ITB bore diameter.. how little is too little?
03-23-11, 05:15 PM
#28
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Injectors are 850cc semiens, and its a fairly big street port. Most of the info for that is here:
https://www.rx7club.com/showthread.p...ht=fuji+racing
Latest HP are here:
https://www.rx7club.com/showthread.p...highlight=dyno
Pushed 165 whp and 132ft-lb of torque ... and yes it is a 12A not a 13B. After changing my fuel pressure regulator which I later found out was bouncing around the fuel read outs, I believe its in the 170 whp now. and maybe closer to 135 torque.
https://www.rx7club.com/showthread.p...ht=fuji+racing
Latest HP are here:
https://www.rx7club.com/showthread.p...highlight=dyno
Pushed 165 whp and 132ft-lb of torque ... and yes it is a 12A not a 13B. After changing my fuel pressure regulator which I later found out was bouncing around the fuel read outs, I believe its in the 170 whp now. and maybe closer to 135 torque.
HOLY HELL
thank you for that car pr0n shot of the day
03-23-11, 05:18 PM
#29
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http://www.motorsportfreaks.com/2002..._GSX1300R.html
03-23-11, 05:30 PM
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Unsure of the size, 46mm sounds right, I'll measure the Hybusa TB's I have at the shop tonight.
When he initially setup his race car he used a Megajunk ooops I mean Megasquirt and was fighting with all kinds of tuning issues for a couple years, he finally got it to run better last summer but no dyno time, so no numbers.
He's a member here on the forum, 23racer.
When he initially setup his race car he used a Megajunk ooops I mean Megasquirt and was fighting with all kinds of tuning issues for a couple years, he finally got it to run better last summer but no dyno time, so no numbers.
He's a member here on the forum, 23racer.
03-23-11, 08:42 PM
#31
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That quad manifold looks like what I plan on putting together for a four port 13B, but with the GM throttle bodies. The biggest issue I'm facing before I start cutting metal is how to make the airbox. There's no convenient flange on the front of what I want to use, and putting the throttle bodies in a big box and then trying to seal off the throttle cable and fuel lines seems a bit uncouth to me. I COULD design the airbox so the injectors actually sit outside the box, with injector cups just mounted in the back wall... hmm.
I can think of a lot of ways to do it, the trick is to make it simple, 100% dust proof, and easily servicable, and none of my ideas hit all three.
Megasquirt rocks... every problem I've ever seen with it was an installation error (floating grounds/bad connections/crappy aftermarket hardware *coughTweakit*) or people who don't really understand what they are doing trying to tune it. Basically, it's all of the problems that standalones have, at a price tag that anyone can afford
I can think of a lot of ways to do it, the trick is to make it simple, 100% dust proof, and easily servicable, and none of my ideas hit all three.
Megasquirt rocks... every problem I've ever seen with it was an installation error (floating grounds/bad connections/crappy aftermarket hardware *coughTweakit*) or people who don't really understand what they are doing trying to tune it. Basically, it's all of the problems that standalones have, at a price tag that anyone can afford
03-23-11, 09:29 PM
#32
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just make an intake box that only incases the velocity stacks. done and done!
http://www.clockwisemotion.co.uk/ima...bre-airbox.jpg
http://www.clockwisemotion.co.uk/ima...bre-airbox.jpg
Last edited by blindboxx2334; 03-23-11 at 09:34 PM.
03-23-11, 09:45 PM
#33
Old [Sch|F]ool
Easy to say, not easy to do.
The throttle bodies I have look like this:
which is a horrible shape to deal with. It's not flat, it's not round.
I don't want to just stick a cone on the thing - testing on customer cars suggests that those quick and dirty cones (in more ways than one) are fairly restrictive and there needs to be a decent volume between the throttle plates and the air filter element.
I run a cheapo cone on the N/A throttle elbow and measure atmospheric pressure at WOT, all the way out to max RPM. I ran two of those units, one per barrel, on the 2x40 throttle body on my peripheral port, and by the time the engine got to 7k, the manifold was running pretty significant vacuum. (Mind you, the exhaust and the soda straw intake were limiting power to maaaybe 120-130hp... at the crank... not talking about large airflow here) So, it would seem that a proper airbox is critical for an independent system, and just sticking a filter on the end is possibly the worst thing you can do power-wise. (And what do a lot of people do?)
The throttle bodies I have look like this:
which is a horrible shape to deal with. It's not flat, it's not round.
I don't want to just stick a cone on the thing - testing on customer cars suggests that those quick and dirty cones (in more ways than one) are fairly restrictive and there needs to be a decent volume between the throttle plates and the air filter element.
I run a cheapo cone on the N/A throttle elbow and measure atmospheric pressure at WOT, all the way out to max RPM. I ran two of those units, one per barrel, on the 2x40 throttle body on my peripheral port, and by the time the engine got to 7k, the manifold was running pretty significant vacuum. (Mind you, the exhaust and the soda straw intake were limiting power to maaaybe 120-130hp... at the crank... not talking about large airflow here) So, it would seem that a proper airbox is critical for an independent system, and just sticking a filter on the end is possibly the worst thing you can do power-wise. (And what do a lot of people do?)
03-23-11, 11:05 PM
#34
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oh that's easy! um get a silicon/rubber boot that will fit on the TB's and then make airbox with like fitting so you can just use like a 2" piece of silicon to hold the box.
its probably 4" but just not round.
i agree mounting the box might be kind funky. you could mount it to the car, and run longer hoses to the TB's but then that add to intake length....
or get really retarded, and run a seal up to the hood, one across over the header, and put a filter in the grille! let the world be your box!
its probably 4" but just not round.
i agree mounting the box might be kind funky. you could mount it to the car, and run longer hoses to the TB's but then that add to intake length....
or get really retarded, and run a seal up to the hood, one across over the header, and put a filter in the grille! let the world be your box!
03-24-11, 11:59 AM
#35
Easy to say, not easy to do.
The throttle bodies I have look like this:
which is a horrible shape to deal with. It's not flat, it's not round.
I don't want to just stick a cone on the thing - testing on customer cars suggests that those quick and dirty cones (in more ways than one) are fairly restrictive and there needs to be a decent volume between the throttle plates and the air filter element.
I run a cheapo cone on the N/A throttle elbow and measure atmospheric pressure at WOT, all the way out to max RPM. I ran two of those units, one per barrel, on the 2x40 throttle body on my peripheral port, and by the time the engine got to 7k, the manifold was running pretty significant vacuum. (Mind you, the exhaust and the soda straw intake were limiting power to maaaybe 120-130hp... at the crank... not talking about large airflow here) So, it would seem that a proper airbox is critical for an independent system, and just sticking a filter on the end is possibly the worst thing you can do power-wise. (And what do a lot of people do?)
The throttle bodies I have look like this:
which is a horrible shape to deal with. It's not flat, it's not round.
I don't want to just stick a cone on the thing - testing on customer cars suggests that those quick and dirty cones (in more ways than one) are fairly restrictive and there needs to be a decent volume between the throttle plates and the air filter element.
I run a cheapo cone on the N/A throttle elbow and measure atmospheric pressure at WOT, all the way out to max RPM. I ran two of those units, one per barrel, on the 2x40 throttle body on my peripheral port, and by the time the engine got to 7k, the manifold was running pretty significant vacuum. (Mind you, the exhaust and the soda straw intake were limiting power to maaaybe 120-130hp... at the crank... not talking about large airflow here) So, it would seem that a proper airbox is critical for an independent system, and just sticking a filter on the end is possibly the worst thing you can do power-wise. (And what do a lot of people do?)
thats the same throttle body i have that i'm working on now it was from a 96 mustang cobra, not the same BBK one but a stock mustang cobra throttle body.
03-24-11, 02:43 PM
#36
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Alright, how about this for a try?
Find out the circumference of the oval using a flexy tape measure (the ones that taylors and such use)… Let’s just say its 4 inches, just for an example.
Then you figure out how tall you want the intake box off the TB. Lets just say 6 inches, for example. So you then cut out a 4x6 sheet of aluminum. Bolt the throttle body to something solid, and then commence bending around the oval! Although then there isn’t a way to mount it on securely… You’d almost have to weld tabs on the TB to make that work.. A lot of work, but that’s what happens when you go the DIY ITB route.
Hmmm... Maybe the silicone hose would be a better idea. haha
Edit: or if you really didn’t want to go the silicone hose route. You could do what I suggested, except weld it to the TB. And make tabs on top of your new piece for an airbox or some v-stacks.
Find out the circumference of the oval using a flexy tape measure (the ones that taylors and such use)… Let’s just say its 4 inches, just for an example.
Then you figure out how tall you want the intake box off the TB. Lets just say 6 inches, for example. So you then cut out a 4x6 sheet of aluminum. Bolt the throttle body to something solid, and then commence bending around the oval! Although then there isn’t a way to mount it on securely… You’d almost have to weld tabs on the TB to make that work.. A lot of work, but that’s what happens when you go the DIY ITB route.
Hmmm... Maybe the silicone hose would be a better idea. haha
Edit: or if you really didn’t want to go the silicone hose route. You could do what I suggested, except weld it to the TB. And make tabs on top of your new piece for an airbox or some v-stacks.
Last edited by blindboxx2334; 03-24-11 at 02:45 PM.
07-21-11, 07:53 PM
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Ive being looking for a post like this for like a year or so lol i had thought of thouse ideas but never got the right direction to go for them now i know i can do something like that... my question would be my engine will be a semi pp street port how can i part the intake ports to make one myself... any pics? If you guys can help me with that it will be most appreciated 
07-22-11, 08:58 AM
#38
Rotary Freak
That quad manifold looks like what I plan on putting together for a four port 13B, but with the GM throttle bodies. The biggest issue I'm facing before I start cutting metal is how to make the airbox. There's no convenient flange on the front of what I want to use, and putting the throttle bodies in a big box and then trying to seal off the throttle cable and fuel lines seems a bit uncouth to me. I COULD design the airbox so the injectors actually sit outside the box, with injector cups just mounted in the back wall... hmm.
I can think of a lot of ways to do it, the trick is to make it simple, 100% dust proof, and easily servicable, and none of my ideas hit all three.
Megasquirt rocks... every problem I've ever seen with it was an installation error (floating grounds/bad connections/crappy aftermarket hardware *coughTweakit*) or people who don't really understand what they are doing trying to tune it. Basically, it's all of the problems that standalones have, at a price tag that anyone can afford
I can think of a lot of ways to do it, the trick is to make it simple, 100% dust proof, and easily servicable, and none of my ideas hit all three.
Megasquirt rocks... every problem I've ever seen with it was an installation error (floating grounds/bad connections/crappy aftermarket hardware *coughTweakit*) or people who don't really understand what they are doing trying to tune it. Basically, it's all of the problems that standalones have, at a price tag that anyone can afford
All of a sudden the car started to fly. It would pull hard and I mean hard enough to spin the rears in 2nd from a roll (225x50x15 Toyo RA1's) and would pull from 3500 rpm to well over 9000 rpm. Getting the car to run this hard has brought up other issues like heat soak issues, plug issues, etc..., but these are normal for a race car. The bodies are 48mm id and I did some thing different in the design. I used the stock Hayabusa injector positions for the outer injectors and am using stock TII injectors. I have plugged the inner Haybusa positions and I am running the stock NA injectors in the stock fuel rail for the inners.
Throttle response with this setup is fantastic now, fuel mileage is better than with the stock setup on my 6 port and the car has enough jam to power past a BMW Castrol Touring Car (about 280 hp) until it gets hot. No we have not put the car on a dyno yet, but that is in the plans for the next month. As soon as we do, I will post the numbers, but seat of pants gets me thinking about 225 rwhp. It doesn't pull as hard as my other racecar that makes 240 rwhp.
Just a few more things to do. Build a cold airbox, better heat shielding, underdriven waterpump pulley and race plugs.
Eric
07-25-11, 03:30 PM
#39
I used a 4.9 truck throttle body. 2x40. Yes, it sucked...
I have driven a 1x45DCOE equipped car and didn't know it wasn't stock until I opened the hood. (That's two 45mm barrels)
The TWM 2x40DCOE (four 40mm barrels) is supposed to flow like a single 48 IDA. Haven't driven one.
I have driven a 1x45DCOE equipped car and didn't know it wasn't stock until I opened the hood. (That's two 45mm barrels)
The TWM 2x40DCOE (four 40mm barrels) is supposed to flow like a single 48 IDA. Haven't driven one.
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