clarkspeed

ummm, not to be a pain in the ass, but 1g acceleration equates to approximately a 9 second quater mile... Only if you can maintain it.

I've ridden the Top Fuel ride twice now. It is a blast, very realistic. My wife loves it more that I do!

Baffles are a must. I'm over 1g in all directions. Sometimes, on rare ocasions, in the Z axis too!

I would go for that if it had decent baffles

Arizona Z makes one for the L6

If used on the track, consult your rulebook for legality. I prefer ATL or Fuelsafe. They are the best. For street, I don't know any one stands out. You get what you pay for. The foam acts as a baffle.

It's a trick I learned from another racer. It's only a slight angle change so it doesn't seem to hurt anything. Probably adds a little bump steer but it makes toe setting a breeze. I mis-quoted earlier, run a poly bushing on the front and the adjustable bushing on the rear. You can set the toe without jacking. I have no idea how I ended up with one pair. If they do come in sets of 4 maybe you can split with someone.

If you only need to adjust toe, you can buy one pair and install one in the front of each arm.

If your timing marks look good then you should be alright. I assume you have advanced the cam to compensate for the reduced deck hight since the marks line up. The only risk is the tensioner jumping out of the housing. If this happens you will have trouble. I think the "How to Modify Nissan OHC Engine" book covers some tricks to limit the travel of the tensioner.

Search for threads on this site. I'm running a set from a Mercedes V8.

Grab a 75 and simply port out the casting tits that protrude into the outlet bores so the inside is round. Also port the inlet to fit a bigger TB. Flows pretty good then!

I think my springs are in the 250-275 range if I remember correctly and car weighs around 2450 empty. Springs are just a little stiff for auto-cross work, a little soft for hard track work, and torture for street drive. Just the right compromise for me. I run Carerra's and love them. Non-adjustable, but it's one less thing I need to worry about. Mystrut nut came loose at Sebring and the thing slapped around in the tube at weird load angles for 20 minutes. I took it out and still couldn't push the rod down with my hand. My struts are 8 years old, with a lot of abuse, and they are still like new.

Make sure your manifold, adapter, TB's and filters will fit into the engine bay. The space fills up fast. My TWM setup barely makes it.

I don't think it is from water. Everything looked like it was sealing and there was no leak path from the water passages. I still had great compression and no signs of a gasket leak although I suspect it would be coming soon. This head has about 1-2K miles since I last took it off. I am wondering if the copper gasket sealer reacted somehow with the aluminum.

Has anyone ever seen a head erode like this? The head has only been run for a few months. 4 out of 5 cylinders show some signs of this. Most of it is at the head gasket seal but some of it worked into the chamber. There were no signs of water leakage.

I'm not sure about your electronics, but it could be mechanical. I had the same problem. Turned out my distributer/oil drive shaft ate itself alive. The crank gear is steel and so is the shaft gear, if you push high RPM's niether one will give. Nissan comp made a brass gear for the crank to solve this problem on the race engines. If there are metal shavings in your oil, better pull it.

I had actually bought a set of 40mm Webers and when I priced getting them tuned I backed off and sold them on e-bay. I knew they would be marginal for my engine, I think they had the 36mm chokes. I knew if I went with the TWM/FI set up, I could build any engine I wanted underneath and push button tuning is free. Did I mention my induction noise is louder than my exhaust? Very pleasing to the ear.

The Cannon manifold seems to act more like independent runners. 6 little engines if you will. Although the cross-over tube has a rather large id, >1/4", each runner "pulses" vacuum with valve lift. The only way to get a steady vacuum reading is to run all 6 together into a small manifold (1/2 id tubing, 1-2' long, minimum).

"However, if you sum the vacuum signals from all of the cylinders together, you will get a much better signal than your current setup does, especially at low rpm. " I had all the vac signals tied into a chamber when I first started tuning. It gave me a little boost to about 10"HG at idle, and around 13" at low speed. It was not enough for the SDS MAP tuning after 2 months of trying. When I switched to TPS it fell right in with about 30 minutes of driving. For track use and even most street driving, the TPS load sensing works surprisingly good. I could hook the vac system back up for brake boosting but I haven't had much of a problem since I idle at 1300RPM and yes the runners have the x-over tube to equalize. "the only vacuum signal I see is going to the brake booster" There is another vacuum line running to the FPR " shouldn't it be connected like this? Pump => fuel rail => regulator => return to tank" It is connected like this???

I’ve seen a few posts recently on the pros/cons of converting to FI and benefits of a TWM set-up. I don’t get a chance to contribute as much as I would like to this forum due to lack of time (usually working on my Z) but I wanted to write a few words on my latest adventure. Engine: What you see in the pictures is a L28, N47 head, flat tops, 1mm gasket, 490†cam, and mild/medium porting. This is NOT a street car. It sees Solo and Open track. My goal is a very quick Z running on pump gas ($). Air: Attached is an old Cannon intake with 3 x 50mm TWM throttle bodies. Attached to them are 6 K&N filters. I had to port out the intake to match the head on one side and the TB’s on the other. It was a huge amount of aluminum to remove. The intake is much lighter now. Those 50mm TB’s are huge. It works great for me but I don’t recommend for a street car. They’re like an on/off switch. I terrorize people in the pits trying to get to the track. I can cruise in 5th gear at 55, and the TB’s are barely cracked off idle so my computer wants to lean it out. In addition, there is very little vacuum to speak of so forget using a MAP for tuning. I chose the K&N’s as an economical solution to filtration. They were made for Kinsler style FI and have a tapered bell for mounting on straight tubing. I ordered and cut aluminum tubing that fit the TB’s and the filters perfect. Fuel: Injectors are from a 75 Mercedes 450 SEL, barb style, about 40lb/hour. I custom machined a Holley fuel rail blank to give the barb injectors an O-ring seal. I have a drawing if anyone wants to duplicate. It will work with stock ones also. 3/8†Aeroquip hoses deliver and all originates at an ATL fuel cell. I have a large body BMW Bosch pump and an adjustable regulator. Management: Fuel is controlled by SDS with TPS load sensing. I chose SDS for $ and built in programmer. I am very happy with it. I had to use an Innovate LM-1 to get it tuned right. Overall: Again, my car is a track car and rides on a trailer so I didn’t make many compromises. I converted from a very trick setup based on stock components. I’m happy with the TWM set-up. It looks and sounds awesome, even better than Webbers. But, I believe the gains are marginal compared to a well-ported 75’ manifold and one large TB. Again, 50mm would be way too large for a street car but works great for me. The SDS is great and I can’t say enough about programmable EFI. I haven’t dyno’d yet, but I put this engine around 225-250 hp at the crank. It had to be driven back to Orlando from the Reynolds, GA Hybrid event and got 21 mpg, BEFORE I tuned it with the LM-1. It has power and correct mixture under most all loads and speeds. Webbers are always a compromise and look at the cost of tuning them if you think that is the way you want to go. Future: The next engine will be some sort of stroker with higher compression. I built this induction system to grow into anything I might conjure up in my normally aspirated dreams. If anyone is attempting to try something similar, let me know and I can try to steer you away from any mistakes I made. Clark

I sold my 81 last year. It had 6 into 3" header. 3" in/out cat. 3" Dynomax race muffler (glass pack) before the axle. The system finished out with a 6" dia. round Dynomax straight through race muffler. It all had to empty on the drivers side. I would think a Flowmaster would fit also.

Dang! And to think I rolled mine with a hammer, dolly, and 2" pc of pipe.

Dan, If you have a jig and still interested in duplicating, Let me know.

Get the book, How to Build and Power Tune Weber & Dellorto: Dcoe, Dco/Sp & Dhla Carburettors (Speedpro) . It's better than the Haynes book and available on Amazon.

You will never get huge power out of that engine without losing the streetability, unless you go turbo. But you can make a nice street car. I just sold my "experiment in free breathing" 81 280Zx. I used a big K&N into 3" tubing before the AFM. 70mm throttle body into a heavy ported 75' intake manifold. Match ported the head to the manifold and pocket ported around the valves before a fresh valve job. Used a 6 into 3" header and ran 3" Cadalytic Converter, glass pack, and race muffler. It made a very strong street car that could dust off most other 4 and 6 cylinder cars. It came alive at 4000 rpm like a cam was in it and sounded awesome. If I did it again I would do the exhaust in 2-1/2 to get more bottom end torque and sacrifice the top end.