estimate tho. Then again, thats already cutting it close to my redline on the toyota
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Joined: Nov 2002
Posts: 17,227
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From: Illinois
Re: (H23vtecEG)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by H23vtecEG »</TD></TR><TR><TD CLASS="quote">
everyone here yaps about how power can only be made at 8k or above, but everyone here also knows that the size of the throttle body and the length of the runner is what determens your power band. good example is people that make diy itbs keep them very short, usually @9 to low 10 inches. and even twm or jenvys are around that length. they were never designed for daily driving. if you want a lower rpm power band make the damn things longers, and play around with them
Modified by H23vtecEG at 10:17 AM 3/27/2005</TD></TR></TABLE>
You have to also take in what chassis and engine the itb's are going into, when I did them on my crx there was barely any room to fit them in, I had to take the air horns off to make them fit. And you don't want them to close to the firewall because I feel the air travel will suffer.
everyone here yaps about how power can only be made at 8k or above, but everyone here also knows that the size of the throttle body and the length of the runner is what determens your power band. good example is people that make diy itbs keep them very short, usually @9 to low 10 inches. and even twm or jenvys are around that length. they were never designed for daily driving. if you want a lower rpm power band make the damn things longers, and play around with them
Modified by H23vtecEG at 10:17 AM 3/27/2005</TD></TR></TABLE>
You have to also take in what chassis and engine the itb's are going into, when I did them on my crx there was barely any room to fit them in, I had to take the air horns off to make them fit. And you don't want them to close to the firewall because I feel the air travel will suffer.
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From: Heinola, Finland
Re: (90blackcrx)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote">You have to also take in what chassis and engine the itb's are going into, when I did them on my crx there was barely any room to fit them in, I had to take the air horns off to make them fit.</TD></TR></TABLE>
Well.. the pipes dont have to be straight, you could basically make them do a 180deg turn, put them under the engine, ontop of the engine (provided theres enough clearance), for example, to increase runner length
Well.. the pipes dont have to be straight, you could basically make them do a 180deg turn, put them under the engine, ontop of the engine (provided theres enough clearance), for example, to increase runner length
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Joined: Oct 2002
Posts: 2,369
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From: Southern NJ, USA
Re: (H23vtecEG)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by H23vtecEG »</TD></TR><TR><TD CLASS="quote">
the bigger tubes go inside quite a bit the smaller tube. they only stick out about an inch, then it was blended in with a deburing tool. it will create turbulance for a better fuel mixture, thats y i changed the angle of the injectors as well. the busa injectors are at an extreme angle and it points right down the side of the tube instead right down the port. by changing the anlgle of the injectors and creating a smoother transition from the itbs to the larger tube hence a better mixture and flow.
fiero 95.............
everyone here yaps about how power can only be made at 8k or above, but everyone here also knows that the size of the throttle body and the length of the runner is what determens your power band. good example is people that make diy itbs keep them very short, usually @9 to low 10 inches. and even twm or jenvys are around that length. they were never designed for daily driving. if you want a lower rpm power band make the damn things longers, and play around with them
https://honda-tech.com/zerothread?id=1182389
heres a setup someone dynoed made 7hp and power all across the rpm range
Modified by H23vtecEG at 10:17 AM 3/27/2005</TD></TR></TABLE>
The injector spray patterns atomize the fuel fine, extra turbulance is just going to cause you to have less power overall because it disturbs the swirl in the combustion chamber.
the bigger tubes go inside quite a bit the smaller tube. they only stick out about an inch, then it was blended in with a deburing tool. it will create turbulance for a better fuel mixture, thats y i changed the angle of the injectors as well. the busa injectors are at an extreme angle and it points right down the side of the tube instead right down the port. by changing the anlgle of the injectors and creating a smoother transition from the itbs to the larger tube hence a better mixture and flow.
fiero 95.............
everyone here yaps about how power can only be made at 8k or above, but everyone here also knows that the size of the throttle body and the length of the runner is what determens your power band. good example is people that make diy itbs keep them very short, usually @9 to low 10 inches. and even twm or jenvys are around that length. they were never designed for daily driving. if you want a lower rpm power band make the damn things longers, and play around with them
https://honda-tech.com/zerothread?id=1182389
heres a setup someone dynoed made 7hp and power all across the rpm range
Modified by H23vtecEG at 10:17 AM 3/27/2005</TD></TR></TABLE>
The injector spray patterns atomize the fuel fine, extra turbulance is just going to cause you to have less power overall because it disturbs the swirl in the combustion chamber.
Thread Starter
Joined: Dec 2002
Posts: 1,506
Likes: 1
From: manchester, nh, us
Re: (xerox445)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xerox445 »</TD></TR><TR><TD CLASS="quote">
The injector spray patterns atomize the fuel fine, .</TD></TR></TABLE>
it is completely changed now that the injectors are pointed differently and further away from the stock location..... but i aslo sand blasted the inside rough to help with the mixture, i dont think it will cause too much turbulance at all, we'll let the dyno prove it though
The injector spray patterns atomize the fuel fine, .</TD></TR></TABLE>
it is completely changed now that the injectors are pointed differently and further away from the stock location..... but i aslo sand blasted the inside rough to help with the mixture, i dont think it will cause too much turbulance at all, we'll let the dyno prove it though
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Joined: Nov 2002
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From: Illinois
Re: (Flashmn)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Flashmn »</TD></TR><TR><TD CLASS="quote">
Well.. the pipes dont have to be straight, you could basically make them do a 180deg turn, put them under the engine, ontop of the engine (provided theres enough clearance), for example, to increase runner length </TD></TR></TABLE>
I think that would decrease air flow, plus you still don't have that much room in some chassis in particular a crx chassis.
Well.. the pipes dont have to be straight, you could basically make them do a 180deg turn, put them under the engine, ontop of the engine (provided theres enough clearance), for example, to increase runner length
</TD></TR></TABLE>I think that would decrease air flow, plus you still don't have that much room in some chassis in particular a crx chassis.
Thread Starter
Joined: Dec 2002
Posts: 1,506
Likes: 1
From: manchester, nh, us
Re: (90blackcrx)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 90blackcrx »</TD></TR><TR><TD CLASS="quote">
I think that would decrease air flow, plus you still don't have that much room in some chassis in particular a crx chassis.</TD></TR></TABLE>
cut the firewall out so you can have them right next to your face............. it will suck the clothes right off them honies plus 400 whp increase at least.... J/K
you shouldnt really need more then 11 inches from the head. if you do then change your tb size
I think that would decrease air flow, plus you still don't have that much room in some chassis in particular a crx chassis.</TD></TR></TABLE>
cut the firewall out so you can have them right next to your face
............. it will suck the clothes right off them honies plus 400 whp increase at least.... J/Kyou shouldnt really need more then 11 inches from the head. if you do then change your tb size