Hello.... im an rpm kinda guy with the love of that godamn ear peircing high rpm rotaries give..


who offers bolt on itb set ups out there

engine 6 port s4/s5

 

tweak it makes one - http://www.tweakit.net/shop/index.ph...521da3961ea534
I have also heard of people using the Suzuki ITB's as well.

What are the goals of the car?

 

http://www.fuji-racing.com/fujiracing_009.htm

http://www.tweakit.net/shop/product_...roducts_id=117

and yes tweak it and i think theres one more

 

If you search ITB within this forum you'll find a couple threads with some good ideas and information. A few of us are using Hayabusa throttle bodies as ITB's others are using more sophisticated setups. It al starts with $$ and ends with a lot of tuning!

 

Thanks guys!.. so tweak sells them for about seven hundred and some change.. not bad at all..

The plans for the ride

micro tech for the brains, i have the full racing beat exhaust, with the lightened fly wheel and a 6 puck.. im ready for some High reving FAST RESPONSIVE N/A power.. i dont care too much about high output, im more concerned about response.

im not porting anything.. just polishing..

those are the plans... its funnest to me ..... just like the 4ag guys

 

some guy on here is running busa ITB's, just type in ITB's in the search and you'll find some nice info man

 

786.36 Australian dollars = $635.850696 U.S. dollars


And if you are a 4AG guy . . . . you rock!!!! AW11 FTW!!!!

 

i got gsxr 600 ITB's for $30 on ebay. and i made my ITB manifold for almost free. got some metal for free, some for cheap.

but the fuel system and tuning might be costly...

 

we need pics and some type of write up for this

 

Try these:

Interesting reading for those who haven't taken the plunge:

The costs: https://www.rx7club.com/canadian-forum-42/real-costs-my-itb-set-up-661987/

This and that: https://www.rx7club.com/canadian-forum-42/itbs-ftw-648413/

600 cycle ITB's are likely choking your motor. You need something more free breathing hence 1200 or 1300 throttles.

 

each TB is 40mm. thats 40mm per port! so thats 160mm TB! picture that in a single form. the 1200-1300cc motor ones ar 44mm i think. not much of a difference. but big enough to have tuning problems and lose power.

stock 2nd gen TB's are around 60mm? i dont know. but even boosted race cars dont have that much CFM flowing to the motor. (in most cases)

aftermarket ITBs dont get any bigger than two 58mm for rx7s. and most use a 51mm with huge bridges or PP. were almost doubling that using bike ITB's. its not the best route at all. but, wayyyy cheaper. if your going to use bike ITB's. go for the smaller ones.

 

Uhm... no. 40mm diameter per port works out to two 56mm throttles or so in terms of area, or one 80mm one. Except you can't directly compare it to one 80mm one because both rotors aren't drawing maximum flow at the same time; ITBs need more flow potential than a plenum setup as the variation on flow through the throttles is a lot larger than if all rotors or cylinders or whatever are drawing through one throttle even if the average works out.

That and some of the aftermarket IDA style throttle bodies get up to 62mm per rotor.

 

I am surprised that the 600's are that big, Busa's are just a fraction bigger at 42mm if I remember correctly.

 

my measurements are at the throttle butterfly. not the opening or closing. most bike ITB's (if not all) are tapered.

kenku, im wondering how you got your math done? not saying your wrong. but i dont see it? good point on stating that the rotor is pulling less air due to being split with no plenum. but still, 40mm per port is pleny large. and still a little exsessive...

 

First off, for the equivalencies, area. Two 40mm butterflies don't have the same area as an 80mm one. 40mm butterfly has 1256mm^2 of area (ignoring the shaft) while an 80mm one has 5026mm^2 of area. Going back and solving for the same area of 2 40mm butterflies ends up with one with about 56mm.

 

I have a set of CBR600RR itbs

I selected them for the following reasons

a) Im just running a half bridge
b) its a 12a
c) wont go higher than 8000rpm
d) 8 nice 190lbs injectors, nice atomization
e) wax rod for cold idle
f) tps (and it was free)
g) vacumm in each tb
h) 40mm

and the best:

25 bucks plus shipping!

 

My math teacher always said we would need to know this stuff
.

Funny part is; I learned that one when figuring out pizza prices. Broke bachelors get very creative for food.

 

https://www.rx7club.com/showthread.p...ht=fuji+racing

 

Well seeing as dj55b set the trend

https://www.rx7club.com/naturally-aspirated-performance-forum-220/my-bridgeport-project-754841/

 

i'm just searching for them saves me from retyping everything

 

It gets worse than that when you figure airflow and not just area. Surface area adds friction to the airstream, so two 40mm tubes will not flow as well as one 56mm hole all other things equal.

 

Oh sure, definitely. And more of the open area's taken up by throttle shaft and butterfly edge with more smaller TBs of theoretically identical area too as well... I wasn't intending to do anything more than a lazyman's approximation.

 

thanks kenku. for clearing it up...i must go back to math class

xlrbplanet, what injectors are you using? from a stock car or aftermarket? are you using the stock rails? got pics of your set-up?

i been wondering wich route to go with injectors. i was thinking four 550's. im running it on a un-ported renesis.

 

I will use the 8 injectors that came with the ITBs, they are DENSO injectors. Same for the fuel rails

 

Isn't the p-port setup carb from racing beat 51mm, so then 4 40mm throttle bodies would be more than that then, correct?