clarkspeed

As one of our many projects, FHPTom and I are currently restoring a 72' 240Z. It served as an ITS car in the San Francisco region I believe since the 90's. We rescued it from becoming a chopped up wide body conversion. https://www.facebook.com/S30-Motorsports-262575520591481/?fref=hovercard We have been documenting the build on our S30 Motorsports Facebook page. We intend to essentially restore the car to full race form and also convert to a tribute vintage CP car. Car is being built to SVRA rules which are nationally accepted and we are upgrading or replacing everything related to safety and reliability. It has a fresh 2.4L, close ratio 5 speed, and a locked 3.9 rear. Current plan is to race it, sort it, then sell it with an extensive spares package we have collected. Clark

Mistake on previous post. I just saw your mild race build comment. Depending on compression and desired RPM range, that cam can work well.

No, thats not what I meant. Adding more than 500 lift AFTER porting is marginal increase. My point is .500 lift is a lot of lift. Duration is another matter and I would never run 300 on the street. That is just my opionion and you can get many others. I hate over cammed engines.

I agree. I tried to explain this recently to someone offline after the Hybrid community had recommended cams for him. Unless you are flow bench porting, it is just not there. And when you are flow bench porting, its still only marginal gain for NA street engines.

Interesting solution. I thought about trying something similar numerous times but never did. The firewall definitely flexes a lot. Especially if you have removed the booster. I had a doubler plate on my last car but it only stiffened maybe 50%.

Correction, I am using Genesis aluminum pillow blocks from Hoerr Racing. With aluminum arms and 3/8 rod ends. Very lightweight package but I run less than 150 lb/in stiffness.

I have seen a number of these on S30's and recently purchased one for the car I am building. Selection involves knowing the spring rate you desire. You can calculate the thickness you need based on bar length and arm length. Rule of thumb is use steel arms for heavier rates. You will need bent arms or bend them yourself. I have seen them mounted using flange mount bearings through the engine bay, fenderwells, and frame rails. I chose an aluminum bearing block I think I got from Pegasus.

Another great product from Dave! Solves a problem AND saves weight.

Never heard of one breaking.

I tap mine and put Allen head NPT plugs in. 3/8 or 1/4 can't remember. Be careful with the front one, it can block an oil gallery and you may need to grind it flush.

Porting manifold means matching to larger TB in my previous post. I prefer not to touch the cam unless I raise compression, just personal preference for streetability and leaving the stock efi alone. Although I will say we got 200hp at wheels with 9:1 compression, huge cam, and aftermarket efi. Just not much fun to drive on street.

Above, with bigger TB and ported manifold ahead of cam work. I would rank the bowl work next, then mild cam, then more compression. Best to combine cam/compression/megasquirt in one project.

Awesome!

A set of Pauter or Carillo are 1300-1600. Normally used in 10k+ race engines

I have been 3d printing my velocity stacks in ABS plastic. Pretty cheap and you can do any length you want. Also 3d printed my prototype for a cold air box.

Google is your friend. There are things called emissions, economy, driveability, that factor in.

Easy peasy. Do you need to run on pump gas? You can do a lot better with some serious compression and different head. Otherwise the N47 is fine for pump gas. Build engine like the book and verify every single tolerance. Stock flat top pistons are fine. Shoot for a little over 10:1 compression. The higher you go, the more octane boost you will need to keep the N47 from pinging on 93. Pocket port clean up the head so there is a smooth blend into the valve seat. Good valve job. Balance out the rockers/lash pads. Use the most open intake/throttle body set up you can afford and port match manifold to gasket to head. Run 2.5 or 3 open exhaust with a good header. If 2.5 use mandrel bends, if 3 muffler shop bends are fine. Personally I would go with a milder cam to keep from moving the power band up and try to keep the rev limit around 6500-6700.

Yep, put R compound tires on any car and it suddenly becomes a race car. Other than that, poly bushings all around, decent street shocks, and all fresh brake components with a track friendly pad/shoes. Good alignment. That would get you started.

Safety, Reliability, Driver Skill, Speed. Modify/Improve in that order.

As long as the tight side stays tight, no problem.

All good advice here. On the race car I had a combination of about 1/8" adjustment slot on the cross member, the big 1"+ TTT strut spacers, stock LCA, modified tie rods with 5/8" rod ends, and I reamed out the steering knuckle to fit a Pinto style 5/8" bumpsteer adjustment bolt. The tapers are cheap from Speedway Motors and ;you can get the pin and shim kits from any circle track store. The pin was a little long for my 16" 4.5" backspace wheels, but a little grinding did the trick. I made the tie rods out of tubing, 5/8 threaded tube end, and cutting the inner few inches off a stock tie rod. It is detailed on Hybrid somewhere. On the next car I will try to do a lighter version of all that. Also agree with higher spring rates for your speeds. The car should really feel planted and solid at speed, not floaty at all. You should be able to drive it with 1 hand.

Jon, that is not fair. You beat me to the post with a better drawing!

Please send the royalty payments to my paypal account. The answer to the camber question is it depends. If you are running a high roll center then technically it would pull out some camber that might be noticed. If your control arms are closer to parallel, then not so much. A 1/4" is not so much movement and most (all?) people who would attempt this already have some form of camber adjustment device to compensate. If you slant the slot to raise inner pivot and increase camber, you will end up with a nice roll center location, increased camber, and very poor bump steer curve. Everything is a compromise.

If you want to minimize bump steer and are not bound by rules, a small 1/4" vertical slot, not slanted, in the cross member (combined with strut spacer if you have lowered the car) is usually all you need. Quick and easy adjustments. And it doesn't take a $150 gauge to get in the ball park. I use what amounts to 2 square pieces of wood connected with a piano hinge. I place weights on it to keep it from moving on the floor. The free side leans against a wheel with what amounts to 2 nails resting on the wheel outer shell about center height. Adjust it until you get both nails touching equally. Remove the springs and sway bars, jack the car up and down through normal range of movement, and watch how far one of the nails will move away from the wheel. It usually moves A LOT. Adjust inner pivot until you can keep both nails touching through the entire range. I think I mentioned before, 0 toe in the rear of my car really added to high speed stability. But your speeds are another deal.

Hey, I only said a "little" different. Point being you can get parts from China manufactured to any quality level you desire. But a crank manufactured to the standards of Sichuan Andes may not meet your expectations and shipped in a box packed full of risks. I have not experienced any bait and hook tactics with my suppliers. But again my products have detailed specifications. It is also a long path to qualification so suppliers that invest into that dont want to lose out due to quality problems.