Macca

Graeme I just had to make this call with the 993. I have 5mm pad left for SITT and have elected to keep the existing pads on and use them up. However I am under no illusion they will last only the trip down and then Teterongia and will need changing with my spare set all round before Highlands. Sure 5mm looks like 42% left but its really only 3mm left out of 10 so 30%! Accelerated wear factors due to heat indicate a square root effect on thermal coefficient for last 25% of life so effectively I expect the last 3mm (30%) of life to be over with 9 times quicker than the first 3mm of life given the application (track). Bushman engineers logic but all supports your real life findings (and others)....


John you should be killing 1.23 by year end! No pressure! My personal goal is to put one lap in under 1.18 next time out at HD. No pressure LOL!!!!

But seriously. You need to sort that seat out. Now you know your engine is strong, your fluids, pads and rotors are all sorted, once you have that seat sorted you need to think about getting those springs replaced. They are will by that stage be costing you time. getting rid of 80 KG would be nice too to reduce wear and tear on components. I think you will be 1.21-1.22 by New Year assumes you can get above sorted....no pressure!

Here is the factory manual read on 993 pads/discs. I'm, sure your 964 workshop manual will read similar for 964 tolerances.

John McM

High 1.25 on 31/8. Biggest time gains remain in the sweeper and less so in turn one. Peter is faster in that sector by 4 seconds.

Macca

Doug. Im not sure what options exist for the boxster. For the 993/964 the only way to do it for the track is properly (IMHO). I suspect similar systems exist for the boxster/996/997....

The top kit is the Techart kit I have fitted. The PITA is removing the front bumper and one one side having to remove the alloy bracket holds the fan in place then jigsawing a hole in it to get the air ducting through to the inside front wheel arches. Then the inside plastic arch needs modifying with the trumpet and deflector. You can see this circled. I removed front and rear disc baking plates a while back and this aids the air getting to the back of the disc.

The blue set up sitting on the desk is a factory turboS duct I installed about 10 years ago before I installed the techart kit in 2010. Jamie now has it installed in his 993. I bought some industrial rubber steel ribbed tubing. This can be run through to the inside wheel arch and a deflector can be fashioned from sheet PU or alternatively the ducting can be run above the A arm with zip-ties to bring air closer to the disc. Removing the backing plates completes the picture. Total cost in parts around $600, compared to the Techart solution which is over double that cost in parts alone (assumes upgrade of fogs to HID).....

Just some ideas here but there must be a front bumper mounted kit for the boxster which is known to work. Im sure those that track the boxster will have some ideas. What about George Randles car?

John McM

Macca,

Steve is sorting out the seat. I'm going to take out more interior. Then look at the rear wiper and a lighter battery.

I already have lighter wheels, primary bypass, lightweight flywheel, fibreglass engine lid, no spare wheel, no front carpet and only one seat. Must find somewhere to weigh it. Paul and I worked out on Saturday that his power to weight ratio is materially better than mine.

Macca

John. Id say you will have shaved 75kg with a race seat, no passenger and those other items you mention. Rear wiper and battery good for another 12kg. If you can get to C2 weight ill be impressed.

Pauls p/w ratio is surely better than yours stock (200bhp for 1120kg vs 250bhp for 1450kg). Id imagine his is now putting out a little more than 200 bhp. Yours is weighing a little less than 1450kg....

Its still remarkable the p/w of that little 1978 car...

John McM

I have some paint tins to dispose of so I'm going out to the Waitakere Refuse Station....in the C4. Choice of vehicle is motivated by the fact they weigh vehicles for $10. All will be known in 24 hours. Any guesses with a full gas load and no driver?

peterC2S

John - just an idea, I have two Racetech seats in the 944 if you need to try them side by side 4009 and 4000W. Im using the 4000W as the drivers as its a perfect fit but I suspect the 4009 would be better for you. Its not the most ideal passenger seat for me though (Fine for Ray!) so sometime down the track I may swap it out. If you want to compare let me know.

John McM

Great idea. When suits?

peterC2S

Sunday would be ideal - and the weather may have quietened down a bit by then. I need to take it for a quick run to make sure all is OK for Tues so I can call past morn or afternoon - whichever suits. Won't be coming up your drive though and I may scare the neighbours....

peterC2S

Anyone thinking of doing the RSG/Playday twilight on 15th - looks like bookings are pretty thin and at this stage only 2 groups. That means LOTS of laps and even better it will likely be wet so great opportunity to hone those skills. We have room for a couple more in the RSG sessions (posted on the RSG forum as well.)

Macca

Good idea John. Lets see who can get closest to the true weight. I think you need to leave the spare wheel in. Its part of the front crash structure as I understand it (well there is mixed debate on this). Alternatively measure it separate on the home scales. Also measure with tool kit and pump. Again can be subtracted on home scales. Essentially you want a touring weight with half tank of gas (again can be adjusted using specific weight of benzine calc). Half tank is the generally accepted norm - adjust down by around 20K for half a tank. So with all factory supplied equip. Then you can subtract items measured separately for "race weight". This way we can make proper comparisons with factory figures and other peoples figures (like mine for example). Im not sure the scales there will be as accurate as the race scales but within 5-10kg should give a good relative guide for later on...

Im guessing with your spare back in and toolkit/pump you will be talking 1412 kg without the passenger seat and half a tank of gas no driver.

John McM

That works for me. No doubt I'll hear you coming.

John McM

I rang the Council. Aside from the service being on their website "Waitakere Refuse and Recycling Centre -The weighbridge can be used to weigh a car or other vehicles. The charge is $10.50" I couldn't get more info on accuracy etc. They likely use it as a relative tool, but it would still have to be very accurate to justify charging by the kg dropped off, for some types of waste.
We will see.

I can weigh all of the things you mention, so it will go as is. Weight for a 964 C4 is 1,475kg (DIN 70020). I need to be at 1,400kg to have parity with Paul's Carrera 3.0, but won't be stopping there....

Maxem

1420, as is with full tank

Maxem

There's already enough noisy Porsches in my street thank you. I am up and down like a yoyo looking out when I hear them coming. There's a dude with a black Faz 430 spider who wins that one narrowly from John.