Another Castle Combe trackday vid, tyre comparison

TomK

Senior member
 West London
As some may know I go to combe pretty regularly as it's the closest place for me to get my track fix :evil: As such it gives me a chance often to test out any mods, chassis changes, tyres to really see how they affect the drive of the car and also the time that might (or might not) be gained.
This video was a day a couple of months ago now, I'd been fiddling around with the geo earlier in the summer and managed to make the car quite considerably worse. Retracing the steps meant that I settled on a setup I felt pretty happy with. I'd been running NS2R nankangs for track work for a while and for the money had felt they were pretty ok, but this summer I found a good deal on some AD08R yokohamas. I put them on before going to Goodwood in August, the car felt great but I had no reference point it being my fist time round. At Combe a few weeks later I immediately dropped a second from my times with the NS2Rs and have on my most recent visit just got into the 1:16s (1:16.9!). Bearing in mind it's quite a power circuit and an M4 has been clocked there just 1 tenth quicker, it's not bad I think.
The car feels so much better on turn in with the AD08R, it's surprised me the difference just a change in tyre can make to the enjoyment of driving the car, let alone the time difference. They have also been wearing incredibly well vs the NS2R, in short the money saved from buying the cheaper tyre is not worth it in the long run.
http://fastestlaps.com/tracks/castle-combe
Here's the vid, I forgot the type at the end about running out of talent might have been a reason :rofl:
[youtube]BsxHyGHcLC4[/youtube]
 
Very enjoyable watch :) on the ragged edge at times but impressive , , silly question coming , is the tc off ? If so why ? :?
 
Cheers, yes it's a bit ragged in places, I find myself pushing closer and closer to the limits there, perhaps I should spend some more time at a different track for a while :scratchhead:
mr wilks said:
is the tc off ?
Yes
mr wilks said:
If so why ? :?
A lot more fun in the wet! Much faster in the dry. Won't kill your rear brakes (TC uses the rears extensively when trying to drive like that).
"M-Track" mode is probably worth using on track if you're a bit unsure of things but tbh I've only used it once or twice I think since coding it a couple of years ago.
 
great feedback!!!! I've got a set of 888R ready to go on after i finish the NS2R which i can lie have served me so well for 2 sets, I'm looking forward to seeing the difference, i knew the budget slick would have it compromises and for the price they have performed so so well for me and I've taken some big competition down at the sprint track scene i love so much, i can only assume from what you've posted this gap will only get bigger when i go premium again.
 
That looks fun Tom 8) I'm sure you're right that the AD08R are faster than the Nankangs, but, it's hard to compare because of the changes made to the car each time. Since setting the shim clearances and the remap 10 months ago you'd mentioned the car felt more powerful, then you've taken out a touch more weight, fiddled with the rear camber and toe, plus I think you've got quicker too. None the less, the stop watch doesn't lie, you're speedy round Combe, not sure I'd be able to keep up now (but I'll have a go)? :driving:
 
I dunno , i guess its like the kart tracks , i know when ive been on them lap after lap you learn the lines & boundaries & push that little bit harder each circuit as you learn from the last .
Would the lap time not be quicker with tc on though :?
 
Beedub said:
I've got a set of 888R ready to go on
Let us know how you get on. Phil and I use the R888R in the PBMW championship on a lighter, less powerful car of course. I've found the R888R to be surprisingly grippy from cold starts, get even better before peaking and starting to slide about a bit by 10 of 15 minutes in. The lap times should certainly fall with them. :)
 
mr wilks said:
Would the lap time not be quicker with tc on though

No, it's definitely slower in the dry, it's too intrusive, although it could possibly be faster on a very wet track just for the confidence it gives. I've not compared lap times but from a seat of pants calculation it feels like M Track is quickest in the wet, maybe even in the dry if driving for a quick lap time.
 
Fishy Dave said:
it's hard to compare because of the changes made to the car each time.
Thing is I did a day at combe just a month or so before with the same engine and chassis changes on the NS2-R so the times I think are comparable. Most importantly though is how much less the car understeered in the slow(er) speed stuff compare to NS2-R. I'm sure that's where all the time was gained and also where the enjoyment increase came from too. The tyre also feels much more compliant on the road than NS2R which is an added benefit.
 
TomK said:
Thing is I did a day at combe just a month or so before
Ah yes, I'd forgotten about that one. I can see the car looked more balanced than I've seen it before, and although you still looked like you were having fun it did appear that your driving was a teensy bit more composed/less lairy? :oops: :D
 
Fishy Dave said:
did appear that your driving was a teensy bit more composed/less lairy? :oops: :D
You mean faster? :D Hmm, not sure, the tyre felt more predictable so maybe that helps the input...
 
Great video!

I'm just trying to figure out what tyres/wheels, Do you think running a 9" up front would be a good idea? When pushing on in the dry I suffer from under steer quite badly.

Tempted to try the Cup 2's...
 
Cheers.
I don't know about moving up the front rim size, it's something I've considered (albeit in a square setup). I've increased my tyre size all round relative to stock so a 265 rear and 235 front, but they're still relatively the same as stock.
Assuming your tyres are in good shape and of a decent quality then I'd suggest that the most likely culprit of the understeer lies in the geo setup. When was it last done and what was it set at? The car is very sensitive to adjustments I've found in my limited experience.
I was going to try the Cup2's also, but came across the AD08R at a good price, don't ignore them by any means, great in the dry and wet, wear well.
 
I have a friend with a hunter alignment system,

We have tried various setups, I'm currently running the CSL setup with as much neg camber as the car would allow on stock top mounts - This was with 225's up front and 255's on the rear, and on stock suspension.

I have KW V3's on order & M3 ARB kit so hopefully that will help matters, May need to get some top mounts...
 
bradz said:
I have a friend with a hunter alignment system,
That's the kind of friend I'd love :lol:
bradz said:
We have tried various setups, I'm currently running the CSL setup with as much neg camber as the car would allow on stock top mounts - This was with 225's up front and 255's on the rear, and on stock suspension.

I have KW V3's on order & M3 ARB kit so hopefully that will help matters, May need to get some top mounts...
Having suffered the same as you and having driven and followed Fishy Dave's car (stock tyre setup) round track I decided to follow his geo direction and introduced a small amount of toe out at the rear (around 1deg iirc). Less than Dave cause shall we say he's more 'comfortable' with oversteer (aka lunatic :D ) but it really really helps the car to turn in and also stop it pushing on so much in higher speed stuff, it does induce some oversteer tendencies though. The camber on the rear is set at stock so -ve1.5deg, I tried going up to 2 1/4 and it made the car rather dangerous so I wouldn't advise altering that. Tyre wear seems fairly even now. At the front I increased the camber over stock by shimming the strut out, I think it was 2mm that gave me another degree so it's at around 2 1/2 now. Outside edge tyre wear is much improved, it was hurting the edge badly before. Adjustable plates would be a good idea of course if you're doing a few road miles as well.
Enjoy the Kw's, they should be great! Personally I haven't felt the need to fiddle with the arbs, but some adjustable ones would be nice :whistle:
 
I was picking Daves brains at the Ace cafe meet about his setup...

We haven't really messed about with the toe much, Thanks I'll give it a go, I too am running 1.5 of negative camber on the rear seamed to help, I have just purchased some power-flex arms, I can't believe how flimsy the stock items look!

I'm currently doing a rear end refurb so I thought while its apart I would do everything at once! From Brake lines to a diff rebuild! A few people on here have fitted the M3 bars so I thought lets get it done, I have a few friends in the trade so I get it all at trade price!

I have had KW's on previous cars and rated them highly.
 
bradz said:
I was picking Daves brains at the Ace cafe meet about his setup...

We haven't really messed about with the toe much, Thanks I'll give it a go, I too am running 1.5 of negative camber on the rear seamed to help, I have just purchased some power-flex arms, I can't believe how flimsy the stock items look!

I'm currently doing a rear end refurb so I thought while its apart I would do everything at once! From Brake lines to a diff rebuild! A few people on here have fitted the M3 bars so I thought lets get it done, I have a few friends in the trade so I get it all at trade price!

I have had KW's on previous cars and rated them highly.


i have the kw club sport and they are nothing short of brilliant, the change to the car was as big as any of my other changes.
 
bradz said:
I have a friend with a hunter alignment system,

We have tried various setups, I'm currently running the CSL setup with as much neg camber as the car would allow on stock top mounts - This was with 225's up front and 255's on the rear, and on stock suspension.

I have KW V3's on order & M3 ARB kit so hopefully that will help matters, May need to get some top mounts...

I fiddled with the stock suspension and geo for ages but couldn’t get rid of the understeer. Decent tyres helped more than anything else (including pulling the camber pins and fitting a strut brace).
In the end, I followed Beedub’s advice and bought KW Clubsports with adjustable camber plates. I also fitted stiffer ARBs front and rear. The result abolished pitch and roll resulting in much shorter braking distances and zero understeer.

I tried various combinations of bump and rebound on my last track day and the current setup is too prone to snap oversteer so I’ll have to look up my previous suspension settings when I have time. I’d be interested to know the specifics of Tom’s and Fishy Dave’s suspension / geo setups.

Bradz, you might need adjustable drop links to get the ARBs and KWs to fit if the V3s are similar to the Clubsports. Also, I now have to use 5mm spacers with some of my wheels or they foul the uprights.
 
BMWZ4MC said:
I’d be interested to know the specifics of Tom’s and Fishy Dave’s suspension / geo setups.
I have b12, dave is on just the eibachs, so no adjustability unfortunately for either of us.
Here's where I'm at with the geo except rear camber is now -1.5
DSC_2023.JPG
 
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