Roy

I must admist I was having long , close looks at your car. I really like how you have done htings. I think there is a definite thinking to how to build a car when you are a frustrated engineer that wants to drive and build cars for a living Not always the easy way, or the quick way OR the the cheap way....but he cool way

The phonecall I just got from Racepace said they doubt the box will make it through Phillip Island. Mostly due to the twin plate Exedy it now has in front if it....its not the power as RB25s are poop and dont seem to want to make any !

Ok, So have wasted time and money thinking about the RB25 and 20G setup and leaning on it for all its worth. I want to be sure that walking away from what has been a champion turbo is the right thing to do. Also will give a good baseline for other setups being trialled So by the end of the day will be interesting to compare: RB20 RB25 TD06-20G. 8cm 12cm Cams Std 256/8.5 Tomei Fuel E85 E85 Both engines run the same inlet and exhaust manifolds. As it is an R32 RB25 it does not have NVCS will be interesting if the better breathing hot side, bigger cams and bigger engine will result in more power then I was making on the RB20

If the RB20 didnt split that heater hose then i would never have put this engine in. This was the "too cheap to pass up in case I got EPA'd engine" that I hoped would never get used. Anyway. So after a Saturday of wasting Racepaces dyno time with fiddling with the 20G and 12cm housing...we are pretty sure we have run out ofcompressor but simply couldnt get thet thing to hold boost. So knowing the Hypergate only had a piss weak 11 psi spring I have grabbed 3 more springs and should be able to find a good combo to get the gate to hold about 19psi...and us bleed what we want from there. So cam gears are in. Tomei 256/8.5mm cams are in. 12cm housing on. 19psi springs in the gate and she is rolling onto the dyno still with the 20G as we speak. Plan is to get a good baseline for the 20G to back to back with the T67 and 73HTA. All this testing is a ball ache, but the engineer in me loves it

Re the Hypertune swirpot Risking posted. I am 99% sure it works fine and there is absolutely F. all difference but technically you shoud try (space permitting) to have the inlet tangent to the circumference of the swirl pot about half way up. You should then run the outlet from the centreline of the swirl pot from a lower point then the inlet. Ideally the bottom but not going to happen on an RB so lower is generally acceptable.

The 265s are ok on 9" wheels. They sit nicer on 9.5 but fine on 9". I was kind of hoping that the 295s could squeeze on a 9.5.Have ou got any pics of the "bulge city" Hopefully the hards last 300-400 track days

So I have slapped on some hard compund Hankook Ventus TD Z221 for Phillip Island. I also have a set of 295/35/18 AO50s but think I am in for all sorts of trouble to get them to fit my car. Has anyone fitted the 295 AO50s onto a 9.5" rim ? Or do they really need a 10" rim?

Looks like you got to it just in time. Would be a very cool daily

Out of interest, I appreciate that no two engines are alike but any thoughts on the Tomei 2.8L kit vs Step 0 or Step 1 HKS Kits?

More expensive/fast tyres that I cant afford. Unless they are bringing out used edition that are half the price $100 slicks for the win

I never noticed a huge difference when I was changing cooler piping and didnt run a BOV with my bush bearing turbo that was borderline too big for a 2L. I think the trick is really how it is fuelled/tuned as the momentary rich/fouing fuel levels tend to cause the thing to bog down more then a drop in shaft speed. But like all things its probably a number of small compounding causes that ends up in a measurable drop in ideal performance.

I think just line everything up at TDC and reference the std markings in the block and timing backing plate etc. Belts can skip a tooth and flop around the crank pulley and when you tensio it back up be a way off where the old markings were. Best go on the block markings and not care about the belt

The compressor wheel is not a positive displacement pump. Its a centrifugal pump...air can pass through its tolerances. When idle a positive displacement pump generally acts as a check valve. A centrifugal pump can be blown through. A twin screw supercharger is a positive displacement pump. An engine is a positive displacement pump when there is no combustion as the turning wheels spin the crank that displaces fixed volumes of air

Yep...and then there is the KE in the wheels.

You are an engineers engineer He said the wheel spins backwards, it doesnt. As you point out it effectively chops the air and all sorts of harmonics are going on as the low pressure high flow (ie fans with big tolerances) compressor basically cavitates. The KE in the wheels along with the engine running as an air pump means that the air on the hot side is still directional and going to keep spinning the turbine. Case in point put your foot over my tailpipe when I am running on the dyno and lift off at 6,000rpm.

Bonnet struts. How lardy dah

Are you sure? Have you witnessed the compressor actually spin backwards? I would be amazed if that were true. You have god knows how much cfm pumping out the exhaust spinning the turbine which I think would stop the compressor ever stopping and reversing . There is nothing to actually cause the compressor to spin backwards What will happen is it will be trying to compress air into a fixed volume and with a turbo effectively being a low pressure high flow pump the clearances will mean the air will be "chopped" vs compressed and you may get reversion of air pulsing back out the air filter but cant see the compressor wheel rotating backwards

I have no idea. Risking got it right I suppose you need to read as much as you can and decide for yourself. Jack ran Alcon kits and not many go as quick or punt a car as well sorted and as fast as his was He ran the Alcons for a few years. He upgraded to Supercar brakes but that was mostly because he could and they were brake porn rather than needed And this is a bonkers fast track car that runs Alcon fronts , though is a bout 300kgs lighter then many track GTRs but then again has over 400rwkws...you get the idea

Further to what others have said calling a caliper a street caliper is not a criticism. Look at cars like 997 GT3s that dont have the ceramic brake option. They can pound around tracks like Spa lap after lap with no brake problems just with some Pagid or Performance Friction pads (talking to owners that's what they tend to use) These are cars beign driven hard often on slicks. So street calipers are not inferior per say. What they are is generally heavier and constructed from more durable materials. Race calipers can often be similar in physical size, often identical in piston sizes but are often lighter and made from material that makes them stiffer and lighter. This sometimes means due to their duty they are lifed more frequently as they are designed for performance, not durability. They also often run titanium pistons and bridge ducts or water lines for added cooling and performance. Short of people actually racing their GTR where they are running for 6+ laps at full speed with sufficient engine cooling etc to permit such use....the Alcon etc kits will be fine for your application. Many people complain about certain AP its and I have heard the same complaint about Alcon Evo guys saying they still use loads of pads and eat rotors. If/when you need to replace a rotor forget about weight and unsprung weight and get a rotor with 70-72 vanes. Dont go running 24, 36, 42 vanes as you will run out of pad pretty quick. Of the people I know who run setups that run a 35mm thick 72 vane rotor they have never had a problem with brakes, had an appetite for rotors or calipers with them running nice and cool. Thats the main reason I like the AP CP5555 over the Alcon, simply because they take a 375/378/380 35/36mm thk rotors where as the Alcons must run a 32mm and typically 365mm. It just means that 1 in 10 person may exceed the Alcons ability where as 1 in 50 will exceed the AP setup with thicker rotor. Also if you are sourcing Alcons then it may pay to check local pricing now that PWR have relinquished distributorship as the pricing is a load better. If you get stung for customs/GST then I think it could well be cheaper to get locally, but if you send the front brakes to your mate at work and the rears to your home address you will probably get away with it

racegtst...gutted to see it end like that. Light damage is still a pain in the ass and timely to fix....Hope repairs are not painful Silkgoid aka bonkers fast guy. You heading down to PI for the PIARC sprint?

PHENOMENAL!

I am still chasing Mobil for where I can get Mobil 1 Racing 0W50. Will have a read of that link tonight

I am hoping to make it and there is a maybe 1/3 chance. Tune didnt go to plan on Saturday and cam gears, cams and another turbo being tried over the next few days. If its all healthy will be bringing it for a run. Otherwise PI at the end of month for me.

Regs are up. http://www.piarc.com.au/files/2013%20April%20Sprint%20Regs.pdf

More proof that Vettel is a farking idiot... The best actor in the world is… SV: John Travolta.