RWD SR20DET ITB's?

[pwr-adr]

I've searched high and low for information on how to run an ITB setup on a rwd (S13) SR. I either I am horrible at researching or there just isn't that much out about them so that is why I am asking you zilvians..


A list of questions that come into mind:
What modifications have to be done to the manifold itself to work/fit?
What sensors do I use? IACV, TPS etc.
What throttle cable do I use and how does it work with the itb's?
What upgraded fuel rail, fuel injectors, and fpr do I use?
Is there any wiring modification I have to do?
How will this affect my powerband and hp/tq numbers?


I hope some of you seasoned vets can shed some light on the subject for me. Any threads or write ups on how to do so, pics? The more info, the better. Thanks Zilvia!!!

[jrbump]

Don't do it.

After all the work if you have the alum welding fab skills or all the money if you don't you will spool sooner and have a flatter curve.

It's alot of work for it though.

I did it and it was troubles for days.

[Jodan]

um, like.
GTI-R pulsars are ITB/turbo. you can run the throttles/lower manifold but you need a custom plenum made as the GTI-R's plenum faces the opposite direction. with enough trial/error/tuning it will be effective overall.

[SoSideways]

Originally Posted by Jodan

um, like.
GTI-R pulsars are ITB/turbo. you can run the throttles/lower manifold but you need a custom plenum made as the GTI-R's plenum faces the opposite direction. with enough trial/error/tuning it will be effective overall.

Are you serious?

You just cut it at the runners and flip it 180* around so it points the right way.

No need for a "customer plenum".

This isn't Monster Garage.

[Sileighty_85]

GTIR Intake Mani will not "Bolt Up" to a RWD SR Head, the intake ports are spaced differently you'd have to cut and weld the runners/TB and redo the linkage to make it work

[Koopa Troopa]

Oh snap, what's this?

Ikeya Formula is prolly your easiest way for ITB's as it will include everything you need minus injectors and works with OEM sensors.... However it is far from the cheapest way....

[Jodan]

Originally Posted by SoSideways

Are you serious?

You just cut it at the runners and flip it 180* around so it points the right way.

No need for a "customer plenum".

This isn't Monster Garage.

never done one myself. i was under the impression that the ports matched up.

[pwr-adr]

Originally Posted by Koopa Troopa

Oh snap, what's this?

Ikeya Formula is prolly your easiest way for ITB's as it will include everything you need minus injectors and works with OEM sensors.... However it is far from the cheapest way....

That is why I asked about modifying the oem one. I know it will cost less than buying a set up from Ikeya F etc. If I wanted to know aftermarket companys that make a kit like that then that is what I would have asked for.

[SoSideways]

Originally Posted by pwr-adr

That is why I asked about modifying the oem one. I know it will cost less than buying a set up from Ikeya F etc. If I wanted to know aftermarket companys that make a kit like that then that is what I would have asked for.

Wow.

Someone helps you out with an alternative way of doing this setup and you give him shit?

Good luck to you sir for trying to find someone to help you with that shit attitude of your's.

[SHIFT_*grind*]

Someone was selling an GTiR ITB setup a couple months back that was supposedly "bolt-on," but probably still required injectors/throttle body and some other shit. Actually, it may be the same one jrbump posted up there...

[jakerps13]

2 or 3 of the bolt holes need to be moved because they don't line up. You'll need to do a bit of port matching because the ports aren't identicle from gtir to rwd.

As everyone else has been saying it obviously points toward the firewall. What I did was cut the runners and added about 30 degrees downward so the plenum fits under the hood. Otherwise it's way to high.

Here's before cut



Here's after 30 degree





After you get all the moch up shit done, you'll need to change your tps wires because it'll read backwards, make your own throttle cable and bracket, rewire the gtir IF you want iacv, and you'll obviously have to go topfeed. If you don't know how or don't want to sync itb's don't bother with the setup. You're going for performance and it comes at a cost of maintenance.

[pwr-adr]

Originally Posted by SoSideways

Wow.

Someone helps you out with an alternative way of doing this setup and you give him shit?

Good luck to you sir for trying to find someone to help you with that shit attitude of your's.

Up yours, I know I can go buy itb's and bolt them up but I simply asked a list of questions that hopefully would give me some information on how to modify the GTIR itb set to work on the rwd.

Thanks to all who have provided some useful info and to the rest great job keeping the stereotypical opinions about zilvia and its members alive.

[GSXRJJordan]

Originally Posted by jakerps13

2 or 3 of the bolt holes need to be moved because they don't line up. You'll need to do a bit of port matching because the ports aren't identicle from gtir to rwd.

As everyone else has been saying it obviously points toward the firewall. What I did was cut the runners and added about 30 degrees downward so the plenum fits under the hood. Otherwise it's way to high.

Here's before cut

Here's after 30 degree

After you get all the moch up shit done, you'll need to change your tps wires because it'll read backwards, make your own throttle cable and bracket, rewire the gtir IF you want iacv, and you'll obviously have to go topfeed. If you don't know how or don't want to sync itb's don't bother with the setup. You're going for performance and it comes at a cost of maintenance.

Great post - that sums it up. Note: cheapest way to do it (if you can fab stuff for free) is to use GSXR1000 throttle bodies on a stock (cut) plenum. The GTI-R setup is much cleaner though, and the plenum is the right shape for the ITBs/etc.

Sync'ing throttle bodies is not a huge deal, and makes an enormous difference in performance/smooth idle - just a vacuum gauge and a screwdriver

[4sfed180]

this is my setup. as previously mentioned you have to redrill a few holes and port match the manifold to the head to make it work.

i cut the plenum at the flange, flipped it, and rewelded it back. after welding did a little bit of smoothing out of the inside of each runner.





i have a rwd sr20 bottom end with a fwd sr20 highport head. since i went with an electromotive standalone i didnt need the CAS and did a crank trigger wheel setup.

[95KA-Turbo]

Most of the benefit of ITBs are lost once you put a plenum around it. Not saying it won't make the car a little more responsive, but it is basically a waste of time/money on a turbo motor. You won't see the massive mid-range gain you see in NA applications because you have to run the plenum which basically screws the whole power curve up.


Just get a massive throttle body and a decent intake manifold (greddy or something). For all of the hassle/price it costs to run ITBs I'm sure you'll see it is better to just run the aftermarket manifold w/ a single large throttle body.

If you happen to have a way to do some dyno pulls w/ an ITB set up and a greddy+70mm TB set up I am willing to bet you'll either see the same or better results from the singe TB set up. I'd love for someone to have done this and post the different graphs....if I'm wrong I'll edit my post and put lots of these .

[GSXRJJordan]

Originally Posted by 95KA-Turbo

Most of the benefit of ITBs are lost once you put a plenum around it.

Well, not exactly.

The benefit of ITB's is that you can tune the airflow to each cylinder - therefore making each cylinder run at peak efficiency. The fact that you have much more throttle body area, and are never hampered by a TB that's too small, is a minor improvement.

There's definitely a reason why the GTI-R and RB26 have ITBs standard.

I would say that there's more of a benefit in an N/A car, and I do agree that the money would be better spent elsewhere unless fabricating everything yourself.

[480sx]

Originally Posted by 95KA-Turbo

Most of the benefit of ITBs are lost once you put a plenum around it. Not saying it won't make the car a little more responsive, but it is basically a waste of time/money on a turbo motor. You won't see the massive mid-range gain you see in NA applications because you have to run the plenum which basically screws the whole power curve up.

Agreed. ITBs with a plenum isnt a good idea at all. Your talking a minute response gain for a huge PITA. Listen to the guy who did this already.. Dont do it.

Tuning your airflow for each cylinder to run at peak efficiency huh.. Why tune something you really dont need to tune at all. With a plenum and runner design each cylinder is getting the same amount of air which is what you want. You tune each cylinder for peak efficiency with individual EGT probes for each exhaust port and a EMS capible of pulling fuel from individual banks.

The main reason for ITBs was to increase your intake velocity. With a plenum it completely defeats the purpose.

[slider2828]

With computers nowadays, you can tune each injector to each cylinder, so you run at peak efficiency per bank. If you spend that sorta time and money, just get a really good ecu and logging and so much better off...

[4sfed180]

ecu alone, especially the craptastic stuff out on the market right now like the god all mighty haltech or aem will not give you the most power.

if you really want to talk about tuning a motor its not all about just injector. as much as you like to make a head that flows equally to each cylinder you really cant. you can come close to it but it will not be exact. to compensate you get engine management that can tune spark advance individual to each cylinder. you will be surprised how much it can help. for all the fan boys out there its not a big deal but when my boss use to rebuilt ferrari f40 engines, usf3 vw motors, as well as ferrari cup motors it makes a difference to make the most horsepower because that is what wins races and in the end gets you paid.

even with a plenum itb's have an advantage over a big single throttle body. pick up any book on fluid flow. its is all about velocity. volume will not help a "high performance" engine when the fluid has no inertia and doesnt fill the cylinders completely.

all racing engines that use itb's still have a plenum. it might be made out of CF but they still have it. in fact in most sanctioning bodies that have inlet size restriction thats how it is regulated.

some pics






btw this motor still had a CF plenum

[smelly240]

those of you that care - plenum>no plenum.

if you dont understand the benefits, dont assume there is none. If you have no idea what you're talking about... piss off.

[1five10]

It looks cool, though. Here's ITB's on my fully built KA-T in a 510. Nismo 555cc injectors, GT2871R turbo, Z32 MAF, Ross Pistons, Crower Rods, Jim Wolf ECU. [IMG][IMG]

[CmR333]

IVE BEEN WONDERING HOW TO DO THIS. has anyone done one with the gsxr set up?

[1five10]

This is a GSXR set-up.

[CmR333]

oh ok..nice. that does look pretty sweet.

[jrbump]

yup was me selling the bolt on ITB setup. I can't even remember who bought it.

It was a big hassle although I have to admit that a big part of that hassle was trying to tune them with my MAP setup. once we went maf we had it tuned in a day.


So if you have the money I say go for it or if you have the fab skills -but, I assume if you had the fab skills you wouldn't be asking.

[brndck]

Originally Posted by SHIFT_*grind*

Someone was selling an GTiR ITB setup a couple months back that was supposedly "bolt-on," but probably still required injectors/throttle body and some other shit. Actually, it may be the same one jrbump posted up there...

i have a f/s thread for these but i think i'ma keep em.

Originally Posted by jrbump

yup was me selling the bolt on ITB setup. I can't even remember who bought it.

It was a big hassle although I have to admit that a big part of that hassle was trying to tune them with my MAP setup. once we went maf we had it tuned in a day.


So if you have the money I say go for it or if you have the fab skills -but, I assume if you had the fab skills you wouldn't be asking.

i bought the setup from jrbump. still haven't installed em yet. but i will be doing so soon. i'll try to keep you all updated with the challenges i run into. (will be running on a redtop w/s14 t28, top feed 550s, power fc ljetro etc)

[iwishiwas-all*]

i have a set of gtir itbs fs if anyone wants them, they would be perfect for starting your itb project

[CmR333]

so for the money wich is better gsxr or gtir?

[4sfed180]

i got my full gti-r setup with injectors a fuel rail for 200 shipped about 2 years ago. it should be a bit cheaper now i hope.

[smelly240]

Originally Posted by CmR333

so for the money wich is better gsxr or gtir?

1. if you gotta ask HOW - you arent capable.

2. if ur asking how much it costs... you arent capable.

3. if someone else has to fabricate it - u might as well get ikeya (its better anyway)

D. If you can make it yourself, you wouldnt ask those types of questions.

5. gsxr bodies need more materials, either way its a bitch.


gtir setups actually went up in price. they're going for 250 without a rail/inj and 300+ with rail and inj. they wont accept normal inj apparently - you have to machine the fuel rail.