Tuscan challenge&Griff/Chim chassis difference question.
Tuscan challenge&Griff/Chim chassis difference question.
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Discussion

chevtrev

Original Poster:

785 posts

265 months

Wednesday 1st March 2006
quotequote all
Spent quite a while today taking measurements and comparing the two chassis's for the possibility of a radical project.
Just wondered why (as the Griff/Chim chassis evolved from the Tuscan and have very similar track)as to why they changed to narrower engine cavity rails and wider wishbone's(75/80mm)
Does any one know the the pro's or cons why TVR changed to a wider wishbone as I assume a change is for the better.

Graham

16,381 posts

313 months

Wednesday 1st March 2006
quotequote all
which is which.

chevtrev

Original Poster:

785 posts

265 months

Wednesday 1st March 2006
quotequote all
Graham said:
which is which.


Griff/Chim has wider wishbones

shpub

8,507 posts

301 months

Wednesday 1st March 2006
quotequote all
Narrower rails mean more passenger room.

chevtrev

Original Poster:

785 posts

265 months

Wednesday 1st March 2006
quotequote all
shpub said:
Narrower rails mean more passenger room.


The tunnels pretty similar,there must be a reason why the wishones are wider,I cant see why besides the road cars having inner arches,and therefore less clearence.
Thought it would be for better geometery?

shpub

8,507 posts

301 months

Wednesday 1st March 2006
quotequote all
More footwell passenger room if you mean that the engine bay is narrower.

griffter

4,143 posts

284 months

Wednesday 1st March 2006
quotequote all
Presumably a wider chassis (with triangulation) is a stiffer chassis, and resulting narrower wishbones would give less suspension travel which might not matter on a racer. On the road car if more suspension movement is required, one way to do this is having a wider wishbone*. Simply increasing the length of the arc of wheel travel with a narrow wishbone would give horrible geometry changes*.

*I think.

neejah

196 posts

255 months

Wednesday 1st March 2006
quotequote all
Could be for more suspension travel?

jellison

12,803 posts

306 months

Wednesday 1st March 2006
quotequote all
Wider is better or longer as in case of bike swing arms, but pivot point coming further under engine.

Allows softer springing for given amount of suspension movement - I think. Wide track F1 Cars vs the narrow track one we have now - er I'd take the early 90's cars ever day, current same width as F3!

Graham

16,381 posts

313 months

Thursday 2nd March 2006
quotequote all
griffter said:
Presumably a wider chassis (with triangulation) is a stiffer chassis, and resulting narrower wishbones would give less suspension travel which might not matter on a racer. On the road car if more suspension movement is required, one way to do this is having a wider wishbone*. Simply increasing the length of the arc of wheel travel with a narrow wishbone would give horrible geometry changes*.

*I think.


Thats exactly what happens on the tuscan racer. they run high spring rates to restrict suspension travel, as too much travel causes geometry changes as you say, and makes driving mmm interesting... we ran a very soft rear at donny in the persuit of traction off the line and it was nasty to drive hard around a corner... rear wheel steering !!!!

Im surprised your saying the tuscan c chassis is wider around the engine as its fecking tight on the rv8, although possibly the engine is further back which may be why why the engine bay is wider ?


do you have the measurements / drawings of the 2 chassis. Im interested to see if i could fit an lsx. which J has proved will go in a chim chassis..

G

Terminator

2,421 posts

313 months

Thursday 2nd March 2006
quotequote all
Graham said:
Im interested to see if i could fit an lsx.
No reason why not. There are at least four of us with Chevy 350 blocks in Tuscan race chassis (including the Thorpedo).



jellison

12,803 posts

306 months

Thursday 2nd March 2006
quotequote all
Should be easier as a tad smaller than Iron (or alloy spec SBC's) or older pre-lsx lumps.

Graham

16,381 posts

313 months

Thursday 2nd March 2006
quotequote all
Terminator said:
Graham said:
Im interested to see if i could fit an lsx.
No reason why not. There are at least four of us with Chevy 350 blocks in Tuscan race chassis (including the Thorpedo).





Yeah but most of those have the chassis modified or the engine not as far back as I want to put it...


Im only interested in doing if it I dont have to modify the chassis /body even to the extent of fabricating new engine mounts to pick up off the old ones ( rv8 or ajp)


I,ve got the chim sat next the the tuscan ( with empty engine bay at the mo) ill have a looky to see realtive engine positions...

G

chevtrev

Original Poster:

785 posts

265 months

Thursday 2nd March 2006
quotequote all
Graham said:
Terminator said:
Graham said:
Im interested to see if i could fit an lsx.
No reason why not. There are at least four of us with Chevy 350 blocks in Tuscan race chassis (including the Thorpedo).





Yeah but most of those have the chassis modified or the engine not as far back as I want to put it...


Im only interested in doing if it I dont have to modify the chassis /body even to the extent of fabricating new engine mounts to pick up off the old ones ( rv8 or ajp)


I,ve got the chim sat next the the tuscan ( with empty engine bay at the mo) ill have a looky to see realtive engine positions...

G



You could fit a big block in that void.
Front of the chassis(top rail)is 803mm, centre to centre of wishbones mounts, against 640mm for the Chim.
Engine mounts are 70mm further back in the Tuscan but relative in position to the Chim having the shorter wheel base.
Graham while youv'e got the two chassis's there,can you give me the measurement from top front wishbone pick up point to centre of ball joint on the Tuscan,I forgot to take it.

jellison

12,803 posts

306 months

Friday 3rd March 2006
quotequote all
Picture would help here - if mounts 70mm further back ten they are 70mm nearer to the point at which the tubes narrow in around the bellhousing / gearbox and surely you will run out of room, if you mounted of the same pint as say myslef or chevtrev. BUT the alloy blocks that go to the LSx and then to the SBC mounts could be altered to be further BACK on the block, therefore keeping the gearbox similarly spaceed out i.e. with a small amount of gap to bellhousing. The TVR chassis mounts should not need to be altered but the lsx or may need to be fabricated from new material to move the sbc mount further to the back of the block. Sound easily do-able.

Terminator

2,421 posts

313 months

Friday 3rd March 2006
quotequote all
Graham said:
Yeah but most of those have the chassis modified or the engine not as far back as I want to put it...
True. My engine is so far back that I can check the oil level by leaning over into the passenger footwell

Chassis has been modified to suit the new engine mounting position.. you can't have it both ways!

jellison

12,803 posts

306 months

Friday 3rd March 2006
quotequote all
Exactly - so what if you mod it - it is not going to have an AJPV8! again, and a Tune LSx is miles ahead in terms of possible power output! You might scare youself if you do do it as lighter Tuscan and Mental LSX will be a Huge jump from what ever RV8 you have (presume 4.0 with weird TVRCC Champ rules).

>> Edited by jellison on Friday 3rd March 10:14

Graham

16,381 posts

313 months

Friday 3rd March 2006
quotequote all
[quote=jellison]Exactly - so what if you mod it - it is not going to have an AJPV8! again, and a Tune LSx is miles ahead in terms of possible power output! You might scare youself if you do do it as lighter Tuscan and Mental LSX will be a Huge jump from what ever RV8 you have (presume 4.0 with weird TVRCC Champ rules).

Just personal preference, i want to leave it standard... engines and gearboxes however are fair game.

rules are simpler this year, so we'll see how it goes with the 4ltr and make a decision for 07... 400/500 bhp has a nice ring to it though in a car 930kg race trim with fuel and driver.. especially as were going from treaded to slicks mmm

jellison

12,803 posts

306 months

Friday 3rd March 2006
quotequote all
still recon possible to not mod the chassis - see how I'd do it with bracket further back.

More tan twice the power WILL make it Interesting!!!!!!!!!!!

Graham

16,381 posts

313 months

Friday 3rd March 2006
quotequote all
chevtrev said:

Graham while youv'e got the two chassis's there,can you give me the measurement from top front wishbone pick up point to centre of ball joint on the Tuscan,I forgot to take it.




center of the front rosejoint to center ball joint 300mm
center of the rear rosejoint to center ball joint 280mm