Pelican Parts Forums - Going to make the leap to ITBs...

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- - Going to make the leap to ITBs... (http://forums.pelicanparts.com/porsche-911-technical-forum/968304-going-make-leap-itbs.html)

Quote:

Originally Posted by dos531 (Post 9720608)

I would go with the triumph itbs, cost vs benefit doesn't seem to be worth it for the benefits on the jenveys.

Is his ms2 setup sequential for fuel? You give up a lot of that throttle response youre looking for if its batch fire. If al can do ms3x with that kit, you should definitely consider it. The ecu is only a couple hundred more and is a major improvement.

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Quote:

Originally Posted by trond (Post 9720669)

following this. ITBs may be my next step. Curious about the comment on sequential fuelling vs batch and throttle response. Why would there be a significant difference ?

I have to ask the same question as Trond. Batch firing has very few disadvantages as I understand it, and I can't see how it would ever have anything to do with throttle response on ITBs. Potentially a bit less fuel efficient at low RPM and part throttle, potentially less smooth at idle or low RPM. Al programs both types of systems with MS2 for batch and MS3 and AEM for sequential. He says he hasn't found any noticeable differences. Its maybe a grand more expensive to go MS3, its not just an ECU in the kit but also COP. Going with AEM its a couple grand more.

But don't listen to me, there is plenty to read on the web about batch vs. sequential. For my needs the batch fire version is a bit more in the budget.

Some links I found helpful:

https://members.rennlist.com/951_racerx/SequentialVsBatchFiring.pdf

Tech Page

Quote:

Originally Posted by evan9eleven (Post 9721403)

Full throttle and high rpm batch fire makes no noticeable difference, but idle and off idle response is greatly improved. This is from personal experience moving from a batch fire system to a full sequential system.

FWIW, I am running my setup batch at the moment and, coming from the stock 964 AFM, I don't know how much more responsiveness I could handle! The response from idle to 4k is pretty stupid. I'm not saying sequential might not be better, but this thing is already touchy--in a good way..

Moving from CIS to Triumph ITBs will be huge. I have Al's kit and even though my tune is **** it's still 1000 times better than the CIS was. The sound and the response is incredible. The benefit of going with a "better" ITB (straight shot to all ports or shaftless) just isn't there for a street car. You might gain 5 horses at most with the best tuning imaginable. Look at the PMO carburetors that everyone loves - those don't have a straight shot either.

A little update, finally SmileWavy

I went with Al's kit, Triumph ITBs, MS2 and EDIS/Crankfire. I'm buns deep in my gearbox rebuild, but after that I'll update my thread here with the ITB upgrade as well. Cheers!

http://forums.pelicanparts.com/uploa...1517173922.jpg

http://forums.pelicanparts.com/uploa...1517173922.jpg

So pretty..! any progress? I wanna put ITB’s on my 3.2... But that’s that’s a long way off atm.

Quote:

Originally Posted by intense1 (Post 10053656)

So pretty..! any progress? I wanna put ITB’s on my 3.2... But that’s that’s a long way off atm.

Getting there! You can also look at my thread, the ITB bit starts on page 11. Direct link here.

I know ther engine crossmember is on backwards in this photo, already fixed. ;)

http://forums.pelicanparts.com/uploa...1527005822.JPG

Hi, this looks like a great project.
Can you tell me what model of Triumph these throttle bodies are from?
Are they T595 or T509 etc ?
Also would you mind posting the throttle butterfly diameter.
Thanks

Quote:

Originally Posted by evan9eleven (Post 10053686)

So nice and clean.

Quote:

Originally Posted by robt964 (Post 10053783)

The butterfly diameter is 40-41mm. The bottom of the stack is approx. 39mm, while the top of the stack is approx. 43mm. I'm using velocity stacks that are very different than Al's.

I've noticed the Triumph bodies really bump torque with these motors, but upper end bhp doesn't change all that much, could be a camshaft thing or harmonic tuning issue above a certain rpm that these t-bodies just don't play nice with. I will find out soon enough as my 2.8L has a DC65 cam. Tuning via AEM.