Making the GT6 a bit more sprint/hillclimby?

[JohnD]

If I may, Andy, resite that cut-off to the inside.

I have one just like it.  It's the three terminal version that lights an LED pilot if it works, so that you know that it has functioned.    First event, I rattled the car quite badly cutting a kerb - and the engine died!    Quick check, no lights. Must have dropped a loose connection to the ignition!   B&gg&r!  End of my race!

But later I found that the idiot pilot light had fallen out into the back of the dash!  It was smugly glowing to tell me that the vibration had fired the inertia switch.  As that was on the dash, and within reach, I could have hand reset it and continued!

If yours is on the bulkhead, you couldn't do that.  Put it between the FIA master and the other two switches?

JOhn

Edited November 19, 2018 by JohnD

[Bumblebee]

Good Call. I had not thought of that scenario. 

Thanks 

[oldtuckunder]

4 hours ago, Bumblebee said:

 It sits above passenger footwell, but as I am lanky and the car tiny  I can reach ok.

 

I know you say you are lanky but you are supposed to be able to reach when in seat and seat belts done up (which means your new four point), now there is a point that as you will probably be running in roadgoing that the cut outs are only advisory not mandatory so you could fit them in the boot if you liked, however it is normally wise to try and avoid having an argument discussion with a scrutineer whilst getting ready for an event, as whilst you may be correct on one point, one may well find that a few other minor infractions are suddenly noticed!

Alan

[Bumblebee]

Understood...And I had kind of thought of that , but the arch bodger in me has already got that sussed ( I Think ). I am going to run a bowden cable through the dash and it will appear where the choke cable used to be. I will install a lever switch there, and that will, in my head anyway cross that off the list. 

I did think about removing the radio and installing the panel there, but the lad likes his radio, and when all is said and done it is supposed to be a road car which we can use for "other fun" 

Thus it is keeping its carpets and door trims and all the other stuff which weighs a ton! He said... I can see this getting out of hand in a year or two! 

And I wont be able to say I wasnt warned. 

 

 

[oldtuckunder]

2 hours ago, Bumblebee said:

Thus it is keeping its carpets and door trims and all the other stuff which weighs a ton! He said... I can see this getting out of hand in a year or two! 

 

My Vitesse also retains all its interior trim, 1) If you want to run in a road going class you have to (although carpets can be removed) 2) It does make it all a bit more civilised and doesn't make it unpleasant to drive on the road still 3) As some competition classes are based on bhp/tonne you may find the extra bit of weight stops you topping out of one class and into a higher one!

Alan

[Bumblebee]

So this weeknd saw me crawling under the car. The diff has been howling for a while so needs looking at,it leaks like a sieve from the sideshaft flanges too. Also the rear spring, whilst dearched is also for a spit, and is too soft for the GT6 meaning it bottoms. 

First issue was diff dis assemble. I took the side shafts out, and ran round the corner to my mates to use his press. 

So the diff leaks might be from here. This looks butchered (it wasnt me) and I will guess that the plate isnt straight hence the leaks. The sideshaft was blue too, so looks like heat, a large screwdriver and a huge hammer was used to separate the bearing from the shaft before. Not sure if this is saveable to be honest 

So Whilst in the area I thought I would clean up and put a small patch where the inner arch drops below the boot floor, it was scabby and a couple of minor holes. Started on the offside. 

I got this 

Wasnt quite what I expected, and means my iffy welding skills will have to come out. There are all sorts of bits of metal welded in here and there so its been a proper bodge 

The passenger side looks much the same externally, so I am in a quandary really. I suppose I will have to remove the fuel tank, which is typically quite full for once, and check it out. Although part of me says ignore it and it will go away! Currently I need outer arch lowers for both sides, inner arch lower for this side. I'm going to patch the hole in the floor. I'm not very good at welding. I will cut off the outer lower with my trusty air chisel and see how easy it will be to do the inner arch. I may end up tacking a portion of it in depending on what I can see. There is also a hole where the wheel arch meets the wing, It was bodged over with some fibre glass but that will need doing too, and access is tight and the bends stupid . Then it will need filler and paint, both of which I am even worse at than welding. 

 

On the bright side I have a de-arched swing spring to lob on the bay. 

 

Terrific. 

 

 

[sparky_spit]

That looks pretty much par for the course on a small chassis Triumph that has had some previous owner bodging over the years.  It can all be repaired successfully if done carefully and methodically.  Lots of practice on sheet steel offcuts of the right gauge will make you confident enough in your ability to do a proper job of it.

I looks as though somebody has tried to repair your howling diff by using Dynamat.......

[Bumblebee]

Not particularly successfully it has to be said. 

It was successfully holding bits of the boot floor to other bits of the boot floor though, so not a total loss .

[Nick Jones]

Yes, ugly but pretty typical. Of the 4 of these areas over the two cars we own, 100% have been at least that bad. The Spitfire also had numerous stress cracks in the wheel tubs and spring arch but not usually an issue with a GT6 due to the extra support of the fastback structure.

All the pieces you need to repair are reasonably straight forward to make. Possible exception being the lower rear corner of the outer wing. There are sections sold for this but the one we tried was such a poor fit that Chris made his own for the other side.

If you diff is howling, why waste time messing about with the sideshafts? The howling will be due to either the CWP being knackered by running largely unlubricated for a while, or running out of true mesh due to bearings knackered in the same way. Service exchange the whole thing.......

[Bumblebee]

So I have been doing stuff whilst awaiting my diff back, which it now is. 

The downside is things I have been doing are things I am not very good at, so I tried to take my time, which is hard for me as I normally just throw stuff together.

I started by repairing the rear wing behind the wheel which had been repaired before, badly. There was filler all the way up to the swage line so I took that all out

Anyhow I welded in new lower secton and inner arch, and a floor patch in the boot. Once the welding was done it looked solid, if welded by Stevie Wonder...

 

All the warping in the panel was there already so I knew I would have to play with filler. I am useless at filling. 6 goes later with filler and I lobbed some paint at it .. Came out like this. The match isnt great, I am not sure the car repaint was a perfect Mimosa anyhow. I will try and polish it in for this year. The car needs paint anyway. I am half way through the same repair on passenger side now. Then the diff and the correct rear spring can go back in it and it can go back on its wheels.

 

[Bumblebee]

I have also been working on trying to get cold air to the webers, following ideas from you guys I decided to build a box of aluminium and feed it with a 75mm cold air universal kit from the bay which would supply the pipework. I made a template from card so I could work out where the throats were as they are stepped and cut a plate out of 1.5mm aluminium. .Now I cant weld aluminium, so I decided to bend sections and pop rivet, then seal with sealer. 

When I went to fit it to the car I discovered that I had forgotten the clutch master was there so I had to gently mod the back of my lovely new box with the tickling stick. So with the box fitted and the throats in it looked ok, but I had to trim some 40mm washers to spread the load and allow the mini throat clamps to sit under and hold the throats in.

[Bumblebee]

After that the top goes on with self tappers, the pipework oges down to the front and the air filter sits in front of the rad. Now time will tell if it blocks too much flow to the rad and makes it run hotter, but it seemed the best place to put it. I will just have to try it and see.

It must be said I am no closer to doing the things I need to do in terms of safety, the ROPS harnesses seat boxing in of fuel tank ( which is really doing my head in) so who knows if I will get close to getting out there this year. Still , I will keep on keeping on and see where it takes me

[JohnD]

Bee,

I did a similar job, but retained the tubular plenum.   The OE  three once diameter is restricting IMHO, and an air box benefits from being as big as possible.   I cut off the strip of the old one with the trumpets in.it, and curled some thin sheet steel.round to make a six imch.tube, the biggest that will fit in.  Welded it all together (delicate work!) And as you found, had to redo it to.clear the bulkhead. Works well, i.think.

John

[zetecspit]

I currently have a MASSIVE k+N oval filter. 100mm deep, over the 4 intakes, remarkably close design to twin webers. But I want to change it into an airbox so thinking of replacing the filter element with a strip of 100mm aluminium, plus the flange as above. Hoping 3" intake pipe is adequate (180ish bhp)

Also wondering if I should try to get the pipe to enter the airbox at the bottom and central. "feels" like it would be a better solution but not sure if I am just creating extra grief? Saying that it may not fit there as the engine is out so unable to check.

[JohnD]

Zetec,

Some suspect that the OE six cylinder plenum is too narrow, as they find evidence of air starvation to the rear cylinders.     Which was one factor in my wantaing to make it bigger.    Flow in a tube - flow in the plenum is MUCH more complex but anyway - is proportional to the fourth power of the internal radius of the tube.    So double the radius and flow increases sixteen times! (2^4=2x2x2x2=16)    A big plenum has the additional advantage that flow will slow down in it, and Bernouille comes into effect raising the pressure and promoting intake.

But a design that has an intake duct with a significant length, such as  Bumblebee's, makes that far more important than the size of the plenum.    Flow is inversely proportional to length, and again radius should be as wide as possible - even small enlargement is useful when it's a fourth power relationship.     But if the intake is wide and short enough, and the plenum is as big as posisble, then the position of the intake into the box is probably irrelevant, and can be anywya convenient.

JOhn

[Bumblebee]

well  my plan is to sort of test and see what gives. if its a problem I can remove the ducting and stuff the filter straight to the end of the outlet which will still pull cooler air than before. I thought I would try  the cold air down by the rad first and monitor what happens. Time will tell. It was effectively all the space I had without cutting the arch back which is what Zetec did, and is an option.

 

[oldtuckunder]

14 hours ago, Bumblebee said:

I have also been working on trying to get cold air to the webers, following ideas from you guys I decided to build a box of aluminium and feed it with a 75mm cold air universal kit from the bay which would supply the pipework. 

 

Should work well IMHO, just about what I have sketched to do for the double Webers on the spitfire, so I can junk the Mankey K&N,'s that spend their life sucking in hot under bonnet air! Advantage of doing it this way is that if you find you have to modify is that it's a bit more cutting and riveting, rather than cutting welded sections. NB I wouldn't be very worried about sealing the joints too much as the plenum doesn't have to be air tight and the box alone will exclude 99% of under bonnet air. Alan

[JohnD]

I think I've posted pics before, but anyway.

I use a large cone filter as shown that goes straight on the front of the plenum.  You may reasonably say, that's going to pick up hot air just like intake mounted filters, but Last year I had to move my oil cooler from where it was below the water radiator, as it had proved too vulnerable.   It's now mounted to the left of the radiator, and works just as well, so I think plenty of cool air is to be found on the right as well.

You may also say that air is drawn through the original orifice into the enlarged plenum, but orifice flow is very different and doesn't suffer from the constriction anything like it would in a tube.

John