3200 throttle body - lock down project.

davy83

Member
Messages
2,809
Its the diameter in the choke that actually affects the air flow and the control, the diameter at the connection face is irrelevant, obviously?
 

Enz0

Member
Messages
108
I know you have all lost interest in my lock down project, but i have made some interesting observations in my testing. I am wondering how many people have a contactless upgrade and have unsteady idle or problems driving and control, especially at low revs?
It seems we have been upgrading these ETMs with hall effect contactless throttle position sensors and yes this stop them wearing out, but they are very prone to interference from magnetic sources , like err well the throttle body motor!!! I have converted 4 of these with contactless rotary sensors and 2 of these were fine and 2 had instability problems after the upgrade, subtle but there nevertheless.
I have had a contactless upgrade on my throttle body for many years and its been very reliable but I have had occasional unsteady idle and odd revving of the engine, and I now see its been the hall effect rotary sensor all along. I have now had various other throttle bodies (8 or 9 in total) on my car and its clearly not the car, it really is the throttle body. With the right ETM the car starts like a rock and idles rock steady.
I have not worked out the perfect solution to this but i am working on it. It may actually be better to put a new high reliability contact, carbon track rotary sensor on the ETM which is not affected by the motor.
Does the "Volvo contactless rotary sensor system" in your item description solve the issue quoted above?

Furthermore, do you happen to know the difference through 585064600 to 585064604?
 

davy83

Member
Messages
2,809
The new Volvo units with the Volvo contactless seem extremely good, and are almost certainly the best around. They go through my tester much better than any of the others including the Maserati ones, and they drive extremely well.

Not sure about these part numbers, it might be code related, I know the newer Maserati ones have a code revision and I am programming everything to the 2001/2 ETM code (I have the older code too and its different). They are probably just numbers for their internal stock system I don't think they are Maserati numbers, not sure.
 

davy83

Member
Messages
2,809
And sorry I only have the new ones advertised at the moment, but I have many throttle bodies (I have 8 or 9 I think and can also 2 Maserati ones I am rebuilding) and just need to find some time to get them re-built and tested, its quite time consuming, and I am busy! I you wanted other options I can probably do something, PM me.
 

Lozzer

Member
Messages
2,280
Hi @davy83 , these tb were also used on the Lambo Gallardo, with what looks like the same connector too, the market may be bigger than first thought ;) , ive tried to research the Lambo front and read some have been converted to the later Bosch unit re Audi V10 , food for thought maybe.
7750377504
 

davy83

Member
Messages
2,809
well yes I was a aware of this, not sure I am that keen to get into another one, and problem would be a car to test any modifications on? Perhaps an excuse to buy one!!!
 

Lozzer

Member
Messages
2,280
well yes I was a aware of this, not sure I am that keen to get into another one, and problem would be a car to test any modifications on? Perhaps an excuse to buy one!!!
Was thinking more utilising the Bosch unit for the 32 , after all it has been done on the Lambo. Are we saying the new contactless Magneti (Volvo) units are sorted now though?
 

davy83

Member
Messages
2,809
I am pretty pleased with the results I am getting with the Volvo units and especially taking the brand new Swedish built Volvo units and converting these for the 3200, its a little expensive but results are great and I reckon it's as sorted as it gets, I have one in my car and prefer it to my old OEM unit, bullet proof reliable.
Results stripping and upgrading older Volvo units is less easy, but equally this has also worked and a small cluster of happy owners it seems so far, and a collection of ETM's in my workshop waiting for inspiration.

The Bosch unit would require a lot of work I suspect just getting the code to work, and yes its possible but since I can get new Volvo units and make them work I am kind of content to just run with that for the moment. The Bosch units would almost certainly be cheaper right enough, and that's attractive. I need to get less busy so I have time to tinker with it!!!
 

Danny

Member
Messages
442
I am beginning to think just that sir. I have had my car for 14 years and its always had a tendency to idle slightly unsteady, and like you i have had a couple of TVR V8's that ticked over like a metronome and I just put it down to the highly strung engine in the Maserati, but it looks like its probably this stupid throttle body. I have one in my car now and it ticks over absolutely steady. I have another couple on my bench where it drifts gently up and down!! its not the engine!!

Do you have the hunting idle issue solved with the new Volvo units Davy?
 

alfatwo

Member
Messages
5,517
I don't think a little hunting on idle is a problem, about 50 RPM, mines always done this
What's more of interest is how's the drivability of this new Volvo version comperes to original factory unit if there is any
Over to you Davy!

Dave
 

davy83

Member
Messages
2,809
I don't think a little hunting on idle is a problem, about 50 RPM, mines always done this
What's more of interest is how's the drivability of this new Volvo version comperes to original factory unit if there is any
Over to you Davy!

Dave
Well when I first got this conversion to work it worked without errors but did not feel right and there was a definite hesitation from idle and low throttle. I initially tried just tinkering with it, but realised that both this is very subjective and also not very repeatable. So thinking about it, its a choke which restricts air flow, so I made a computerised test rig which measures the air flow choking effect and mapped several original Maserati units and then started to try and match the air flow profile of the converted units to the Maserati ones
77567
77568
These are a couple of examples, the green trace is the Maserati unit and the yellow one is the converted Volvo unit. Below 3/4 throttle its within 1-2% of the original.

At the wide open and the air flow is higher and that's because its slightly bigger choke. Not much I can do about it. I did build 3-D printed choke inserts which cured this issue, but I was really nervous about these coming loose and getting sucked into the engine. So I am not proposing that.

As you can see I have managed between tweaking the code and altering the shape of the choke to get a pretty good air flow match.

And it drives really well, I am running one in my car, as I have said and prefer it to the original as I have not removed the idle section of the choke profile completely so its easier to control at low revs, and idles more steady.

There is a chance the engine will run a little lean at full throttle because of the larger bore, but the ECU already uses the knock sensors to remap the mixture and advance and I think this sort of 5-7% increase is within the scope of that system and I have no problems with the car so far.

I really was just a bit alarmed at the absence of available ETM's and just thought it needed solved!!! :)
 

davy83

Member
Messages
2,809
I don't think a little hunting on idle is a problem, about 50 RPM, mines always done this
What's more of interest is how's the drivability of this new Volvo version comperes to original factory unit if there is any
Over to you Davy!

Dave
Also i think the hunting is possibly a product of the engine, ands its almost impossible to remove this completely, but it can be kept to a minimum.
 

alfatwo

Member
Messages
5,517
Nice one mate, very impressive!
Except for throttle body and pedal potentiometer problems the old 3200's are good to go...
The rest is just worn out old car stuff, which is the same as in any 4200 and GS of the period

We could keep these lovely old cars going forever... lets hope we don't get stitched with this going green sh*te only to find out ten years or so later it was total bollox!

Dave
 

Oneball

Member
Messages
11,075
Well done.

I reckon the hunting at idle is a function of the large x section of the throttle body and the fact it needs a very small change in air volume to raise the revs.

If you look at the like of the efi on Rover V8 they use an air bypass channel and needle to set idle and a lot of more modern stuff has a separate idle control valve with much smaller x section than the main throttle body. Doesn’t happen with a carb as there’s no feedback loop.
 

davy83

Member
Messages
2,809
Well done.

I reckon the hunting at idle is a function of the large x section of the throttle body and the fact it needs a very small change in air volume to raise the revs.

If you look at the like of the efi on Rover V8 they use an air bypass channel and needle to set idle and a lot of more modern stuff has a separate idle control valve with much smaller x section than the main throttle body. Doesn’t happen with a carb as there’s no feedback loop.
Well yes I reckon you are right there. However its worth noting that some of these throttle bodies when not on the car sitting with a fixed demand on them the flap moves gently, suggesting a problem with the feedback system in the electronics. Its a lot worse with the contactless rotary sensors than with the original carbon track units, which also suggests these sensors are affected by interference from the main motor magnetic field. But with careful set up and a bit of messing around it can mostly be cured, I have a few here I think will just go in the bin as I cant get them to run stable at all.
 

Zep

Moderator
Messages
9,110
What amazing work. Awesome!

I am not surprised there are minor variations in flow as the larger choke will have a different valve authority as they call it in water systems, but given all the other factors at play it’s unlikely to give issues.
 

rs48635

Member
Messages
3,181
So impressed - well done chaps.
My 2001 3200 has the original TB and think it is causing huge issues.
What is my the best option to plug and play a replacement? Happy to send my own back as part exchange or rebuild
 

alfatwo

Member
Messages
5,517
I wonder if a little bit of old school cylinder head work on a 3200 now you can flow more air with Davy's TB, maybe a genuine 400+ hp is possible

I've recently tried this with my 1980's Uno Turbo, once you get over170hp at 1.2 bar boost pressure the magnetti marelli digiplex old school ecu can't cope with the fueling even with larger injectors
It runs lean at the top end, runs out at about 130mph.... then its melted pistons!

Dave
 

rs48635

Member
Messages
3,181
I wonder if a little bit of old school cylinder head work on a 3200 now you can flow more air with Davy's TB, maybe a genuine 400+ hp is possible

I've recently tried this with my 1980's Uno Turbo, once you get over170hp at 1.2 bar boost pressure the magnetti marelli digiplex old school ecu can't cope with the fueling even with larger injectors
It runs lean at the top end, runs out at about 130mph.... then its melted pistons!

Dave
Wondered about this too. Then remembered that the last thing my own 3200 needed was more power :). Better headlights, more rear grip and maybe reduced thirst. One rolling road day measured my car 390bhp. Many others went on the same kit, several modern Ferraris at 90% of quoted stock values, Gallardo measured under. Only other things that measured up was freshly restored Daytona and devilishly loud 911 (964 with modified exhausts).
 

Nigel A

New Member
Messages
1
I am pretty pleased with the results I am getting with the Volvo units and especially taking the brand new Swedish built Volvo units and converting these for the 3200, its a little expensive but results are great and I reckon it's as sorted as it gets, I have one in my car and prefer it to my old OEM unit, bullet proof reliable.
Results stripping and upgrading older Volvo units is less easy, but equally this has also worked and a small cluster of happy owners it seems so far, and a collection of ETM's in my workshop waiting for inspiration.

The Bosch unit would require a lot of work I suspect just getting the code to work, and yes its possible but since I can get new Volvo units and make them work I am kind of content to just run with that for the moment. The Bosch units would almost certainly be cheaper right enough, and that's attractive. I need to get less busy so I have time to tinker with it!!!
Hi how much are you Volvo conversions - 2001 3200 GTA Assetto Corsa. Thanks, Nigel