Next Stage of the Project

[Mothy]

Well the prices justification tribunal has approved some more work on the car, so as a firm believer in "When you get to yes, stop negotiating and place/get the order", the car is now booked in for the next round of mods.

All internal this time - gearbox stuff, so it's ready for when I finally get to the engine.

• Overhaul
• Modena limited slip diff.
• Billet side plate
• Carrier plate
• Close ratio gearset (34&5)
• Lightweight clutch

All booked in with Grant for mid June, right after the Motorkhana.

The last trackday really showed up how the car suffers from no LSD - a number of times I found I was slipping the inside wheel when powering out of corners.

Will be interesting to se what a difference it makes next time at Wakefield - less slip and better drive out of turn 2 with a lower 3rd gear.

Tim

[Mothy]

Well it's now with Grant and they have pulled it apart. Looks like the box was generally OK with just the syncro on 3rd needing attention - i was expecting that as I often beat the syncro when changing 2nd to 3rd at track days.

Now we know what gear sets I had, Grant is working out the planned replacement ones. I doubt if the car has ever been redlined in 5th gear previously and at the speed Grant calculated I doubt if I would want to be driving it at the time! So who knows - maybe Conrod at Easter 2013 will be it's first time!!

Bit like a kid waiting for Xmas morning - with luck I'll get the car back by the weekend.

Tim

[strikee]

Evening Tim.

For us novices, who is Grant? and what is LSD. Limited slip something?

[Mothy]

Grant Geelan owner of Auto Haus Hamilton at Brookvale. LSD is limited slip differential.

Without the LSD my car has a tendency to lose drive out of tight corners due to the inside wheel getting unloaded and breaking traction.

[Mothy]

Well it won't be back by the weekend - it's getting the full rebuild job with all the bearings being replaced.

Whilst none were broken or badly worn, the box is 280,000kms old and it just did not make sense to spend all the money on the new bits and then reassemble with old bearings. They might have lasted another 150k's but the potential labour cost of stripping it down again in the future more than justified doing it now.

Also there was WAY too much play in the CV's - so a new set of axles is going in - cheaper to replace the whole axle including CV's.

As for gear ratios, Grant and I have come up with a plan which sees standard 1st and 2nd, then fairly constant 1600rpm drops between each of the remaining ratios. My old 2-3 drop was 2000rpm, so I should notice a difference.

Will have to wait till next week now.

[9er]

Sounds good Tim, I have looked at similar options thru Mark Poole motorsport here in Adelaide, but have not been cashed up enough to pull the trigger.
The Modena alone will be a great improvement, and bulletproof.
Short term for me I have just rebuilt an early case gearbox with 7:31 R & P and plan to swap that in. It doesn't stop the wheelspin issue though obviously.

[Mothy]

Well I got the car back yesterday and OMFG it is so much fun. Have not had much chance to test out the LSD but the close ratio gears make such a difference, along with the lighter clutch.

PR Technology are having another of their open track days at Wakefield in late July - looking at going to see what a difference it has made compared to previous.

Tim

[JET951]

Tim, its going to improve the car so much i can see the times coming down as we speak. Not only will the LSD help in increasing traction out of the corners but it makes a huge difference to trail braking. control is improved out of sight. Some of the best mods you can make to a track car.
Sean

[Andrew (Tiger)]

Tim I recently did the same to my race car without doing anything to the engine. Best modification if you can't afford an engine rebuild. Shorter gears will give you the equivalent/feeling of 15-20% extra power and LSD will give great drive out of corners as well as mechanical grip into corners. Fun fun fun ! FWIW anyone wondering about cost, allow about a $7-8K cost depending on parts and gears you want.

[333pg333]

That's great news Tim. Congrats. You will be amazed at the differences I'm sure. Makes the $pend all worth it. Lookout lap records!

[Mothy]

I'll be interested to see if I need to change any of my sway bar balance - it used to be pretty much spot on with a little understeer in the slow corners (or a lot if I lifted a front wheel up). Ive already noticed coming off roundabouts that the car tends to want to push straight ahead when I plant it - I guess both wheels are now pushing evenly rather than only one doing most of the work in the past.

Motorkhana will be interesting.

Tim

[Tigrah]

Interested to see how you go through turns 4 and 5 at Wakefield. I always felt I could do with a 2 1/2 gear

[Mothy]

Yes. Also turn 2 for me. It will be interesting to see where my get change points occur now. I'll find out at end of month I guess.
Tim

[333pg333]

The new LSD could be increasing slow speed push as well Tim. You'll possibly have to adjust your driving as well as the suspension setup.

[Mothy]

Well some of this might be moot for a while.

Started the car this morning and after about 3 seconds of cranking, it did a very loud backfire -- much louder than the normal coughs and farts of a cold engine.

As I went to drive off, there is now a very worrying metalic knocking sound which follows the revs of the engine - so it's not gearbox.

Did the usual airbox checks - all OK so it's something internal......... ouch. Its down at Auto Haus Hamilton now to see what the damage is.

Bit worried

[gwiggill]

sounds like something in the airbox. I blew mine (no pop valve) a few years ago and it had huge crack it in. A new airbox is a partial drop of the engine isnt it?

[Mothy]

I have a pop valve (dunny lid) in mine and it's still intact. The noise is very mechanical in sound - could be one of my chain tensioners has gone south. I already have the Carrera upgrade to hydraulic ones.

chunk chunk chunk chunk chunk chunk chunk chunk!!!!

Sweating.......

[Mothy]

Looks like something has come adrift inside the air-box when it backfired and a bolt/screw has made it's way to number 5 cylinder. They have checked each pot with a camera scope and found the debris in #5.

Stripping it down next to check what damage has been done. Might be a labour only job or could be mechanical depending on the damage to the P&C.

If damaged I may be in for some pain - as my P&C are USA spec and are the Alusil type rather than Nikasil.

Nervously waiting.

[Tigrah]

Better schedule a hearing before the Prices Justification Tribunal just in case.

[JET951]

Sorry to hear about the problem Tim, On the upside if there is some damage now would be a good time to upgrade to the LN engineering Nickies. I think they around $4500 of a set including pistons/rings and a custom compression ratio.
Im not sure what engine you have in yours, could be a 930/04 at 8.5:1CR or maybe the 930/07 at 9.3:1. the Custom pistons can be set up as high as 11.5:1 and you get the extra torque from the increase capacity.
"Nickies™" Cylinders for Porsche 911 models
Sean