Kevin

I have received my new valves and new pistons. Enclosed are the new 9.0:1 compression pistons sitting next to the GT3R 11.3:1 pistons. I have to weigh the pistons and will post the specs later. In the design I asked for a little more meat under the dome and a wider skirt. You can definately see that the stock "R's" were graphite moly coated. In the next few days I will be doing "coating" the pistons and new valves.

Kevin

Here is a picture of the skirt detail. The ring lands have been dropped down, to provide some seperation from the combustion temps and high pressures. These pistons look larger, but keep in mind that there is no dome, but a dish.

Kevin

Chad;

Turbo engines over 750hp have had seperation of the piston crown. These are reinforced pistons, forged to handle the duty at hand. Most of the dimensions have been widened. The wider skirts prevent piston scuffing that occurs with the small Mahle skirts. I have a shelf of turbo pistons that have had excess piston scuff from slap that was occuring. They do look bulky, I will weigh them shortly.

m42racer

Kevin,

Your Piston looks like a domestic type. JE, Wisco etc. You discuss the wider skirt for helping with scuffing. How are you managing the tipping with all of the extra clearances these types require? BTW, the forging you have posted is not as strong as the Mahle forging. This has been well proven. In fact one domestic manufacturer has had problems with Pin Bosses cracking resulting in major failures. For sure you may require a fuller skirted Piston, but you need to have material that has very small expansion rates, so that the clearances can be kept as tight as possible negating the "scuffing" effect. Big clearances with big skirts could be working against you here. Good luck though. This has the makings of a great engine program.

Kevin

Simon;

PM me the alledged failures. I have closed the tolorances. Mahle does not offer a lower compression piston in this configuration. This piston has been run with some good success in the PCA racing community using these exact specs.

Kevin

I know that this doesn't apply to the engine build, but here are the rear seat brackets that add up to the alledged 31 pounds of rear brackets and steel hardware that was printed in this months Excellence mag... I had to drill out 10 spot welds per each bracket..

KSA Turbo

thats some complicated stuff your up to. best of luck

Kevin

I spent most of this weekend, grinding away seam sealer and orbital sanding interior panels so that I could stitch weld the rear area of the shock towers, and inside quarter panel assy. This is the prep work for welding in my rear roll-bar.. I have removed most of the underbody seam sealer, and undercoating allowing me to weld the seams.. The water based seam sealer does like to burn.. in fact I used map gas to to burn the area prior to welding.. When finished I will prime and paint the full rear area.. I felt that since I have cut the sunroof roof panel out, nows the best time to get the steel work and welding done.. I was amazed to see how many holes are in the steel panels.. many were just covered with asphalt based acousta-mating and blue tape..

HBdirtbag

great thread Kevin.


Looks like a fun project


FYI, a little dry ice does great at removing the hard sound deadening material.

Kevin

I received my new Tilton carbon/carbon clutch today! The entire assy with my lightweight flywheel weighs a grand total of 13lbs.. All contact surfaces are carbon fiber.. It consists of 4 floater plates with one that just sits against the flywheel surface, and 3 driver plates that are on the spider hub.. which drive the input shaft to the tranny.

This baby can handle a tested capacity of 1695 Nm or 1250 lb ft.. Clamp load is 4326 lbs!!! This clutch is completely rebuildable. In the purchase price of this unit, they supply 2 extra plates, in theory I have 2 extra rebuilds included in the price..

Almost all of the ALMS GT3R's are running the 5.5" version of this clutch.. This unit measures out to 7.25"

ashoof

nice clatch kavin how much dos it cost if you dont minde and dos it rattle in idle i have a ruf 550 hp upgrade would it be a good setup for the ruf thank you

Kevin

This clutch is worth 4K.. There is no rattle, you have a very progressive clamping force. It is a very good clutch, the 5 disk sytem might be better suited vs the 7 disk..

Moogle

that is a HOT clutch

AeroGT3RedWing

Wow. What an amazing clutch.

Kevin

Chad, I knew that you had the Tilton, but I didn't know which one you actually used. Which flywheel did you use?