SPOautos

Hey guys I'm working on a cold air set up and have a question. I realize this isnt single turbo spacific but I also realize where the folks with the most knowledge hang out so mods please dont move this.

Anyway, the intake is going to have a fiberglass airduct drawing air from the front of the car thats basically going to create a ram air. My question is this, If I'm going 150mph at a track is this going to be bad??? Or even if I'm cruising at 85 and under vacume. It seems as though the ram air is going to basically create pressure in the intake pipes. I guess it depends on how much and fast the turbo moves the air. If my ram is more than that will it pressurize in front of the turbos? Will it make the turbos spin faster? I guess not cause the exhaust will control that.

What potential problems am I looking at if any????

Is ram air a bad thing for turbo cars???

Thanks a ton!!!
STEPHEN

rotorbrain

i replied to this on the 3rd gen forum. i think its a good idea.

paul

SPOautos

I'm also thinking it would be ok but I just though I would make sure. I guess my main concern is really in a cruise mode when I'm going 90mph on the interstate and under vacume.....is the ram air going to try and create boost or will the turbo block it?

I guess if it doesnt work good I can take it out but its going to be a lot of work to make and I was hoping there were some examples for daily driven ram air turbo cars.

STEPHEN

SPOautos

So basically either people must think I'm a dumb *** for thinking about this and dont want to waist thier time discussing it OR no one knows.

Maybe the right person just hasnt read it yet. I'll keep pushing it up in hopes that the right person will read it lol

STEPHEN

peejay

It wouldn't hurt. Any gains in PSI at the inlet would be minimal at best. Besides, the wastegate would handle any "over PSI", and anyway the turbo would have to work less for the same manifold pressure - less air heating. This in addition to the colder air going into the turbo in the first place.

Don't worry about when you're under cruise. If the engine makes "too much" power, you will reduce throttle to compensate and maintain speed. No problems.

rotorbrain

well, i made a post to the same thread in the 3rd gen forum, but it got deleted evidently. that sucks. i said basically the same thing that peejay said. adding a little more about looking iinto port velocity as a way to make the ram air tube as efficient as possible. sure a tube running to the front of the car would work, but why not make it over-engineered, ya know!!! this would only benefit the turbo(s). id say that throttle response would go up significantly due to the air readily available to the comp. wheel. im gonna look into something like this too. have fun.

paul

maxcooper

Ram-air would be fine with a turbo. Don't worry about unwanted boost -- it won't make any. If properly executed (which is harder than it sounds -- aero isn't simple) you should get some increase in pressure at the compressor inlet, but that might really mean less vacuum rather than actual boost. The turbo will have to do less to make your target boost level, which will reduce the backpressure in the exhaust manifold (= more power at same boost level), and as peejay said it will reduce the temp at the compressor outlet becuase the air needs to be compressed less. But don't expect the changes to be large or even measureable without sensitive instumentation. It isn't going to give you 3 psi at 90 MPH or anything like that. Go for cool air with an unobstructed path to the turbo inlet first. If you get some ram air, that would be a nice benefit, but probably not a huge effect.

So, there is no problem, but don't expect a huge gain from the ram effect. The biggest benefit may simply be that the intake air is cooler, but that is a positive effect, too.

-Max

SPOautos

Awsome, this is pretty much in line with what I was thinking I just needed a little confirmation.

And yea, I'm really doing it just for the cold air but have a feeling the design I came up with is going to create ram air......I guess we'll see!!!!

Thanks so much guys!!!!
STEPHEN

rotorbrain

rock-n-roll stephen!!!! i was coming up with some drawings last night while at work (and no i wasnt doing what i was supposed to, haha). this is something for me to think about. i havent had anything to mess with in a while. . . its really been driving me crazy.

max- in the other post on the 3rd gen forum (which was deleted) i made some comments just like you are saying. about the turbo not having to work as hard to move the same amount of air. it would have a surplus to pull from with the ram air. im glad that my assumptions (and i say that because i have had no schooling on any of this past highschool, haha) were at least agreed with if not correct. i came up with something that i think will work using a sort of expansion chamber effect. i dont want to say anything right now cause my car is still down and i will wait till i get it running to try all of this. thanks also. . . and thanks stephen again for bringing this up as i have a new toy to tinker with. haha.

paul


oops!!!!!!!! almost forgot the signature. haha.

SPOautos

LOL, cant forget the sig!!!!

Maybe we can have our intakes done by Nov and compare!!!! I'd like to see what you come up with.

STEPHEN

rotorbrain

sounds like a good idea. . . ill be having a couple of other goodies that ill reveal in nov also. haha. did we ever get those dates checked out. i need to know as i might have drill on that weekend. i can make it up no prob (i hope), but i need to be sure. have fun.

paul

ill let the sig slide on this one. . . since it was only a post ago. haha.