heavy85

Been thinking about how to get a few more tenths and realize aero is a cost effective tool - especially after playing with wing angles and seeing a very measurable improvement. I'm trying to understand what to do with the wheel wells and side skirts (if any). I currently dont have any fender liners and am thinking of doing something in this space. What comes to the top of my head is to add a 'floor' between the bottom of the fender (rear of front tire) and the frame rails then cutting a big vent into the lower side of the fender just behind the tire. My thinking is this would force the air out the sides and limit what is allowed to flow underneath. Think of the Hemi-Panter for example. Second topic, the skirts, and I see from the wind tunnel testing that the skirts hurt if anything. Why was that as it seems to be a potential plus? Last topic is what to do behind the rear tires. Mine are completely open but I'm thinking the rear valence is a parachute and should be addressed. Again, any ideas here? Thanks Cameron

The 'return' doesn't come from the engine bay. On the Camaro the pressure lines comes out of the tank to a filter, then T's and goes forward to the engine and back to the tank. This back to the tank lines I think feeds the in-tank regulator in parallel with the engine feed. My only reasoning here is they want the regulator flow to be filtered?? I used this tee, filter, lines, etc from the Camaro. Cameron

I went the donor route and it's convenient if you plan to really use the donor. I used EVERYTHING out of the donor which most people dont. Wiring harness, fuse block, throttle cable and pedal, fuel tank, fuel lines, trans, driveshaft (until I blew it up), etc. HOWEVER it is a real, real, real PITA to part out a car. Four years after I started and I still have crap I cant get rid of. I still have a complete hatch I cant give away believe it or not. So it's convenient and can save $$ if you have the time and patience but it's a pain to get rid of unless you just scrap it. Cameron

Bump - anyone? Even a close approximation?

A class I'm running in requires a heater system which I don't have. So instead I want to put a weight in equivalent to the heater system and see if that will pass. Anyone know how much a stock 240Z heater system incl core, valve, blower weighs? Thanks Cameron

I've got the exact same mod. It's fun to watch rain drops work their way to the vent and then all of a sudden take off vertical clearing the top of the car when they meet the outflowing air. Cameron

Update: Ended up getting the three row Champion (brand ledfoot sells). It came as advertised. Quality is ok not perfect. The mounting tabs were bent up but once straightened fit right up. The hoses fit without issue. The tank is semi-polished but appear to be hand bent as you can clearly see hammer marks. Don't think it will affect anything just wasn't bent on a press brake. The billet filler neck is just bling IMO as since it's softer than the stamped steel ones it's a bit hard to get the cap off as it digs into the billet aluminum. So far it's what you paid for. Now for cooling, the ls1 with stock 240z radiator would get to 230 degrees before I backed off fairly easily. This would take maybe 10 or so minutes of track time if it was 80 deg out. So 20 minute sessions were alternating hard lap and cool down lap to manage not overheating. If it was hotter out it would 230 degrees with 3 laps. So last weekend was first outing with the champion. Really fun track named Grattan in western Michigan. Saturday was in the mid 70s and water never got over 200 over 20 minute sessions. Sunday was around 80 and I never saw over 210. So I would say the three row champion dropped water temp at least 20 degrees over the stock radiator. So overall I'm happy and glad I don't have to back off all the time to keep from overheating. Cameron

Bump - anyone else?

Decatur Illinois.

Yes I would sell the 3.9. PM me an offer as I haven't thought about value was hoping for an even swap for the lower ratio. So anyone else?

Looking for a 3.36 R200 for my 240Z to get a better ratio for road racing. Have a 3.9 for trade or possibly willing to trade my 3.7 for it if I get no other takers. Also willing to buy but prefer trade since I already have a couple sitting around. Thanks Cameron

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.

Are you still running mass air sensor? If so wouldn't the leak cause it to run lean as the engine was getting more air than it thought? Cameron

How fast do you want to spend? My 240Z is ~2350 lb without any expensive weight reduction. You cold probably get down to ~2000-2100 lb if you were willing to spend the $$ and take the complete gut route (remove side windows, gut doors, toss the dash, ditch the bumpers) which I have not. Expensive stuff I'm talking about stuff include light weight trans / aluminum flywheel (T56 is huge), small battery, CF body panels, Lexan windows, light weight wheels, two piece rotors, etc, etc. Cameron

Jon - do you really think you'll need more power for autox? If your planning track stuff I definitely agree but can't imagine that it'll help in autox. Anyway, I've been wanting a cam for a long time and was looking at the ASA cam. It's got TONS of duration, low lift, 110 LSA and makes good broad power. It was developed by GM for the spec ASA (low level Nascar) series engine. They say it likes an open exhaust and idle is rough but I figure if GM designed it for constant high RPM abuse it should be pretty easy on the valvetrain. Fr me any cam will have to wait until next year but thought I would throw this out there. Cameron

I've done most of the list on my car. See my galery for pics. Feel free to post any of the pics but I'm not taking the time to do it. Cameron

I've done most of the list on my car. See my galery for pics. Feel free to post any of the pics but I'm not taking the time to do it. Cameron

Your missing that the Z is relatively short. I'm ~6'2" and always had head clearance issues with a helmet on. I cut out the seat mounts and use 1" square tubing on the floor to mount the seat. I also switched to an aluminum seat which is very thin. I had to raise the seat off the floor an inch or two to be able to see over the steering wheel. No matter how low you mount the seat it will never be low enough ... especially if you like to see over the dash. There just isn't enough headroom to make it work out like the reference cars. Cameron

Yes. Since I mostly track mine anymore, the stock '02 LS1 is underpowered in the unlimited type of classes you end up in with a swap. I would really like another 50-100 hp to have a chance to somewhat keep up. However my competition include a 600 hp C6 Z06 or a certain 450 hp 1500 lb Lotus clone (roadrace car that runs 10.0 in the 1/4!!!), etc. They LEAVE me on the straights. For the street I think a stock LS1 is just about right. Get good tires and a reasonable gear ratio and traction is not that hard to find. 3.9 with crusty tires does not hook-up well. 3.7 with sticky tires make it very controllable. For autox, hp is not very important. I gained probably 100 hp with the swap and very little if any weight and it's not any faster at an autox than the L6 was. Cameron

WOW!!! Counterfeit labels.

That was me last year. I bought some cable so testing is now in order.

I wonder if too much droop is the source of my inside tire wear. I even went down to 0 camber and still see more wear on the inside but that was with relatively soft 300/250 springs. This year I'll be running 375/300 which should help some but not totally if I'm dragging the insides around with excess droop. I added the '0' lb/in helper springs just to keep them from rattling around but there's probably an inch or two of droop beyond the main spring being relaxed on the front end. Rear the spring is just tight at full droop with essentially zero preload. This is on a road course - concrete parking lot event will destroy the outside edge with that little camber ... ask me how I know. I dont want to add any preload just thinking about using the limiters to effectively shorten the strut so that when the spring is completely relaxed the suspension stops going down. Thoughts? Cameron

Plus the factory arms put the swaybar mounting in the middle of the arm so that it does not try and rotate it. This minimizes twist put into the T/C rod. Cameron

Anyone seen or used one of these? I need more cooling than the stock 240Z radiator if I'm ever going to race more than two laps at a time. It's for a roadrace LS1 240Z and from the description is too good to pass up. Seems like there must be more to the story for that price?? http://cgi.ebay.com/ebaymotors/ALUMINUM-3-ROW-RADIATOR-1970-1971-1972-1973-DATSUN-240z_W0QQitemZ220558419762QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item335a4e6732 Cameron

I'm outside anything I have first hand experience of but have derived Bernoulli equation back in school .... so that make me an expert right Anyway, I think it depends on how you are trying to use it. It seems there are two potential phenomenon. First is creating a stagnation point right above the splitter while preventing air from going underneath the car. This creates a high pressure area above the splitter that effectively pushes the splitter down thus creating downforce. Your idea would accomplish this. I'm guessing you would want the splitter to be flat or even slightly down for this. The more advanced but difficult to implement function would be to use the splitter to increase the speed of the air going under the car. As the air speeds increases the pressure goes down (Bernoulli) effectively 'sucking' the car down. This is where flat undertrays and diffusers are required to make this more effective. This also makes the angle of attack critical to get the air to accelerate like you want it to. If the angle is too steep it may actually cause lift due to mechanical forces of trying to push extra air down. Then again I could just be all wet. Cameron