TR7's first track day

[Jammez]

We took the TR7 on it's first track day last weekend at Ingliston. We weren't the fastest but probably had the most fun!

Really pleased with how the car handled, very neutral and flattering to control. Had some problems with fuelling, after exiting fast right handers it would get starved of fuel. It's running a tweaked Dolly Sprint engine with standard twin carbs and fuel pump. Little bit of reading suggests either uprated fuel pump or Cooper S float chambers? Any thoughts?

[tapkaJohnD]

Do you know that Cooper S carbs are specially fuel surge resistant?

Carburettors by their design don't get fuel surge problems, as the float chamber 'filters out' any bubbles that reach the carbs, and the small reservoir in them stops there being an even momentary failure of fuel delivery. Experiment by driving in trcak day style with a full tank and with a near empty one. If the car hesitates with a full tank, then the problem is not air bubbles in the fule delivered to the carbs.
Tank fuel surge is mainly a fuel injection problem, and a swirl pot is essential for motorsport use if you have that - which you don't!

You say that handling was good, but your second pic in particular shows a lot of lean at the front, with your outer front wheel in significant negative camber. Stiffer front springs, +/- an stiffer antiroll bar would help. If that, then you should consider the rear springs amd perhaps antiroll there also, but you need someone with TR7/8 experience to advise on that balance, which I don't have.

Lastly, even if you are going to use it for track days, may I strongly suggest you consider a ROPS (Roll Over Protection System)? If you wnat to eneter motorsport you will have no option but to do so. Look at your last pic, and draw a line from the top of the windscreen to the back of the car - it goes right THOUGH your head! Even if the screen surround held in an inversion, which I doubt, you would be vulnerable.

John

Edited by tapkaJohnD on Sunday 20th April 13:55

Edited by tapkaJohnD on Sunday 20th April 13:57

[Jammez]

Hi John

Thanks for the response. A couple of people have mentioned the level of fuel in the tank and possible contamination so we're going top check that out.

The Cooper S thing was something I seem to remember reading as being an upgrade but I can't remember where or exactly what it was related to.

The car isn't mine it belongs to my father-in-law so I can't remember the exact spec for the suspension but it has had stiffer springs, adjustable Spax and poly bushes all round. Not sure about the roll bars, I think they're standard.

I guess my comments on the handling were relative to the 30 year old convertible that it is,driving the car in it's standard form and also my own TR7 fixed head with standard tired suspension. The car can seem a bit firm on the road but it really did work so much better on the track, the turn in was very sharp and it the whole car felt very flattering to my "not very experienced on a track style of driving!"

I think it helps that the cars not very powerful so you're not really approaching the corners at terrifying speeds so it does flatter you.

I'm not sure how much we'll use this one on a track, we have a 3rd as yet unrestored FHC that we may make into more of a track car. At least we'll have something over our heads in that!

[madsvlund]

A small teaser of TR7 racing, my frien Per in his TR7V8 on a wet city trail today (and I won't mention that my TVR brusted the diff andn made a DNF#

https://www.youtube.com/watch?v=SMC6fW6L4lg&fe...

[tr7v8]

7's with good suspension handle pretty well. My 8 was on lower (10mm) stiffer springs (25%), with Spax all around. They are quite softly sprung as they were built for the US market, so need stiffer springs, the problem is that the closer you go to a good track build the worse it becomes as a road car. But it was completely polybushed, including subframe to body. It also had subframe spacers to give carb clearance.
One thing that makes a difference is an antidive kit.
As for a roll over bar the 7 was designed to a set of crash standard that were vastly in excess of of what the UK asked for. I've seen crashed ones & mine was hit by a securicor van & they are very strong. The problem with ROPS is it gets in the way, needs mods to hoods, tonneaus etc.