# My custom ITB build: start to finish. (Lots of pics)



## NTRabbit (Mar 28, 2001)

Well, I'm finally done with my GSXR ITB setup that I started back in January (it's been a side project). When I started on this project, I spent a lot of time trying to find ideas on the vortex on how other people did theirs, so I wanted to share this with everyone. I took pictures all along the way. The car is on the road now, and everything is working just fine. I am running it on megasquirt, and I've only put an hour or two of tuning in to it, although it's good enough now to drive to work (10 mile drive). It is starting to pull pretty well, and it is LOUD AS ALL HELL! I can't believe how much louder the car is. It's pretty fun though. Enjoy. 
Engine is 2.0L 16v with 1.8L head, and 276 techtonics cams.









































































































The following two pictures are fake injectors that the machinist at my shop made for me. They fit on to the GSXR fuel rail just like a regular injector, but they have 1/8" holes drill down the middle for a vacuum pick up. I then run my brake booster line straight to the fuel rail.


----------



## tbeck (Sep 12, 2004)

*Re: My custom ITB build: start to finish. (NTRabbit)*

WOW, nice build, I really like the injector idea. Ive got a couple questions, what gsxr itb's are you using. And whats the pricing of your setup been thus far?


----------



## NTRabbit (Mar 28, 2001)

*Re: My custom ITB build: start to finish. (tbeck)*

The ITB's are from a 2001 GSXR750. Pricing.... lets see what I can remember. 
-ITBs: $100
-Aluminum tube: $25
-Air filters: $70
-Misc supplies (radiator hoses, hose clamps, etc...): $50
-Full Race CRX radiator: $320
-Radiator fan & mounting pieces: $50
This doesn't include shipping prices and stuff. I would say that I spent about *$700* in the end. Although more than half of that price was for the radiator and fan. I have to say that this radiator cools even better than the stock one, and it is only half the length (a little thicker though). Also, I got to pick up a lot of free stuff at my shop like sanding bits, welding supplies, aluminum rod for fake injectors, scrap metal, and misc hardware. 


_Modified by NTRabbit at 12:14 PM 7-20-2007_


----------



## xr4tic (Dec 10, 2001)

Nice. Which radiator is that?


----------



## RoadRunner219 (Mar 1, 2006)

*Re: My custom ITB build: start to finish. (NTRabbit)*

http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif


----------



## Kemper (Mar 8, 2005)

*Re: My custom ITB build: start to finish.*

Nice







http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif


----------



## NTRabbit (Mar 28, 2001)

*Re: (xr4tic)*


_Quote, originally posted by *xr4tic* »_Nice. Which radiator is that?

http://www.full-race.com/catal...d4bb3
eurotrashrabbit got me on to it. It's a great radiator.


----------



## Breadfan5968 (Mar 25, 2007)

*Re: My custom ITB build: start to finish. ('93 Passat GLX)*

Looking really good. 
Won't the welds in the pipes reduce the flow?
I wish I could do so much myself, great job! http://****************.com/smile/emthup.gif


----------



## NTRabbit (Mar 28, 2001)

*Re: My custom ITB build: start to finish. (Breadfan5968)*


_Quote, originally posted by *Breadfan5968* »_Looking really good. 
Won't the welds in the pipes reduce the flow?
I wish I could do so much myself, great job! http://****************.com/smile/emthup.gif 

There is one photo where you can see the bore of the pipe. I sanded down all of the bores with multiple different sanding bits and the finish came out just right. All of the welds penetrated through the cuts in the tube, so there aren't any lines or anything left on the inside.


----------



## wobvintage3 (Jun 10, 2005)

*Re: My custom ITB build: start to finish. (NTRabbit)*

Great job Nick http://****************.com/smile/emthup.gif Cant wait to see this thing in person.


----------



## at_the_speed_of_2.l0w (Jun 18, 2006)

Beautiful build. Very nice. I see that you use the dummy injectors for brake boost vacuum. It looks like you're using the throttle body's own vacuum/idle air ports as well. I see the line going to the FPR. What else? MAP? Is there any reason why you kept the two separate? Or why you didn't just plug the TB injector holes and use the built in vacuum ports alone? I'm just curious.


----------



## Breadfan5968 (Mar 25, 2007)

*Re: My custom ITB build: start to finish. (NTRabbit)*


_Quote, originally posted by *NTRabbit* »_
There is one photo where you can see the bore of the pipe. I sanded down all of the bores with multiple different sanding bits and the finish came out just right. All of the welds penetrated through the cuts in the tube, so there aren't any lines or anything left on the inside. 

Are you gonna polish them too?
On the inside I mean.


----------



## H2Zero (Apr 25, 2003)

*Re: My custom ITB build: start to finish. (NTRabbit)*

Nice built. By the way how the new radiator handling the temp. Does it sufficient cool the car?


----------



## FATGUYINALITTLEDUB (Aug 1, 2006)

*Re: My custom ITB build: start to finish. (NTRabbit)*

http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif


----------



## NTRabbit (Mar 28, 2001)

*Re: (at_the_speed_of_2.l0w)*


_Quote, originally posted by *at_the_speed_of_2.l0w* »_. I see the line going to the FPR. What else? MAP? Is there any reason why you kept the two separate? Or why you didn't just plug the TB injector holes and use the built in vacuum ports alone? I'm just curious.

The line going to the FPR also goes to the MAP sensor. I didn't use these ports for the brake booster because they are too small. When I looked at the stock port for the brake booster vacuum line, the nipple had an inner diameter of roughly 1/4". I was affraid that the small vacuum ports on the TB's just wouldn't be enough for the booster. 


_Modified by NTRabbit at 4:18 PM 7-23-2007_


----------



## NTRabbit (Mar 28, 2001)

*Re: My custom ITB build: start to finish. (Breadfan5968)*


_Quote, originally posted by *Breadfan5968* »_
Are you gonna polish them too?
On the inside I mean.

No, no polish. You don't want to polish the intake ports or runners. The slightly rough surface helps create a little bit of air turbulance to help atomize the fuel. I finished it with 120 grit. 
To *H2ZERO*'s question about the radiator: It cools extremely well while I am driving it. It will drop the temp from 200 to 180 in a matter of seconds once you start moving, and will maintain it at that temperature. I need to modify my fan setup a little bit for when the car is sitting still though. Even with the fan on, it will start to creep up to 207 or so when I am sitting still. I have been turning on the interior air fan at stop lights to prevent this. I think that a fan shroud (or a more powerful fan) would solve the problem.


_Modified by NTRabbit at 4:19 PM 7-23-2007_


----------



## eurotrashrabbit (Oct 25, 2001)

*Re: My custom ITB build: start to finish. (NTRabbit)*

Looks good Nick it is a blast to ride in


----------



## xr4tic (Dec 10, 2001)

Did you get the full-race fan with the radiator, or something different?
Got any pics of how the radiator is mounted?


----------



## Fox-N-It (Jul 23, 2003)

*Re: My custom ITB build: start to finish. (eurotrashrabbit)*

Looks good! I'll have to scope it out next time you bring it to eurotrash's

_Quote, originally posted by *eurotrashrabbit* »_Looks good Nick it is a blast to ride in









More fun than your rabbit?


----------



## NTRabbit (Mar 28, 2001)

*Re: (xr4tic)*


_Quote, originally posted by *xr4tic* »_Did you get the full-race fan with the radiator, or something different?
Got any pics of how the radiator is mounted?

The fan is just a random 10" fan that I got off of ebay. It was rated at 1600CFM for the air flow, although I don't think it really flows that much. No pictures of the bottom of the radiator. It was pretty easy though. There are two pegs on the bottom of the rad. One goes in to the original radiator hole, and you just drill a hole for the other peg. I don't have anything holding the top of the radiator right now, although it needs something.


----------



## Chronicsinners (Mar 13, 2003)

*Re: (NTRabbit)*

looks like a sick setup http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif


----------



## Breadfan5968 (Mar 25, 2007)

*Re: My custom ITB build: start to finish. (NTRabbit)*


_Quote, originally posted by *NTRabbit* »_
No, no polish. You don't want to polish the intake ports or runners. The slightly rough surface helps create a little bit of air turbulance to help atomize the fuel. I finished it with 120 grit. 

Strange...


----------



## sleeperstatis (Mar 22, 2005)

*Re: My custom ITB build: start to finish. (Breadfan5968)*

is there any evidence to support the statement that atomization doesn't occur with polished intake runners and ports on the head?
or is this just widely "known"?


----------



## xr4tic (Dec 10, 2001)

IIRC, a polished port will help fuel pool up as it hits the walls, and a rougher port will help the air tumble a little bit more, and prevent pooling.
From http://www.theoldone.com/ 
"This might come as a shock to many of you, but this particular port would never run on one of our personal engines. It's not due to any deficiencies, it's due to the finish. A port finished like the one in the previous shot will perform just as well as this "cosmetically" nicer port, and since performance is king around here, we'd do the final sizing with the carbide finish for our own stuff. If it's our own, we don't need to bother with other's preconceived notions about "looks", so we don't bother. This particular head is for a customer and we feel somewhat bound to make the appearances "acceptable", so nobody will make any cracks about "unfinished" ports. "
The exhaust port is different though, I think polishing helps.


----------



## eurotrashrabbit (Oct 25, 2001)

*Re: (xr4tic)*

Think of water running down smooth rocks then think of water running down jagged rocks similar principle but only gravity move the water and not a vacuum


----------



## sleeperstatis (Mar 22, 2005)

*Re: (eurotrashrabbit)*

thats just hear-say. where is the evidence to support this, where are the dyno's or lap times or quarter mile? shouldn't the injector atomize the fuel, causing proper mixing? 
and not to mention the fact that when your injectors are timed properly they are only open when the valves are open. Air is either being pulled or pushed past them at very high speeds, where does the fuel find the time to "pool"?
and i'm not talking about CIS, because if you feel that you need to port and polish a head because its a good way to get power, why not put it on standalone first so you can really utilize everthing you already have?
it seems to me this is all regurgitated information over the tex.


----------



## 4RingsRuleALL (Mar 25, 2004)

*Re: (sleeperstatis)*


_Quote, originally posted by *sleeperstatis* »_thats just hear-say. where is the evidence to support this, where are the dyno's or lap times or quarter mile? shouldn't the injector atomize the fuel, causing proper mixing? 
and not to mention the fact that when your injectors are timed properly they are only open when the valves are open. Air is either being pulled or pushed past them at very high speeds, where does the fuel find the time to "pool"?
it seems to me this is all regurgitated information over the tex.


Well there is a dif between wet(fuel delivered in the intake manifold) and dry(fuel delivered after the intake) intake systems and the way they need air to flow..this has been a long discussed topic in the world of SB cheveys and such... in a wet system a slightly rougher wall will allow the air to mix better with the fuel that is being misted..the injector can only spray a particle so big...you need it tomix on a molecular level....so itd be the difference between stir granulater sugar in a glass vs corn syrup...which is a better mix? i bet the corn syrup will be more finely joined...and speed matters in this situation..if you cant atomize the fuel in that millisecond it takes to travel from the injector to the cylinder then explode than whats the point of having great airflow from being polished to a mirror?...id rather know that all the fuel im putting in the cylnder chamber is going to be ignited and burn evenly and thouroughly hence the slightly rougher wall allowing turbulence nad therefore mixing the air and fuel completly and firing all of it evenly. make sense? its been proven amny times over...
do some research b4 pointing fingers...this guy knows waht hes doing and you should respect him fo rthe impressive work hes done.


----------



## sleeperstatis (Mar 22, 2005)

*Re: (4RingsRuleALL)*

i respect the work that he has done without a doubt. The ITB's look awesome!


----------



## Breadfan5968 (Mar 25, 2007)

*Re: (4RingsRuleALL)*


_Quote, originally posted by *4RingsRuleALL* »_
Well there is a dif between wet(fuel delivered in the intake manifold) and dry(fuel delivered after the intake) intake systems and the way they need air to flow..this has been a long discussed topic in the world of SB cheveys and such... in a wet system a slightly rougher wall will allow the air to mix better with the fuel that is being misted..the injector can only spray a particle so big...you need it tomix on a molecular level....so itd be the difference between stir granulater sugar in a glass vs corn syrup...which is a better mix? i bet the corn syrup will be more finely joined...and speed matters in this situation..if you cant atomize the fuel in that millisecond it takes to travel from the injector to the cylinder then explode than whats the point of having great airflow from being polished to a mirror?...id rather know that all the fuel im putting in the cylnder chamber is going to be ignited and burn evenly and thouroughly hence the slightly rougher wall allowing turbulence nad therefore mixing the air and fuel completly and firing all of it evenly. make sense? its been proven amny times over...
do some research b4 pointing fingers...this guy knows waht hes doing and you should respect him fo rthe impressive work hes done.























That's what the forum is for, to ask.








I was just asking about this cause it would seem like the logical thing to do. 
But the single pieces need to be smoothed to make one "tunnel", right? I mean, to not have any edges between the pieces of the intake.


----------



## 4RingsRuleALL (Mar 25, 2004)

*Re: (sleeperstatis)*


_Quote, originally posted by *sleeperstatis* »_i respect the work that he has done without a doubt. The ITB's look awesome!

Changed your tune real fast...lol as far as the pooling thing...fuel doesnt have to be moving ata very low rate of speed to "pool" it cna just mean it hits a area of bad flow so it creates a spot kind of like a Waterfall crashing into the rocks below nad making an indent..when the water turns and twists at the bottom of the falls b4 it gets pushed out of the way by more water is more of how it happens...if that makes sense...lol







ive been working to much this week


----------



## 4RingsRuleALL (Mar 25, 2004)

*Re: (Breadfan5968)*

judging from waht i could see...the closest to have an "edge" in the intake runner is the lip from small to big which isnt really that bad..if the lip were higher on the head side than o nthe ITB side then ya it would make a big disruption in flow but im sure he smoothed off that edge some to help flow...but we are only working with 14.7PSI so i dont think a lip going the same direction as the flow will effect it much at all


----------



## Breadfan5968 (Mar 25, 2007)

*Re: (4RingsRuleALL)*


_Quote, originally posted by *4RingsRuleALL* »_judging from waht i could see...the closest to have an "edge" in the intake runner is the lip from small to big which isnt really that bad..if the lip were higher on the head side than o nthe ITB side then ya it would make a big disruption in flow but im sure he smoothed off that edge some to help flow...but we are only working with 14.7PSI so i dont think a lip going the same direction as the flow will effect it much at all

True, didn't think of it being that way around. http://****************.com/smile/emthup.gif


----------



## 4RingsRuleALL (Mar 25, 2004)

you have alot of posts for being around since 07...how is that?


----------



## rivethead (Nov 27, 2004)

*Re: (4RingsRuleALL)*

Rough - Smooth. I have been down that rabbit hole. People still argue which is better. Bench Racing at its finest. The best explanation I have heard is it depends. Some ports/manifolds do better with it - some less. A rough port can cause a thicker boundry layer which can decrease flow but make up for it in better fuel suspension. Some ports do better with a rough bottom and sides but a smooth top and vice versa. Spend your time thinking about your tuning not your port finish. You will get more power and be happier with your motor.
Just a little information - I just picked up my new head which was done by one of the better head porters on the East Coast (pro race teams and a 1 year waiting list). A real engineer and very good at what he does. The ports have a fairly smooth finish - Not a mirror finish though.


----------



## Breadfan5968 (Mar 25, 2007)

*Re: (4RingsRuleALL)*


_Quote, originally posted by *4RingsRuleALL* »_you have alot of posts for being around since 07...how is that?

Post-whore status.


----------



## C LePoudre (Jan 19, 2005)

*Re: (Breadfan5968)*

hp? dyno? seat-o-pants?
Thanks


----------



## 4RingsRuleALL (Mar 25, 2004)

*Re: (rivethead)*


_Quote, originally posted by *rivethead* »_Rough - Smooth. I have been down that rabbit hole. People still argue which is better. Bench Racing at its finest. The best explanation I have heard is it depends. Some ports/manifolds do better with it - some less. A rough port can cause a thicker boundry layer which can decrease flow but make up for it in better fuel suspension. Some ports do better with a rough bottom and sides but a smooth top and vice versa. Spend your time thinking about your tuning not your port finish. You will get more power and be happier with your motor.
Just a little information - I just picked up my new head which was done by one of the better head porters on the East Coast (pro race teams and a 1 year waiting list). A real engineer and very good at what he does. The ports have a fairly smooth finish - Not a mirror finish though. 

PLEEEEEASE post pictures????? i wanna see it, im really open to learn as much asi can about any of these topics


----------



## C LePoudre (Jan 19, 2005)

*Re: (C LePoudre)*


_Quote, originally posted by *C LePoudre* »_hp? dyno? seat-o-pants?
Thanks

Also, what diameter and thickness of Aluminum tub did you use? 
Thanks again.
Chad.
BTW: Best custom itb setup I've seen so far. http://****************.com/smile/emthup.gif


----------



## 4RingsRuleALL (Mar 25, 2004)

*Re: (C LePoudre)*


_Quote, originally posted by *C LePoudre* »_
Also, what diameter and thickness of Aluminum tub did you use? 
Thanks again.
Chad.
BTW: Best custom itb setup I've seen so far. http://****************.com/smile/emthup.gif 

ya what he said....beautiful work man


----------



## 16v dubber (Dec 1, 2004)

*Re: (4RingsRuleALL)*

very sick.


----------



## NTRabbit (Mar 28, 2001)

*Re: (C LePoudre)*


_Quote, originally posted by *C LePoudre* »_
Also, what diameter and thickness of Aluminum tub did you use? 
Thanks again.
Chad.
BTW: Best custom itb setup I've seen so far. http://****************.com/smile/emthup.gif 

Sorry for the delayed response. I just moved across the country to Colorado, so things have been a little hectic. Had to leave the rabbit back in Virginia for now too (tear). Here is a thread talking about the pipe I got http://forums.vwvortex.com/zerothread?id=3064336 
If you go to http://www.mcmaster.com , it is part number: 4561T512 . Or you can just go to mcmaster and type in "schedule10 aluminum pipe"




_Modified by NTRabbit at 9:01 AM 8-27-2007_


----------



## peter139 (May 4, 2005)

*Re: (NTRabbit)*

next question:
why did you make the intake so long. For torque or horsepower or what?
Ive seen itb setup's with much shorter set up between cilinderhead and throttle.


----------



## hyperformancevw (Mar 15, 2007)

*Re: (4RingsRuleALL)*

research why there are dents in a golf ball.


----------



## NTRabbit (Mar 28, 2001)

*Re: (peter139)*


_Quote, originally posted by *peter139* »_next question:
why did you make the intake so long. For torque or horsepower or what?
Ive seen itb setup's with much shorter set up between cilinderhead and throttle.

Well, I did some simple equations for size of engine and where you wanted your power band to be, and that put my ITB runner length somewhere between 14" and 16". If I did it again, I would probably make them about 2" shorter so that I could play with the velocity stack length a little more.


----------

