ITBs on a CA18DET?

[Sil40sK]

Anybody tried it, just wondering cause I got a hold of a spare CA18DET block and I'm trying to think of something interesting and different to do to it. I've heard people say that ITBs on a turbo car are a bad idea, I know they're a little bit more difficult to tune with but I still think it'd be pretty cool to do.Post your thoughts, ideas, photos, whatever.

[sideways danny]

I've thought about building a high compression CA18DE on ITBs and running it n/a.

at one stage in it's development the Norris Designs s13 ran sunny GTiR bodies but that only lasted a few months IIRC.

Decause you'd have to run a Plenum anyway you're always going to have a restriction in the same way the standard TB is. A well designed plenum with good trumpets and a well sized single TB would be just as good IMO

[originalsin]

kinda a crazy idea, but making a totally custom setup, having 4 smaller runners coming off the outlet of the intercooler and into each tb, you could use some tb's off a bike. ot just having a regular pipe coming off the ic and going into a "collector" that would obviously be reversed

idk just an idea me and a friend thought up a while ago

[float_6969]

It could be done, but as was stated before, you'd have to use a plenum anyway, and that kinda defeats the purpose. If you're worried about the intake mani, get a custom one with internal velocity stacks for each runner and a good sized TB. Easier to tune, easier to build.

ITB's a best when applied to a high revving NA motors, at least IMHO...

[btustison]

I suppose you could get another set of the small butterfly plates and run essentially 8 throttle bodies. Of course I don't think it would be worth the work without some serious port work, and then you would need larger butterfly plates... and so on. That was just a thought that crossed my mind when I was staring at my spare intake manifold.

[CA19DET]

GSXR 1000 ITB's



cut the stock manifold runners and custom intake plenum..

[originalsin]

yup

[themadscientist]

there is a carb manifold sold. Use that and DCOE-type sports injection bodies with a surge tank. no fabrication required.

[sdtouge]

rb26stock has turbo and itb

[float_6969]

So do GTiR's, now that I think of it....

[r34 gtr]

my friend retrofitted a set of gsxr1000 ITB's on his prelude without a whole lot of trouble. the thing screams! i dont think it would be particularly hard, but would just require some custom parts. for the bada$s factor alone i would consider doing it. seeing the application though it might not be worth it....

- tim

[CA19DET]

i already have the parts and materials to do it, jsut waiting to see if my car sells, which it may not cause the locals are all talk.. anywho, i may install it in the new year.. i run haltech too so no AFM porblelms and i can use the GSXR TPS..

[CA19DET]

GSXR 1000 ITB's on a NA KA, just imagine a plenum over that and you got what i want to do for my CA

[tyrannix]

where did you come across this item?maybe using this with a 4 port intake ukdm head+runners, and that CPC plenum with a dummy 90mm TB for the IC piping to connect to.. seems to me that would increase flow and remove all bottlenecks with increased response as a bonus

im no expert of course, but if noone has done it by next summer, ill do it on my next engine (the one that is also getting a frankenstein stroker kit)

-CJ

edit>new thought, with ITBs, where would you stick a map sensor? in one of the runners?

GSXR 1000 ITB's



cut the stock manifold runners and custom intake plenum..

[SeVa-S13]

A bit of theory here, ITB's are generally a hinderance in turbo engines going for decent power. They add turbulence and there's no need for velocity stacks or air scavenging in any way because the plenum will be pressurized.

[straightedge]

not to knock your theory but the exhasut system also has pressure, yet x pipes on dual exhausts are for scavenging

[themadscientist]

Even pressurized air exhibits flow characteristics. Just watch a politician talk in the winter.

[float_6969]

edit>new thought, with ITBs, where would you stick a map sensor? in one of the runners?

[tyrannix]

+1

Even pressurized air exhibits flow characteristics. Just watch a politician talk in the winter.

[tyrannix]

ok, cool, but it brings me back to, i googled for a bit, and couldnt find anything about that

where can i find that? is that a custom piece? do gxrs come like that, or are the TBs on there assembled and welded onto a flange or runner of some sort?

i like to build almost more than i like to drive, im serious, i want to do this intake (CPC plenum, that GXR ITB unit, and if better flow, a UKDM 4 port intake side head (and runners, if the TB unit doesnt replace the runners) then something rediculous, like a 7 way valve job.... then if i can get ahold of a tomei valvetrain, i use that, if not ill make due with HKS cams, whatever valve springs i can find (little help Dee? ) and the HKS cam cogs.

but thats on the next engine... sofar i have a stripped CA.. with a 6 bolt nismo full counterweighted, increased stroke crank on the way, 6 bolt tomei 5kg flywheel, and planning on boring it to match the stroke, all forgies, and then a topmount with a t3/t04e to start, then maybe move to a GT turbo, and round it all off with a haltech (might even get the haltech early and replace the PowerFC and MAFs with Haltech and a map sensor.

but that all next year, im still waiting on Harpreet (taka motorsports) to give me a final price on the custom dealy turbo and fuel lines so i can get my current engine installed

[QUOTE=float_6969][/QUOTE]

[float_6969]

Nothing custom there. All 4 TB should have nipples on them for that exact reason.

[CA19DET]

for kicks and giglges i have started this last night, i got my other 8 port manifold, seperated it, and gave it to my roomie to fab a flange to bolt up to it and weld on some 2" (dia) i" (long) runners to then attatch the GSXR ITB's to (probably use 2" hose for now, maybe weld them on eventually if it gets good results).. i will also be using some 5" aluminum pipe for the plenum (tapered down to number 4), i will be using some velocity stacks (from some ol mukuni side drafts from my old corolla), and a 80mm inlet on the plenum to connect to my existing 80mm intercooler pipes..

i will be collecting manifold presure form the vac ports on the GSXR ITB's (will be using fittings and teflon line to get them to one line to a distribution block for MAP, BOV, EBC, BG)

i have removed the secondary butterflies, welding the holes up. I am running haltech so no AFM, and i will be removing the GSXR injectors and pluging the hole and using the TPS from the ITB's.

the ITB's are 42mm, really ideal for a 1.8L, the honda guys get really good results from ITB's and i will be tuning on this same theory, tuning the car at first with no boost, NA (charge pipe disconnected - rememerb map) then slowly introduce boost, as ITB boosted cars act very differently to part throttle and full throttle, so it eill be a learning process, if i inly pick up 10 or so ponies i will be cool, i think the bling and innovative factors are cool. and i think it will sound BAD ***..

i found my GSXR ITB;s locally at a bike shop, but they are all over Ebay.. usualyl for about 150-250 depending..

i'll post some photos tomorrow if i get the manifold back..

[SeVa-S13]

not to knock your theory but the exhasut system also has pressure, yet x pipes on dual exhausts are for scavenging

Sorry, I didn't mean to imply that flow didn't matter in a pressurized condition but I think the possible minor throttle response increase would outweigh the added turbulence for big old velocity stacks jutting out into the plenum. When I had my TopHat custom front-facing plenum made for my RB I didn't worry about velocity stacks but I did make sure to kind of port and funnel the air ports for smoother flow. On a side note: that manifold is a pretty hacked-together, bondo'd ghetto plenum. I think they should advertise them as unfinished so people know they need to clean them up, alot.

[tyrannix]

thats part of what i was getting at, is that unit with 4 TBs how a gsxr works? i dont know bikes all that well, do gsxrs use I4 engines? (that happen to have roughly the same spacing as our CAs?)do they come as single units and that 4 deal is custom, or what?

also, if this going ahead, very interested in what your results end up with, (and if the stock plenum vs 5 in pipe vs CPC plenum would make a difference)(if the ITBs w/aluminum pipe end up great, then that saves $800 for the CPC plenum)

im also on the fence on where i want to go next with my ECU, i have a CA PFC now, .... its either S14 SR d-jetro PFC, SDS or Haltech next (for the stroked engine.... maybe even earlier... i want a MAPs )

Nothing custom there. All 4 TB should have nipples on them for that exact reason.

[float_6969]

GSXR. I4. ITB's stock. Most modern sport bikes work like that. My friends carb'd R1, essentially was ITB's, but they were each little carbs too. All they do now is fuel injection. I think as far as the spacing goes. it doesn't really matter. You can make any spacing work with the correct length of pipe. My brother in law has ITB's on his race-only CRX. He just hacked the mani like they did on that KA and it worked great.

[CA19DET]

^^ exactly,

i got teh flange cut, runners to weld on, pics to come

allot of bike parts work great on cars, i have ben looking into using CBR600 ignition coils on ym CA for a while now i know the AEM guys do it,

as far as the spacing its close enough..

look at this CA motor using RB26 throttles.. watch how the runners are angled to mate to the ITB;s

[81na ZX]

Besides the GTiR and RB26 ITB's, almost every ITB is not built to be pressurized.

I talked with TWM, who make AWESOME ITBs, and they only suggest 1 Bar positive pressure, and won't warranty them under boost.

[tyrannix]

what makes it bad to be pressurized?

if thats the case, then gtir itbs would be the ticket

edit> dont hayabusas use itbs too?

[straightedge]

Sorry, I didn't mean to imply that flow didn't matter in a pressurized condition but I think the possible minor throttle response increase would outweigh the added turbulence for big old velocity stacks jutting out into the plenum. When I had my TopHat custom front-facing plenum made for my RB I didn't worry about velocity stacks but I did make sure to kind of port and funnel the air ports for smoother flow. On a side note: that manifold is a pretty hacked-together, bondo'd ghetto plenum. I think they should advertise them as unfinished so people know they need to clean them up, alot.

ok i see what you were trying to say, but the thing about velocity stacks as i understand it, is that they pull air up and around from the bottom of the trumpet therby increasing velocity hense the name. ive seen them on handmade 1000 horsepower supra motors and someone correct me if i am wrong but dosent jun use velocity stacks on their plenums?

[float_6969]

Besides the GTiR and RB26 ITB's, almost every ITB is not built to be pressurized.

I talked with TWM, who make AWESOME ITBs, and they only suggest 1 Bar positive pressure, and won't warranty them under boost.

I'm not 2nd guessing you by any stretch of the imagination, but I wouldn't mind seeing a little reasoning or logic behind this statement as well.