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Re: 12v ITB's

Posted: Sat Jul 27, 2013 1:33 am
by SydneyJules
Jim, the 2.5 is in the car- it's built to ex GpA specs with 11.3:1 comp, big valve heads and ex Luigi racing GpA cams- the only thing left is the ITBs!
The thought of going to 24v is appealing, but I'm not sure I want the effort of a naturally aspirated build anymore, considering a blown build of the 2.5 will quickly reach the car's limit- the gearbox! Without needing to switch engines and sell one off, modify a 24v to fit etc.... And as you say in your book- for the 24v you need two of everything!!

I will stretch to this final mod on the NA 2.5!

So Jim, why do you prefer the triumph ones?

I'm happy to have a 12v plate adaptor made to offer for sale...

Re: 12v ITB's

Posted: Sat Jul 27, 2013 9:54 am
by Jim K
No special reason, I just liked the fact they are a 'triple' set and two such sets would cover the engine -12 or 24v.
The task of doing an ITB base plate is not insurmountable; after all, we even have 24v headers now, and believe me, this was a far more difficult undertaking! I'm sure if I had enough free time and the proper urge, I could come up with a good solution for a plate, but its not something I want to tackle just now; remember, I already have a 24v ITB set and will probably decide to sell it soon... :roll: Given the 12/24v port differences two designs would be required, having a common top surface, in order to accept the same ITB's -whichever type is chosen. Come on, let's see someone work on a ...cheap (affordable a better word?) prototype! 8)
Jim K.

Re: 12v ITB's

Posted: Sat Jul 27, 2013 1:57 pm
by 75evo
How about this, 164 inj. plates, then custom runners so 3 runners point to 1 side and 3 runners point to the other side. You then adapt runners to 2 sets of 3 throttle triumph sprint unit I think, pretty damn cheap at $60 a set on ebay. The only thing is for a race the runners are way too long. Good for a road car, lots of midrange punch.

Im going to use Alpha N for this, no more pesky vacuum pipes. Just straight TPS. Race car only. Simplify things a little. For a road car....errr Alpha N isnt the best. But for a weekend car, may not be a bad option. Lots of E30 M3 owners usethis method, and maybe the CSL also uses motronic with Alpha N because I dont see any BIG MAF in front of the HUGE carbon airbox.

Re: 12v ITB's

Posted: Sun Jul 28, 2013 12:13 am
by SydneyJules
I had found the gsx r ones more plentiful and cheaper...

I know the inlet spacing is different- I'd planned on just doing one for the 12v.
I will see if I can convince my fabrication guy to help out with a 24v one as well.

I have access to a non running 12v for the process ... Not sure if I can get access to a 24v just yet.

I've seen some guys use multi-t piece vacuum fittings for the booster to still work, taking a line off each TB port and grouping them...

I had planned on trying to fit them in a cross-ram (similar to the jenvey ones), with the butterfly closer to the inlet valve (using the adaptor plate to set the distance)... And I had thought you could vary trumpet length to fine tune the total length.

I had just planned on using socks for filtration and maybe having a NACA vent and some extraction grills for airflow, rather than box them up and have a cold air feed.

Jim, Zamani, anyone else, your thoughts?

Initial idea was to use wood to refine the plate, before having one cut.

Z, you're using autronic, aren't you?

Re: 12v ITB's

Posted: Sun Jan 19, 2014 12:35 pm
by enzo
a guy in italy is selling a set....

Re: 12v ITB's

Posted: Sun Jan 19, 2014 8:35 pm
by 75evo
I think it's missing the lower part which has the injector bosses.

Re: 12v ITB's

Posted: Mon Jan 20, 2014 6:40 am
by Jim K
75evo wrote:I think it's missing the lower part which has the injector bosses.
That's right, half the set is missing.
Jim K.

Re: 12v ITB's

Posted: Tue Jan 21, 2014 12:20 pm
by 75evo
Let's come up with an ITB.

We waited for headers since 2001. It came about 12 years later. If we start planning now, we could get it by 2026! Yessss!!!

:mrgreen:

Re: 12v ITB's

Posted: Wed Jan 22, 2014 1:29 am
by Duk
75evo wrote:Let's come up with an ITB.

We waited for headers since 2001. It came about 12 years later. If we start planning now, we could get it by 2026! Yessss!!!

:mrgreen:
What is stopping someone from having these CNC machined from billet aluminium?
Plenty of other stuff gets made that way and most of it is surprisingly well priced (I suppose the work would get done done in China or Taiwan). If someone comes up with a design that is in a similar fashion to the original, where 4/5 major parts just (he says :P ) need to be replicated for all 6 cylinders and make sure any and all linkages are just (there he goes again :shock: ) off the shelf stuff, surely said parts could be reproduced for realistic money................

:wall:

Re: 12v ITB's

Posted: Wed Jan 22, 2014 11:20 am
by 75evo
Actually look for OBX 350Z ITBs on ebay. Looks sick. 1/2 the price of others. Not an exact fit, but you gets whats you pays fors. But it's not a total disaster, needs minor work that's all.

Re: 12v ITB's

Posted: Wed Jan 22, 2014 3:55 pm
by Duk
If the 6 TB were smaller, like say 42mm, then they'd be a good starting point. But 48mm is way big.

Re: 12v ITB's

Posted: Tue Jan 28, 2014 2:23 am
by Alfa 75 Racer
Hello Jim !

How are you, ... I hope you can remember me I´m the Austrian guy who is racing with an Alfa 75 3,0 V6 12V.

Right now I´m building up a new 24 V Race Engine for that car.

I just wanted to ask you if you still sell the 24 V ITB´s and what is the price please ?

See some pics of building up.

Many greetings from Austria
Wolfgang

Re: 12v ITB's

Posted: Tue Jan 28, 2014 2:26 am
by Alfa 75 Racer
Hi Jim

Just some more pics !

Cheers
Wolfgang

Re: 12v ITB's

Posted: Tue Jan 28, 2014 5:39 am
by Jim K
Hi Wolfgang, nice work there! How did you get the block so clean :shock: ? Or is it new? I like the 75 Motronic pulley, I prefer it over the newer fwd parts and flat belt. I assume you are going to properly balance the rotating assembly, right?
I will also start on the 3.2 engine ...soon :roll: ...Definitely before summer!
Yes, the 24v ITB is still for sale at 1000€ +shipping.
Jim K.

Re: 12v ITB's

Posted: Tue Jan 28, 2014 9:33 am
by 75evo
You have 24V itb for sale? I didn't see it in the FS section. Can you post pics? I might be interested too.