Sydneykid

Wheels are always a good place to start, then titanium exhaust, carbon fibre tailshaft, kevlar bonnet, no spare, no tools, no jack, carbon fibre seats, carbon brake rotors, ceramic brake callipers, alloy wheel nuts ......... Let's see .........that's $14K spent so far to save ~100 kgs. That's a 6% weight saving, how much would it cost to get 6% more power? That's right, I got a 30% power increase for ~$300. PS I was going to add to Brazen's "empty the coin box", by suggesting that you leave your wallet at home to save weight, but it would be so empty after buying all the lightweight stuff that it wouldn't save much.

Well, I know an R33GTST/Stagea S1 solenoid works just fine so maybe try and get one of those. If you want lower than 10psi, then I suggest spacing the wastegate actuator away from the compressor body, that will lower the spring preload and thus the base pressure.

Hi Steve, yep too large a rear roll couple has the same efect on the front as too small a front roll couple. Same logic as stabiliser bars, too big a rear bar makes the car oversteer same as too small a front bar. Lowering the car too much has 10 dissadvantages and only 1 advantage, the lower CoG has stuff all effect on handling compared to the other 10. The reality is lowering the car is done for looks, not handling. We did a test for a magazine about 3 years ago on 4 X GTST's and the highest one was the fastest one around the circuit. The lowest one, was the slowest one. Keep the height reasonable and spend the saved money on better tyres or bigger wheels or more power, the car will be faster, more sideways and much easier to control.

Post up the measurements (wire ID, coil ID and the number of coils) and I will work out the spring rate for you:cheers:

Whether we pay retail for a GTST and retail for a GTR or wholesale for a GTST and wholesale for a GTR it doesn't matter, the GTR will still cost twice as much. We have built 3 X GTR's to the same circuit race spec as the GTST and twice the $'s would be a bargain. It all mounts up, two LSD's instead of one, ATTESSA controller, extra clutch plates for the ATTESSA, 4 X lightweight drive shafts, 2 X lightweight tail shafts, a triple plate clutch (GTST has twin plate), Brembo callipers, Brembo rotors, transmission cooler, alloy winged and baffled sump etc etc It doesn't cost more to build a RB31DET, it costs much less if you take into account the original cost of an RB30 versus an RB26. The reality is if I spend the same money buying and modifying an R32GTST, as I do buying and modifying an R32GTR, the R32 GTST will be faster. Ultimately, if I have enough budget, I could get the R32GTR to be faster but it would need to a pretty BIG budget As for the GTR badge creedance......GIVE ME A BREAK..... 95% of the people who see my R32GTST think it's a GTR anyway. Even when it is parked with the 2 X GTR's.

Hi Dan, the car is set at a ride height that is lower than Tein intended they be used at. This is both hugely illegal and a little bit dangerous. Either raise it so that the springs are trapped or buy a set of helper/tender springs and intermediate spring seats.

I think this previous post answers question #1....... #2. Bump steer is a change in toe settings as the suspension moves up and down, such as over bumps, hence the term "bump steer". To correct bump steer on a MacPherson Strut car you have to change the relationship between the lower control arms and the steering arms. Usually by inserting a spacer between the steering arm and the upright (ie; at the steering ball joint). You can also remove bump steer by lowering (or raising) the steering rack, but this causes problems with location for the steering shaft. So most people do it at the steering arm ball joint. #3. This can be caused by too small a roll couple, bump steer or excessive dynamic camber change. If by raising the front you improve the front end grip, then it is going to be one or more of these three things. If raising it doesn't improve the front end grip then it is a spring, shock, front stabiliser bar or caster problem. Note that you should always reset the static camber on a MacPherson strut car when you change the height. Simple stuff, as I do it everytime we build a new race car:cheers:

Wooohoo, what a fun thread...............some random thoughts...... Shoot Out, versus Non Shoot Out.....SO mode attempts to equalise the power readings by correcting for temperature and barometric changes and adjusts back to a common. For example, forget baromnetric pressure for a moment and let's say 20 degrees. If you have a hotter day than 20 degrees then the SO power will be higher than NSO power. If you have a colder day than 20 degrees, then SO power will be lower than NSO power. The idea of SO is so someone in Darwin in summer could compare their cars power with someone in Hobart in winter. It also removes MOST of the tricks that dyno operators get up to to fudge power figures. Speaking of tricks, I notice that it is becoming a common trick to select a high starting speed or RPM for the power graph, makes the engine look good from an average power point of view. But it doesn't fool me, if it hasn't got 50% of its maximum power within 3,000 rpm of its rev limit, then it's a DOG with a standard ratio gearbox. Stick a close ratio dog box in it and it's a different matter. As for big singles and drag cars, last time I looked the Croydons GTR had a big single and it ran 8.5 sec at 165 mph. Many regard the BMW F1 Turbo engine as the most powerfull of the 1.5 litre turbo era, 1300 bhp in qualifying and yes, it ran a big single. WRC cars run singles because they are required to have a SINGLE 34 mm RESTRICTOR located not more than 50 mm from the compressor, that's pretty hard to do with twins. The only Japanese time attack circuit that has any meaning is Tsukuba and that suites twins because of its layout. If it was Philip Island, then maybe a big single would be the go. Sure the 2 fastest GTR's at Tsukuba last year were running twins, but they were both beaten by an Evo running a big single. Vehicle manufacturers liked sequential twins because they can more easily pass emmissions standards. The very first Porsche 911 Turbo had a single KKK turbo mounted behind the LHS rear wheel. Champ cars have a single turbo because the regs say they have to. For every example of a twins being used effectively, there is an example of a big single being used equally effectively. It depends on which side of the fence you sit as to which example you will quote.

Why upgrade the RB20? I bought an R32GTST, upgraded the suspension, wheels and tyres and stuck an RB31DET into it and it still cost less than half what a similar age and condition R32GTR would cost. Plus it weighs 200 kgs less and looses 20 rwkw less through the drive train. So a 400 kw R32GTST is much faster than a 400 kw R32GTR. And a 400 kw 3.1 litre engine is a damn site easier to drive/keep on the power/get off the line than a 400kw 2.6 litre engine. Plus with 200 kgs less and the same brakes it stops better for longer and doesn't overheat the tyres anywhere near as fast.

Hi Steve, suggestions follow; Roll centre projection is best done via a drawing, you won't be able to do it "on the car". You will have to take the measurements on the car and then draw it to scale. Change the drawing until you achieve the roll centre you want, then transfer that to metal work on the car. Usually, in a front engine rear drive car, you would have a higher rear roll centre than than front, because the CoG is higher in the rear. It is the roll couple that is important. Yep, hopping is a sign of too low a rear roll centre, thus the roll couple is too big and you get the amplified pendulum effect. Once the wheels are spinning you have basically zero grip, the problem is when you are setting up for the drift, while you have some rear traction. You get the pig rooting and you can't pick or control the slip angles. It looks like poor technique, but it is really chassis set up. The front roll centre adjustment is more necessary because of the shortcomings of the MacPherson strut design. It is very sensitive to excessive lowering and the Japs love to have them looooooow. Somewhere at home I have the drawings for a MacPherson strut roll centre on a Datto, if I can find it I will post it up. PS; If you do roll centre adjustments on the front, you will also need to do bump steer correction. Because of the steering rack location, moving the lower inner mounting point really stuffs up the bump steer.

The polyurethane upper control arm bushes themselves are not expensive, but they are a bugger to fit, both time consuming and requiring special tools. Try your local Repco, AutoOne, AutoPro, AutoBarn, SupaCheap for Nolathane brand. I would strongly suggest getting adjustable camber bushes, they don't cost much more and the labour to install them is the same. Being able to adjust camber is a big advantage.

Hi Steve, very hard to describe using words. Best to look for diagrams. Simply put; S13's have MacPherson struts at the front, so the adjustment for roll centre is the inner lower bush verticle locatiion. Noting that the angle of the lower control arm needs to be maintained, so any adjustments at the inner bush must be matched by adjustments at the upright. The rear is bascially double wishbone so the roll centre is determined by the verticle location of the inner upper and inner lower bushes of trhe control arms. As with the front, the angle of both control arms need to be maintained, so any adjustments at the inner bush must be matched by adjustments at the upright. I have found very little issue with the S13/14/15 chassis as far as roll centre is concerned, but you can get problems when they are excessively lowered. This reduces the roll couple (difference between roll centre and centre of gravity) and they tend to hop (pig root is the term most often used) rather than slide progressively. The Japanese solution (as always) is to stick huge spring rates in so that there is practically zero roll. Then the roll centre becomes irrelevant because the only roll is tyre compression.

Hi guys, some clarification; The standard upper arm bushes are synthetic rubber, which (like natural rubber) has trapped oil bubbles. This means a hardness rating around 50 to 55. The rubber is bonded to both the inner and outer cases. This meandsit doesn't need lubrication as the air bubbles expand and contract to absord roation and deflection, this make then qiet in operation (low NVH). The disadvantage is the air bubbles allow dynamic camber change by compressing and expanding due to load. Since the yare bonded rubber bushes don't allow adjustment. Polyurethane does not contain air bubbles, so it requires floating bushes (crush tubes) and lubrication to enable it to rotate. The lack of air bubbles means a hardness rating around 90. The big advantage is less deflection under load and more consistent camber (very little dynamic camber change). Since the crush tube floats (its not bonded) there is the ability to adjust via offsetting. Nolathane is a combination of the words Nolan (the brothers who did a lot of the early work in this field) and Polyurethane, the material used. This brand name was sold by the Nolans several years ago. You can buy Nolathane brand bushes from all sorts of retail outlets, mostly as replacement parts for high volume vehicles (Commondoors and Foulcans). Noltec www.noltec.com.au is the company now run by Greg Nolan (one of the brothers) and his son David (he races in Improved Production). They have continued developing polyurethane bushes for high performance and race vehicles. They have a number of products for Skylines including sliding adjustable upper arms with polyurethane bushes. Whiteline www.whiteline.com.au have their own supply of polurethane and have a range of adjustable bushes that are fitted into the standard arms. We use their products a lot on Improved Production race cars as wee are not allowed to replace suspension arms. Some adjustable arms use spherical joints instead of rubber of polyurethane. They have a hardness of 100. They need lubrication and have very high wear rates, for example on the Super Tourers we replaced $2K worth of sphericals every second race meeting. When extra caster is added, via adjustable bushes or replacement radius rod with sphericals, extra loading is applied to the control arms (both upper and lower). This accelerates the wear on the bushes which necessitates frequent lubrication and more often replacement. In summary, as with all performance products there are compromises. The standard rubber allow deflection, the polyurethane requires lubrication and the spericals require. But The standard rubber is quit and basically service free, the polyurethane allows much less dynamic change, has adjustment and so assists handling and the spericals are the easiest to adjust and have the least amount of unwanted deflection. It's your choice.

R32GTR's have large square hole under the LHS headlight. Feed the cold air from in front of the LHS of the radiator though that hole and into the shielded area around the POD.

Idiots, they show a 911 Porsche that has different sizes wheels and tyres front and rear STANDARD.

What model GTR?

In NSW it is the maximum rim width fitted to that chassis plus 1". So if a 260RS came with 9" rims, then we could have 10". It could be argued that a GTST is the same "chassis" as a GTR (R32/33/34) and therefore the same would apply. The rule for us is what the tyre placard shows on the car, so I made sure mine (when it was complied) had all of the possible tyre and rim sizes on the sticker. You can get new stickers, they do wear out and can get damaged, so you have to replace them.:idea:

Wooohoo, that is a test of ingenuity. Personally I would; 1. move the catch can to the RHS, behind the battery. 2. move the boost control solenoid to behind the LHS strut tower 3. remove the standard boost control solenoid 4. make up a cardboard template that is inserterd vertically from the power steering reservoir to the radiator and seals agains the bonnet when it is closed. When you have design that you are hapopy with, transfer it onto a piece of 1.5 mm alumium sheet. 5. feed the ambient air from the LHS bumper vent, up though a hole in the inner guard near the intercooler pipework. If you use the entire LHS bumper vent to supply ambient air there should be sufficient airflow such that (when the car is moving forwards) there is positive air pressure within the contained area. Hence the filter will not injest any hot air, like it currently does in spades. Hope that was of some help:cheers:

I got mine from the US direct, we have a race team that we supply in Florida and they get stuff for us. Cost around $US370, plus $A30 freight. Innovate Motorsport have an Australian agent, it's on their website.

In the spiriti of "no such thing as a free lunch".........if I don't reach my 200 4wkw target because of the R34GTT intercooler. And you do reach 200 4wkw with the ARC intercooler (but not 220 4wkw) then I would like to buy the ARC intercooler off you for the same as you paid for it, plus freight of course. Did that make sense?

Hi Al, those are the MINIMUM requirements, remember good Jap mechanics charge like brain surgeons.

Hi Ali, ask your engine builder what he recommends. He built it, he knows the tolerances, he knows what sort of rings and bore hone he used, he knows what the bearing tolerances were etc etc What I do; 1. Use 100% mineral oil (Castrol GTX in my case) 2. Run for 10 minutes (not at idle) 3. Change oil filter 4. Drive to Bathurst and back (~500k's) lots of different up and downs, mountains, no constant flat running, change the engine loadings frequently 5. Change oil filter and oil to 100% synthetic (Castrol Formula R in my case) 6. Stick it on the dyno and tune it If I am unsure of the tune (new spec engine or turbo etc) then I stick it on the dyno between #3 and #4 just to make sure the A/F ratios are good and it has no knock.

For the NSW rounds try www.ipransw.com.au

www.whiteline.com.au

Changing the pump shouldn't make any difference to the fuel pressure, the fuel pressure regulator determines the fuel pressure, not the pump. You have something else wrong, I would strongly suggest that you or the mechanic have a good go at trying to find it. My suggestions for things to check ; 1. the vacuum line to the FPR 2. the fuel return line from the FPR 3. the fuel return lines under the car 4. the fuel return into the tank Adding a second FPR in series with the standard one is good for raising the fuel pressure above that determined by the standard FPR. But you can't do that to lower the fuel pressure since the standard FPR is first in line. We use the Nismo replacement style FPR, Nenun have them for ~$150. Hope that helps:cheers: