In a message dated 2/2/98 7:49:23 PM Eastern Standard Time,
> I always read with great interest the discussions regarding engine swaps for
> TR-6 and Spitfire. I have a Spitfire 1500 that I was thinking of upgrading
> with a GT-6 motor. I was also going to upgrade the vertical link and
> from a GT-6. However, I was wondering with the larger increases in
> horsepower: V-8 in TR-6 or V-6 in Spitfire, what break modifications have
> been considered and are acceptable?
This subject always generates a lot of heated discussion, but I'll give you
the answer given by Ken Costello, the creator of the first MGB V8s, when asked
what brake/suspension upgrades were required for his conversions -- none!
(The key word here is "required")
Why not? If you do the swap properly, the car will not weigh significantly
more than it did before (maybe even less). If the brakes are not up to
stopping the car with the V8, then they were inadequate when it had the 4
cylinder. Unless you are a maniac, you will not be driving the car on the
street any faster than the car was capable of before, so if the brakes are not
up to stopping from those speeds, they never were (the key words here are
"capable of"). My stock TR6 is capable of 100 mph speeds on the interstates
now. I am not going to drive it that fast, and certainly not any faster, when
the V8 is finished.
Granted, when you are doing a lot of spirited driving on some winding back
roads, your average speed will be higher, so the brakes will fade in fewer
miles than before (if you drive sufficiently "spirited" they will fade anyway
- just not as quick!). Yes, you may approach a curve at 50 that you may have
approached at only 40 before, but, somewhere, there is a curve just as sharp,
with a longer straight leading into it, that you take at 50 now. It doesn't
matter how quickly you get to 50, the only thing that counts is can you stop!
That just covers what is required -- what is desired is another matter all
together. Brake improvements to even a stock car could be benificial. I have
upgraded my rear drums from 9" to 12" so I have significantly more braking
power there. I am still investigating what improvements to make to the front,
and I would love any input from the list. If I can't improve the front to
match, then I will have to add a proportioning valve in the lines to the rear
to decrease their power to match the front. Somehow, that doesn't seem right!
The same basic arguments apply to suspension upgrades as well.
That's my 0.0025 cents worth!
'71 TR6---------3000mile/year driver, fully restored
'71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion - see:
'74 MGBGT---3000mile/year driver, original condition, slated for a V8 soon!
'68 MGBGT---organ donor for the '74