This is interesting. Tell me more about this throttle body and it's operation.

How much more power would you make with an ITB set up on an otherwise stock internal 3.2? Just recently bought my first aircooled and aside from an EFI set up, the internals are stock.

There’s no definitive number and where that power is made in the rpm range is again relative to a lot of factors.

You can search the forum and find stories of 10% power increase, 17% etc, you can find dyno charts showing all sorts of numbers but none of that will be directly transferable to your engine

The main reasons for efi/ITB are usually increased throttle response, the look, the sound, the move away from CIS, having a fun and challenging project, because it’s possible and cool, and finally power.

Now, if you’re changing pistons and/or cams as well then you can start making more power for sure but again it’s all relative.


Sent from my iPhone using Tapatalk

Have read through this thread as I am thinking ITB’s for my stock 3.2. But I am a sucker for the aesthetic of the Rothsport or Rasant plenum. Engine builder is suggesting Clewett ITB’s with a GT3 style plenum. I cannot find that intake on the Clewett website. For those with the plenum intake set up, could you let me know whose part you used?

Not ITB
 

Here’s my common plenum with single throttle body, however. Just put engine/ trans back in the car last week before leaving for work travel. Obviously, 964 intake halves here. Adapt Motorsport DBW conversion pieces & parts.
Patrick

http://forums.pelicanparts.com/uploa...1731294435.jpg

I don't think I posted in here with my project before. 3 liter, RHD throttle bodies, MaxxECU, Web 120/104 cam, Wiseco piston, all built by Mark at Exotech. It runs fantastic, no stumbles, great power, and starts with nothing more than a press of the starter. It came out great and 2 years in I'm really happy. At some point I need to get the IAC setup in, MAP sensor, and I want to go drive by wire.

Something cool with the Maxx is the ability to send CAN in and out. I send speed, lap, and fuel pressure over (it was already to the dash). Now I can see when things happened on track and it makes fine tuning way easier.

http://forums.pelicanparts.com/uploa...1731414103.jpg


http://forums.pelicanparts.com/uploa...1731414103.jpg

http://forums.pelicanparts.com/uploa...1731414443.jpg

After getting my car back together, my air box developed a crack. Everything else on my CIS is working fine but I think it's time to bite the bullet and install with ITB's rather than put in a new air box. My car is 1980 911 Targa. I've already ordered the parts to back date the heat.

I think I've read through just about every thread on ITB's. I do have two questions.

1 - The Racehead setup is substantially cheaper than the PMO brand. The PMO products are currently on sale with our host. Even with that discount, Racehead is a lot less. Is there any reason for this? I know Al at X-factory uses Racehead with great success in his kits. I was honestly considering buying Al's kit but I'd like to try DBW like this guy did and I'm not sure which ECU I want to us. I'm leaning towards Haltech.

https://youtu.be/w2xtVX-kCsU?si=aESvxVy0Hnaw86ns

2 - Can I fit a Sanden 507 with ITB's? Did I miss someone already doing this?

I haven't used the different systems, but the RHD ITB seem good to me. I haven't had any problems in two years of track use with them.

On the ECU, I would suggest seeing who can help you the most locally. If you're local help is on a system, strongly consider that. There are a lot of good systems and some bad :) The DBW takes a little calibration, but offers a lot of capability. The drive for it can pedal end can get expensive.

Thanks Matt,
I've got another reason for playing around with the DBW. I've got an old Jag. The pedal linkage has a lot of rods, bell cranks, bushings, etc. That's next up for an EFI conversion. What I learn on the 911, I'm hoping I can use on the Jag.
Dave

montauk....you've been PM'd

regards,
al

The RHD setup (I run one) is by far the most economical way to convert to EFI/ITB. Because the system is modular, the price is much lower. While this may upset some purists who don't like the more modern look of the RHD set up, functionally it's no different than any other ITB set up.

One of the drawbacks I found with the RHD set up, is that balancing the individual throttle bodies is much more difficult than on other systems where the throttle bodies are not modular. There are so many linkages and nuts and screws and bolts with the RHD ITB's that it just takes more time and more precision, but it's not impossible and if you're focused, it's readily achievable.

If economics is a priority, then you will have to budget more time and energy to make the system work. If you don't have time energy or the capacity to work on cars yourself, then I would suggest saving up for a more turnkey solution from AT power, JSR or PMO.

All in all you can build an EFI/ITB RHD Megasquirt system for probably about $4k or less.

Thanks Julian,
I think RHD is fine for me. I'm used to tangling with SU and Stromberg carb linkages. I can't imagine it could be worse.

I also think that while I won't install it right away, I want to go with COP. I think I'll buy the Clewett brand trigger wheel and cam sensor.
Dave

I built this about 8 months ago. 3.2SS, DC GT2-EVO cams on 108 LC, PMO ITBs , early SC large port heads, twin plug with Toyota COPs. Run by MS3x.

Sanden SD7 with custom mount driven by Clewett serpentine with crank trigger and Clewett cam sensor.

http://forums.pelicanparts.com/uploa...1732159651.jpg
http://forums.pelicanparts.com/uploa...1732159651.jpg
http://forums.pelicanparts.com/uploa...1732159651.jpg

Beautiful workmanship. How difficult was the serpentine belt install? Any problems keeping all the pulleys in alignment?

Where did you get the A/C bracket?

Thanks
Dave

The Clewett part of the serpentine was easy and took.care of the crank trigger at the same time. The rest I created.

I replaced the single tensioner pulley with a double idler on a custom bracket. The compressor mount (made on my mill) attaches to the air pump mount on the chain case. There is a rear mount on the chain case to engine case stud.

I made a custom cam oil line with a banjo fitting at the case end for clearance. The heater duct was also reshaped for compressor clearance.

It works great and really tucks the compressor out of view, along with having a very short belt run. It requires removing the distributor, of course, so coil packs or COP only.

Here is a picture during the sheet metal surgery of the heater duct:

http://forums.pelicanparts.com/uploa...1732194056.jpg

Wow, that's great work. I'd like to put my compressor in the original spot but I'm still not sure if it will fit with ITB's.

BTW - I've got your shift coupler in my car. I also bought your headlight relay kit many years ago. It may be the only JWEST Engineering item in an E-type. I never installed it in the 911. I needed to get the electric load off the ignition switch so I wired in the relays to take care of the radiator fans and AC compressor. Good stuff!!!!

That is the cleanest install of an AC compressor on a 911 motor I have seen. VERY well done!

Here are my thoughts on the AC compressor in the stock location with ITBs. I would plan to use PMO or other Weber manifold ITBs that curve forward. Using the straight-up type would take away room. I've seen SD508 compressors with Webers, so it should be possible. The newer SD7 is shorter, so it would offer even more clearance. They do come in a v-belt version, but of course your brackets would have to be custom.

Funny about the E-type. I just pulled my '68 OTS out of the barn for restoration a couple months ago. So I guess that will make mine the 2nd JWest equipped Jag!

Good advice - thanks!!! BTW, my car is a 70 Coupe.

Just chiming in on the Maxxecu front.

I am a dealer and tuner for Maxxecu and I know I am biased in saying so but it is hands down my favorite to work with. But this comes from being a professional calibration specialist for 20 years working with all your typical brands and systems on everything from air cooled street motorcycles to all out max effort championship race vehicles.

Here is the last 911 I was involved with. I provided the Maxxecu and tech support to the shop installing it and wiring it. Provided a base map and then calibrated using my Dyno Dynamics Dynotech chassis dyno and then road tuning after. The engine combination and calibration made for a terrifically smooth power delivery and excellent street manners.

Engine is a mild 3.4 liter with a Will Pyle assembled top end using KR75 cams, Apgar spec CP pistons, stock ports, PMO throttle bodies, SSI small tube headers with modified Dansk muffler (great low end torque but sacrificing top end power) and a Maxxecu Street ECU.

Video shows a dyno graph with calculated flywheel HP and torque with math developed in house by Dyno Dynamics (manufacturers of engine dynos as well). Graph posted below is HP and torque as recorded to the wheels.

<iframe width="560" height="315" src="https://www.youtube.com/embed/97wGUD929DA?si=iQ3X1t-GjrqmIC1u" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>

http://forums.pelicanparts.com/uploa...1732297744.jpg

http://forums.pelicanparts.com/uploa...1732294681.JPG


http://forums.pelicanparts.com/uploa...1732294681.jpg




This is my personal 3.0 liter, I went with RHD individual throttle bodies go with a Maxxecu Race ECU. This one will be a high rev'ing, big port, high output setup to push my targa around.

http://forums.pelicanparts.com/uploa...1732294681.jpg