HomemadeTurbo - DIY Turbo Forum - All motor cams in a turbo setup? work?

Some all motor cams work great, others don't. Depends on the engine/setup.

The Crower 402 is a very mild cam, I've had a large amount of success with turbo LS + 403s and hear good things about LS with 404s. Your B20 is just an LS with a bigger bore.

It is VERY easy to overcam a turbo engine. The BRMS racecar ran Brian Crower stage 2 NA cams for a hot minute. With their old stage 2 turbo cams the car made 405 whp @ 11 psi, with the NA units 417 whp @ 11 psi, nothing else changed. The very first pull the engine would bog or miss for a second, but once heat soaked it made power reliably and repeatably (up to a point). As soon as the boost controller turned on spool became delayed, but power was still excellent into the 550 whp area. In the low to mid 600 whp range the car would fall on it's face momentarily in mid-spool as power was coming up hardest. I ended up getting 767 whp out of it but the power band was garbage and it was obvious the car didn't run right.

Uhm, 8.5:1 CR B16 with Skank9 stage 2 cams and a T67. It barely pulls 14 in/Hg at idle, and getting the car to idle is a pain in the booty hole. Cam gear settings were completely retarded and I had to dial a lor of overlap out to spool or make any power, something like +2.75/-5 for int/exh. Best idle was incidentally at this setting. It makes around 300 whp at 10 psi, maybe a hair more, and will make 510-525 @ 30 psi when I get another MAP sensor on it next week (made 492 @ 8000 rpms when it hit 29 psi boost cut, engine peaks at 8600 revs to 9200, easy 510+ at 29 psi alone). It's fun to drive but if you try to take off from a standstill without revving to 3K+ and slipping the clutch it stalls. Once going it has nice off boost power (spools at 5K lol) as long as you don't try any low rpm nonsense.

For any of the Honda B-series, whether VTEC or not, aiming for something around a GSR or ITR profile (403-404 for LS) is ideal unless you're going 600+. 403s pull a good amount of vacuum at idle and have great manners, 404s can be wierd. Some LS w/ 404s I can get to idle stable at 800 rpms and you can't detect any lump and the car just makes nice power. Others are somewhat bumpy and need to be idled at 1000, with some idle consistency issues due to vacuum drifting a little bit.