Sydneykid

If you are still using them, the originally posted spring rates are way too low for slicks. The extra grip means additional G force and hence weight transfer which the 6/4.5 spring rates can't handle. You need to to look at around 10kg/mm in the front and then using the 6kg/mm's in the rear. You could try setting the swaybars on maximum, but I don't think that will be enough. Obviously you need to be sure that the shocks can control those sorts of spring rates. Slicks require a very different set up, not just spring rates. Alignment settings, particulalry camber will be different so you need to work through the processes like we discussed above for the R type tyres. Cheers Gary

Duncan is correct (of course) 110 nm or 80 lbft Cheers Gary

I have had a few people ask me about a timetable, so that they know when to turn up and watch. My response has been that a timetable would be pretty useless in this style of event. Cars split into sessions, sessions that may or may not be delayed due to offs, recoveries and track clean up. Then in the afternoon two, one car at a time, flying lap shoot outs for 5 cars. Personally I think the earlier sessions will be more interesting for specators with multiple cars on the track at the same time. For people who can't be there all day that's what I have suggested, what do others think? Cheers Gary

Simple answer, for the best response, is the closest to the throttle body that you can get. That way the ariflow doesn't have to reverse direction to vent, then reverse direction again when boost is required. Cheers Gary

Spark plug leads = YUK Haven't had a car with plug leads for over 10 years. Cheers Gary

I think you will find that they are a K20 front wheel drive engine and gearbox as found in Integra and Civic Type R's. Cheers Gary

Why do you think it might not be fine? Plenty of clearance to the piston crowns, if that's the question. Too crazy for what? The extra 20% capacity of the 3 litre makes smooth what feels like lumpy cams in a 2.6. More lift won't hurt, but I wouldn't be going for more than 272/280 duration, the RB30 doesn't need the rpm range that longer duration would provide. An often argued question, for which I don't believe there is one correct answer. I only went for the longer duration so that I could get the higher lift on the exhaust cam as I know the exhaust valves are too small in proportion to the inlet valves. For the RB25.5 I used larger exhaust valves with the same lift and duration cams on both inlet and exhaust. Cheers Gary

Mine has Jun 272 / 10.5 inlet and 280 / 10.8 exhaust. I didn't fit larger exhaust valves to this head and the longer exhaust duration and higher lift is there in an attempt to compensate for the standard mismatch in valve sizes. Cheers Gary

In regard to setting up a 2wd drag Skyline, I posted this recently (that's why the Search button is so handly) and it all applies to an S15; You want no more then 3 kg/mm rear springs, around 2.5 kg/, is better. You want rear shocks with very little low frequency bump valving but a large amount of low frequency rebound damping. If the shocks are a decent brand then you can leave the high frequency valving alone. The soft spring rate allows the rear to squat and absorb the torque hit, the large amount of low frequency rebound damping holds the rear down for maximum weight transfer onto the rear tyres. The problem is you get a lot of dynamic negative camber when you get enough squat, so you need to set the static rear camber slightly positive (around 0.5 deggres). A rear subframe alignment kit installed in the "Maximum Traction" positions is also a must. Around 3.5 to 4.0 kg/mm front springs are OK (hardly "hard"). You want front shocks with a large amount of low frequency bump valving but with very little low frequency rebound damping. Similarly to the rear, if the shocks are a decent brand then you can leave the high frequency valving alone. The limited amount of low frequency rebound damping allows the front suspension to extend therebye reducing the weight over the front and hence more effective weight transfer to the rear. The reasonable front spring rate helps to hold the front tyres onto the track, you may need to steer at some point. The front suspension geometry is pretty much irrelevant, just make sure the wheels are pointed straight ahead (zero toe) so they don't provide too much drag. In a general sense the average Japanese aftermarket coil over kits are not suitable for drag racing and the standard suspension is better. But (there is always a "but") the problem with the rear standard shocks is that they don't have anywhere near enough rebound damping. That's when they are new, let alone 15 or so years old. So you get bad axle tramp, the kind that breaks drive shafts. The more power the car has, the worse this problem becomes. In a standard'ish Skyline (boost up, FMIC, exhaust etc) you might just get away with it (standard shocks) on street tyres. But drag radials or slicks and decent power don't mix well with poor rebound control. You will spend more money/time replacing drive shafts than you will spending the extra on buying the right shock spring combo. I did this type of set up for BU5TER and his R33GTST which did a 1.5 for 60' first time out. Cheers Gary

Have you read the Stagea suspension thread? It answers most questions on Stagea suspension. Cheers Gary

Is that the stand out 1.1'ish neg G on the 51.49 lap? Still 1.1 G should be the target, if the braking capacity is there for "holy crap" moment then you can do it every time, braking performance deterioration not withstanding. I notice that there is a lot of braking at ~0.7 G, the capacity is there to pull 1.1 G, what is it that prevents you from using the max every time? I know I do it, my brain says the car doesn't need to slow down that fast. I know the route to faster lap times is to spend longer acccelerating and then brake harder, use the maximum capacity. But the signal from the brain to the right foot somehow gets lost. I only glanced at the current RE this morning on the way out, I'll have more of a read tonight, after 3 of 4 readings I generaly get what they are on about. Cheers Gary

For reasons that a smarter person than me could workout, I have found that maximising the LongG doesn't align with what the dyno says. It's closer with an N/A engine but with a boosted engine there can be some noticeable variations between gears. I put this down to the turbo response to the differing loads that each gear provides. So these days I definitely rely on the LongG for gear change points, plus what gear is the best to use. Personally I get caught up in the rpm thing, more rpm = more noise so I think the car is going faster, when an upchange may well give higher LongG (more acceleration). That age old question, "is it faster using 2nd gear at 6,500 rpm out of turn 2 or 3rd gear at 5,400 rpm?" Maybe there is more wheelspin in 2nd, so the actual LongG is higher in 3rd even though the horsepower is lower. It takes the guess work out of what gear to use where on the circuit. Do you subscride to Race Car Engineering? One of the things I like about the current format is the section on practical data logging that is in every issue. For example, in the current issue there is an interesting practical example of using a derived maths channel for examining understeer and oversteer by overlaying the speed corrected steering angle with the LatG. Well worth the monthly investment. Brakes wise, so you can't activate the ABS even with really big push on the brake pedal? That's unusual, I can't say as I have ever had an R32/33/34 that I can't get that level of braking from. Maybe only once, not lap after lap, but once is all it takes to get an idea of the maximum LongG possible. Cheers Gary

GTST's are not the same, the bolts to the hub are a different diameter for a start. What about the 280 mm rotors versus 324 mm rotors? You need calliper adaptors (try UAS), rotors and brake lines. Changing the fronts only is not a good idea, I would do the rears at the same time. Personally I think the Brembos are overrated and not good value for money. They are hardly any better than the standard Sumitomo/Nissan 4 spot fronts and 2 spot rears. Cheers Gary

After they changed almost all of the the suspension settings to suite the 18's ie; they didn't just bolt them on and go 0.5 seconds faster. Cheers Gary

Nobody I know measures camber in mm, it's always degrees. You can only have one front camber kit, there is only one place to install it, the outer upper control arm joint. If the one front camber kit doesn't set the camber correctly, then the car is too low. On the rear there are two places (actually 4), the inner and outer joints of the upper control arm and the traction rod. That's why you can use 1 or 2 kits. If 2 rear camber kits don't set the camber correctly, then the car is too low. Cheers Gary

Is that a parrallel coil, ie; 146 mm all the way? Cheers Gary

Sorry I haven't been back to this topic for a few days, I was at Eastern Creek all weekend. Lots of cars running that needed input. By looking for chassis set up data you are tackling the hardest to diagnose with the limited data you are logging. It's the last thing I try and work on from data alone. My order for getting more speed out of the driver and car are; 1. Engine rpm, throttle position and LongG for maximising the acceleration. Look for the rpm range where the engine produces the highest postitive LongG and make sure the driver knows to keep the engine in that range whenever he is at 100 WOT. 2. Engine rpm and LongG for gear change rpm optimisation. Make sure the upchanges are done at the rpm that produces the highest LongG. Plus gear change speed is obvious from the rpm and TPS, work at shortening it as much as possible. 3. Transition from acceleration to braking, look at reducing the time spent in limbo between 100% WOT and maximum negative LongG. No dallying, get of the throttle and straight onto the brake. Do some straight line tests and determin what the maximum G under brakes is for that car set up, then aim to achieve that maximum on every stop. 4. Speed, KPH or wheel rpm is the most often used data. If I only logged one parameter it would be KPH. It's obvious why, increasing the KPH lowers the lap times. This is really #1 but I fnd it easier to work with the driver and maximise 1,2 and 3 above and then work on speed. I navigate my way around the track straight by straight, corner by corner looking for places to increase the KPH. Obviously acceleration and braking are fairly well covered by the above, so this part mostly involves increasing the corner speed. The ability of the software to select the potential best lap time from multiple laps is a feature I use a lot. Either automatically or manually cut and past the sectors. I don't really care if the car is oversteering or understeering, I am looking to simply increase the corner speed, generally raise the LatG. I tackle it in one corner at a time, the most important corners (the ones leading onto straights) being first priority. I sit with the driver and look at as many laps as we have available, why was the speed in corner 4 faster on this lap than that lap. Look at the data and talk to the driver, higher LatG, less steering input, earlier throttle application, later or earlier braking, whatever made this lap better. Move on to the next corner, do the same. Since you are both the driver and data analyst you have some advantages which should outway the dissadvantages. What I find works for me is to sit in the car immediately after a session has finished and make some quick notes, before I look at the data. I know what sectors the lap is divided into by the logging software, so I make my notes the same way. Or it can simply be be Corner 1, braking, entry, mid corner and exit, corner 2 etc. For novice drivers I have a prompter sheet pre printed, with some boxes to tick and space for comments on each straight and corner. Then I have 2 semi independant records, the written notes of the driver straight after the session and the data to refer to. On a busy day, I might not get to look at each session individually, so the written notes help at the end of the day or a few days later when I have time to look closely at the data. If I am driver, mechanic, race engineer and data analyst all in one, I tend to find driver improvements are done during the day, as as are important/easy set up changes. Major/ time consuming set up changes are generally left until the car is back in the workshop. If I have a crew, then we may do some major set up changes during the day. But that's pretty rare, due to the previously gathered data I have a pretty good book of what set up works at what track. So we only do minor tuning on the day. The logging software I use has provision for notes and set up data for each session, I either use that to record what we had in the car that session, tyre pressures, swaybar settings, camber, caster, toe, tyre temperatures if we recorded them etc, everything goes into the log. You can't have too much data. Cheers Gary

I don't think we will, very underdeveloped car with a rusty old driver. I have very low expectations for what will it's first time out. Cheers Gary

Let's try a couple of examples; 1. I reckon a 250rwkw R32GTST at 1200 kgs with $20K spent on it would be faster than a 250rwkw R32GTR at 1500 kgs with $20K spent on it. 2. I reckon a 400rwkw R32GTST at 1200 kgs with $60K spent on it would not be faster than a 400rwkw R32GTR at 1300 kgs with $60K spent on it. Whadyareckon? Cheers Gary

OK spring rates for slicks, too high for everything else. Cheers Gary

http://www.skylinesaustralia.com/forums/in...showtopic=79157 Cheers Gary

First off, what reference books do you have? My data favourite is Competition Car Data Logging by Simon McBeath followed by Data Power by Buddy Fey. If you haven't read both of those, then I strongly suggest that you do. My guess is there are only a handfull of guys on SAU that will have any idea what we are talking about, but here goes; The first thing I look at is the TPS, I want to see 100% as much as possible, that's maximum acceleration. If it's not 100% then it should be 0%. On the transition from 0% ot 100% I like to see a smooth progession on corner exit. Jerky, on, off throttle indicates that the driver is compensating for something. What? Understeer or oversteer? If you have it logged, look at the steering angle. If not, then wheel speed and lateral G force................. Hang on......I am going to ask more questions than give answers.................what have you got logged? Cheers Gary

Like Z33's, V35's and M35'S have different movement and leverage ratios front to rear. Particularly the rear where the springs are located inboard on the lower control arms, separate from the shocks which are mounted closer to the wheels. So you can't simply compare the front and rear spring rates. The effective (what the tyre and chassis feels) springs rate calculations are; Tein (green) lower front 1.2" and rear .9" Spring rates front 6.4 (effective = 4 kg/mm) and rear 4.9 (2 kg/mm) Are you sure these aren't the wrong way around (front 4.9 and rear 6.4)? Tanabe (red) lower front 1" and rear .6" Spring rates front 5.3 (effective 3.5 kg/mm) and rear 6 (2.5 kg/mm). That's much more sensible. Based on the above I would prefer the Tanabes over the Teins. Not saying the Tanabes are any good, just that their springs rates are better than the Teins. To avoid confusion with the R32/33/34 which have very different suspension layouts to the V35, I suggest you post further questions in the V35 specific section. Cheers Gary

Qualifying softness tyres start off OK and, because of the incorrect set up, they turn to mush, you don't buy them "mushy". Anyway, that's not my point, the problem is we could achieve the times without qualifying tyres if we had the set up right. If we then use qualifying tyres with the right set up, we go even faster. As BOZ points out we have strayed, I stick by what I posted, for the same total amount of money spent there is no reason why a GTST shouldn'y be as fast as GTR, if not faster. The GTR definitely gets ahead when the power level exceeds the rear tyres capacity to maintain traction in a driver controlled fashion. Cheers Gary