Okay, kill me now. I can see it now, this project is going to be a massive headache and complete waste of time for small gain. To hell with it, let's see if it works.

So yeah ... I'm thinking of going with ITBs on my Z, as well as adding a T3 turbo. My plan is to use RB26 ITBs mounted on custom runners, with a Volvo T3 turbo. I've been getting negative feedback from a friend of mine who is very knowledgeable with vehicles, induction setups most notably. Something to the effect that it's very complicated to do such a thing.

I think otherwise.

Trying to think logically, I've come to the conclusion that ITBs would work just as well on a forced-induction engine as it would on an N/A engine. All the main components are shared between the two setups: TPS, MAP sensor, O2 sensor, with an exception being that the MAP sensor for the boosted engine would read pressure, not just vacuum. Really, that's all one would need, no?

I want massive input on this - and please, by all means, correct me if I'm wrong on something. Thanks in advance guys.

-Dave-O

 

Yeah That would take some time... I dont believe it would be the same on a turbo because ITB;s have no manifoldtheres basically a shared air filter at the end of each TB.. With a turbo obviously you would have to make some kinda box aropund the filters to get the air to the TB. and the fact that you have to tune each TB diff. to idle would be a bitch. If one is running lean it would be hard to tell then "BOOM" there goes yhat ONE cylinder, and the whole moptor.. I definetly would not do it.. Just my opinion But if you think your capable it would be interesting to see..

 

http://home.no.net/glesne/Sider_no/M...filvelstad.htm

^Yes, I know it's in German, and it's on an Audi L5. But take a look at the engine pics on the bottom of the page. That's what I'm going for. It's even a non-crossflow head setup, like our L-series.

s/c, you bring up a good point. However, the RB26 ITBs, to the best of my knowledge, are all directly linked with one another, so in theory there's no adjusting needed between TBs, since they should all open the same angle at the same time. But, I could be wrong. And I had already planned to build a box around the intake trumpets - that's a given.

Thanks for the input, keep it coming.

-Dave-O

 

First of all, you are obviously going to need a programmable stand-alone fuel injection setup to make the ITBs worth the time. Also, there is a company that makes ITBs specifically for L28s. I don't remember the website but if you search on www.hybridz.org you will find it. Good luck man and make sure you take lots of pictures.

 

I'm sure he knows he'll need a stand alone.

Wasn't this a thread not too long ago? I seem to remember talking about this. I used to talk w/ a guy from cardomain a lot about turbo setups. He's since disappeared, but his theory was to use the L24 Intake runners... http://www.cardomain.com/ride/484024/7

 

Dorifto,
Is your idea to use 6 TBs?

 

Yep. Actually, the ITBs from an RB26ETT engine as one unit.

Drew, I already plan on running a Megasquirt system, so the management won't be difficult at all to work out. If I recall correctly, lww posted a link to an ITB setup specifically for L28s that used the SU carb manifold pieces from the 260Z.

Nismo, that is an interesting design, thanks for posting that. Gives me some fuel for thought. Also, I do recall posting something similar, but not directly related to ITBs. I think it was combined with that thread about a Toyota CT16 turbo being too small for my engine.

 

You don't need stand alone and you don't need a MAP sensor to make it work. What I don't think is getting relayed here is the GTR uses ITB's stock. It also uses an intake manifold just the same as the Z does. The difference lies in the fact that the skyline has a throttle plate in each of it's runners and not throttle plate in the opening to the intake manifold. So the easiest way to do this is to find a known size of a throttle plate and fabricate a set of runners that could house those throttle plates. Then you would have to link them all together so they would open simultaneously.

Also of note is the fact that the Skyline uses a MAF. That's right. It doesn't even use a MAP sensor stock. The reason so many have a MAP sensor is because when the switch is made to single turbo (which is often) only of the MAF sensors would be working and well that just wouldn't work out. So you don't need to change anything as far as engine control is concerned to make the ITB's work. And if you go the route of how the GTR's manifold is set up then it's VERY feasible with this car. What this will do for you is increase throttle response greatly. And since you can still control runner length and manifold volume you can still control where the powerband will be. If you or someone you know has any skill with a welder and a tape measure then this project isn't as complicated as you might think. But it is precise and error won't turn out nicely. Everyone is so used to the filter or air horn at the end of the ITB's that's so common, I thought I should clear that up.

Oh and by the way, I'm not saying don't use stand alone. You would see even greater benefit from the ITB's with the tuning of a stand alone. I'm just saying you don't NEED it

 

Thanks for the input J - you pointed out a few items that most miss.
I think a lot of people miss that one.
Exactly why I'm doing this.
I don't think it's complicated ... everyone else is proving me wrong!

Okay, so here's what I'm going to do - I'll start simple, by re-using the stock computer with a rising-rate fuel pressure regulator. The TPS won't take but 5 minutes to get in the right place and accurately working. AFM will be placed where it is stock.

Hell, I might just do the ITB thing before I get the turbo. I'll run it that way to work out the kinks, then add boost to the equation.

 

Dorifto,

Found this while lookin @ some Bimmer pics... tis a BMW 2.5L engine. I imagine this would be close to what you'd want.

BTW... someone turned off the IMG posting again.

 

Mmmm ... yes. The sex.

I dig the velocity stacks too - very hot.

I've decided to skip the N/A temp build, and go full turbo ITB. An acquaintance of mine on HybridZ.org will take a Q45 TB and $50 in trade for his RB26 ITBs, so technically, I'm getting them for $100. Turbo's $200 from a friend, and welding supplies kindly sold by my good friends at Harbor Freight Tools. I'm psyched!

Nismo, I'm going to be looking for a ZXT exhaust manifold, would you by chance have one laying around I could buy off ya?

 

Dual twin throttle bodies to replace SU carb's:

http://www.twminduction.com/Throttle..._throttle.html

Triple twin throttle bodies to replace triple Mikuni & Weber setups:

http://www.twminduction.com/Throttle...eBody2900.html

"Pressurized" airbox:

Unfortunately, it's not for sale...

 

^ Very nice. Thanks for the links, lww. Good info there.

 

Stupid question. What the lell is an ITB? I have no idea what one is or looks like. I'm still learnin bear with me here.

 

Individual (or Independant) Throttle Bodies... like the pic I posted above.

Dorifto, I don't have a spare L28ET exhaust manifold @ the moment, but I gotcha covered if I come across one.

 

Go to Zcar.com and search for post from 1fastZ, he has that set up but on an NA. May give you some ideas on what you are trying............

 

1fastZ has ITBs? I've never noticed anything from him about his car pertaining to ITBs ... I'll check that out.

Isn't 1fastZ the guy doing the KA24DE head sectioning to get it to fit on the L28 block?

Thanks Nismo, it's much appreciated. I was up at the Pick-n-Pull yesterday, and saw quite a few Zeds there, and a Maxima with the MN47 ... if you ever want an F54 block with 12:1 CR, snag that head. I was too poor though, couldn't even get the decent headlight buckets there.

 

I gotta hit up the PnP tomorrow to get some Saturn parts for my GF's car. I'll deff check out the Datsun / Nissan section.

Also, check this fine product of ITB's on ebay (to go along w/ this thread):


http://cgi.ebay.com/ebaymotors/SK-50...QQcmdZViewItem

 

Dude, Those things are HardCore!!! That's way over the top... I like it

Rod.

 

What ever you do make sure your paypal information is up to date before bidding on those suckers

Did anybody else notice that part?

 

"BUT.......................
If you have any non-pay feedbacks in the past 6 months,
Or your eBay account has been idle for more than 3 months,
Or your eBay account is less than 2 months old,
Or any of your eBay contact info is incorrect,
Or if you have the security on your e-mail set so high,
that when I try to contact you, it bounces back,
Or if your ship-to info does not match what Paypal shows 100%,
Or if you live in the US, and
and do not have a verified account and confirmed address,
Or I think ANYTHING is fishy at all...........
FORGET Paypal !!"

 

Paypal is good for making payments but... www.paypalsucks.com
if you read that there is alot they can screw you on.. When I was selling ALOT on ebay they froze my account 5 times because of transactions were too large (over 10k) So I stopped using them and just have everything wireed directly to my bank account

 

I guess I won't be using paypal to conduct my business. I hadn't planned to anyways but that site has definitely cemented the fact. I've never had a bad issue with them so I'd just as soon keep it that way and stick with a merchant account and do it all myself. No sense in asking to be ripped off, right?

 

HOT DAMN! And for an RB20/25, too. Shame those ITBs would cost more than my engine, trans, and ECU shipped to my doorstep.