shocks and springs
Discussion
in the late 70's i had a rover/bop block in the car
making about 200hp. just recently i started a
ford v8 conversion/restoration of the car. the new engine is a 302 crate motor from ford motor sports.
it's supposed to be rated at 320hp. even allowing for
some exageration that's at least 100hp more than the rover/bop engine was making. in the process of stripping the the car to a bare chassis
i noticed that some of the diff and rear suspension
mounting tabs were bent or twisted. i don't know
if the rover/bop engine caused this or it came this
way from the factory (i've owned the car from new).
dual shocks/springs and lsd diff seemed like a good
way to relieve stress on the suspension and keep the
tires planted.
frank
making about 200hp. just recently i started a
ford v8 conversion/restoration of the car. the new engine is a 302 crate motor from ford motor sports.
it's supposed to be rated at 320hp. even allowing for
some exageration that's at least 100hp more than the rover/bop engine was making. in the process of stripping the the car to a bare chassis
i noticed that some of the diff and rear suspension
mounting tabs were bent or twisted. i don't know
if the rover/bop engine caused this or it came this
way from the factory (i've owned the car from new).
dual shocks/springs and lsd diff seemed like a good
way to relieve stress on the suspension and keep the
tires planted.
frank
This has recently been posted on either the usa-tvr or TVR-pre1980 egroups, in the UK I only know of one person who has done this Dave Smith who is running a hi-spec 302 engine in a 3000S. He can be contacted through Colin Ltons (TVRCC USA Coordinator) aka Terminator on Pistonheads.
Hope this helps
davidy
ps Dave Smith found a number of suspension issues in his upgrade including cracked wishbones and the wishbones requiring further cross bracing, the dual shock route may solve some potemtial traction problems, but it won't stop the wishbones trying to tear themsleves apart.
Hope this helps
davidy
ps Dave Smith found a number of suspension issues in his upgrade including cracked wishbones and the wishbones requiring further cross bracing, the dual shock route may solve some potemtial traction problems, but it won't stop the wishbones trying to tear themsleves apart.
Frank,
How many monicas have you got? Like the gamekeeper I could not see why you were asking the question at first. Plenty of people have modified M series cars used for sprinting or as track day cars, some have 300 bhp but I have not seen one with dual rear shocks and springs a la Vixen. ( The general feeling now among Vixen owners tend to work against each other to a limited extent. )
The problem with your car relating to the rear diff - bent and twisted mounting tabs. This is common for the early cars with Triumph diffs - I have even seen the mounting bars at the front snap. People have stiffened parts with gusset plates but the later cars with Salisbury diffs have a completely different mounting system.
Solutions successfully employed include:
i)Leda springs and shock absorbers, fully adjustable for ride height and damping. 250 lb/in springs should suffice.
ii)Rear anti-roll bar and uprated front anti-roll bar
iii)Solid cast aluminium steering rack mountings
iv)Polyurethane bushes all round
v)16"x6.5" wheels with a zero offset or 16"x7.0" wheels with a -7mm offset. Tyres are 205/55VR16.
Exactly TVR can supply i), ii) and iii). Superflex and powerflex can supply iv). Compomotive or Image can supply v).
Good luck and let us know how you get on.
Jonathan
How many monicas have you got? Like the gamekeeper I could not see why you were asking the question at first. Plenty of people have modified M series cars used for sprinting or as track day cars, some have 300 bhp but I have not seen one with dual rear shocks and springs a la Vixen. ( The general feeling now among Vixen owners tend to work against each other to a limited extent. )
The problem with your car relating to the rear diff - bent and twisted mounting tabs. This is common for the early cars with Triumph diffs - I have even seen the mounting bars at the front snap. People have stiffened parts with gusset plates but the later cars with Salisbury diffs have a completely different mounting system.
Solutions successfully employed include:
i)Leda springs and shock absorbers, fully adjustable for ride height and damping. 250 lb/in springs should suffice.
ii)Rear anti-roll bar and uprated front anti-roll bar
iii)Solid cast aluminium steering rack mountings
iv)Polyurethane bushes all round
v)16"x6.5" wheels with a zero offset or 16"x7.0" wheels with a -7mm offset. Tyres are 205/55VR16.
Exactly TVR can supply i), ii) and iii). Superflex and powerflex can supply iv). Compomotive or Image can supply v).
Good luck and let us know how you get on.
Jonathan
If you are putting a 302 lump in, you MUST change the diff, you will tear the TR6 diff apart with the increased power and especially torque. I suggest either a Salisbury for which you can get all the bits for from TVR specialists or a Cosworth (Quaife) diff.
I am one of those people who has torn the front plate off a TR6 diff with only a 190bhp Essex Engine. If you go for modern sticky rubber you will put even more of a strain on the transmission.
The Salisbury diff also had some stabiliser bars (you will need to all two brackets tthe lower part of your chassis), these prevent the diff from twisting under high torque.
Hope that helps
davidy
I am one of those people who has torn the front plate off a TR6 diff with only a 190bhp Essex Engine. If you go for modern sticky rubber you will put even more of a strain on the transmission.
The Salisbury diff also had some stabiliser bars (you will need to all two brackets tthe lower part of your chassis), these prevent the diff from twisting under high torque.
Hope that helps
davidy
davidy
as usual i have more project on my hands than
i had anticipated. i'll be happy just to get the
engine swap sorted before i run out of cash. i was
going to put an lsd in the stock tr6 diff to save $.
from what i'm hearing from the group this is just a
waste of time and money. if i do eventually come up
with a salisbury diff with lsd what else will i
need to install it in a 2500m? thanks.
frank
as usual i have more project on my hands than
i had anticipated. i'll be happy just to get the
engine swap sorted before i run out of cash. i was
going to put an lsd in the stock tr6 diff to save $.
from what i'm hearing from the group this is just a
waste of time and money. if i do eventually come up
with a salisbury diff with lsd what else will i
need to install it in a 2500m? thanks.
frank
You will need :-
1) A diff (different ratios available, standard TVR 3.31:1, could get a 3.54:1, depends whether you have a five speed box or not), try and get a Powrlok (LSD) diff.
2) Diff Mounting Carrier, probably copied in US but available from most UK TVR M parts sellers
3) Modify your chassis lower horizontal tubes to mount stabiliser bars onto, you will also need the stabiliser bars and a couple more suspension bushes (go and look at a later M to see how its mounted)
4) Spacer Plates and new UJ mounting plate to allow Triumph driveshafts to mate. (same suppliers as 2 above)
You will have to either take the body off or put the diff through a hole in the boot floor, the Salisbury goes in from the top unlike the TR6 diff which you can get out through the side. I suggest that if you are going for the 302 conversion you wait until you have enough funds to take the body off, as sorting out the engine mounts/exhaust etc will also be easier with no body around
Best of Luck
davidy
1) A diff (different ratios available, standard TVR 3.31:1, could get a 3.54:1, depends whether you have a five speed box or not), try and get a Powrlok (LSD) diff.
2) Diff Mounting Carrier, probably copied in US but available from most UK TVR M parts sellers
3) Modify your chassis lower horizontal tubes to mount stabiliser bars onto, you will also need the stabiliser bars and a couple more suspension bushes (go and look at a later M to see how its mounted)
4) Spacer Plates and new UJ mounting plate to allow Triumph driveshafts to mate. (same suppliers as 2 above)
You will have to either take the body off or put the diff through a hole in the boot floor, the Salisbury goes in from the top unlike the TR6 diff which you can get out through the side. I suggest that if you are going for the 302 conversion you wait until you have enough funds to take the body off, as sorting out the engine mounts/exhaust etc will also be easier with no body around
Best of Luck
davidy
davidy,
i've got the car stripped to a bare chassis. i guess i'm gonna have to bite the bullit and find a powrlok
and install it now. putting it in through the boot
later sounds like major back pain. any idea which
vehicles i should be looking for as i tour my
local junkyards? thanks again.
frank
i've got the car stripped to a bare chassis. i guess i'm gonna have to bite the bullit and find a powrlok
and install it now. putting it in through the boot
later sounds like major back pain. any idea which
vehicles i should be looking for as i tour my
local junkyards? thanks again.
frank
Diff fitted to TVR orginially was a Salisbury 4HU
Jaguar/Daimler XJ saloons are your best bet, was also fitted to E-Types, Aston Martins, etc.
I believe some XJ-S have the 4HU other have a 4HA which can also be made to fit.
What gearbox ratios are you going to have and what are you going to use the car for, that will help you work out the required ratio.
Hope that helps
davidy
Jaguar/Daimler XJ saloons are your best bet, was also fitted to E-Types, Aston Martins, etc.
I believe some XJ-S have the 4HU other have a 4HA which can also be made to fit.
What gearbox ratios are you going to have and what are you going to use the car for, that will help you work out the required ratio.
Hope that helps
davidy
davidy,
do all of the examples you mention have the powrlok
differential? the diff in the car at present is the stock unit and i think it has a 3.45 ratio. the tranny is a t5 with a 2.95 1st and .80 5th. it has also been converted to a front shift tailshaft housing to move the shift linkage forward from the stock ford position. at present i plan to use it for fair weather street use and to show at regional british car shows. a tvr is a very unusal car in this part of the country.
if all goes well someday i may autocross it in my local scca club meets.
frank
do all of the examples you mention have the powrlok
differential? the diff in the car at present is the stock unit and i think it has a 3.45 ratio. the tranny is a t5 with a 2.95 1st and .80 5th. it has also been converted to a front shift tailshaft housing to move the shift linkage forward from the stock ford position. at present i plan to use it for fair weather street use and to show at regional british car shows. a tvr is a very unusal car in this part of the country.
if all goes well someday i may autocross it in my local scca club meets.
frank
No not all Powrlok, should be a metal tab on the side of the diff with ratio and Powrlok on, if not I believe ratio is stamped on end of crown/pinon gear inside diff casing, I would suggest searching PH for Salisbury as its come up quite a bit lately in the Wedge section of the Gassing Station.
Regarding your choice of ratio its up to you, if its mainly for cruising then with the box you've got a 3.31 or 3.54 should do the trick.
davidy
Regarding your choice of ratio its up to you, if its mainly for cruising then with the box you've got a 3.31 or 3.54 should do the trick.
davidy
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