I drove an F-Type with a manual transmission. I don't remember it having rev matching, but the guy in this video seems to say that it does. Go to 3:42.
Does the F-Type have rev matching or not?

 

Yes it does: in the form of a driver, throttle and clutch pedal. There is no automation in the shift process. The imprecise clutch engagement mentioned in the video is due to a throttling valve (clutch delay valve) in the hydraulic system that is unrestricted when depressing the clutch pedal and restricts the flow of fluid when releasing the clutch pedal. Removal of the Check Valve / Clutch Delay Valve (CDV)
The sensation of rev matching the presenter experienced might be due to the slow engagement of the clutch.

 

Well, I was asking about automatic rev matching, but you knew that. I'll buy one anyway without it, but I would certainly prefer to have it.

 

This rev matching

 

I'd never heard of this valve so I checked the parts catalogue, it's not listed as a separate item and I can't see anything in the drawing that looks like a throttling valve.

Unless it's built into the slave or bleeder?

 

That is sad news. On the most recent BMWs they have indeed been building that valve into the slave throwout cylinder. To resolve this issue will therefore require transmission removal and modification of that cylinder rather than a simple valve replacement on the hydraulic line. Bummer.

Cambo, is there any way you could post a pic of the clutch system parts explosion? Also a part number for the throwout cylinder would be helpful. If I can get my hands on one, I can see if that modification can be easily implemented.

 

This explains a lot. I thought after 50 years of driving a manual I thought I lost my touch. When I first test drove my mt at the dealers which is on a steep hill in SF, I had to stop at a light at the first corner. Of course a car pulled up behind me. There was no way I was going to roll back into this guy so I engaged the clutch and gunned it. After that, I smelled burning something but hoped it was new car tailpipe stuff burning off. Now I see it was clutch pressure pad. The clutch didn't fully engage when I took my foot off and the pressure plates slide. The question is, how do you modify your take off style to accommodate this valve? I've been slowly releasing the clutch after engagement in first. No problem in other gears. Another question is this must slow times in the 0-60 time trials. Would the mt be as fast as the automatic if the clutch engaged immediately?

 

This is the same trans as used in the BMW 1 series, so it should have an external CDV that looks like this.

 

That could be small part of the difference, but the 2 main reasons the auto is quicker are: 1) the auto has better and more gear ratios putting more power on the pavement more quickly, and 2) the computer shifts a heck of a lot faster than the fastest human can work a clutch and shifter.

There's a good reason you don't see manuals on any of the professional road racing circuits anymore.

 

You mind if I use this in my sig^? Lol

 

I'll have the car up on a lift in early December (new springs) and will look for it then. Hope faded after Cambo's review of the parts schematic.

Could certainly improve 0-60 times, but unlikely by as much as the .4 second deficit. The gearing is lower on the ATs, so they have more available average horses during that run.

 

Not at all . . . :-)

 

Not the best quality picture ever but here it is.



Can't see anything in there that looks like the throttle valve in Stohlen's pic.

The bleeder #1 in the pic is JDE27755
Item #6 is a "pipe" T2R15965

There is a 2nd bleeder bolted directly to the slave cylinder, same part number JDE27755

Now, interesting enough I checked the manual transmission for the XE, and there is something shown on one of the pipe assemblies that looks exactly like the valve in Stohlen's pic... but there is no separate part number for it, it'd be part of that hose assembly.

 

And here is the slave cylinder.



The slave is p/n JDE32591 - with release bearing

 

Cambo,
It turns out that #1 in the pic (JDE27755) is in fact the bleeder that attaches to the transmission and is connected directly to the slave cylinder. That unit contains the Torque Peak Limiter. I have put one on order with BritCar and will dissect it as soon as it arrives. Thank you for your help. PM sent.

 

True, but aren't those cars actually "manuals" but with the computer doing the clutch work? I know both BMW (DCT) and Porsche (PDK) use a twin-clutch setup rather than the traditional automatic transmission's torque convertor. On the BMW at least, the odd numbered gears have one clutch and the even numbered gears have a second clutch. That lets the computer engage/disengage the next gear in anticipation of what the driver is doing.


The F-Type still uses a traditional torque convertor (although amazingly well), right?


EDIT: And yes, BMW uses that CDV, the idea being to prevent a driver from "shocking" the transmission if they drop the clutch at stupidly high RPMs. It takes some getting used to. Or some removal and replacement with a valve that's been drilled out.

 

Though it's true, at least in Formula racing, that true automatic transmissions, launch control, and traction control are illegal, a full automatic tranny will be able to shift faster than a dual clutch that has to disengage momentarily, even if just for nanoseconds. The torque converter will continue to transfer torque throughout the gear change.

 

My definition of an automatic transmission extends to the BMW DCT and Porsche PDK boxes, but yes they are based upon clutch-based manual transmission technology as opposed to the traditional torque converter in traditional automatics.

 

Are you certain about that? From what I've read the upshift time in the ZF 8 speed that the F-Type uses is about 200 milliseconds. BMW's DCT has a shift time of about 60 milliseconds, since one clutch is already engaging the next gear before the current gear is disengaged. The torque convertor continuing to transfer torque doesn't really factor in as far as how long it takes to change from one gear to another.

Of course this is just what I've read online. I don't claim to be some kind of transmission engineer.

 

In that case, then yes I agree 100%.