heavy85 Posted July 26, 2009 Share Posted July 26, 2009 My car is reasonably fast as it sits - easily a cople seconds faster than I am. So now I'm at a quandary where to take it next. I do not want to go wheel to wheel with this car so that's out. I've been running low speed autox for years and seem to be in a rut where despite many updates dont seem to be making any ground on the faster cars. I've also grown a bit bored with it. Last year I started high speed autox (autox on a full racetrack - one timed flying lap starting from pit road) and immediately got hooked. I've since run four HSAX, track drivers school, open track days, and recently completed my first NASA event where I got signed off for HPDE Group 4. So next event I should be able to get signed off for Time Trial license and start to compete. On a full track my car is relatively much faster than parking lot stuff. It's an LS1 swap (~350 hp) and 2600 lb race weight 240Z on Hoosier slicks so it keeps up with most cars out there. I was having a ball playing with 600+ hp C6 Z06's at the NASA event. Full out to full out they are probably a couple seconds faster than me but I could keep up and even passed them a time or two. The car as it sits is very easy to drive fast. Very neutral and I can manage 4 wheel drift during track out by more or less throttle. Biggest problem is putting down the power as it spins the rears easily. The brakes fade easily but that's mostly due to the pads and need for cooling. I'm also seeing wear on the far inside edge of all tires. I dropped a degree of camber and am now getting fairly even tire temps but am still wearing the inside wear indicator. I've got some basic aero like a pedestal wing, front spoiler, ducted radiator, vented lid and more or less fully adjustable suspension. 300F, 250R, big 'n little bars, Koni SA, etc. So I'm looking for advice where to take this next. I realize a good drivers school would be beneficial but that's a years worth of racing funds so it's hard to swallow. I also realize that A6's would be faster but am worried about life. I'm also getting scared my luck will run out and something major will break and leave me stranded or worse ... Given the economic situation I'm also not wanting to spend a lot of $$ anytime soon. Really just looking to have fun and try new things and keep getting faster. I realize this post is a bit rambling but I'm really just looking for ideas on what to do next? Thanks Cameron Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 26, 2009 Share Posted July 26, 2009 It's tough to understand what you want by reading the post. The thing that sticks out to me that you say you're making changes and they aren't having any effect on the car's performance/times. That to me indicates that your next move should be chassis stiffening. With a sloppy chassis the chassis can actually absorb spring rate and bar changes rendering them useless. The stiffer the chassis the more you'll be able to feel changes as they're made. After that I'd suggest a tow vehicle and trailer so you can jump way up on spring rates and use the tires to their fullest potential. 2600 lbs must be with you in the car... If you don't want to spend much money, spend a little and find some pads that work for you. You might bring some real race pads with you and swap them at the track. It doesn't take that long to do and then you don't have to worry about crashing into somebody on the street because your pads were cold. Quote Link to comment Share on other sites More sharing options...
heavy85 Posted July 26, 2009 Author Share Posted July 26, 2009 Yeah it's rambling but I'm looking for ideas on how to best have fun with the car. Try a hillclimb maybe? Focus on designing a new rear suspension that will put power down better maybe? Data acquisition so I know where to gain time maybe? I can fabricate so am wondering if there is a lot to be gained in the suspension? That sort of thing. I would like to add a cam, rollbar, A6's, aluminum radiator, pads, brake cooling, splitter, ... but in the end this is my toy that's to relieve stress and I want to spend my time and $$ wisely to accomplish that goal. Over the last year I've been exploring all kinds of racing with it running with different regions, tracks, clubs, & even took it to the drags. This has been a LOT of fun. Now I'm wanting to keep having fun with it but also keep developing it and am looking for ideas and bang for the buck in terms of lap times and fun factor. So how much are springs really worth? Yeah #2 2600 is me and passenger seat and ~1/2 tank. Chassis is already relatively stiff so I dont think that's it and I believe on track I'm gaining every time ... it's the low speed autox stuff where I've run out of talent. Cameron Quote Link to comment Share on other sites More sharing options...
tube80z Posted July 26, 2009 Share Posted July 26, 2009 I think your next step is a Datsun support vehicle, aka trailer. You're probably getting close to the point where you are going to start having some issues with reliability. Going faster will mean things break. Quote Link to comment Share on other sites More sharing options...
heavy85 Posted July 26, 2009 Author Share Posted July 26, 2009 Cary - That's the wrong answer - you actually get a lot of respect not being a 'trailer queen' + the ~14 MGP daily driver makes that painful. OK so tow vehicle + trailer is step one that I know is inevitable, unfortunately. Now step two - what about the car and the events? What area should be focused on? John mentioned stiff springs. Any other cool events out there I should try? Cameron Quote Link to comment Share on other sites More sharing options...
trwebb26 Posted July 27, 2009 Share Posted July 27, 2009 Boost the LS! Turbo powa 4eva! Seriously tho... If you don't want to enter a competetive door-to-door racing series - You've got the foundation to do just about anything you want without too much trouble and money. If you aren't having fun at the autocross events... I personally think that some 500 lb springs and try out drifting would be a complete blast. A Z would be a really neat car to see do it, too. You'd have to check into the rulebooks for drag racing - but you aren't far from having a sweet drag car. It is clear knowing you that you are just like Ryan C. You need a challenge and you want to kick everybody's ass. Now that you are blowing the doors off of the "casual" racers at the weekend auto-X events... gotta get either anti up and go compete at that kind of racing or switch it up and do somethings else. I feel your pain tho - central illinois sucks terrible for opportunities to race. Quote Link to comment Share on other sites More sharing options...
tube80z Posted July 27, 2009 Share Posted July 27, 2009 Okay, so no trailer. I'd opt out of any hillclimbs then as the chance to wreck your car is higher there than just about anywhere. I can't recall if your car has a cage or not. While not sexy or go fast good safety gear would be essential just in case. My self I found that doing work to make the driver more comfortable was almost as important as things I could do to the car. Your car is probably too soft. It seems to me that you're aiming for a car very similar to an EP car with a V8. That means springs from about .8 to 1.0 of corner weight (assuming frequencies in the high 2s to maybe 3 Hz range). That should get you into the ballpark. You've already mentioned brake pads. Do as Jon said and take a set for changing at the track. Then figure out the next things to tackle (I'd work on suspension first). You'll probably find as much time in learning to set the car up for conditions and the track your at than you will in new developments. Once you've got this nailed then you may want to look at trying to see what you can do to get rid of lift/make some downforce. This will cause all the suspension stuff to change again and brakes may become an issue again. And then maybe think of more power. Look at first principles, those are newton's three laws and there variations. And look for low hanging fruit, like seeing what weight can be shed. Then of what's left what can be moved lower in the car (mass and Cg). Even simple things like lowering your seat can reduce the Cg of the car. Increasing track width (more grip), more tire, etc. It will be a never ending list that once you touch something new you get to revisit all that you did. Feel free to ask specifics. I'm sure there's a lot of good advice to be had on this list. Cary Quote Link to comment Share on other sites More sharing options...
heavy85 Posted July 27, 2009 Author Share Posted July 27, 2009 No cage but rollbar is very high on the list. Your talking in the 500 lb range. Ouch. While I have a set that came with the car on the street it feels unsafe. We have rough roads and the car felt like it was skipping across the road as if there was not enough compliance. This year I went from 225F up to 300F and did not notice a reduction in street manors - if anything it may be a little better. I wonder how high I could go and still drive 2-3 hrs one way to the track? I've thought of increasing track width since it's relatively easy to do but what is the practical seat of the pants benefit? I agree that optimizing at the track is probably a big benefit but I'm always a little lost where to focus efforts there. I dont have a good feel for minor changes so it's hard to see unless it's a major change. I play with air pressure and to some degree camber based on tire temps but that's about it. It's like when I was racing karts I would play with the easy stuff like track width, caster, air pressure, etc and couldn't really make gains. Now after talking with a 14 time national champion he is playing with seat stiffness and kingpin angles and stuff I wasn't even dreaming about. In a scalar analysis kind of way where are the key areas to focus on? Unfortunately with the weight its pretty optimized without spending on composite hoods, lexan, small battery, basically spending $$$ but I will have to give it some more thought. Any specific thoughts on how to apply power better without spin besides larger rear tires and how to keep from wearing the inside edges? Thanks for the reply Cameron Quote Link to comment Share on other sites More sharing options...
trwebb26 Posted July 27, 2009 Share Posted July 27, 2009 Take Ryan to the track with you one weekend. Quote Link to comment Share on other sites More sharing options...
EMWHYR0HEN Posted July 27, 2009 Share Posted July 27, 2009 Any specific thoughts on how to apply power better without spin besides larger rear tires and how to keep from wearing the inside edges? I'm thinking.. Better weight distribution/transfer Stickier rubber Taller rear end for better modulation Traction control Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted July 27, 2009 Share Posted July 27, 2009 Do you have Targa road rallies in your area? Quote Link to comment Share on other sites More sharing options...
jt1 Posted July 27, 2009 Share Posted July 27, 2009 Safety stuff: Brakes, roll bar or 6 point cage, good helmet, fuel cell, fire system. Lighten the car up all you can. Track time. There is no substitute for time behind the wheel. If you think the car is two seconds quicker than you are, you've got a ways to go. As you get faster, the improvements get smaller and smaller, but that's what separates the good from the average. Quality instruction, from somebody who can help, goes a long way. A datalogger helps a lot also. Once you get to 80 -90%, most of the speed increases come from mental improvements, not mechanical ones. John Quote Link to comment Share on other sites More sharing options...
tube80z Posted July 27, 2009 Share Posted July 27, 2009 No cage but rollbar is very high on the list. Then your car isn't that stiff and it will limit what you can do with suspension. You can work around it but it will cause issues given the amount of force your car can generate. Your talking in the 500 lb range. Ouch. While I have a set that came with the car on the street it feels unsafe. We have rough roads and the car felt like it was skipping across the road as if there was not enough compliance. This year I went from 225F up to 300F and did not notice a reduction in street manors - if anything it may be a little better. I wonder how high I could go and still drive 2-3 hrs one way to the track? The springs aren't really the problem with compliance. It sounds like you have shocks that are not matched for higher rate springs if you have skipping. A number of us have lighter cars with stiffer springs and don't have these issues. A friend of mind used to run a LS1 car (2500 pounds) on 400/450 springs and it worked really well. Probably could have run a little stiffer. Since you want to drive your car to the event one trick I could think of is to stack coils, say a 200/250 rate and a 500 or so. You'd need a plate on top of the smaller rate coil that allowed you to compress it flat. When you get to the track and remove your wheels to change your brake pads you can clamp down the lower rate spring and have the benefits of stiffer springs. This probably means you need some adjustable shocks you can back down for your trip to and fro. (versus a single set setup correctly). This is all something that can be done fairly easy. I'm assuming you've already put the suspension on heims/monoballs. If not that would be a nother good option to help make it more controllable. These two areas will probably make the biggest change assuming you can't remove a lot of weight. Any specific thoughts on how to apply power better without spin besides larger rear tires and how to keep from wearing the inside edges? What I've seen 8 out of ten times in the past is that you're car is too soft and the excessive roll causes the wear. In the other cases compliance can cause dynamic alignment changes that cause it. We're assuming you don't have some alignment issues on the car. The cheapest method to go quicker is a stop watch, tire guage, pyrometer, and a camera. You're tires will tell you how how the chassis is working, the stop watch if you faster, and the camera can stop time when the car is loaded in a corner. You'll learn a lot by analyzing those photos. We make more changes based on photographic evidence than anything else when we're trying to get a new car to work. Most of the people I play with don't have the budget for data acquisition and enough sensors to gain any real insight (chassis tuning requires wheel position). Cary Quote Link to comment Share on other sites More sharing options...
Jon 74 260Z Posted July 27, 2009 Share Posted July 27, 2009 Get someone good -- I mean really good -- to drive your car with you in the passenger seat. If they turn lap times 2-3 seconds faster than you, then you'll know that you need to "tighten the nut behind the wheel" before you do anything else. You'll be able to see what your car can really do and where you are losing time at specific places on the track. It's scary to hand over the keys to someone else, but if you've got the right person, you'll feel comfortable because it will be such a good learning experience. (btw, I don't think the typical NASA instructors are good enough for what I'm talking about. Not trying to bash them -- just basing this on my experience, which is that they're good for teaching the basics and HPDE stuff, but not so good for pushing a car AND driver to the limits. Find out the reputation of the instructors or racers there -- if you get a 100% response of "oh-yeah-he's-fast," you've found your guy.) My experience also has been seeing drivers slow down their learning curve by putting go fast parts on their car. Example: Guys put slicks on and go 2.5 seconds faster per lap then with street tires. The increased grip made them turn faster laps but it hindered their development because it hid flaws and made up for their mistakes. It's almost a question of do you want to go faster or do you want to become a better driver... As anyone moves up the "pyramid of speed," eventually they have to decide whether they are going to have a street car or a race car. Sounds like you're pretty close to being forced to make that decision. Oh, one other thing, you mentioned that you're basically as fast as some Z06's. Hmmmm....., same speed as a car with 30+ years more safety technology (impact zones, air bags, etc etc) -- think about it. Quote Link to comment Share on other sites More sharing options...
heavy85 Posted July 27, 2009 Author Share Posted July 27, 2009 Do you have Targa road rallies in your area? No but that would be probably one step even more extreme and dangerous I'm thinking plus with roads around here you'd rip something off for sure. Oh, one other thing, you mentioned that you're basically as fast as some Z06's. Hmmmm....., same speed as a car with 30+ years more safety technology (impact zones, air bags, etc etc) -- think about it. So what are you trying to say do you want to go faster or do you want to become a better driver... That's a very good question and I suppose both is not the right answer .... A friend of mind used to run a LS1 car (2500 pounds) on 400/450 springs and it worked really well. Probably could have run a little stiffer. Was this street driven and what shocks. I now have the Koni SA 'Race' struts but had some old Tokico's with the original 500 lb springs that were so terrible. I have heim joint front end but not the back. Maybe rear LCA should be the next fabrication project. What about increasing track width since it's relatively easy to do but what is the practical seat of the pants benefit? Is this a fine tune or bigger knob to turn? This is all very good insight and just the perspectives I was looking for. Yes I agree I need to find a GOOD instructor which I've yet to come across but will look harder. I also MUST install a rollbar for safety sake before anything else (thanks) - in perspective this needs to be on the top. I'm also not quite ready to take it off the street just yet so it will have to remain a compromise for now. Cary mentioned that tires will tell you a lot but I've searched and can't seem to find good reference material that teaches you how to read a tire - any suggestions? This is all great stuff that's got me thinking. Keep it coming. Cameron Quote Link to comment Share on other sites More sharing options...
heavy85 Posted July 30, 2009 Author Share Posted July 30, 2009 Bump - Cary or others any additional thoughts to my last couple questions in the previous post? Thanks Cameron Quote Link to comment Share on other sites More sharing options...
heavy85 Posted June 8, 2010 Author Share Posted June 8, 2010 2010 update: Over the winter I built a rollbar and upped to 375F/300R springs. So far so good and I like the feel of the stiffer springs. I've only run one low speed autox dusting the cobwebs off but the mid corner push seems better. I'm running more high speed autox this year but in the unlimited street tire class instead of the race tire class. I've also run one NASA event running TTU. Got my arse kicked by 9 seconds in TTU but that's to be expected - the winner beat out Danny Popp track record and I was having a hard time getting up to speed on a track I've never been on. I need more tire, more power, more aero, and more skill to have any chance in TTU but that's the way it goes with the swap. Anyway a couple thing I've learned that I thought I would pass on to others. The new springrate completely evened out tire temps front to rear - with the old 300/250 the rears were always 20+ deg hotter than the fronts. It's not conclusive but seems the inside tire wear and temps across the tire are better with the upped springs. The first event of the season in TT the first day I was dog slow and knew it was my old Avon tires that were relatively fast last year but rocks now ... so I put on my street tires and went just as fast confirming the old tire theory. For the second day I had my new to me used Hoosier radial R25 slicks mounted (note to self: tire mounting at the track is 2x normal at $120 a set ouch) and immediately dropped two seconds. The tire guy warned me that the radials did not have the load carrying capacity of the bias. I had poor life in the radials a couple years ago but I thought it was my soft 225/250 springs at that time. Well the tire guy was right and I corded three tires in four 15 minute sessions and the tires noticeable went away towards the end of the third session. These are the radial FA tires - I never had these problems with the bias FA tires. So the next two high speed autox events I ran Potenza RE01 140 treadwear street tires since I was out of race tires. I learned I really like street tires. The FA slicks IME lack feel and are difficult to read. I am happy I ran the street tires as they give much better feedback than the slicks, are fun to drive, and wear like iron comparatively. The Potenzas are several years old with probably 5000 miles and about the equivalent of one track day before I raced on them and are right at 2 seconds slower than 'good' slicks. The Potenzas are also only 245 and are mounted on the non-ideal Rota group buy 17" wheels (9" front, 9.5" rear, wider rear track - but hey they look good) so with optimal street tires i.e. wider tread mounted on properly sized wheels and not half heat and age cycled out they could be maybe another second (??) faster. From magazine comparisons and talking with other local racers R-compounds are typically ~2 seconds faster than street tires. This tells me that R-compounds should be faster than slicks but ~1 second. I've never run R compound but am convinced they are fastest but so far have been too cheap to run A6's. Maybe next year. These Potenza's still look new! With the slicks I was pulling ~1.2 g and with street tires and only down to ~1.15 g. Last thing I forgot before was the switch from Hawk HP+ to HT10 pads. Do NOT run HP+ on a track as they pad fade bad and with little warning! Anyway, the HT10s are now pulling closer to 0.8-1.0 g of braking. I'm having front tire lock-up issue that I'm not sure where to start with so that's my current challenge. Good luck to everyone else's season. Cameron PS: I wussed out and bought a full size van (the kids love it) and open trailer. Man it's nice not to have to pack into the Z. Quote Link to comment Share on other sites More sharing options...
heavy85 Posted August 15, 2011 Author Share Posted August 15, 2011 2011 Update: Hopefully my lessons learned can help get others up to speed faster so I thought I would post them up. I'm now running High Speed Autox with Midwest Council of Sports Car Clubs (mcscc.org). These are single timed laps from a standing start on racetracks. No cones just a full racetrack. Also running HPDE with NASA trying out new tracks. Road America, Mid-Ohio, Putnam Park, Grattan, Blackhawk Farms, Autobahn North and South, Milwaukee Mile. After about 30 track days I've come to the following set-up. Note that my philosophy is start with bare bones and add only what's absolutely necessary so each of these items has been carefully chosen based on experience and to lower laptimes and make it dead nuts reliable: - '72 240Z - ~2400 lb w/out me - 4-point rollbar - Full length subframe and misc bracing on the chassis - '02 LS1 from a Camaro - bone stock, zero problems except one thrown belt - these throw belts if you hold on the rev limited w/ stock tensioner, now use Katech tensioner - All systems from the parts Camaro - fuel system, throttle cable, wiring, computer, etc but DONT try to have the Camaro driveshaft shortened - Custom aluminum driveshaft (see above) - R200 rear - replaced bearings over the winter but have had zero issues other than wearing out the bearings - Former factory 3.7 LSD, now modified OBX - puts power down much better with the gear limited slip - Keep going up and now to 425F / 375R springs - puts power down really well finally - 3/4 or 15/16 front bar and NO rear bar - took the rear bar off last year and haven't looked back - ~1/8" front toe out, ~1/8" rear toe in - rear toe in settled it down under braking - Camber to match the tires - always at least 1 degree more in the front than the back - Caster ?? but moved the EMI camber plates back as much as I can and shimmed the stock T/C rod as much as possible without running out of threads - Hankook RS3 tire 255/45-17 tires - these are f-ing awesome tires - Champion three row radiator - ran the stock for ~2 years but could only run hard for a couple laps before it would get hot, now runs ~220 degF - Front end blocked up except fresh air and radiator opening - Mocal Engine oil cooler (came in a box marked FBI evidence ...) - APR rear wing with custom extra tall mounts w/ add 1/2" Gurney strip - steep angle of attack gets best lap times - 240sx rear brakes Hawk HT10 pads - Two-piece 12.19x1.25 Wilwood front rotors, Outlaw 1 3/8 four piston calipers, Hawk HT10 pads - Ultra lightweight rotors crack too easy - Front brake cooling ducts from airdamn - Super Blue fluid - never boiled fluid but didn't with Motul either - 280ZX CV half shafts - never had a single issue with the stock 240Z half shafts but the bolts would loosen after a track day - 3/4" 'bumpsteer' spacers, would probable run the 1" ones but had to cut these down to clear the 15" rims I run with slicks - Rod-end steering rods adjusted close to no bumpsteer, stock tie rods had a bunch of bumpsteer - Sectioned struts with Koni SA 1437Race inserts - EMI camber plates - these came with the car and if I had to buy would probably get something else - Front control arms ~ flat w/ ~1/2" rake with rear higher - Penzoil Platinum 10W30 changed every two track days - Custom PCV catch can - the LS1 sucks oil through the PCV system so keep an eye on oil level - LS1 also starve for oil especially on left hand sweepers so keep it 1+ quart over full mark w/ 2 quart accusump - Group buy Rota 17" wheels but switched the fronts to the rear and vise versa, if I had them I would run the rears all the way around So how successful is the set-up? I've won fast time of the day among ~70 cars and I was on street tires. Two track records for fastest car ever on street tires. Equal speed to Porsche GT3 RS on several occasions and they were on race tires. Faster than any stock C6 Z06 Corvette I've ever come across on equal tires, even with decent drivers. I'm now to the point the car is completely reliable, very well sorted, fast, and I'm comfortable running 10/10ths on courses I know well. Please dont let this come across as bragging because that's not the point. It's taken me three years of track events to get to this point so thought I would share the experience to help others get up to speed faster. Cameron Quote Link to comment Share on other sites More sharing options...
johnc Posted August 15, 2011 Share Posted August 15, 2011 The main point I think is: time and testing. It takes a lot of both to get the car and the driver sorted and fast. There are no magic bullet combinations and bolting on parts is only 25% of the work involved in making a car fast around a race track. Quote Link to comment Share on other sites More sharing options...
heavy85 Posted October 9, 2012 Author Share Posted October 9, 2012 (edited) Stumbled across this old thread and in case anyone is interested here is the 2012 update. Ran High Speed Autox season again (single timed lap on a full racetrack - no cones) with the Midwestern Council of Sports Car Clubs and a SCCA hill climb down in North Carolina so it was a light year due to hectic life. After about 35 or so days on racetracks after previous years of low speed autox and kart experience I'm finally to the point of getting close to the full potential out of the car. Ended up taking 1.8 seconds off previous best lap time on our home track and scored two or three FTD still on street tires to boot. The car is really quite fast. Here's thread on the hill climb - I was thrilled with the results http://forums.hybridz.org/index.php/topic/106904-hill-climb-set-up/page__p__1000354__hl__%2Bcameron+%2Bdragon__fromsearch__1#entry1000354 Continuing the theme here are lessons learned: - Splitter dropped 0.5 seconds of 1:20 sec lap time but hurt cooling (actually done in 2011) - Bigger wing + cam (guess +40 hp? to 365 whp) dropped another full second off laptime - Splurged on scales and setting corner weights from 48% cross to ~50% cross dropped another 0.5ish seconds - Down to stock front swaybar and no rear bar with same 425F/375R springs. Smaller front bar really helped prevent front wheel lock-up under braking. It's very drivable but need to find more mechanical front grip. - True dual masters work much better than stock set-up - Video showed the outer rear urethane bushings deflect a LOT as you apply power. UHMW bushings finally all but eliminated wheel hop and noticeably helped the launch. - Making a car track worthy (brakes, cooling, aero, rollbar) adds weight so now car w/out driver and ~1/4 tank is right around 2,500 lb - LS1 need dual catch cans and the LS6 valley PCV conversion doesn't do squat to oil consumption through the PCV system. - Now starting to reach the limits of the OBX and getting a little wheel spin but it's pretty minor and workable. Would a pimp OS Giken diff help much? - Hankook RS3 work really well with heat but suck in the cold so the internets tell the truth on something. Now what for next year? Need to take weight out and figure out a way to get more front mechanical grip. Shooting for sub 2:00 run at the Dragon hill climb and what else we will see. Still going faster about each time so the challenge and reward is worth keeping advancing but am starting to get to the point of $$ just for the sake of going faster. Cameron Edited October 9, 2012 by heavy85 Quote Link to comment Share on other sites More sharing options...
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