Thanks !

 

So is it safe to say that a port and polished heads with JWT cams are good for about 50whp? also what is the diffrence if i dont change the springs? thanks!

 

If you choose the 264 or 268 variety, you will push the power band further upstream, which means more power further into the RPM range, at the expense of some trq and power in the midrange.

For a 650whp+ motor, I think they are a great idea, but you can still get very solid results with the JWT cams, springs, but using stock valves. But at some point, even the JWT setup will be a restriction...but once again...nobody really know at what point, becuase there arent a whole lot of 700whp street driven Z's on the road.

XBR, when you swap cams, it is highly advisable that you also upgrade the springs, as the stock spring isnt going to provide enough seat pressure for high boost and high lift cams...when operated at 7000rpm+.

 

cams will help, but the secret is in the tune

my tune, stock heads, stock cams...look at the power after 5500rpms!!!

 

And just think how much better it would look with an additional 30-50 Rwhp added to it with a good set of cams and ported heads added

 

This is a great point, Sharif. Most folks think if you go more aggressive on cams it always means more power, but you definitely need to look at the tradeoff. You could hurt your area under the curve in regards to torque production. While you may gain more peak power, ultimately the car could "feel" less quick because your low-mid range power is suffering.

IIRC, you can get pretty aggressive with the cams but the further you do the closer you have to watch the duration overlaps and such. There is a point of diminishing returns for many cams.

I'm running the Nismo cams now (about all that was available when I upgraded) and am putting down some great numbers for having a stock bottom end. If I were doing it all again, I'd probably run the JWTs (very similar to the Nismos with higher lift).

 

You are correct. With any mods you do to any car they have to be matched to what the goals are for the car.

The bigger more aggressive cams are better suited for those people seeking top end power. They would not be suited for a stock motor car with a single turbo kit. It is all about matching the parts to the proper car and power goals.

 

Time to derail the thread for a moment...

Kyle, what power/times are you running with your Z32? We have a guy in our club that is hitting mid to high 10s in the 1/4 @ 130+mph

 

Last time my car was run was late in 2000 in full street trim and it ran 10.4 @ 140 mph. It has been in multiple pieces since that time and it is doubtful that it will run again.

When I was with the "other" company I built a customer's car who unoffically ran a 9.89 @ 143 Mph. I say unoffically because I have seen the slip but the customer doesn't want it posted since he is a big street racer . That car was also full street trim with full interior, stereo w/sub, A/C, Power steering, etc....

 

I was thinking the exact same thing, Todd. You would be well over 600whp+ (true whp at sea level) with the addition of some cams...at this boost level. On my car, with cams, porting work, but stock valves, I am pushing 622whp at just 16.5psi of boost, and 589whp at 15.5psi. These numbers would not be possible, at these boost levels, without cams, at a minimum. When I tuned Paul's car with stock cams, built motor, we only acheived about 520whp at 15psi. Still great numbers, but the cams really open things up significantly, particularly at higher boost.

McDucks car is another great example. 450whp+ at just 8-9psi with a Vortech SC.

 

ya whatever guys, i hate you all...


j/k!!!

just wanted to be a smart a$$ and post the power past 5500 rpm continuing to ramp up!!!!

on my next darton sleeved motor, ill through in some cams and make 800wheel hp...then what!?

 

I mean ur power continues to climb quite a bit, but your trq settles down a little, which probably has plenty of reasons? Im really looking to have a trq curve that after the boost is fully built, is very horizontal. I'm gonna have to do a lot of research. But, your dyno is one of the beter ones ive seen.. unlike the untuned jwt tt one (which when tuned is awsome^2), and a lot of APS ST ones.

edit..i reread and it sounds like im hating on jwt tt and aps st...i'm not, its just the nature of the tune for jwt tt (from the dyno that was posted here that stopped at 5250), and i'm not sure of the aps st.

 

Hey plump. There are several reason for the trq drop off. Namely the mechanical design of the motor, and more importantly, the tune. Trq tends to drop off becuase the timing cannot be sufficiently advanced without resulting in detonation on pump fuels. If you retuned this car with race fuel, and added significantly more timing up top, the result would be a much flatter trq curve.

In fact, a lot of tuners will tune AF's first, and then keep adding timing until the to the point at which the power/trq starts to fall off between runs. This is a sign of reaching the detonation limit, as engines that are detonating produce less power. One sign of an excellent and safe tune, and a well built motor/cam/head setup is a motor that continues to make power, nearly to redline.

Power that drops off prematurely is a sign of imminent danger...especiallly on high boost cars.

 

sharif

u know im not detonating where the tq falls off...don't be silly
that's my motor suffocating

 

Ahhh...damn tune has so much to do with everything... Why wouldnt a tuner purposley pull timing from the bottom so the torque curve is more linear on a Turbo car?

 

Oh I know..in your case.....you are helpless!! hahaha...

 

You are correct, they do this all the time. I am just refering to the point after the trq peak...as redline approaches....and the area were peak power is going to be made.