likwidchz

Howdy,

After doing some google foo and posting here, turns out a skunk2 intake manifold, with throttle body is the same price as OBX ITB's.

The nice thing about this will give me a good chance to take a look at the ITB's and clean up any bad items regarding it as well as some better photos as it seems like there is a lack of photos of these things.

I really would love to take these fully apart and paint bits and peices of them and re assemble with stainless steel components and really customise it.

Has anyone installed these before?
what kinds of things have to be done on a stock engine tune with Neptune to work with these ITB's and is it really a bitch to tune? does anyone have any before/after tunes available for any software really that I can take a look at to compare with my neptune H22 map to see what kinds of changes i'll be expected to make getting these to run.


How does the brake booster connect on itbs?
How does the map sensor connect on itbs?

Thanks,
--Aaron

Golding.racing

hi mate, you wont use a map sensor on itb's, use throttle pos instead.
the twm's i have, have a small take off on each runner that can be piped together to create a vacume for servo

DAmnquickDA

im wondering the same thing. ive been looking into itbs for my h2b and im not sure if its worth it.

m_shake

You can run a vacuum line from each runner to a vacuum manifold for your brake booster and map sensor. Some people will tune the car to run off the map sensor at idle and small throttle inputs(10-15% tps) then once you pass that tps threshold you run on alpha-n (tps vs rpm).

likwidchz

Yeah I just dont know what kind of gains are to be expected. I know that having some aggressive cams makes the world of difference.

I'm also curious if there is a air filter solution or does one have to be fabricated for it.

What id the car is something that you dont race? alpha N is horrible :\

I'm just wondering if its a bad idea if its a car you intend on driving around town all the time

DAmnquickDA

the killcarb site in your sig is very eye opening.

m_shake

haha thanks! **** CARB!

m_shake

Tell that to BMW, m3 csl runs that stock

dellas

I have tuned one of these on a H22A with skunk2 Pro2 cams using Neptune. It idles great and has instant throttle response. Not hard to tune if you know what you're doing, takes a little more time to get it right though. This one was tuned using TPS mapping only.

We used a vacuum manifold to connect map sensor and brake booster.

GhostAccord

Just wondering. why you hooked the MAP sensor up to a vacuum manifold. When you tuned using TPS sensor only? Why not just get rid of it all together.....

vladimir_GT

i used OBX ITB's this year for several weeks, but unfortunately the car was crashed soon after final tuning...

i've polished it inside cuz the factory obx casting is very weak. we've used a vacuum box made of 1cm diameter pipe, to supply the brake booster and map sensor... it should be a bit bigger than i had then the iddles would be better and map sensor would also work more properly....

my experience is that for daily use it was pain in the ***, the car behaves savage a bit, and fuel consumption doubled, which at this amount of torque gain was not acceptable as the car had to be daily driven....

but, as soon as you go WOT, it was fantastic... vtec sound best ever, torque gain... really nice as for a stock h22 with 10:1 CR and H22A7 cams and some 2.5" exhaust, I assume i had around 20-30Nm extra torque and around 10-20hp... much better acceleration on high speed cruising like 60 to 140mph... more convenient overtaking - i could use 5th gear and 'just do it' without vtec, didnt have to shift gears at all...

tuning was painful also, it took some time, we tried with the MAP and TPS... but final conclusion was that we should leave the map at all, only for idles, and do all of it with TPS only.

another things - some aftermarket fuel pressure regulator is needed to work properly, without it it won't idle right, and i used 400cc injectors from some mitsubishi turbo.

so finally i think it's a good deal that OBX stuff even if its chinese, and works much better than home-made ones made of motorcycle throttles - another guy here made it with those, and there was no such power/torque gain as i had....

GhostAccord

Nice to see some more real experience posted. Should post up what software you were using for tuning as well. Alpha-N is probably the more popular method for tuning IABs vs speed density (MAP & TPS).

eDm cRxXx

Here is my experience (in pictures) with the OBX ITBs for the H22: https://www.facebook.com/media/set/?...1672027&type=3

The engine is not running yet, so i can't comment on that part.

I would say the build quality of the throttlebodys them self look good. Same with the trumpets.

The runners on the other hands are really ruff on the inside (like vladimir also mentioned). Especially on the side towards the throttles.

The bolt pattern towards the head was not drilled correctly. The ports matched good on the #1 cylinder, but on the #4 the ITB runner was way to low. But all I had to do was drill out some of the holes, and the lift the flange up some on the left (#4) side. I did some regular port matching to, but not much was needed once the runners aligned properly against the head.

So all i all. If you want ITB's, but don't want to pay for Kinslers, I guess they get the job done. But remember, some porting is needed to get proper gains.

Close up of the #4 runner before I modified it: https://www.facebook.com/photo.php?f...1672027&type=3

vladimir_GT

My setup was all tuned with P28 ECU and Crome software

Some pics of work done over it :






here's the factory casting which really sucks :



while working on it :



and AFTER :




Coming back to what you gain of that, cuz that's probably what's everyone most interested in, as i said - i had nice power and throttle gain on stage1 stock bottom end h22 with 10:1 CR... so, if someone is planning to install it on something like eDm_cRxXx is building, you can expect much more... asuming around 50Nm (30-40 lbs/ft) of torque and astonishing throttle response for sure

i have a short video recorded on the "unfortunate day" when i crashed, showing how the car idles WITHOUT the fuel pressure regulator which is definitely needed to idle like a honda, not like subaru which you'll be able to hear couple weeks after my car was done, the same garage installed another OBX itb's on H22A motor ( with nice custom exhaust header, built head and stage2 cams ) and it idles perfect and did 260HP and some similar torque around that

that's the vid : http://www.youtube.com/watch?v=cInTH120zqY

so the final verdict is that it is a nice and not too expensive device, that needs some work on it as the OBX wanted to make it cheaper - so the casting is not perfect... some metal parts of throttle bodies mechanisms maybe would need to be replaced with some stronger and higher quality pieces, but still it gives you exactly what you wanted out of ITB's - great throttle response and much more torque...and an EPIC VTEC SOUND ! :D

for a track day car - great deal, for some amateur drag racing - the same, for a daily driven street car... needs a lot of work, but possible some air plenum with high flow filter + big vacuum box to get nice MAP sensor readings, fuel pressure regulator and nice tuning and it is possible to drive it - especially in US where gas is much cheaper than here in europe ! :D

dellas

Map sensor still provides valuable data about the engine....

DDTECH

Map is always important to keep. It should also be used for lower RPMS tuning, while the purpose of alpha-N is to use Map AND TPS...

I've tuned ITBS using both methods. I've also tuned my own personal set i had back a few years, using just MAP. I created a bigger vac log then the GE one which gave a more "accurate" vac reading. With bigger hoses coming from each running.

hussain-vtec

Agree

GhostAccord

My point is that if you tuned TPS only, what good is any of that MAP data?

IMO blending the two is a good way to keep some reliability. Using speed density (MAP) when it's available and then crossing over to Alpha N (TPS vs RPM) is the way to go. Using straight Alpha-N isn't as good as using both. I was wondering why you hooked up the MAP and never used it for tuning idle and low load (cruising) conditions is all.

dellas

We use the map data for information about the intake performance.

GhostAccord

OK so are you using a plenum or some sort of air box over the throttles?

q16racer

nothing wrong with having data. I'll definitely still be running a map sensor even tho ill be using tps

GhostAccord

I never said there was anything wrong with data. I have tuned a few MAP to TPS and using the MAP data works great. However, once the MAP - TPS threshold has passed a certain point. The MAP data is kind of a moot point. Unless you start to see vacuum again in higher rpm/load conditions or you start to see + pressure (N/A boost phenom). It is definitely useful for mapping that sort of data.

dellas

Open throttles, no filter or airbox...

unuselectus

Any more feedback on anyone running these lately?

MOCrxHf

I'm running them. No issues. Tps is kind of funky. They've been great otherwise.