DIY d-series ITB's

[Kracer427]

I fell in love with the DIY individual throttle body project featured on Homemadeturbo.com and i'm just trying to work out some bugs before i go for it...

How do you get around the EVAP system from the old intake manifold? Would not having this pluged in throw cel's everywhere? Would the engine still run fine without it and throwing a code? I'm running a stock P28 ecu right now on my little D, would i have to switch over to a Hondata or ZDyne unit in order to make this run? Because if i don't need it....i'm sure i can dump that cash into something cooler like head work or new pistons. I've heard many different views on ITB's, "they don't make good power compared to a usual aftermarket manifold", "they only help above 5k", etc.... ITB's for about the same price as a Skunk2 manifold, sign me up But any help you can offer as to how to get this running is appreciated.

 

[MikeBergy]

I'm pretty sure the EVAP system is independent of the ECU, but not entirely sure. I am sure as hell you wouldn't pass a visual inspection at the smog stations here in CA. and yeah, ITBs are only useful if you are driving at like 5k+ everywhere. Kiss any lowend you thought you had good bye.

 

[StyleTEG]

I am running into the same issue as you. I plan on putting my ITBs on this weekend, but thats the only aspect I am unsure of.

I might try connecting it to my vaccum manifold and see if thats all it needs. If not I will probably either ground it out, or try and create some sort of emulator to prevent the ECU from throwing a code for it.

Its not one of the codes that throw the system into limp mode though.

 

[Kracer427]

"Its not one of the codes that throw the system into limp mode though"

see, now that's kinda what i was thinking too but wasn't sure. Cuz i could just see the engine sputering after warm up for some reason like when you disconnect other emissions bs, but then look at the ITB kit Toda has for the B16. They don't have anything for the EVAP when you look at it...it's the exact same as the DIY setup really.

I'm keeping the old manifold and intake for when emissions come up, but i really only want this car to make power from 4500rpm on up (vtec). I launch at 3k but i'm only interested in VTEC hp gains for the top end in drag.

 

[Kracer427]

Is anyone else on this board running ITB's?

 

[MikeBergy]

Airjockey, I think is running individual carbs for his AE86, but I think that is as close as you are gonna get on this forum.

 

[rsaeini]

why don't you guys check out HomeMadeTurbo's website because it outlines how they got around the issue with the TPS and everything else.

 

[Kracer427]

Originally posted by Kracer427@Apr 29 2004, 01:57 PM
I fell in love with the DIY individual throttle body project featured on Homemadeturbo.com and i'm just trying to work out some bugs before i go for it...

oop: the site gives lots of info but doesn't really adress getting around the emissions bs or what kind of engine management is needed....

 

[StyleTEG]

How do you plan on getting the TPS sensor to work?

I am almost done with mine, just need to do the throttle cable (easy) and TPS (AGH).

 

[Kracer427]

it shows how to get the TPS working on the site, basically you're just making an adapter plate to fit the Honda TPS where the old Suzuki one used to be. Doesn't seem to be that difficult but then again i'm sure it will prove to be a challenge when you get down to doing it.
The whole project is pretty straight forward except when it gets down to making it run like it should. You are just choping the old manifold off after the fuel rail bolts, adding an inch of aluminum pipe to each runner, and clamping the GSXR throttle bodies to the runners.

 

[StyleTEG]

Yeah, the adapter is a bit tricky.

It looks like he took out the threaded rod that goes though the honda throttle plate, cut the rod down, threaded it into the ITB, then made the adapter plate.

Definetly wasn't working for me.

So I am going to try and use the Suzuki TPS and recalibrate it with my e-manage. Its not that far off except for idle voltage wise.

 

[JDMilan]

either way for optimal tuning and reliabablity and driveablitly your going to want to go with a standalone

 

[StyleTEG]

Well, the only real way to tune them that I can think of is using EMS.

Even with hondata or a PowerFC you can't turn off the MAP and tune via the TPS, or switch the MAP for a MAF.

As long as you can prevent the car from running lean, I don't see any reliability issues. Drivability is definetly going to be interesting, but I hear people say its not bad once tuned decently. And these are the same people that claim 404s idle rough.