I bought a BMW throttle motor and pedal. I'm waiting for my PMO EFI setup to be delivered. I bought the BMW stuff because it was not very expensive and because I've seen it used before.

I've got one problem (probably more, I'm new to all this). The BMW throttle motor is the older style with only one position sensor output. I need two on the throttle motor and two on the pedal. The pedal has two so no problem there.

I think I have four options for the throttle motor:

1 - swap out the BMW sensor for a newer one that has two sensors - I haven't found one that fits.

2 - Use the sensors on the PMO throttle shafts - I'm not sure that would work. I read somewhere that the ECU is looking for different voltages from the sensors so might need a resistor. The second problem is that they're not on the same shaft so even small differences in movement could be a problem.

3 - Attach a separate TPS to one of the throttle arms - seems easy but a bit of a kluge.

4 - Use the single sensor on the throttle motor and make up a second output with a small resistor (I read about this on a Link ECU forum). Not a great idea because I'm removing the safety factor of dual sensors.

Any ideas? Thanks

Why not buy the throttle motor that has dual output and use that? Seems a much easier and cheaper (in time and money) than kludging something together.

I believe most dual output TPS have one that goes 0-5 and another that goes 5-0. A resistor will not help with that. There are dual output sensors available, but they are about the price of the cheap BWM throttle bodies.

Two reasons, one I already bought one without realizing I had a problem and I don't want to spend $1000 for one but that may be the best way to proceed. I think you're right about one going positive and one going negative. I'm not sure how that guy got it work with a resistor - it's very likely he didn't.

One good thing about buying a throttle motor from a BMW is that they made 1000's so the track record is there.

The DBW throttle bodies are about $500 and can be way cheaper if you buy aftermarket. Also look at the GM depending on what size you need.

Your first mistake is the cheapest.

This is the part I bought used for $250. There's a lot of throttle body motors attached to throttle bodies but not many separate throttle motors.

https://www.pelicanparts.com/More_Info/13627840537.htm?pn=13-62-7-840-537-BOE&gad_source=1

You really should look at the EFI Hardware DBW actuator I posted about earlier. It uses the same Bosch motor used all over the Industry and is packaged in a flexible way that will work in a lot of installations. Sometimes it is not cost effective to buy the “cheap” solution.

I can tell you from experience that you want the position sensors in the DBW actuator and not on the ITBs.

I agree with Winders the EFI Hardware actuator is the better solution and will save you headaches in the future. Reliable Bosch unit too.

I opted for a single unit with a combination of the linkage my Clewett ITB kit came with. Paired with the Toptunning 997 pedal and adapter bracket you have a working solution.

https://www.topperformancetuning.com/shop/p/911-dbw-997-pedal-and-mount-kit

https://uploads.tapatalk-cdn.com/202...8c03ec431f.jpg

Kinsler has a really nice looking DBW unit, but it's $$$

The Kinsler DBW actuator is fantastic. But, it is over $4000 and only a reasonable option for people with stupidly deep pockets…like probINSA teams. Remember, it’s a good idea to have a spare if you need high availability of your car. The EFI Hardware DBW actuator seems to work extremely well and is super reliable.

That’s a nice setup.

Sometimes I think I should have gone with a single actuator setup. It would have been simpler from wiring, ECU programming, and fabrication perspectives while being quite a bit less expensive

My tuner persuaded me to go with dual units as there is more control and less issues with linkages.

I was planning to buy the toptuning pedal and throttle bodies with the built in throttle motors. I emailed the owner and he was very helpful but I wanted to see an older car like mine with his stuff installed along with an A/C compressor. So in the end, I went with PMO stuff.

The toptuning setup would have been a lot easier.

Thanks - I appreciate your help. The EFI hardware does look like it will be easier to mount. I'm planning on using what I learn on the 911 on my old Jag. The Jag has a ridiculous amount of parts from the pedal to the carbs. If there was ever a car that needed DBW, the jag is it. Two $1000 throttle motors versus two $250 throttle motors is significant.

One of the problems I have with these new products in the EFI market is that they might not exist tomorrow. Was it Rasant that bowed out not too long ago? They seemed well respected in the space. I guess the sale volume, $$$, just wasn't there. There's been quite a few small time product makers here on Pelican that have vanished too.

The EFI Hardware actuators are under $800 shipped to the USA. You only need one if you do what SiracHaile did...unless you want to keep a spare on hand.

Rasant is back up and running under new management.

I’ve just returned from EFI Hardware with my actuator. I’ve also bought one of these on recommendation from someone watching this thread https://www.topperformancetuning.com/shop/p/911-dbw-997-pedal-and-mount-kit

I’ve also got PMO TBs so we can work through this together. I’m currently working out how best to mount the actuator and have something mocked up in cardboard.

If anyone has the dimensions in the photo attached I’d be grateful.

http://forums.pelicanparts.com/uploa...1733892135.jpg

I need one for each car. It's an expensive habit.

Good luck. I hope you work faster than me and post a lot of photos.

I think my TPS problem has an easy answer. Haltech and others sell what seems to be a very robust sensor. It's contactless so it should last a long time. The CW rotation is used as one input and the CCW rotation is used for the other.

https://www.haltech.com/product/ht-010408-throttle-position-sensor-motorsport-contactless/

I believe it this product:

https://www.variohm.com/products/motorsports-sensors/rotary-position-sensors-for-motorsport/euro-xpd-d-shaft

Any idea on how the EFI Hardware DBW solution compares to the OEM BMW one? I'm looking at converting an ITB setup to DBW.

https://www.pelicanparts.com/More_Info/13627840537.htm

This is video by the garage time guy. He just ripped out his new PMO ITB setup because it was too leaky for his engine. He said he simply could not get it to idle so he switched to Kinsler. I'm wondering if his ITB's are just too big. It's hard to imagine that much leaking from a new set of PMO ITB's.

https://www.youtube.com/watch?v=ZPhB-Q1cKBI

The PMO ITB setup is not great, that's for sure. I think the AT power ITBs are better than the Kinslers and a less expensive.

That "garage time guy" is not doing himself any favors by trying to do a non-standard cable throttle setup. But he seems to love making big mistakes....he made enough of them already.

The EFI Hardware DBW actuator uses a Bosch motor used all over the Industry. They just put their own custom billet housing around it. The same Bosch motor is used in the C8 Corvette and a bunch of other GM and Ford products (and I am sure many other makes). It's equivalent, at worst, to that BMW unit.

One comment I read said the BMW on was "good" because it was designed to handle 6 return springs. Don't know if there's any truth to that. I did come across a comparison table of some DBW actuators (torque, speed etc) but can't find it now.

http://forums.pelicanparts.com/uploa...1733979003.jpg
http://forums.pelicanparts.com/uploa...1733979003.jpg

Angle grinder, tape measure, verniers, drilll, files and 2mm aluminium plate. Ist’s not perfect but it’s going to do the job. Only thing with the orientation of the actuator is keeping the loom out of the way of the actuator rod.

Flip it around 180 degrees and shorten the rod....

I started there and there are some packaging issues with that too. For me I think this orientation will work well. Just need to see the loom in place to be 100% ��

As you can see in the photo of my setup, the connector for the wiring harness is right below the arms on both DBW actuators. It’s not a problem with judicious use of zip ties.

Amazing how many times zip ties are the answer!

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Single EFI Harware controller with RHD ITBs
 

I find the great benefit of the DBW setup with ITBs is the scaled progressive throttle response curve that can be programmed in at the ECU. It can smooth out low speed / low RPM driving and add in the the aggressive response deeper in the pedal where it's needed and appreciated.

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I've mocked up a cardboard template for the throttle motor. I think I'd like to make one platform for the throttle motor and vacuum line collector. I'm planning on attaching it to the three studs for the original throttle shaft assembly and two bolts on the side of the intake manifold. These are the same bolts that hold the throttle cross bar. I may need to tie to one or two of the studs on the breather too.

Scott - I see that your throttle motor bracket attaches to the two rear breather bolts. Where else does it attach? I like the twin setup.

BTW, if anyone else is taking this route, this 6 wire throttle position sensor fits the BMW throttle motor.

https://www.digikey.com/en/products/detail/variohm/EURO-XPD-2832-812-214-911-00/22286984?so=90135047&content=productdetail_US

There are two press fit dowel pins along with the two breather studs. The two breather studs are actually enough to hold the motors and the bracket in place. The holes in the bracket were purposely drilled just big enough for the studs so there is almost no free play. The dowel pins are present to locate the bracket on the cover and to prevent movement. The forces applied operating the ITBs are not enough to move anything.

The twin DBW motor setup is the best way to go especially since we are using the throttle position sensors in the DBW motors. Not using all the extra linkages required for a bell crank setup as needed with a single DBW motor setup is a very good thing. It’s much easier to setup each bank individually as there is less slop to start with and there are far less linkages to get sloppy or out of adjustment and PID setup is easier/better.

My tuner (works for an IMSA GTP Championship team) basically insisted on the 2 motor setup because of his experience with single motor setups on 2-bank engines.

Thanks Scott. I agree. Your setup is the better way to go. Unfortunately, with the PMO ITB's, there's no easy way to use two throttle motors without a lot of extra work. I suppose I could attach levers to the throttle shafts between the ITB bodies but at this point, I'll stay with it as it is.

dyno yesterday!!!
 

finally, ups and downs its running great! my 82SC....

178 buff horses ... woohoo http://forums.pelicanparts.com/uploa...1734711762.jpg

Looking good, I like the amber rain covers!

Are they PMO ITBs?

I've cobbled together a plate to hold the throttle motor. In the photo, the motor is just laying on the plate. I don't think I'll cut the plate to fit the belly of the throttle motor. I think I'll put it on stand offs. I've got quite a bit more work to do on the plate to clean it up like welding the corners and adding a rib for strength to the underside.

I left extra space on the plate for the vacuum manifold.

BTW, I had to remove the arm on the throttle motor and put it back on 180°. I also disabled the return spring on it. With the setup shown, the throttle motor rotates 20° more than needed to get full motion for the throttle arm. I'm planning to leave about 10° of motion at both ends and never rotate the throttle motor to it's limits. Make sense?

http://forums.pelicanparts.com/uploa...1735155534.jpg

Having just fitted a single motor to my PMO set up I cannot see how 2 would be required. Like you say it would in fact be very hard to package even if you decided it was best to go that way. And not to mention it’s far more expensive. You can always run a Clewett TPS as well as a single motor (with its own TPS).

The PMO setup has never been a favorite of mine. The only reason I would ever select those ITBs would be if I needed that particular period look. There are MUCH better ITBs out there from a variety of sources. I prefer the AT Power ITBs as I prefer the benefits of the shaftless butterfly design (higher intake air velocity for any given air volume requirement which results in more power and torque). Plus they look super sexy. Finally, the PMO linkage setup is not great. The AT Power setup, for example, is much less likely to fall out of adjustment and is more precise.

Again, using the two DBW motor setup with most ITBs eliminates all the bell crank linkages and connects to the ITBs directly via a rod with rod ends. All super precise and with even lower chances of falling out of adjustment. Yes, it could be viewed as over kill but professional experience tells me otherwise.

In my case (a race engine in a race car), I was looking for the most power along with the highest reliability. So the extra cost was not really a factor. You, in your situation, may have less demanding requirements.

I don't have personal experience, but I've always seen multiple motors on engines with mutliple banks of ITBs. The photo of the GM LMDh engine with the two Kinsler dbw motors is the one that always sticks out to me.

I was able to achieve a bit of a milestone, for me at least. My DBW setup is working. I wanted to make sure the DBW worked before I did anything else so I bought a Deutsch connector kit and dug up my old Daniels crimper.

I made a few mistakes. Number one, I hooked up the pedal connector incorrectly twice. The first time, I had the wrong pinouts. The correct pinouts can be found here.
https://openinverter.org/wiki/BMW_Electronic_Throttle_Pedal

When I remade the connector, I had my 1 2 3 4 5 6 backwards because I was thinking about the wrong side of the connector. I imagine I'll make that mistake again. For now I'm trying to make sure I look at the numbers by looking into the socket side not the plug side.

My next mistake was forgetting that the hall effect position sensor must be mounted correctly. The D socket is free to rotate 360° but if you put it on 180° wrong, it essentially reads high and low only. There's no linear output and it won't calibrate. It's wrong in this photo.
http://forums.pelicanparts.com/uploa...1735513416.jpg

With it installed the right way, it calibrates perfectly. It's correctly oriented in this photo.
http://forums.pelicanparts.com/uploa...1735513416.jpg

With that done, I was able to control the throttles with the pedal. FYI, I bought the pedal used for about $30 and the throttle motor for about $225. My mounting plate works fine and leave me enough room for the vacuum manifold but it's ugly so I may take it out and make another one.

So far, I've found the Haltech hardware and software to be easy to work with. The wires are all color coded and bundled neatly. Each bundle is labeled so it easy to find what you're looking for which is good because there are a ton of wires.

DT and DTM connectors are labeled correctly at the insertion point. The AS line are labeled as well, but not with every pin.