The Lotus Cars Community banner

1 - 20 of 27 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1 (Edited)
I'm having a little trouble with the sequentail transmission in my 2015 Exige V6 Cup R. I'm hoping to find some insight on this board as to what is causing the issue and if it's been seen before. Or a referral to someone who 'truly' knows Lotus's sequential transmission setup; Xtrac transmission with Shifttec GCU paddle shift control and actuation.

The car and transmission have been running great. Used for HPDE's with a little under 2000 miles now. I've recently run into the issue of the factory Xtrac transmission downshifting from 4th to 3rd, or 3rd to 2nd, on its own, without being told to do so. Obviously, this is unnerving when driving hard at high RPM's.

It seems to only do it on hot track days, 80+ degree weather, but on Friday it did happen on a 75 - 78 degree day. I thought it was happening because of high temps but the 75 degree day may have disproved this theory.

It doesn't happen very often, maybe one or two times per 10-15 lap session, sometimes not at all. It only happens on the downshift, it has never happened on the upshift.

Over the weekend, my friend, who also has a 2015 Exige Cup R, was at the event and his was running perfectly, no issues.

I spoke to Xtrac USA about it, they were very helpful, great service, though it seems clear this isn't an issue with the gearbox itself but an issue with the paddle shift control unit/actuation unit/GCU which is made by Shiftec. I have yet to get Shiftec on the phone. Lotus North America and Lotus Motorsport are none existent, I've emailed and called them both with no response.

If anyone has any real insight, or a very solid referral, it would be very much appreciated.

I've added a photo of a basic heat shield we put next to the GCU to try to shield it from some of the heat created by the transmission. It seemed to do the trick at first but issue has came up again over the weekend.

IMG_5879.jpg
 

·
Registered
Joined
·
34 Posts
Not much people have experience on V6 cup R , Jack is one of them. I ask him a lot of questions regards gear box before I got my V6 Cup R.
 

·
Registered
Joined
·
1,249 Posts
Also, assuming you can get a hold of them, try contacting VSA and/or DRS, maybe even Dietsch motorsports. All of these guys support multiple Lotus Cup teams and individual racers. If anyone has the most experience with a very limited amount of Xtrac cars, it's one of these guys.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #4 (Edited)
Thank you, Lambog and F1 SML8R.

I was in contact with Allen at VSA on Friday while at the track. He was very helpful and generous with his input and support considering he doesn't really know me and the car hasn't been serviced there. He's offered to trouble shoot the problem in partnership with my local shop. This process will begin next week.

I think JackCup services his car with VSA, so in theory VSA should be as 'up to speed' as JackCup. But I'd love to hear from JackCup if he wanted to give some input.

I thought I'd post something on this chat board to see if I could find someone with experience specific to this issue and/or extensive experience with the Xtrac/Shiftec combo. But like Lambog mentioned, there are very few Cup R's around so experience and knowledge is limited in the USA.

I appreciate your input.
 

·
Premium Member
Joined
·
4,667 Posts
@Shooey, I've never experienced the problem when my paddle system was stock but have heard of its existence. IIRC, it has to do with the electrical switches/layout of pins/grounds used in connection with the paddle shift system installed by Lotus on the steering column.

I recently changed out my paddles from the column to the steering wheel as Lotus is currently doing on the 3-Eleven, which alters the wiring/contacts used for the paddle system … I suggest you look into this. VSA did the work on my car, so Allen may possibly consult with your shop as to what parts are needed for the conversion if you are interested.

Feel free to PM me and we can exchange phone numbers, if you would like to communicate in person on this subject or other matters in the future -- makes the communication process more efficient. ;)

There aren't many of us with CupR's, so it's good to have contacts with whom to share info.
 

Attachments

·
Registered
Joined
·
4 Posts
Discussion Starter #9 (Edited)
I've made a little more progress ...

Swan Motorsport, who have installed 20 Shiftec kits on open wheel cars, responded yesterday with good insight and put us in contact with the head tech at Shiftec UK. He advised the problem is likely a short in the downshift wiring. Either a loose or pinched wire, or a screw too tight in the micro switch thats part of the paddle mechanism on the steering column. He says its a simple system that should be relatively easy to troubleshoot.

I've contacted Shiftec UK and expect to hear from them soon. Hopefully they can provide a simplified troubleshooting procedure. Allen at VSA basically said the same thing and has been a great help. Between my local shop (Cantrell Motorsport), VSA, and Shiftec we should be able to get this sorted relatively quickly and pain free. Can't waste these dry summer days in the Northwest!

JackCup - thanks for the insight. I've followed all your build threads etc on your Cup R. With so little info being available on these cars your posts have been read with great interest. All great stuff you've done, and great driving! My friend with a Silver Cup R just installed VSA aero upgrades (diffuser & winglets etc) and exhaust based on VSA's input and your photos/videos. We were just talking about your ABS upgrade over the weekend because as we get faster running Yoko Slicks the stock ABS is becoming more and more intrusive;-)

Back to the transmission ... Allen has advised us about your steering wheel paddle conversion like the 3 Eleven. Very nice! I'm happy with the paddles on the steering column for now but this is definitely an option if this issue turns into something larger than expected.

I'll pop you an email to exchange contact info, thank you. Like you say, not many of us Cup R's around. Would be great to stay in contact on this or other matters.
 

·
Premium Member
Joined
·
4,667 Posts
@Shooey ….. My pleasure.

I believe that I saw your friends CupR at Allen's shop, if it's the silver one. ;)

As far as the stock Bosch abs system, it's great if you were running the stock OD R-compounds. Once you go with slicks which have significantly more grip and a significantly different overall diameter compared to stock, the abs will become way to intrusive and impede any attempt at threshold braking ….you can alter your braking style as a work around, but it's not ideal.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #11 (Edited)
That was definitely his car at Allen's shop, it's the only silver one I'm aware of. I'll include him in my email so we're all in contact.

We moved from R compound tires to slicks this season. Big improvement, amazing grip, predictability and drivability, but the stock ABS system immediately stands out. Like you say, you adjust you driving style to compensate but would be much faster to be able to threshold brake.
 

·
Registered
Joined
·
10 Posts
Hi

To the V6 cup r owners how many km do you think the xtrac can usually do without a rebuild and what are the usual parts replaced and costs?

I currently own an exige 260 cup but I m interested in a v6 cup r.

I have a friend with a v6 cup r used only on trackdays but he s very gentle with it and the car is almost new it s working well but not enough km to give advice.

BTW I heard that in Italy they are doing an upgrade for the std abs to improve it with slick tyres.

Thanks
 

·
Premium Member
Joined
·
4,667 Posts
Hi

To the V6 cup r owners how many km do you think the xtrac can usually do without a rebuild and what are the usual parts replaced and costs?

I currently own an exige 260 cup but I m interested in a v6 cup r.

I have a friend with a v6 cup r used only on trackdays but he s very gentle with it and the car is almost new it s working well but not enough km to give advice.

BTW I heard that in Italy they are doing an upgrade for the std abs to improve it with slick tyres.

Thanks
Not too many CupR (sequential) owners in the States, but I will give you my experience.

I currently have ~6800miles (10,943KM), mostly tracking but some racing, on my 2015 CupR. Took it in for it's first refresh with ~3300 miles (5310KM) last year and the tranny shop said it was perfect and needed no new parts. His instruction to me was to keep doing whatever I'm doing…shift strategy-wise and maintenance-wise. Just had my second inspection done last week (6800mi/10,943km) with the same verdict…..all looks well. We are changing out the main pinion shaft bearing on a preventive basis, as my race shop has seen some failures of this part on the Evora GT4s they maintain. Also, whenever the trans is out, it's time to replace/maintain the clutch … we changed out the stock AP clutch to a Tilton at the first trans service last year and friction material can be changed/replaced.

When you say that your friend is easy on the car, depending upon what you mean, that could actually prove problematic for the sequential. The Lotus programmed flat-shift and auto-blip strategies for the X-trac work best when up-shifts are done at higher RPMs and always under load. Likewise, downshifting can't be done too early or too late when under braking….there's a fine line where the auto-blip is optimized with the least amount of wear on the dogs. For many of us who have never had a sequential, you need to learn how to drive/use it properly.

As for routine maintenance, you can't change out the trans fluid too often, IMHO -- Motul LS gear oil 75-90; Also, it's helpful if you can monitor trans temp, so you don't push hard until the trans is at its optimal operating temps -- 180*F-230*F (82-110*C). Unfortunately, Lotus does not provide that data, even though they mention in their Supplemental Manual for the CupR that you should tape up the trans cooler when ambient temps get low….kind of humorous, no? How can you do that unless you install your own sensors to get trans temps. Of course, I did install that sensor as well as several others….I'm just a data freak. ;)

Just for general info, the X-trac manual recommends that the tranny be inspected every 1200 miles. :crazyeyes


As for my ABS, a change is needed if you are running slicks ….. I just pulled the trigger on the Bosch Motorsport ABS and what an improvement. :coolnana:
 

·
Registered
Joined
·
10 Posts
Thanks for your reply

I knew that xtrac suggested revisions was something like every 2000km but I also tought that probably the transmission can last much longer

Of course it depends on driving condition oils and temperatures but they seem to be quiet reliable for a racing gearbox

The std ap clutch is a not damped plate clutch right? I s the tilton the same kind of clutch and material and do you know if there are other clutches that fit that are either damped (don t know if possible on a racing gearbox or not) or carbon clutches?

My friend is a gentleman driver and he s usually very careful not to overrev or he s not too aggressive on the kurbs he s very careful about his cars but don t get me wrong he s not a novice and know how to drive he s doing the lotus cup italy since many years with the newer elise equipped with slicks and quaife sequential and he also own a 2 11 gt4 with the sadev gearbox but he used the v6 only on trackdays and was very gentle with running in the motor and as I say not over aggressive.

Do you know about any v6 cup r fitted with power upgrades?

I was looking at the komotec kit as the ex460 but I don t know if that kind of kit is reliable enough for hard use on track.

Thanks a lot for the advice
 

·
Premium Member
Joined
·
4,667 Posts
Thanks for your reply

I knew that xtrac suggested revisions was something like every 2000km but I also tought that probably the transmission can last much longer

Of course it depends on driving condition oils and temperatures but they seem to be quiet reliable for a racing gearbox

The std ap clutch is a not damped plate clutch right? I s the tilton the same kind of clutch and material and do you know if there are other clutches that fit that are either damped (don t know if possible on a racing gearbox or not) or carbon clutches?

My friend is a gentleman driver and he s usually very careful not to overrev or he s not too aggressive on the kurbs he s very careful about his cars but don t get me wrong he s not a novice and know how to drive he s doing the lotus cup italy since many years with the newer elise equipped with slicks and quaife sequential and he also own a 2 11 gt4 with the sadev gearbox but he used the v6 only on trackdays and was very gentle with running in the motor and as I say not over aggressive.

Do you know about any v6 cup r fitted with power upgrades?

I was looking at the komotec kit as the ex460 but I don t know if that kind of kit is reliable enough for hard use on track.

Thanks a lot for the advice
You're welcome.

I'm familiar with PB Racing and Stefano -- had a chance to meet him when he was out here at Spring Mountain Motorsport Ranch earlier this year.

I will check on the clutch -- I relied on my race shop and really didn't pay that much attention to the type of clutch. They recommended the change based upon their racing experience with the X-trac in the Evora GT4 in both Pirelli World Challenge and Lotus Cup.

Virtually impossible (if not totally impossible) to over-rev with the X-trac/paddles -- rev limiter when on throttle/power and ECU/GCU won't let you over-rev on downshifts. ;)

By the way, I did move the paddles from the steering column to the steering wheel …. much better -- that's where that should have been all along. Photo below. ;)

Don't know of any CupR's with power upgrades. There are power enhancements available for the V6 (headers/tune) w/o changing pulley size or superchargers that can make a meaningful increase in "reliable" power. It would be easy if we had a manual trans. It's my understanding that for everything to work right with the sequential, special tuning expertise is needed … some thing about torque/load measurements/signals that the ECU needs to send to the GCU for the sequential to operate properly. I don't want to be the guinea pig on this science project so I'm waiting for some future developments. I don't think Komo-tec's power packages would work with the X-trac sequential unless they have changed out the stock Lotus ECU/GCU, but I, of course, could be wrong.

Hope this makes sense.

All the best.
 

Attachments

·
Registered
Joined
·
10 Posts
Your exige looks really cool in orange and flat black.

I saw the pictures of your paddles and I really like the display too, If I get a v6 cup r I would consider fitteng one of the newer aim display.

Stefano should be able to make that oem abs software upgrade to make it work better with slick tyres, of course now you have an even better abs system so you won t need it but in case someone else want that they should be able to do it.

As my friend is racing in the Lotus cup italy I am also many times with them on the track and I rented a few times their racing elise cup to do some laps and even if the engine feel not too powerful and not revving very high it s really fast around the track and fun to drive aggrissively.
 

·
Registered
Joined
·
433 Posts
As for my ABS, a change is needed if you are running slicks ….. I just pulled the trigger on the Bosch Motorsport ABS and what an improvement. :coolnana:[/QUOTE]


Jack , could you expand a little on what the Bosch Motorsport ABS brakes are like compered to OEM ...
What have you found to be the biggest difference ?
Lap times any better ?

Cheers
Barry
 
1 - 20 of 27 Posts
Top