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HybridZ

different cam needed just which one ?


gacksen

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Had my car on the dyno those days and it´s not bad. it´s 3.1 with flat tops in it. didn´t measure the

cam yet but will do the next days. as you can see from the torque curve it´s fully flat from 2500 above until 6000 and then falls off.

as it is a stroker with the ld28 i am a little bit worried about piston speed. it has triple webbers on it that are not fully tuned up yet.

will get that done in december. idle is perfect with the car. don´t drive it regular it´s just a weekend toy.

 

what mods would be necessary to shift the redline safely to 7k also what cam should be a good choice to get a more sports car like

curve ? mine reminds me of a diesel.don´t need the car for inner city traffic.

 

Dyno240_Z.jpg

Edited by gacksen
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More info on the pistons, compression ratio, is the head ported or just bolted on stock? Current cam info would be a big help as well. Is it a stock cam? What size webers?

 

That torque curve is pretty nice...223HP is not terrible if you have a small cam and a stock head.

 

I would be starting with a cam in the 0.480" lift range, but keep in mind piston-to-valve clearance! Make sure you have enough piston crown thickness to cut the valve reliefs in.

 

Can't really give a lot more suggestion till we know what you've got to start with

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had some busy days with my work and not much time to take care of the car.

 

as far as i am aware head is fully ported and webbers are triple 45" with 50mm chockes. need to take the valve cover of the see what cam it is.

 

drove it last weekend and ran into antoher problem. gearbox crunch on downshift only from 3rd to 2nd gear. no other crunches also not in reverse.

had replaced master and slave when i got the car as the fluid had been fully black. will try to adjust the slave and pedal to see if it is possible to cure

the problem. only thing that worries me is that the crunch appers only on downshift from 3rd to 2nd at higher rpm´s. maybe worn snychro but not sure.

when shifting into second gear the click sound of the gearbox is missing that i have in all other gears. it´s a 5speed trans from a zx 71B  mated with an R200.

 

if it would be the synchro i guess i would replace the box completly and go for an FS5W71C or FS5R30A.

 

have read some posts about the swap with the FS5W71C swapping bellhousing etc. but could not find much

regarding the 300zx turbo trans FS5R30. anybody has done this and what mods are necessary ?

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45 mm webers cannot have 50 mm ventureis it would be physically impossible. The biggest they can have is 42 mm. It looks as though your torque comes on too early for a fully ported head. If the head was ported as large as possible the airflow would be too slow on the low end for that. It could very well have a port job that is appropriate for a street car. A good street port with the Robello 63di cam and a set of 45 with 39 ventureis when properly tuned will make 300 lbs of torque around 4500-4800 rpm and 320 hp from 6600-6900 rpm and have shift points from 7000-7300 rpm.

 

A zx 5 speed in good shape is fine for a N/A stroker. Unless you are going to make big amounts of torque you will be adding unneeded weight and $ swapping to a 300 t trans. The 280zx is a direct bolt and the r200 is plenty strong too.

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It's metric, power in kW, torque in Nm.

 

In the posted graph, power is shown in PS, i.e. metric horsepower. But yes, that "magical" 5250RPM is only so for power units in hp and torque units in lb-ft.

 

Generally speaking: power = torque X RPM. The rest is just conversion factors.

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45 mm webers cannot have 50 mm ventureis it would be physically impossible. The biggest they can have is 42 mm. It looks as though your torque comes on too early for a fully ported head. If the head was ported as large as possible the airflow would be too slow on the low end for that. It could very well have a port job that is appropriate for a street car. A good street port with the Robello 63di cam and a set of 45 with 39 ventureis when properly tuned will make 300 lbs of torque around 4500-4800 rpm and 320 hp from 6600-6900 rpm and have shift points from 7000-7300 rpm.

 

A zx 5 speed in good shape is fine for a N/A stroker. Unless you are going to make big amounts of torque you will be adding unneeded weight and $ swapping to a 300 t trans. The 280zx is a direct bolt and the r200 is plenty strong too.

 

have bled the clutch yesterday but it is still raining so hopefully will try it out tmr and see if there is any cure to the crunch. have adjusted the pedal and slave too. as for the carbs will get the cover off

and pull the jets to see whats inside. it´s my first car with carbs so quite new to that field :)

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  • 2 weeks later...

if it would be the synchro i guess i would replace the box completly and go for an FS5W71C or FS5R30A.

 

have read some posts about the swap with the FS5W71C swapping bellhousing etc. but could not find much

regarding the 300zx turbo trans FS5R30. anybody has done this and what mods are necessary ?

If it's not bad, switching to Redline MT90 gear oil, or a blend of Swepco 201 and ATF might get you by for a while.

 

Here are a few links on the 71C swap - 

 

http://www.motortopia.com/cars/1973-datsun-240z-11118/car-pictures/240sx-transmission-swap-14041/DSC04293JPG_Thumbnail1.jpg-266482

 

http://home.comcast.net/~zheimsothtn/transmission.htm

 

http://www.atlanticz.ca/zclub/techtips/240sxtransmissioninstall/index.html

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