djr81

Well any company that names their product for an obscure dimensionless number has my vote. Stickers would just be a bonus. http://en.wikipedia.org/wiki/Biot_Number More importantly, how can I get my hands on this stuff? Appears to be cheaper/friendlier than the straight up Brembo kits...

Easy. Click reply (not fast reply). Type some stuff in. Find the browse button which turns up. Click it, then find your jpeg file. Click upload. Wait for a bit. Click add reply. Job done

Yeah. I got different numbers. MAybe you need to show how you workerd them out. My method was. Find gearing in km/h per 1000rpm. Select a speed an/or a speed range (doesn't matter) Work out how much Kinetic energy (or change in) a 1kg mass has in a llinear circumstance. Work out its equivalent for the flywheel. Divide one by the other. I got slightly less than 2 for the car in fourth.

Well the explanation wasn't the issue. The conclusion & the equivalence was at issue. Anyway I don't have the thickness & diameter for the RB26 flywheels, so I can't do any calcs..... Anyone know how big they are???

Oh. Well I was going to get a stroker kit for my Rb26. But seeing as it will add the equivalent of about 100kg of mass to the car I guess it will just make it slower. (Joke, don't get angry) If you really (really, really) want & you can find the flywheel dimensions (diameter, thickness) I can do the calculation to and thereby find an equivalent mass (in each gear) for some flywheel lightening. Oh and don't forget when you change up a gear whatever energy is stored in the drivetrain is then returned to the car...

http://www.skylinesaustralia.com/forums/in...=169697&hl=

If you have the money, yes.

Well for my 10 cents worth I would decontent the car. What the hell does that mean? Simply find some ok rims & put them on your GT-R. Then advertise it for say, $20k. Sell the Gt-R rims seperately for $2k. You should get much more interest at a lower price. There again sometimes it is just easier to take the pain & get on with life....

I don't disagree with your explanation, just your conclusion.

Yes. If you are replacing it anyway & can live with the lesser flywheel effect when you are driving/launching the car then put one in. The second paragraph has me baffled, however. The general rule of thumb is that for a less powerful car you will be using all of its power (however much that may be) more often. So the gains of a lightened flywheel will be more important (Although as I have tried to explain, ad nauseam, not significant) If you want to confuse the mechanic you could ask him what the "minimum standard" is.

Well try this plot then. What I am saying is that a near on 45% gain in rwhp doesn't produce anything like that difference in acceleration. A change in mass (yes rotating mass) that is much less than one percent of the total will have a proportionally smaller affect on the acceleration. My point is that I characterise that change as being negligible. But you are right, ofcourse you can feel the difference of much more powerful engine - although you do get used to it really quickly. You are correct in saying it is more significant in lower gears at lower speeds (less aero drag for one & more rpm per km/h), but this is fairly unimportant because you are invariably traction limited. Well up to you, but I was trying to quantify the change & give people an idea of what sort of order of magnitude to expect. Make 5kg if you like, but you don't chuck 5kg worth of gear on your car and suddenly turn it into a slug. All of which goes to show the minor influence the flywheel has on proceedings. Which is my point. Thanks for theo offer, but budget is a bit tight this month. Anyway I already have a lightened flywheel, so to a degree you are preaching to the converted.

Yeah I was hoping that there would be enough room to mount a smaller version (It is possible I have fewer hp than the Saurus Gt-R) above the radiator support crossmenber thingo. The bling cooling panel should stuff enough air into the general area, just a case of getting enough cross section for the duct immediately above the radiator. Maybe if I just unbolted the one from my Falcon & used that as a start point.....

Well some bloke called Fred (apparently not on these forums) did it this way. Maybe that is the proper or even only solution. Would mean extensive hacking of the radiator, but looks doable.

But the N1 vents sit hard up against the cooler. Atleast mine do.

Yes. That is what I am saying. If you have a look at the two plots (blue is more rwhp) the difference in acceleration (measured in gees) is not massive. Certainly not different by the close on 50% increase in hp. I am using that to try & demonstrate that when the clutch is engaged the small change in flywheel weight would be much smaller & hence undetectable to the driver & difficult to detect by a data logging system. I suppose the analogy would be demonstrated by asking does your car feel substantially different on the way back from buying 2 litres of milk at the corner shop? Sure rotating components are more influencial, but only by degrees. For what its worth the peak terminal velocity on my old car was 204km/h st the end of the main straight at Wanneroo. The 435rwhp version gives 211km/h. Now there is a little extra braking for the second case, but you can see that all that horsepower really makes a relatively small difference to terminal speeds. Basically when finding speed for a car there is no silver bullet. If you need say 0.5 seconds around a circuit chances are you need to find four or five things to get it....

Me please for the drgs. Did you have any joy with the bracket drawings as I still would need to figure out how to mount them to suit either a 13.5" or a 14" rotor. I was also going to need some new rims (LMGT-4's - hmm cheap night out). I see you had some 17's, did the calipers clear them in terms of trackwidth ok? Thanks in advance for your time, Roy.

Well said.

Take your pick. The stock ecu can be remapped if you deem it necessary. The Power fc base tune can be cleaned up also. I used to run my old car on a power fc with the base tune in it. Works fine as does the stock ECU with the same settings. At the end of the day the tune is more important than the ecu - get so it checked on the dyno. Lastly don't listen to the full time harbingers of doom about the turbos. They are fine, just don't run them outside their envelope & don't abuse the car. Same as anything.

You need to be a bit careful with you terminology. The dump pipes bolt up against the turbo. They are bastards of things to get at and replacing them will provide little power gain on a stock car. The front pipes which go from the dump pipe to the cat are easier to get at, but don't provide a big gain. Importantly if the car has a cheap compliance cat this can be an issue. Try either a stock unit (very good) or a good aftermarket one. The remainder of the exhaust can be bought relatively cheaply & is worthwhile - some for the power but mostly for the noise. As had been said the fuel pump if you want to replace it will be mostly for insurance rather than performance. Air filter (K&N) plus 14# boost + exhaust will run over 300rwhp on an R32 Gt-R. You can throw some cam gears at it for some more hp. After that you need to shop for bigger turbos.

For me it is more important that the air be cold than I get every last bit of pressure gain from infront of the car. A pod box (not really, but a plate between them & the remainder of the engine bay) is on the agenda, but it is difficult to fabricate because of the 2 afms, power steer reservoir & all the other crap Nissan saw fit to jam in there. You can't find room for a 100mm duct (the requisite size) if it is round - hence the over the radiator preference. And, no I am not going to hack holes in the bonnet. Actually, as to your last point there is a high pressure area at the base of the windscreen. It is common for cars (Mostly track cars) to take their air from exactly this position. Check the old Brock VL Commodores for but one example.

Well first things first, Matt. Be nice. There is no need to resort to vitriol to try & make a point. In fact it is usually indicative of someone who has run out of logical argument. I did not say that the lower mass/lighter flywheel car would be slower. So maybe read what I posted again. What I said was it would be marginally quicker, but that in gear you CANNOT feel the difference by the seat of your pants. For the record you can barely detect it with good data logging equipment (which I have). See the attached plot of lateral versus longitudunal gees for my two gtr's. Once has 435rwhp, lightened flywheel etc etc, the other 305rwhp & stock pretty much everything. See how inconsequential the differences are in longitudinal gees? Given that, what chance do you think you would have of detecting a 2 kg difference??? I do in fact have an understanding of polar moments of inertia - certainly beyond the rock swinging, rock ape stage which you have attained. It is high school physics level stuff, after all. My car has a lightened flywheel. Amongst a heap of other components to bring the weight down. But according to your expertise I have never been in my own car, so maybe I just don't know. Maybe next time you decide to hang shit on someone you could consider using more substantial examples than what you managed to do on some lame arsed computer game. You could even try quantifying it with some numbers. That is what people who are professional engineers (like me) do for a living. Lastly try not to make wrong assumptions about what others may know or for that matter do. Champ.

I hate it when people you know from work find you on internet forums that you shouldn't be using... at work. Gotta go to Kemerton for a dull meeting. Will try & catch up later.

Well that is great, but how do you get cold air to the airbox?

Thanks, man.

HKS. There may be some room to the centre of the blanking plate.