RB25 turbo conversion on RB20?

[Cool Hand Luke]

25% increase where in the rev range? Its a common mistake, especially on naturally aspirated engines too go for to large a cam which gains top end power, but sacrifies too much bottom end/midrange which in effect makes the car alot harder to drive, and unless is screaming, less powerful. The RB's arn't under-developed like all the push rod dinasours, meaning that i would be sceptical with the money and research nissan put in and the power gains people claim on standard engines especially.

[Cubes]

Just for comparison last night on the way home from work I was looking at where the car would start to pull hard and make full boost.

Pulling out of a corner in second gear from around 2000rpm It wouldn't really get going until 4000rpm. It would make full boost by 3500rpm.

Some thing didn't feel right as I've got that damn hesitation back that disappears at around 5500rpm and then pulls to redline..

[J.B.E]

Originally posted by Cool Hand Luke

25% increase where in the rev range? Its a common mistake, especially on naturally aspirated engines too go for to large a cam which gains top end power, but sacrifies too much bottom end/midrange which in effect makes the car alot harder to drive, and unless is screaming, less powerful. The RB's arn't under-developed like all the push rod dinasours, meaning that i would be sceptical with the money and research nissan put in and the power gains people claim on standard engines especially.

Well i'm not to sure about exactly where in the rev range the extra power is claimed to be but i'm guessing that would be similar to the standard power band but last slightly longer through the rev range. they make the cams so they can run on the factory computer and factory valve train. So for $400 nz thats not to bad considering what people spend to get slight increases in power. An average exhaust system is around $800 here. :burnout:

[Cool Hand Luke]

Some thing didn't feel right as I've got that damn hesitation back that disappears at around 5500rpm and then pulls to redline..

Did you find out what the hesitation was caused by?

[Cubes]

Origionally the fuel reg. closest to the firewall had its vacume hose off so it was leaning out.

I've lost power every where since I fitted this Bosh 910 fuel pump as it just runs to rich, it pops and farts all the time some times loud enough to sound like its a good old Key banger like I used to do in the old Cortina.. Drive a long turn off the motor pump the accelerator turn the key back on and BANG!. The old days when I was 16.

[Cool Hand Luke]

Nothing wrong with the ole' key bang. My car pops as loud as a key bang almost every time i drive it as it has a gutted cat. Only when the exhaust is hot, but when i accelerate, and start slowing down i just have to tap the throttle and it goes BAAANG! Good for a laugh and in busy closed spaces such as cities:)

[Cubes]

I did one with the ol' Cortina quite a few years ago now and it started running on 5 for a little while then smoothed out and all was fine again. Don't know what happened there.?!?!?