johnc

Hiten Patel is a person - long time 240Z guy in Southern California and past President of GroupZ. He's building an EP 240Z and is creating the parts for his car with the intention of selling them to other Z folks. His e-mail address is: little.simba@cox.net.

http://streetmodified.org - for general info. http://www.wincom.net/trog/stu/sm2_rules.html - for the specific SM2 classifications. And yes, I'm shooting for the 1,900 lb. weight break, but I don't think I can get there. My car currently weights 2,260 lbs. with 1/2 tank of fuel and without driver. The new motor weighs less than the old by about 70 lbs and the Quaife transmission with the Quartermaster clutch weighs the same as the old Type B. So that gets me down to 2,190. An aluminum radiator, new lighter racing seats, and some legal parts removal will save me another 50 lbs. Now I'm down to 2,140. Today, Hitel Patel showed me a carbon fiber hood that weighs 7 lbs including attachment hardware. That can save me 40 lbs over the stock hood and hinges. He is also making a front fender/headlight bucket combination that will save 40 lbs. total for both sides. If I spend the money for these parts I can trim another 80 lbs and get the wieght down to 2,040 - but that's probably the best I can do legally. Hiten also has a rear hatch/polycarb rear window combination that weights 8 lbs including attachment hardware. That saves a whopping 62 lbs over the stock rear hatch, glass, hinge, and strut assembly. But, replacing those parts is illegal in SM2.

True to some degree but sometimes we forget about inertia. If we can keep the mass of air going into (and out of) the combustion chamber moving at a high rate of speed then we don't have the delays associated with accelerating that mass of air. That mass moving at speed also dampens reversion which tends to slow down or stop the mass of moving air.

The issue with the rods is not the rod breaking, but the big end staying round. Sunbelt has given me explicit instructions to pull the rods every 50 hours and measure the roundness of the big end (and these are forged Carillos.) If they are out by .001 or more then I have to replace them. Rod bearings get replaced every 25 hours.

I received an education when I watched my L6 on the dyno. Velocity is more important than flow. My L6 3.0L is currently making over 300hp using a 60mm TWM TB. I also saw an LMP 675 3.0L VQ motor making 450+ horsepower through a 40mm restrictor. Careful about going too big on the throttle body.

Carillo.

The R180 4.11 from the 200SX NA can use the old style halfshafts if you swap in the early diff stub axles.

Assuming nothing is bent... Sounds like the car's racked. Basically the front crossmember is pushed to the left and the rear suspension mounting points (the front and rear crossmembers) are pushed to the right. For the front, unbolt the engine and support it on a jack. Loosen the front crossmember and try pushing it to the right. You mght need to use a bottle jack. Snug it up and measure to the front tension rod mounts to see if things are square. If you can get it square, buy new nuts, bolts, backing plates, and torque to spec. For the rear, you first have to replace the bushings. I suggest you also check and replace the lower caps that clamp the control arms in place. They distort over time. Also, buy all new nuts, bolts, washers, and locks. Assemble the rear crossmembers and control arms and lightly snug in place. Measure to some known good points on the frame to determine if things are square. Carefully tighten to spec and then re-measure. If things move, then one of the crossmembers is probably bent.

Do you mean the ring gear around the flex plate? If so, I suggest you search a few junkyards and find a good flex plate to replace the one you have.

The damper is an ATI Super Damper - supposedly the same part used on NASCAR Winston Cup motors. Sunbelt is a huge fan of good harmonic dampers. If you mention the word "Unorthodox" near any of the guys there they just roll there eyes and laugh. Jim Thompson has stories about blown up BMW World Challenge motors after an engine builder started eliminating the dampers in a futile attempt to get more horsepower. The pulleys themselves are Moroso parts with Sunbelt fabricating the attachments to the damper, water pump, and alternator. Alternator mount is fabricated also; it needs to be positioned farther forward than the stock mount allows. Gilmer belt is 1.5" wide, 31" long. Oil pan and pump are Nissan Motorsports parts.

Bob, I was always impressed with what you got out of your street 3.1L. Some of the writeups you've done helped convinced me to build up an L6 instead of going with a VG motor (which is legal in SM2.) Jim discovered a number of important things about the L6 valvetrain through his computer models. Most of what he discovered he's keeping secret, but a telling point is that L6 cams have been based on computer models of the early BMW SOHC valvetrain layout. That's the only model that was available in the last 20 years and cam grinders have been using ramp and nose profiles appropriate for the BMW motor (the only exception that Jim mentioned was Don Devendorf at Electromotive). Jim found significant differences between what the BMW valvetrain needs and what the L6 valvetrain needs.

The car is being built for the new SCCA Solo2 Street Modified 2 class. OTC is secondary, but it should be fun beating up the Porsches! Engine is pretty open with my only limits (based on trying to hit a 1,900 lb weight minimum) being a max 3L displacement and normal aspiration. I emphasized a broad, flat torque band as the overriding goal for the motor. Engine is an early N42 block and a late N42 head. Pistons are forged JE giving 13.6 to 1 compression with an 87.5mm bore. Heads are heavily worked with the main emphasis on exhaust port flow. Jim Thompson developed a number of new computer models of the L6 valvetrain which payed off in a bunch of ways. The most startling is that the engine runs valve spring pressures 25% less than a stock engine and its still good to 8,000 rpm! There are no inner valve springs. The assembled engine, minus the spark plugs, requires 38 ft.lbs. to turn over. Because its a torque motor there are no individual throttle bodies. It has one custom TWM 60mm throttle body opening into a huge 4" diameter plenum feeding 5" long tapered runners. Jim also developed two separate custom headers. The first is a stepped design with long primaries and the second is another stepped design with shorter primaries and some long collectors. These will be tested this week. The cam is custom and even I don't know the numbers on it. Suffice to say that I've got at least 200 ft.lbs. of torque from 4,000 to 7,000+ rpm. Here's a shot of the left side of the motor. Its not pretty because none of the parts have been cleaned and sent to the coaters yet and the wiring harness has not been loomed.

Comparing R160s and R180s gets difficult because both were offered with either two or four pinion diffs. The four pinion R160 is much more common than the four pinion R180. Remember: four pinions in the diff are stronger than two pinions in the diff. The R180 got a bad rap because most folks put a lot of power into the two pinion variety. A R180 with four pinions (or a Nissan Comp, Quaife, or Torsen LSD) is pretty strong. I plan on pushing 300hp and 250ft.lbs. though mine. BTW... I learned the other day that the whole R100 through R230 series is designed and manufactured by Hitachi for Nissan, Subaru, and others.

Take the rear cover off the diff and look and the gearing numbers stamped on the ring gear. Divide the larger number by the smaller number to get the ratio.

I beg to differ on how much the car flexes at the C-pillar seam. Depending on the quality of the roll bar/cage installation, you'll see many track Zs with cracks in that seam. You will also often see cracks in the floor pan at the rear of the driveshaft tunnel. Torsional rigidity is not as important in the Z as horizontal rigidity. The car flexes like a hinge in two places: at the firewall and behind the seats at the rear bulkhead.

Its a custom distributor housing that holds the optical triggers for the ignition and FI reference. In the picture, the coils are on the left side, mounted to the dyno frame. The engine management system is a Motec M48 with an extended ignition module.

My new L30 on the Sunbelt dyno. Break in finished Tuesday night at 10:00pm. This morning we made 3 pulls with no individual cylinder mixture or ignition tuning and the engine running very rich at 11.1:1. 289 horsepower at 6,600 rpm and 246 foot pounds at 5,400 rpm. 200+ ft. lbs. from 4,000 to 7,000 rpm. Further tuning (including two different custom headers) to be done this week. The ultimate horsepower and torque numbers won't be posted...

Don't know yet. I have to pull the transmission and then drop the car to see. I'll get that done this week and post another photo.

You do have to get a referee station to inspect the initial engine swap. You do not have to get annual smog checks after that first inspection.

The bump steer spacers are a "second best" option compared to raising the control arm pivot point. Do one or the other, not both.

They REALLY fill up the wheel well. I'll have to roll the fender lips a bit more and trim the rear side of the front spoiler. I can barely squeeze my little finger between the tire/rim and the 2.25" coil over spring perches in front and back, but they fit and I didn't want to put flares on the car. If I'm going to be beating up Porsches I want them to think (a least for a little while) that its only a slightly modified 240Z.

Monocoque 16 x 9, 5" backspace wheels with Hoosier R3S03 245/45-16 tires.

The only way to be sure is to take the rear cover off and look inside. Most likely you have a regular open diff. Its common for them to spin both tires if the traction is right.

Coast Fab: http://www.coastfab.com/ Go to Products/Services - Ultra Lightweight Racing Muffler.

Taylor sells the transmission for $1.00. The mandatory crate costs thousands...