260DET

quote: Originally posted by Mikelly: Guys, When I got my Cutler FI hardware a busch pump came with the system. the numbers on it are:0-580-254-984. There is another number below that one: 466-15. I need to know what this pump will flow and if it will be OK pushing 42# injectors on a V8 383 application. Mike That should be the Porsche K-Jetronic pump, flows 3.1 liters per minute @40psi, up to 520 bhp.

An intercooler reduces the thermal load on the engine and increases engine efficiency by helping the delivery of more air (oxygen) to it. Both as a result of delivering cooler air. Don't know specifically about the Z31 engine, but others can run 15psi boost without an intercooler. But, as a rule of thumb, around 15 psi is the limit as far as efficiency and engine safety are concerned. Depends a lot on the engine design, ambient temperature, fuel, engine management system efficiency, etc. The best part about running high boost is that kick you get when the turbo spools up from zero to big boost in a split second

Have a new set of Toyo Proxes RA1 225/50ZR 15 to try out this coming Saturday, in place of the Yoko 032R 225/60R 15 previously used, before making any alignment changes. The Toyo's give a lower ride height which by itself should improve things, not that the handling was bad previously.

Thanks for the responses, much appreciated, plenty to think about there. ZROSSA, the FJ engine conversion was done about four years ago, bought two used ex Japan engines with gearboxes for AUD2,000. The MoTec and hi-flow turbo cost more than that. Not an easy conversion due to engine height but it performs very well, it is stock otherwise, I just don't like the L series engines.

My '77 is used for both road and circuit track work. All the suspension bushes are OE, except for the tension rods which are poly. At present the front end is aligned: toe in 3mm, caster 3 degrees, camber 2.5 degrees negative which is at full adjustment. The car had excellent straight line stability but is a bit reluctant to turn in to a corner. So I am looking at reducing the toe or caster a bit but don't want to lose that straight line stability. Any suggestions as to settings?

OK, have looked at the previous discussion on aerodynamics. Someone made the point about disrupting airflow to spoil any lift effect. It now occurs to me that an alternative airflow for radiator exit air could be made near the front of the bonnet, or hood if you prefer. As you know, some cars do this, large rear facing scoops. Air exiting from the front of the bonnet may also disrupt airflow further back along the bonnet, so reducing lift generated over the stock curved surface? 200 mph in a Z !?! Best of luck, mate, I'll stick to going round and round on a circuit

Didn't mention that the bonnet is vented near the rear for air exit purposes, plus cut some holes in the rear sides of the engine bay for the same reason. The guards (fenders) are also vented behind the wheel arches. Given that the engine stays cool without an engine driven fan I figure that the cooling aspect is OK. Belly Pan. Yes, John, the pan is slightly higher at the front. The reason for this is to increase air speed under there which will lower air pressure, on my understanding a venturi effect. The car is slightly raked ie the front is lower than the rear. About 190 kph (120 mph ?) so far on what track is available and she feels rock solid. Film shows that the nose stays down at that speed. Have looked at making a rear diffuser but, yes, the fuel tank restricts that option a bit. Thanks for the references, will look them up.

Can't see a recent discussion on this so here goes. My 77 is a road/track car with 220 RWHP and a standard radiator. It has a full front air dam and a rear whale tail spoiler, to which I fit a 1" Gurney lip for track work. The base of the front air dam is slightly higher than the front X member. Using around 1mm aluminium sheet, I have run a flat plate from the air dam thru to the X member and boxed in around the sway bar etc. On my reading, there should be some downforce generated at high speeds under the flat plate, which is reinforced so it won't deflect easily. Certainly the car handles well at high speed, no nose lift. And engine cooling is never a problem. What do you think? Has the above added much? At what speeds would any advantage come in?

For the ventilated rotor conversion on my 77 260Z using Toyota 4 spots, I used Peugeot rotors from a 80's 504, 405 or 505 or something from memory. The ID has to be opened up and new holes to match the hubs drilled. But the ID is ok and they align to within about half one mm with the calipers so no spacers needed.

A suitable aftermarket ECU (EMS) for running 15psi boost would have a manifold pressure sensor capable of sensing up to 15psi. That sensor would tell the ECU to alter fuel injector and ignition timing requirements to suit the current boost pressure. Unless your present set up can do that (I'm not familiar with your cars particular ECU) you are never going to be able to set it up to run properly. And that can result in expensive engine damage.

Of course shocks come into the equation, too, I use Koni adjustables and set them on the softest setting for road use, makes a huge difference. Plus its subjective, if you changed over from a softly sprung limo to mine you would probably notice the difference!

I fitted one of these into the rear brake line circuit and have assumed that if you turn it clockwise braking pressure to the rear brakes will be reduced. Is this correct? Mind you, using a front Toyota 4 spot caliper conversion, 15/16 ths master cylinder and a PBR rear disc conversion, neither fronts nor rears lock up at speed.

Yes, 2" travel is about what I have on the front of my lowered 260 which has around 50/50 weight distribution. Was using 220 pound (inch?) springs on the front, getting a lot of front end dive under heavy braking and probably using all travel under extreme cornering, even though I use heavy sway bars front and rear. Changed to 250 at the front, same as the rear, and its a lot better. Still rides ok on the road, in fact it seems better over the bumps.

Just wondering why go for progressive rate springs? They do tend to give a softer ride but for circuit work this would be a disadvantage. May work on a rally car that has a lot of suspension travel and probably would be more comfortable for general use. But if your car is lowered you may run out of suspension travel when hitting a big bump etc. Just my thoughts.