XKR manual gearbox
#1
XKR manual gearbox
Hello all you XKR fans!
With a bit (or rather, a lot) of help from Norman Durban and Tom Lenthal, I finally got a 6 speed Tremec in my XKR. So far, it works fine. On a slow and flatish journey through Denmark (I live in Sweden), I compared the consumption to whet I got under similar conditions with the auto box. With the auto, I could just get under 1L/100km (about 28mpg) :-( . With the manual box, I reduced this to 7,7L/100 (about 36mpg) with aircon ON :-) .
Of course, the real fun is the driving. I poped a short film on Youtube (Jaguar XKR manual gearbox) - check it out.
With a bit (or rather, a lot) of help from Norman Durban and Tom Lenthal, I finally got a 6 speed Tremec in my XKR. So far, it works fine. On a slow and flatish journey through Denmark (I live in Sweden), I compared the consumption to whet I got under similar conditions with the auto box. With the auto, I could just get under 1L/100km (about 28mpg) :-( . With the manual box, I reduced this to 7,7L/100 (about 36mpg) with aircon ON :-) .
Of course, the real fun is the driving. I poped a short film on Youtube (Jaguar XKR manual gearbox) - check it out.
Last edited by Willafizz; 08-23-2014 at 11:17 AM. Reason: Not sure how to use smilies!
The following 6 users liked this post by Willafizz:
Cambo (08-24-2014),
Don B (12-01-2020),
franksm (08-25-2014),
jaguarcraver (08-23-2014),
JgaXkr (08-27-2014),
and 1 others liked this post.
#3
I agree. As you can see on the Youtube clip, the car has been modified quite a lot, both inside and out. The gearbox is a Tremec T56. The ratios are quite different compared to the auto box which takes some getting used to. Comparing the auto and manual is a bit like comparing a bomber to a fighter: the auto (bomber) is smooth and comfortable, no surprises. The manual keeps you quite occupied but man, this is fun!
The following users liked this post:
MarcB (08-23-2014)
#6
Nice. Aston came with a Tremec T56 I think, I assume you used all Aston accesories (clutch, bearing, scattershield etc).
Does it use a "normal" 10 or 26 spline T56 input shaft or some special Aston only jobber? What about slave cylinder and pedals? What you did to the computer to make it all work?
Does it use a "normal" 10 or 26 spline T56 input shaft or some special Aston only jobber? What about slave cylinder and pedals? What you did to the computer to make it all work?
Last edited by auburn2; 08-24-2014 at 12:32 AM.
#7
Trending Topics
#8
Hello again,
Yes, you had the right youtube clip (Jag#4). The link is
.
The real brain behind the project is Norman D. He has designed the mechanical parts together with Tom Lenthal. The Tremec T56XL. The XL part means extra long which is needed to get the gearstick to end up in the right place (even then a small extension is needed to move the lever back from the radio a little bit). The ratios are (1) 2,97:1 ; (2) 2,10:1 ; (3) 1,46:1 ; (4) 1,00:1 ; (5) 0,80:1 ; (6) 0,63:1 ; (R) 2,90:1. In the end, we used a single plate clutch from McLeod. The bellhousing and flywheel are custom parts, as is the shorter propshaft. The engine is (now) a 4,2L with a KenneBell 2,1L s/c. The diff is also swapped for a Quaife limited slip type. All in all, very nice! Norman provided the pedal assembly - when I get a moment, I'll change the pedals so they match. Of course, the gearstick needs a gaiter but before doing that, I need to install some switches to control the digital gear/oil-temp indicator that is now integrated in the instrument cluster.
With reference to Aston Martin (which I love but can't afford!), there are no intentionally borrowed parts. If, like the gearbox, the parts are the same, it is coincidence.
Norman also provided the 'black box' which fools the engine ECU into thinking there is still an auto-box connected. From time to time, I was thinking of doing this myself but as someone else has already done it (and it is a tricky job!), it made life easier.
By the way, Norman has a similar conversion for the XK8.
To be honest, the clutch is pretty heavy and needs a servo. This will be added in due course. When up to speed, this is not an issue.
The actual driving experience is just as you can imagine: The old auto box is comfortable. You just sit back and watch it all happen. Apart from the lack of involvement, what used to bother me was the changes which only seemed smooth when accelerating more strongly. Of course, the manual box is the opposite. You get involved in a whole new way and I like that! One thing that can be worthwhile remembering is that the gear ratios are higher now. I am going to switch down from a 3" to a 2½" upper puller on the s/c to compensate.
One thing that would be interesting is to push the rev limiter (now around 6000rpm) up a bit. From what I understand, the engine will cope with higher speeds - the reason for the low upper limit is the torque converter.
-> Is there any setting in the engine ECU that can be adjusted?
Of course, the brute force solution is to use another ECU. This may allow for some better engine settings.
Yes, you had the right youtube clip (Jag#4). The link is
The real brain behind the project is Norman D. He has designed the mechanical parts together with Tom Lenthal. The Tremec T56XL. The XL part means extra long which is needed to get the gearstick to end up in the right place (even then a small extension is needed to move the lever back from the radio a little bit). The ratios are (1) 2,97:1 ; (2) 2,10:1 ; (3) 1,46:1 ; (4) 1,00:1 ; (5) 0,80:1 ; (6) 0,63:1 ; (R) 2,90:1. In the end, we used a single plate clutch from McLeod. The bellhousing and flywheel are custom parts, as is the shorter propshaft. The engine is (now) a 4,2L with a KenneBell 2,1L s/c. The diff is also swapped for a Quaife limited slip type. All in all, very nice! Norman provided the pedal assembly - when I get a moment, I'll change the pedals so they match. Of course, the gearstick needs a gaiter but before doing that, I need to install some switches to control the digital gear/oil-temp indicator that is now integrated in the instrument cluster.
With reference to Aston Martin (which I love but can't afford!), there are no intentionally borrowed parts. If, like the gearbox, the parts are the same, it is coincidence.
Norman also provided the 'black box' which fools the engine ECU into thinking there is still an auto-box connected. From time to time, I was thinking of doing this myself but as someone else has already done it (and it is a tricky job!), it made life easier.
By the way, Norman has a similar conversion for the XK8.
To be honest, the clutch is pretty heavy and needs a servo. This will be added in due course. When up to speed, this is not an issue.
The actual driving experience is just as you can imagine: The old auto box is comfortable. You just sit back and watch it all happen. Apart from the lack of involvement, what used to bother me was the changes which only seemed smooth when accelerating more strongly. Of course, the manual box is the opposite. You get involved in a whole new way and I like that! One thing that can be worthwhile remembering is that the gear ratios are higher now. I am going to switch down from a 3" to a 2½" upper puller on the s/c to compensate.
One thing that would be interesting is to push the rev limiter (now around 6000rpm) up a bit. From what I understand, the engine will cope with higher speeds - the reason for the low upper limit is the torque converter.
-> Is there any setting in the engine ECU that can be adjusted?
Of course, the brute force solution is to use another ECU. This may allow for some better engine settings.
Last edited by Willafizz; 08-24-2014 at 02:06 AM.
The following 8 users liked this post by Willafizz:
BurgXK8 (03-22-2015),
Cambo (08-24-2014),
Count Iblis (09-18-2014),
Don B (12-01-2020),
franksm (08-25-2014),
and 3 others liked this post.
#9
#11
The following 4 users liked this post by Willafizz:
#17
Just so there is no misunderstanding - of course, I havent just spent x thousand quid on this sort of car to save a little fuel. It was just a note for general interest. I think part of the saving comes from the higher ratios and the other from a less lossy setup. The second point is another way to say 'more available power at the rear wheels'.
The main interest for me is the involvement factor. I don't use the car as a 'daily ride' - it's a hobby, a passion, ...
The main interest for me is the involvement factor. I don't use the car as a 'daily ride' - it's a hobby, a passion, ...
#20
Now I have the manual box, it allows me to compare the two. I never thought I would say so but I understand why such cars are made with auto boxes. It all seems so smooth and refined and comfortable. What a ride. The manual box needs more attention and it will take some time to learn to drive it properly. But if you like that sort of thing (and I love it!) you simply can't get enough of it!