Trailing arm Tasmins DO handle!!
Discussion
It's often heard that the trailing arm Tasmins are a poor chassis, that the cars don't handle well, that they suffer from poor geometry, high unsprung mass and a general feeling of "engineering on the cheap".
Well they can be made to handle very nicely thnkyou! and I think we've probably reached near the end of trailing arm development with Ceejay's race tasmin in the Dunlop Tuscan Series.
Our car runs a development of the original Tasmin suspension, we have rose joints on all arms but the std location points are maintained as closely as possible to the originals bar the extra bracing for the rose joints .. but just look at the times from these races in our class B:
Brands Hatch
Griff 500 53.398
Tuscan Racer 53.646
Tasmin 54.13
Next best Taz time 56.746
Mallory Park
Tuscan Racer 50.091
Griff 500 50.336
Tasmin 51.286 (2nd lap of race!!!! before exhaust detached itself)
Next best Taz time 52.988
Silverstone
Griff 500 1:05.794
Tasmin 1:07.563
Tuscan Racer 1:09.406 (4 litre engine but had problems)
I still haven't managed to completely give Ceejay the car he would ideally want, but he peddles the damn thing well all the same and the mechanical grip from our car is right up there!! One thing is certain .. there's life in those old cars!!
Our Wedge has done us proud
Well they can be made to handle very nicely thnkyou! and I think we've probably reached near the end of trailing arm development with Ceejay's race tasmin in the Dunlop Tuscan Series.
Our car runs a development of the original Tasmin suspension, we have rose joints on all arms but the std location points are maintained as closely as possible to the originals bar the extra bracing for the rose joints .. but just look at the times from these races in our class B:
Brands Hatch
Griff 500 53.398
Tuscan Racer 53.646
Tasmin 54.13
Next best Taz time 56.746
Mallory Park
Tuscan Racer 50.091
Griff 500 50.336
Tasmin 51.286 (2nd lap of race!!!! before exhaust detached itself)
Next best Taz time 52.988
Silverstone
Griff 500 1:05.794
Tasmin 1:07.563
Tuscan Racer 1:09.406 (4 litre engine but had problems)
I still haven't managed to completely give Ceejay the car he would ideally want, but he peddles the damn thing well all the same and the mechanical grip from our car is right up there!! One thing is certain .. there's life in those old cars!!
Our Wedge has done us proud
Edited by trackcar on Friday 8th September 19:41
Joolz, not sure if you're aware but the Tasmin rear suspension is almost identical to the Esprit's. Up to the late Series 2 the Esprit used the driveshaft as the top link, then they added a third link (which suggests Lotus knew it was an issue) and switched to CV joints... but TVR for some odd reason ignored that and came up with the A-frame.
Both cars even use exactly the same trailing arm bush which on the TVR lasts weeks but practically never fails on an Esprit, even though the weight of the engine is just over it. Bizarre.
Maybe a 3-link Tasmin needs to be created...?
Both cars even use exactly the same trailing arm bush which on the TVR lasts weeks but practically never fails on an Esprit, even though the weight of the engine is just over it. Bizarre.
Maybe a 3-link Tasmin needs to be created...?
Somebody posted a great article here a few months ago about one of the motoring legends, Hawthorn I think, explaining that he was hugely successful as a racing driver but actually useless as a development driver. The problem was that he was so good that he immediately adapted his style to suit the quirks of any car you put him in and never had any problem with any of them, no matter how strange the handling was he'd come back and say "yup, that's fine" as he put another trophy on the shelf. With CeeJay driving it may not be safe to give the car all the credit!
PS
PS
GreenV8S said:
Somebody posted a great article here a few months ago about one of the motoring legends, Hawthorn I think, explaining that he was hugely successful as a racing driver but actually useless as a development driver. The problem was that he was so good that he immediately adapted his style to suit the quirks of any car you put him in and never had any problem with any of them, no matter how strange the handling was he'd come back and say "yup, that's fine" as he put another trophy on the shelf. With CeeJay driving it may not be safe to give the car all the credit!
PS
PS
lol except ceejay can't adapt (sorry ceejay!)! he spun my S three times at elvington and described it as "a pile of poop" .. I think the same about the race tasmin .. it's as focussed to his driving style as i can make it given what we have to work with. I can't get on with it at all. i can't adapt and neither can he
but it *can* be made to fit in with a certain driving style and has some handling adjustability which says something about the inherent platform. It only needs a bit of rear aero to tame the high speed oversteer and it'd be a very capable car all round
The main thing is it generates very very good grip and corner speeds are not dis-similar to Tuscan race cars ..
I love the way my S goes and have only spun it maybe 4 or 5 times in 4 years of owning it
.. though when it goes it tends to be in a big way 
Edited by trackcar on Saturday 9th September 18:28
trackcar said:
lol except ceejay can't adapt (sorry ceejay!)! he spun my S three times at elvington and described it as "a pile of poop" .. I think the same about the race tasmin .. it's as focussed to his driving style as i can make it given what we have to work with. I can't get on with it at all. i can't adapt and neither can he but it *can* be made to fit in with a certain driving style and has some handling adjustability which says something about the inherent platform.
It only needs a bit of rear aero to tame the high speed oversteer and it'd be a very capable car all round
The main thing is it generates very very good grip and corner speeds are not dis-similar to Tuscan race cars ..
I love the way my S goes and have only spun it maybe 4 or 5 times in 4 years of owning it .. though when it goes it tends to be in a big way
but it *can* be made to fit in with a certain driving style and has some handling adjustability which says something about the inherent platform. It only needs a bit of rear aero to tame the high speed oversteer and it'd be a very capable car all round
The main thing is it generates very very good grip and corner speeds are not dis-similar to Tuscan race cars ..
I love the way my S goes and have only spun it maybe 4 or 5 times in 4 years of owning it
.. though when it goes it tends to be in a big way Edited by trackcar on Saturday 9th September 18:28
Elvington was quite amusing, Joo passengered in the S while I had my first ever go in it and as Joo said it was a pile of poop, set up for 'fun' low speed slides rather than a lap time. It was waaaaaay too soft at the back and had a really odd dead throttle where nothing happened at all for the first inch of travel. Net result, in fast corners it wanted to kill you and when it oversteered you couldn't balance the car quickly enough on the throttle (well I couldn't anyway). Seem to recall Joo stiffened the rear up a bit and knocked about 3 seconds off his lap time but said it wasn't much 'fun' lol.
As for the Taz it can be very quick, it is veeeeery hard to drive but I love it. The standard steering is heavy, especially with the slick tyres and has too many turns lock to lock, an electric power steering rack would fix this. The traction is pretty good out of slow corners when on boost and the car is fairly neutral in fast sweeping curves but oversteer is never far away. The Cossy 24V engine install is quite heavy so the car tends to understeer in slow corners but the lightweight one-piece frontend has helped. I think there are 2 main reasons why the car has shown good pace at the last 2 rounds. 1, I've had a bit of time in the Taz now so I understand how to get a decent lap out of it and 2, we have slightly harder compound slicks which are less prone to overheating. We know what pressures to use now too so we can now get some decent grip from the slick tyres for longer.
Ceejay
Edited by ceejay on Saturday 9th September 19:04
I think it's fair to say it's a car which rewards the brave and confident driver .. so it probably suits you quite well .. not lacking in bravery or commitment whereas I'm a complete wuss who hates fast corners
We're looking for a driver for the Tasmin next season on arrive and drive basis so if anyone fancies putting a 25 year old car in amongst the Tuscan race cars give us a bell (Cliff has managed 2nd row on the grid with the car so that's the score to beat!!)
Ian : yeah I've seen the Esprit rear, interesting that they went upper and lower link and CV joints, no idea why TVR didn't go similar
how is your Esprit compared to the 390 ?
whereas I'm a complete wuss who hates fast corners We're looking for a driver for the Tasmin next season on arrive and drive basis so if anyone fancies putting a 25 year old car in amongst the Tuscan race cars give us a bell (Cliff has managed 2nd row on the grid with the car so that's the score to beat!!)
Ian : yeah I've seen the Esprit rear, interesting that they went upper and lower link and CV joints, no idea why TVR didn't go similar
how is your Esprit compared to the 390 ?
kevsmev said:
wedg1e said:
Maybe a 3-link Tasmin needs to be created...?
Just making a start on a prototype of a double wishbone setup. My little project for the winter!
Kev
Aye, I dunno (well I do: I bet it was down to cost) why TVR didn't do this instead of the A-frame. They were nearly there, you just rather get the idea that old fag-breath came down in a strop and told them to sign half the job off for production
ISTR a big discussion some years back where Joolz et al tried to decide what the hell the A-frame's tie-rod was supposed to do: IIRC Joolz thought it was torque reaction, someone else reckoned it was just to keep the A-frame parallel to the chassis centreline under power...
trackcar said:
not me saying the torque reaction thing, it's in completely the wrong place. it needs to be above the hub
Yeah, I remember that bit... it's too close to the rotational centre of the driveshaft to have any leverage.
Something also about the huge rubber bush that they fitted: was it to allow it to deform far enough as the A-frame pivots... rather negating the locating aspect of the tie-rod
To be honest... comparing the Lotus with the TVR is not really fair. Yes they may well have similar suspension but I suspect that the geometries involved are very different and it is the lengths and angles involved that determine the handling characteristics. In my experience and according to my computer models, the Taz set up is a big compromise. It can be dramatically improved but for most, the sacrifice of comfort is simply too much.
The main issue with the Taz trailing arm is wheel stability and stopping it moving sideways. The A frame does a pretty good job at controlling that.
The main issue with the Taz trailing arm is wheel stability and stopping it moving sideways. The A frame does a pretty good job at controlling that.
Boosted LS1 said:
kevsmev said:
wedg1e said:
Maybe a 3-link Tasmin needs to be created...?
Just making a start on a prototype of a double wishbone setup. My little project for the winter!
Kev
Are you running a monoshock?
Boosted.
The initial plan is to make a cradle that will carry another diff and the inboard ends of the wishbones and use fabricated hub carriers with outboard disc brakes. It should bolt to existing chassis points and use the original springs and shox. I want to do it so as not to modify the chassis and be able to put all the original stuff back on.
Kev
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