I went down to Courtenay Sport yesterday to have my car looked at. I hadn't felt very quick recently so I wanted then to check it out and also fit a VXR AFM.
I got up at 4am and headed up there with my mate Paul. About 10 miles from Courtenays, my radiator sprang a big leak - great!
I managed to get to Courtenays who got straight onto finding a radiator locally and sorting out this problem first. The radiator that was delivered was missing a few essential brackets for use with the Z20LET, so it was then taken to a place to weld on the required brackets. Once done and fitted, we threw the car on the rollers.
I am running CS4 with a Regal inlet cam, and was interested to see what the cam was doing. Well, it turns out that the cam was doing very little. The graphs was almost identical to other cars with CS4 but with a standard inlet cam - although I had lost some torque at around 4000rpm.
One thing that became apparent is that I had plently of power, I was simply feeling the drop in torque, which didn't feel good on the road.
Anyway, the VXR AFM was then fitted, along with 80mm Samco Extreme induction hoses. Back on the rollers, the curve looked prety much the same, except the torque dip reduced (although not at good as non Regal cammed CS4 graphs), but on the upside, the power held on for a fair bit longer - possibly an extra 1000rpm.
On the road the car felt much better as the dip was less pronounced and the power held on for longer. Spinting was now much better and drivability was much better thanks to adjustments to the base CS4 map.
In conclusion, the Regal cam made little difference below 5500rpm, in fact lost a bit of torque at 4000rpm, but the cam did cause power to be held for longer.
Regal claim an increase of 40bhp with this cam - I saw no such thing. The cam made no increase in power at all, but did hold the power the engine already had for a bit longer.
The loss in power low down verses the increase at the top is down to personal preference really. My setup with the Regal cam would be better for high rev sprinting, but the standard cam would be better for on the road drivability. To add to this, the Regal cam makes the idle a little lumpy. I guess you had to decide what you want to use your car for.
I'm not going to bother removing the cam to gain some torque. At least I know things are running ok now.
I big big thankyou to the guys at Courtenay Sport for sorting out the radiator problem and sticking around till 8pm until the car was finished - great service!!