Sydneykid

Hi Roy, I think you know our philosophy pretty well by now. But just in case.... We run the softest spring rate we can and use the stabiliser bars , anti squat and anti dive to control those aspects of chassis motion. Standard R32GTST springs are ~125 lbs per inch, Whiteline usually add ~30% so that would be ~165 lbs per inch. Kings (based on my experience will be a little higher) around 175 lbs per inch. In the circuit R32GTST we run between 300 and 450 lbs per inch front springs and between 175 and 250 lbs per inch rear spings. The most common, as you have suggested is 400/200. We run big anti roll bars, 27mm adjustable front and 24 mm adjustable rear. Sometimes 22 mm adjustable rear if is raining or slippery/dirty tack. With the 200 lbs per inch rear springs, we can get a bit too much squat, so we run the rear subframe bushes to give a little more than standard anti squat. If we don't it lifts the front inside wheel up on corner exit under power. This can give slight understeer which can slow the entry speed onto the straight, and we don't want that. The 400 lbs per inch front springs are pretty good, not too much dive under brakes. If really necessary we can run a little anti dive on the front radius rod bushes. If you still have excessive front dive then I would suggest the rear brakes aren't doing enough, maybe try a higher coefficient of friction compound for the rear pads (or adjust the brake bias). Camber, toe and caster you have prety well covered, lot's of caster and as little camber as you can get away with. Height wise, the staying "low is slow" applies to Skylines. Don't get caught in the fashion statement, around 350 mm centre of wheel to guard is not a bad height. With 10 mm of sill rake to the front on a GTST (GTR's are best flat, zero rake). There must be enough travel to jump the ripple strips without upsetting the balance. If it's on the bump stops, it's too low. It's shock absorber time.......... The Bilstein rebound valving controls the Whiteline spring and stabiliser bar rates perfectly. One of the reasons why Bilsteins are so good for Skylines is their multiple stage valving, add a bit more spring rate and they handle it easily. We have tried up to 550 lbs per inch in the front and the rebound is still controlled. Bilsteins are a monotube design, so the piston area is a large as it can be for a given outside diameter. This means the maximum oil is moved for even small movements in the suspension. This is critical for heavy vehicles with lots of suspension travel and high unsprung weight (like an R32/33/34 Skyline). So I would stay away from a twin tube design shock on a Skyline for that reason. Obviously the Bilsteins have no problems handling the 175/250 lbs per inch rear spring rate as it is only marginally higher than the Whiteline rear coils. If you want to go over and above the Bilsteins, it becomes very expensive to get anything that is actually an improvement. Jamie Drummond (DMS) does an OK set up, Murray Coote (Proflex) is much better. Then we get to Penske or Ohlins (that's the real Swedish made Ohlins, not the Japanese ones). We run remote cannister Ohlins on the race cars, being double adjustable (bump and rebound) we can control the springs and bars with rebound adjustments. And independantly adjust the dive, squat and roll with the bump adjustment. Sometimes the combinations of spring, bar and shock rates can get you going in big circles and my brain aches. But once you get a set up that works, the adjustments are fairly small (in a narrow window) and we don't do anywhere near the number of spring changes that we used to with single adjustable shocks. Hope that was of some help:cheers: PS; the Whiteline Group 4 shocks for Skylines are progressing, but I am not holding my breath.

Good, your calculator works the same as mine, which I have checked by running the engine up on the engine dyno and the chassis dyno. Can't afford to have an unverified calculator. No only makes sense, but is in fact true. I would never suggest taking a perfectly good RB26 out and replacing it with a standard internals RB30. That would be pretty damn silly. But if you have an RB20, or an RB25, or a badly stuffed RB26 bottom end, then it makes perfect sense. It will cost less and give a much higher average power. Irrelevant question really, the limit is 475 bhp, so reving a standard internals RB30 over 6,500 rpm is a waste of time. And they make so much average power (at that max power level) it is actually slowing the car's acceleration by reving it too far. Around 7,000 rpm is OK and 7,500 rpm, if it is balanced well. But if it is still making power at 7,000 rpm, then it is making over 600 bhp and you have exceeded the 475 bhp limit anyway. Hope that answered your questions:cheers:

We use the Bosch LSU4.2 5-wire, wide-band O2 sensor. Cost is $US80 plus freight (no import duty, good on you Johnny, Feee Trade Agreement). Works perfectly with the Motec, Autronic and LM1 A/F ratio meters.

Yes, I assembled it myself. The problem with a standard RB30E is everything (except the crank and block) has a ~475 bhp limit. So replacing pistons alone does very little for increasing the safe power limit. You need conrods, head studs, main bearing studs, decent bearings, oil pump etc etc So I either have a 475 bhp RB30 or a 750 bhp capable RB31, anything in between costs me the same anyway. We have added block mounted oil squirters (it's a bitch of a job) and ceramic coated the pistons with conrod oil squirters. Both methods seem to work equally well at the power levels we run. Cost wise, go the ceramic coated piston crowns and conrod based oil squirters. Hope that makes sense:cheers:

I have done this calculation a number of times, if you add up; the price of the turbo itself the extra parts you have to buy the stuff that has to be fabricated the frustration when it doens't fit or something is missing the amount of time your car is off the road And then compare it to a swap to a high flow that can be done in a couple of hours, you will find it much cheaper in total. Plus with a GCG ball bearing hi flow there are at least 10 Skylines I know of, and 4 that I have personally been involved with, that make the 450 bhp that the tubo is rated at. That's as close to a guaranteed result as you are going to get. And it looks standard and you will never get EPA busted for that. My 20 cents worth

Hi Adam, I stumbled...... 1. The R32 intercooler is supposed to be slightly less efficient in internal airflow than the R33 or R34. The external dimensions and appearance are almost identical however. The generally accepted number is 300 rwkw from the R33/34 until we start to run into noticeable restriction. But I have run 420+rwkw though an R32 GTR intercooler and it was pretty damn good, better than many aftemarket coolers. However I was using a turbo and engine configuration that didn't require a lot of boost to make that sort of power. I don't know what power target you are aiming for but I would be totally comfortable in using an R32 GTR intercooler up to 300 rwkw. 2. Oh dear! The old pipework question, I reckon the most often asked one on the forum. I have tested moved throttle bodies on standard plenums and the air distribution is terrible, personaly I wouldn't even think about it. If your power target is over 300 rwkw (that means forged rods and pistons) then the Greddy plenum is the one I would use. RIPS, UAS and Sub Zero have fabricated designs but they cost almost the same as the Greddy. If you are sticking with standard internals, then the 120 degree bend at the throttle body style of intercooler pipework is the go. It takes a noticeable amount of volume out of the pipework (compared to behind the radiator or under the intercooler styles) without compromising the inlet distrbution. I first saw this design on the Gibson R31 GTSR and over the years we have fitted it to a number of cars and it has been copied by quite a few pipework fabricators. This is the latest generation If you want to know more, I suggst doing a search, I have posted (numerous times) the calculations for the pipework volume and amount of delay in throttle response from various designs. Hope that was of some help:cheers:

There is not enough width in the main bearing saddle to handle larger diameter bolts. We use ARP studs, stronger than bolts.

Hmmmmm, the only parts useable from the Kei Office coil over are the springs and the top spring seat. You can buy a coil over threaded section, a bottom spring seat and a lock ring that fits over the Bilstein shock. You will need a more substantial bump stop than that one on the Kei Office, maybe that's why the Konis got killed. PS yep my feet just love to get in on the act

No forgies, it was a STANDARD bottom end, that means standard RB30E pistons. Any Holden wrecker will have an RB30 or 2 in stock, just don't mention "Skyline" they will double the price. Says it is for an "old VL" or something. Pick the closest one to you as they weigh 100 kgs or so and you don't want them freighted around, they get dropped. I would always rebuild an RB30, they are 19 years old after all.

Would have like to have seen a picture of your face at the end of the front straight at Sandown when you ran out of brakes :wassup:

Bilsteins for Skylines are a full replacement shock, you don't use any part of your standard shock absorbers. This is a standard GTR front shock and a Bilstein replacment shock, with spring seat lowered on the circlip grooves for the correct height;

Unfortunately Ben you have to know what questions to ask, and that is sometimes not so easy. Stuff like "the original ECU would then control .....auto trans shifting" seems to indicate the the auto would work normally. But it doesn't, because of the reasons you now know. I get a lot from reading the posts on SAU, not all of it is answers. Sometimes I find out the questions I need to ask.

Hi Ben, if you use the Wolf to run the ignition then you won't get igntion cut on gearchanges. This will adversely effect the shift quality and cause premature wear of the gearbox. The standard ECU has extensive programming for this purpose. You could just use the Wolf to run the injection, but an SAFC or equivalent would do almost as good a job for less than 1/3 the cost. PS; there has been lots of discussion on this topic, I strongly suggest you do a search.

No, they are supposed to be a straight swap.

When I added it up for myself (and several others since) the RB30DET was cheaper for the same power output. For example a completely standard RB30 bottom end will get you 280 rwkw. I built one that has been going strong for nearly 5 years now at that power level and it cost less than $1200 for the bottom end, rebuilt and balanced with new seals, gaskets, rings and bearings. You can't do an RB20/23/24 with that much power for twice that much. Plus it will have to run higher boost and rev to higher rpm which will shorten its life. Easiest decision ever, I went for the RB31DET and I already had the RB20 block, RB20 cylinder head, RB26 crank, RB26 rods and 4AGZE pistons

On the Stagea I didn't have to do any wiring changes anywhere esle other than at the ECU. The standard wiring was fine at the solenoid. Please let us know how you find the IEBC in operation:cheers:

Just gotta ask..... Why do you want coil overs? Are you going to be adjusting the height often? Or are you going to put them in, set the height once and never touch them again? Because if it is the latter your are waisting your money. Get a set of Whiteline low coils and a set of Bilsteins shocks with multiple circlip grooves for the bottom spring seats. The select the height you wan't and stick them in. You will end up with a much better ride/handling compromise than 95% of the coil overs out there. If you want to have a look at Bilsteins thsi sort of height adjustment, pop over to the Stagea forum and have a look at my posts on Stagea Suspension. There are quite a few pictures as well as the handling philosophy.

I am not sure I understand the question, but I will have a go...... The RB25DET turbo produces 10% more airlfow at 7 psi, than the RB20DET turbo does at 10 psi. So if you bolt on an RB25DET turbo and use the RB25DET wastegate actuator you will get 7 psi and about 10% more power. However if you use the RB20DET wastegate actuator on the RB25DET turbo it will produce 10 psi and you will get 25% more power. That is provided you have the support parts (intercooler and exhaust) in place to handle the increased airflow. If you really want to get the best from the increased airflow you really need to tune it. R32GTST's have an easily chipable ECU. Either that or an SAFC (or equivalent) will do a reasonable job of removing the exccessive richness that the standard ECU provides whenever the airflow is increased over standard. There is another 15% more power to be had from simple tuning. That's more than enough to give a 255kw Commondoor a thorough thrashing. Hope that answered your question:cheers:

Tein HA's, are yes, that explains it. Rediculously high spring rates, particularly in the rear. Hence a lack of compliance and the tyres skip from ridge to ridge in the road surface and the result is poor traction. My low cost suggestion is (as always), put the rear springs in the front and spend $150 and buy a set of rear springs with more suitable spring rates. Stabilser bars are for controlling roll, not springs. Springs are for holding the car up and providing compliance for bumps. Horses for courses as they say.

Let's get this one out of the way first, that's :bs!: Get whoever told you that and :kick: I have 2 cars with GCG ball bearing hi flows, both of them had the standard ECU for some time after the turbo was fitted. And neither of them stalled because of the turbo. Open to atmosphere BOV's were the big problem. If you close the throttle, then no airlfow can get from the turbo into the engine, it is bypassed by the BOV. If the BOV recirculates to the inlet after the AFM, then there is no excess airflow through the AFM, and therefore no rich running. If the BOV is already plumb back, then there is another problem. SAFC2's have 2 sets of tuning corrretion, one is for 100% throttle and the other for less than 70% (usually, but you can adjust it). This is so you can have leaner settings for cruise fuel economy and still have suitable A/F ratios for high power (full throttle). Have a look at what corrections have been applied in the SAFC for less than 70% throttle, particularly the lower rpm settings. You can lean it out there and see if that helps. But I seriously doubt that is the problem, I would be looking for something else like an air leak, or a dirty AFM, too high fuel pressure etc Hope that was of some help:cheers:

My 20 cents..... The LM1 wide band A/F ratio meter is a better buy for not much more cost. Noting that the cost of wide and fast lambda sensors has dropped considerably as there use becomes more common. Ditto the cost of meters for utilising the lamda sensors. Like discopotato03, I have tuned a car using a narrow band lambda sensor for maximum fuel economy, idle and off idle stability. The A/F ratio I was aiming for (for best economy) was in the range that the "narrow" lambda sensor covered with some accuracy (around stoich). Also the lambda sensor was "slow", meaning that its reponses to changes in A/F ratios was not instantaneous, it took a little while to record the movement. This is obviously not a problem when tuning for economy. But (there is always a but), when tuning for power and response, I don't want stoich A/F ratios and the changes are rapid, so I can't use a narrow and slow lambda sensor.

Time for some suspension work then Mark:cheers: