356 Race Car

[911hillclimber]

Cracked my 911 engine back fire under load!
Small air leak in the inlet manifold gasket on #6 cylinder. now sealed and it runs good and hard on all 6.

[steve wright]

great news!

rubbish day for me. managed to pour petrol all over myself when filling car for the first time using pump and jerry can, made a mistake with the template for the speedster seat so scrapped one mount, STILL chasing the MSA for my HTP papers, my new exhaust got delivered to Ian's old address so I need to do a 3 hour round trip trip tomorrow to pick it up (he's moved up north) and every little job went pear-shaped

still, a bad day in the workshop is better than any day in the office

[Jeremy 356 (Jez 356)]

Where is your first race?

DDK might want to come and support you

This project is extremely inspirational although i think I would only be able to dream about putting my 356 on the track !


Keep up the great work


Regards Jeremy

[steve wright]

Hi Jeremy, first race is next weekend at Silverstone. Then Snetterton 3 weeks later which is a three hour endurance race. MSA confirmed HTP papers are finalised (phew) and picked up new exhaust yesterday so tomorrow should be a busy day getting the seats and exhaust in. Race numbers are sorted, tow hook is on, and new filler cap (lightened with more holes!) is fitted. Filled the tank and added it to the weight of the car - turns out the car weighs in at 806 so we have some opportunity to take out weight before we hit the 780 minimum. Assuming nothing breaks this season (hah!) we will focus efforts on taking weight out of the drivetrain over winter. Probably getting ahead of ourselves in saying this but we might as well have plans

[neilbardsley]

Some silly questions. I'm guessing that 20kg of none moving weight (trimings and other stuff) doesn't make that much difference but 20kg off the drivetrain is more signficant? What cars will you be racing against and what performance will you need to see from the car for it to be competitive? I don't even know how to measure that? Since I suspect 0-60 is meaningless. HP is useful but only relative against weight and other factors. I saw that you have race tyres and a spare set have you gone for a general purpose tyre or dry only? I can only relate my cyclocross racing where tyres are key and top chaps can bring 5 wheel sets (and 2+ bikes) to a race!

Good Luck. I might be up in Northamptonshire next weekend 19/20 what time are you racing?

[steve wright]

Hi Neil.Yes it's better to take the 20kg's out of reciprocating mass as it takes power to turn it as well as the weight it adds to the car. Others will have more knowledge of this than I but I think it's something like a factor of six when it comes to the benefit of taking weight out of moving parts, so it's obviously advantageous to focus efforts there. I've just had the entry timetable and list through so it's all very real now! They have split the Guards race between GT and sports racers, so we're not in with the Chevron's, Brahams and Porsche 910's (!!!), but in the GT race we're up against a couple of early (i.e. '65 911's), E-Type Jag's, a gaggle of MGB's, Lotus Elan's, Austin Healey's, TVR Grantura's and Shelby Mustangs, so it's a real mixture!

I'm not sure what bhp per tonne we need to be competitive (I expect no amount of horespower is going to make up for a lack of experience or talent ) but the 356 weighs 806kg's all up, with a homologation limit of 780, so we've some trimming to do. In it's current guise I figure the car is making about 120hp, so we're getting 149hp per tonne. The only reference point I have is the '65 911, which weighs 950kg's and develops about 180hp in race trim, so they are are making 189hp per tonne, so there is quite a disparity. Some of the other cars however should be at or slightly less than the 356 figure, so it will be interesting to see how we go. As I said though, this is our very first race, so all I'm worried about is finishing the race, staying out of everyone else's way, and not bending my (or anyone else's!) car

[PhilipB]

Steve, you're not as far out as you think. 911s have to weigh at least 1005kg and it's quite a challenge to get a genuine 180hp out of a small valve 2.0 litre on Solex carbs. Most are running quite a bit less in the interests of drive ability. 160 - 170 hp per tonne is more likely. Just getting my excuses in early!

[steve wright]

[steve wright]

phew, so here we are, all done. a huge thank you to Barry for sorting the seat mounts which were quite a big job, to say the least. Not only did the lad do a mighty fine engineering job, but he didn't finish until 10pm on Friday night


The new exhaust is a huge step forward: far quieter, more power, better ground clearance, and better engineered. Here's why we were getting popping and banging from the Sebring. brand new blown gasket:

because the flanges aren't substantial enough, here's the comparison versus the new one...
[/img][/img]
or reinforced to stop flexing as the ne one is...


nice merged collector with equal length primary pipes...

and stepped primary pipes to improve low down torque without sacrificing top end


and finally a tow hook for the rear. Nowhere to mount it on the bodywork obviously, so... double-sided velcro to attach to bodywork, and mounted to bumper bracket. not pretty but it works!


so we're off to Silverstone on Thursday for testing and assuming the HTP papers arrive tomorrow, racing on Saturday - wish me luck

[Winston Teague]

Good Luck! W

[ims101]

Yes good luck

[MdR]

Good luck

[Jeremy 356 (Jez 356)]

Best of luck old chap, have a blast !

I presume you will provide a full update on your return.

Rain scheduled for Saturday so hope all goes to plan.

Regards Jeremy

[left4dead]

Good luck for Saturday, Steve.
Shame you weren't racing at Silverstone last weekend as we could have all cheered you on from the observation deck of the Experience Centre.

[vicpolky]

Good luck, hope it goes great.
We need a full report