I am a frequent troll on quite a few Subaru-centric websites and I often stumble upon people tossing turbos on cars that were originally naturally aspirated. I have absolutely no experience with turbocharged gas engines and the only turbo diesels I have worked on had air brakes so my knowledge of the subject is not applicable.
My question is this: What happens to your vacuum operated accessories (brakes for instance) when you add forced induction?
I don't care if this makes me look like the most ignorant noob on the planet, I MUST KNOW!!
Check valves keep boost out of places that need vacuum, e.g., brake booster, PCV valve, vac-controlled HVAC flaps (via an accumulator tank), etc.
Most of the time, a turbocharged car isn't actually under positive pressure conditions; only when accelerating, and even then, some cars don't see much boost unless you lay into it.
yup.
nothing happens to them. most cars have a factory check valve on the booster, and that works fine.
proper tuning is most people's biggest problem.
procainestart wrote:
Most of the time, a turbocharged car isn't actually under positive pressure conditions; only when accelerating, and even then, some cars don't see much boost unless you lay into it.
That's the important part. Turbo cars don't run boost all the time, only when you ask for it.
If you are running boost long enough to lose all vacuume in your accessories.. you have bigger problems to worry about
You've never towed through the mountains with a Toyota truck with a homebrew turbo kit and a big race trailer, have you? That thing would stay in boost from gas station to gas station. The cruise didn't really work at all.
However, most people let off the gas when braking, and your vacuum comes back when that happens to help with the brake booster.
This is what happens when you boost a NA motor:
In reply to furcylndrfoury:
So what happens when you boost a NB engine?
Esprit Turbos have a separate vacuum pump. It is the same part as used on GM Diesel trucks (pickup sized).
forged Hbeams = teh sek-z
I've tracked my turbo'ed Miata quite a few times and never noticed a problem with my vacuum powered brakes.
furcylndrfoury wrote:
scardeal wrote:
In reply to furcylndrfoury:
So what happens when you boost a NB engine?
I LOL'd.
That's not my department," says Wernher von Braun
Thank you gentlemen, it seems I was all worked up over nothing.
What were you planning on putting a turbo on? As some cars tend to take being turbo'd better then others.
Andrew
I wasn't planning to turbo anything I just didn't know if there were any drawbacks to plopping a turbo on a car that was not originally equipped with one.
NGTD
HalfDork
5/6/10 11:10 a.m.
It depends on the engine. Volvo guys do +T's all the time.
I have been warned away from doing it on my B23E though 10.3:1 compression from the factory plus a turbo is not likely to lead to a good outcome.
Overbuilt engines like Volvo's work out well. Other cars that are already close to being maxed out blow up like crazy.
some times even those aren't enough.......
oldeskewltoy wrote:
some times even those aren't enough.......
Damn. You proper-berkeleyed that one.
