John Coffey
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Everything posted by John Coffey
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The car owner had four cans of spray paint (two red and two white) and some time on his hands. I'll bet his wife was really pissed when she got home from the store.
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1. Remove the rear wheels and tires and place under the car. 2. Unbolt driveshaft (4 bolts) and hang out of the way. 3. Unbolt halfshafts (8 nuts) and hang out of the way. 4. Unbolt front diff crossmember (4 bolts) and let diff hang off moustache bar (don't worry about the rear LCAs). 5. Put a jack or your chest under the diff. 6. Unbolt the diff from the moustache bar (2 nuts). 7. Slide diff forward onto the jack or your chest. One person car R&R a diff in 20 to 30 minutes, depending on how hot the diff was when the car came off the track.
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I've never heard of "catastrophic harmonics" at 7,500 rpm! I need to tell my ITS racing buddies about that and have them stop revving their L24s to that rpm. L6 engines on mildly modified cranks can spin to 8,000 rpm plus with having a catastrophic failure - if they are running a harmonic balancer. There are harmonics (2nd, 3rd, 4th, 5th order, etc.) throughout the rpm range of the engine that need to be dampened. BMW 6 cylinder engines are famous for breaking cranks when the bling bling racer boys install cheap aluminum crank pulley/balancers. Thankfully this trend hasn't made it into the Nissan L6 world.
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Well... that's true at some order of harmonics, but a reciprocating assembly can never be perfectly balanced internally. You need masses as each end to help dampen non-primary order harmonics.
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Take them off the car and put them on a shock dyno. If that's inconvenient then put all 4 shocks on setting 1 and drive the car around a curvey/bumpy road for about 5 minutes. Put both fronts on setting 5 and drive the car around for 5 minutes. You should notice a big difference in how the front of the car feels. Put the fronts back to setting 1 and set the rears to setting 5. Drive the curvy/bumpy road again. If you don't notice a difference or one side of the car (left or right) feels different then the other then you've got one or more bad shocks.
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An anti-roll bar (ARB) should be installed so that there is no pre-load on the bar as the car sit levels on the ground with the driver in the car. Without seeing better pictures my guess is that the ARB is installed incorrectly. The ride height issue is probably more related to the car not being settled on its new suspension.
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The lack of compression travel has to do with how much your car is lowered. Keeping the same spring and shortening the strut will get you back some of that suspension travel. Lowering a 240Z any more then 1.5" requires strut shortening IMHO.
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FYI... the Tokico springs for the 280Z are linear front and rear and have the same rate as the Arizona Z Car springs (185 lb. in. front and 200 lb. in. rear). They will work on a 240Z but you have to cut coils to get the ride height you want. FYI2... shock compression damping has a much larger affect on felt ride harshness (impact harshness) then spring rate. A really good shock with stiff springs is a much better ride then a crappy shock with soft springs.
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Not measurably. The power to drive the electric water pump makes up for most the parasitic gains. A harmonic balancer has no effect on horsepower - same as a lightened flywheel.
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Dumb idea. it will be loud and stinky inside the car. I've had racers ask me to build exhausts just like this and every one has come back and at least had me run the exhaust out the back of the car or to the side just in front of the rear wheel.
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I never weighed a S30 that was anywhere near 2,800 lbs. I corner weighed a stock 1977 280Z with AC and it came in a 2,671 lbs. (with fuel, spare tire, aftermarket stereo, etc.) I've weighed racing 240Zs that came in a just over 2,000 lbs (no fuel) and street 260Zs that came in at 2,556 lbs. with fuel, spare tire, stereo, etc.) A racing 260Z with a SR20DET swap almost weighed exactly the same as my old racing 1970 240Z with an L6. The preparation level of the car has a lot more to do with its weight then what the factory listed 35+ years ago.
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Over the years I've purchased parts from Roger at ZBarn, Eric at ZParts, and Danny at Danny's Datsun. All have provided great service and fair prices. Unfortunately Danny is shutting down 8/31 this year.
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I've had good luck with Porterfield R4s on a stock 240Z brake system using then at open track days and autocrosses. They do need to be bedded properly and they need some heat to start biting. But I have had poor luck with them in track sessions lasting longer then 30 minutes. On a stock 240Z brake system then get overheated and start to chunk, at least that's been my experience. For longer sessions I would go with Hawk Blues.
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Based on my experience with the 43s and 41s on a 3,200 lb. 350Z, I would say no to street use. Rotors are a consumable item with these or any true race pads. They are also dusty and noisy. I did not feel much responsiveness when cold and I think they need a couple hundred degrees in them before you get good bite.
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I've actually had experience on a race track with almost identically prepared SCCA ITS spec L24 and L28 engines with SUs in the same car. The L24 had a higher rpm limit (7,200 rpm vs. 6,750 rpm) and made more horsepower as a result (190 vs. 180). On the race track the L28 had faster lap times because of a couple corners where the L28's better mid range torque got it out of the corner quicker. On the long front straight the L24 could match the top speed of the L28 but it couldn't make up the corner exit speed difference. With gearing better adapted to each engine the lap time difference would have been less, but the L28 would still have been faster around the race track.
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If originality is not a concern, Tacoma Screw Products has metric class 10.9 bolts in any thread needed. Its hard to find class 10.9 M10 x1.25p bolts which are used a lot in the suspension and chassis. TSC has them.
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Step 1: Go to http://www.hybridz.org and search, read, search, and read.
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HELP!!! Tokico Illumina install issues
John Coffey replied to Thecabtsmith's topic in Suspension & Steering
That's normal for most lowering springs and coil over swaps. Once you lower the car the springs will seat in the perches just fine. And no, its not something to worry about when you get the car airborne when racing at the Nuremburgring. EDIT: Also, where you put the jackstands in the picture at the bottom of your post is not the best place. Its generally better to put jackstands between the wheelbase. -
FYI... my post above regarding the 32310-58S54 gearset giving a .86 overdrive has been proven wrong by Bryan Lampe. Back to the drawing boards. Sorry.
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Molds that can make more the 5 parts typically cost $1,000 and up. A Bonnet (hood) requires two molds, one for the outer skin and one for the inner frame.
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I use slip on wheel spacers all the time on customer cars and my cars. If they are good parts, well machined, fit correctly, and the wheel studs are long enough then there shouldn't be any issues. In 10 years I've never had hub or wheel bearing failure using spacer from .125" to .750" on dozens of S30s. On my own Rusty Old Datsun I used wheel spacers to tune handling and that car regularly saw track speeds in excess of 140 mph and cornering loads over 1.25G. I currently run a set of 1/2" front and 1/4" rear spacers on my 350Z and have seen track speeds at Cal Speeday over 150mph in turn 2 with G loads peaking at 1.31G.
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West coast guys run stiffer rear/softer front to get the car to rotate more on corner entry with a welded diff. Most of the tracks here on the west coast are pretty bumpy and have more low and medium speed corners then high speed corners. WSIR and Cal Speedway are the two exceptions.
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Bob Sharp Racing 1972 Datsun 610 B Sedan Trans Am Race Car
John Coffey replied to Mike B's topic in Internet Finds
You're right. Its a 710. My mistake. -
Bob Sharp Racing 1972 Datsun 610 B Sedan Trans Am Race Car
John Coffey replied to Mike B's topic in Internet Finds
Isn't Bill Baker still trying to sell his racing 610? Its serial number 3 or 6 or 16 and was the first 610 ever raced here in the USA and has been a racer, with full log books, for all its life. -
One tip: Remove the fill plug first before removing the drain plug. Reversing the order can leave you high and dry if you can't get the fill plug out.