Boost bleed
#1
Registered User
Thread Starter
Join Date: Jul 2004
Location: N. Cacalacky
Posts: 122
Likes: 0
Received 0 Likes
on
0 Posts
Boost bleed
Humor a newb for a second.
Correct me if I'm mistaken, but Comptech/Vortech blowers are efficient up to ~15ish psi. However, this isn't practical for our application due to 11.1 compression. Swapping internals and thicker head gaskets aside, why not run a ridiculously small pulley spinning 15 psi as early as let's say, 3-4k rpm but bleed off the excess boost and only push 5,6,7,8psi or whatever into your engine. Right from a dig you'd be at full boost. You'd have a torque monster at lower rpm and essentially identical performance at upper rpm compared with a stock pulley'd blower unit building up to and finally hitting 6-7psi at redline.
Thoughts?
-Slippy-
Correct me if I'm mistaken, but Comptech/Vortech blowers are efficient up to ~15ish psi. However, this isn't practical for our application due to 11.1 compression. Swapping internals and thicker head gaskets aside, why not run a ridiculously small pulley spinning 15 psi as early as let's say, 3-4k rpm but bleed off the excess boost and only push 5,6,7,8psi or whatever into your engine. Right from a dig you'd be at full boost. You'd have a torque monster at lower rpm and essentially identical performance at upper rpm compared with a stock pulley'd blower unit building up to and finally hitting 6-7psi at redline.
Thoughts?
-Slippy-
#2
I believe that they did do something like this in the 50's and 60's with pop off valves. I'm not sure why they quit using them. I have some thoughts on it, but nothing coherent enough to post. I think there's plenty of research that would support this as either a good or bad idea.
Tim
Tim
#3
Registered User
Thread Starter
Join Date: Jul 2004
Location: N. Cacalacky
Posts: 122
Likes: 0
Received 0 Likes
on
0 Posts
I just had another thought that goes against what I had said earlier. If the blower was pushing 15psi @ 3000rpm it would putting out 45psi at redline so that's not going to happen with either Comptech's or Vortech's. I guess you'd have to size a pulley that would spin 15psi at redline and bleed that off once you hit whatever you were trying to run. The effect I was talking about earlier wouldn't be as pronounced but I'd imagine it'd still be quicker than slowly building up to 8psi from zero. You'd probably be running at 8psi around 5000rpm. But wow, would you be in a world of hurt if you redlined with the blow off/bleeder valve stuck shut. Boom...
#4
i imagine that the parasitic losses from spinning the blower that fast in the upper rpm range would make this very impractical.
i've noticed everyone around here wants to reinvent the wheel. there's no way to have your cake and eat it to. if you want a nice featherweight car you're going to have to make some sacrifices. if you want torque downlow and hp up top, you should have gotten a V8.
the best compromise is a mid sized custom turbo setup. you should be able to hit boost before 3k rpms, and have a nice healthy torque curve from there throughout the rev range.
i've noticed everyone around here wants to reinvent the wheel. there's no way to have your cake and eat it to. if you want a nice featherweight car you're going to have to make some sacrifices. if you want torque downlow and hp up top, you should have gotten a V8.
the best compromise is a mid sized custom turbo setup. you should be able to hit boost before 3k rpms, and have a nice healthy torque curve from there throughout the rev range.
Thread
Thread Starter
Forum
Replies
Last Post
12gage
S2000 Under The Hood
4
10-30-2002 02:00 PM