Uh oh.... overported!
#26
Daily Domestic Killer
Join Date: Mar 2001
Location: San Antonio, Tx, USA
Posts: 2,425
Likes: 0
Received 0 Likes
on
0 Posts
I just made mine the size of the flapper door, and made the inside of the wastegate hole more rounded so the exhuast doesn't have to make 2 90 degree turns like Ted says, it pretty rounded to about 60 degrees or less on both sides, although now my boost bleeds, of coarse I get know spike but if I crank up my MBC to 12psi, it shoots up there pretty quick but only stays there for like 1k rpms then begins to bleed to about 6-7 psi by 7k rpms, is this normal for a ported wastegate?
#27
10 lb. boost, 5lb. bag
iTrader: (1)
Originally posted by BlackRx7
I just made mine the size of the flapper door, and made the inside of the wastegate hole more rounded so the exhuast doesn't have to make 2 90 degree turns like Ted says, it pretty rounded to about 60 degrees or less on both sides, although now my boost bleeds, of coarse I get know spike but if I crank up my MBC to 12psi, it shoots up there pretty quick but only stays there for like 1k rpms then begins to bleed to about 6-7 psi by 7k rpms, is this normal for a ported wastegate?
I just made mine the size of the flapper door, and made the inside of the wastegate hole more rounded so the exhuast doesn't have to make 2 90 degree turns like Ted says, it pretty rounded to about 60 degrees or less on both sides, although now my boost bleeds, of coarse I get know spike but if I crank up my MBC to 12psi, it shoots up there pretty quick but only stays there for like 1k rpms then begins to bleed to about 6-7 psi by 7k rpms, is this normal for a ported wastegate?
#29
any pics?
Is there anyone who has before and after close-ups of their ported wastegate? If so could you post them or please send them to RTGavin@aol.com
#30
creep is when you barley press on the gass, and boost goes up crazy
When I was porting mine, I made it so the flapper sits inside of the hole. There is no way its going to get stuck in there (left ample room for metal expansion) but the hole is not 25% bigger than the flapper. Best of both worlds... I guess.
#31
Full Member
Join Date: Oct 2002
Location: spring hill, tennessee
Posts: 142
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by 88IntegraLS
Ok, I give up. All you turbo guys talking about this stuff is making me sick.
I am going to install a turbo on my NA.
Ok, I give up. All you turbo guys talking about this stuff is making me sick.
I am going to install a turbo on my NA.
#32
Full Member
Join Date: Dec 2002
Location: seven heaven
Posts: 148
Likes: 0
Received 0 Likes
on
0 Posts
hey guys, I use a profec A and set to about .7 bar it'll over boost to 1 bar on first on a majorly quick luanch. Is this caused by the wastegate flap being too small?
It happens on other gears too, but not to that extent. maybe 3-4 psi.
Profec ! has fuzzy logic functions, to eliminate boost creep, and also has a active boost sensor on it.
It happens on other gears too, but not to that extent. maybe 3-4 psi.
Profec ! has fuzzy logic functions, to eliminate boost creep, and also has a active boost sensor on it.
#33
Rotary Enthusiast
Join Date: May 2002
Location: Boston
Posts: 1,203
Likes: 0
Received 0 Likes
on
0 Posts
Mine runs at 12psi all the time, but it falls off at high revs too. The turbo is running out of breath at that range, it's nothing to do with the wastegate...
Last edited by RylAssassin; 04-17-03 at 08:31 AM.
#34
10 lb. boost, 5lb. bag
iTrader: (1)
Assassin... was your motor ported? Mine is, that may have something to do with it. If the motor breathes better at high rpm under boost, the apparrent boost in the manifold will be less. ****, I can get 12psi at 2000 rpm in 5th gear because the air has nowhere to go at that low rpm. (not recommended!)
I don't think WG has much to do with max boost unless it's getting pushed open by the exhaust pressure even when it's supposed to be 100% closed, which can happen
I don't think WG has much to do with max boost unless it's getting pushed open by the exhaust pressure even when it's supposed to be 100% closed, which can happen
#35
SCCA Rookie
Join Date: May 2001
Location: Sterling Heights, MI
Posts: 1,936
Likes: 0
Received 0 Likes
on
0 Posts
Whatever you do, remember, doubling the radius of the hole will increase the area for air to flow through exponentially.
area = pi * r ^ 2 (r ^ 2 is r-squared)
Same principle for exhaust.. Going from a 2.5" pipe to just a 3" pipe adds almost 50% to the area the gas has to flow through.
2.5" pipe area - 4.9087
3" pipe area - 7.0685
Going from 2" to 3" more than doubles the area. (3.1415 for 2" pipe)
So adding some size to the porting helps a LOT more than it looks like to the eye.
area = pi * r ^ 2 (r ^ 2 is r-squared)
Same principle for exhaust.. Going from a 2.5" pipe to just a 3" pipe adds almost 50% to the area the gas has to flow through.
2.5" pipe area - 4.9087
3" pipe area - 7.0685
Going from 2" to 3" more than doubles the area. (3.1415 for 2" pipe)
So adding some size to the porting helps a LOT more than it looks like to the eye.
Thread
Thread Starter
Forum
Replies
Last Post
sleeples
3rd Generation Specific (1993-2002)
4
05-29-07 02:30 PM
fc3sxtasy87
2nd Generation Specific (1986-1992)
15
08-11-05 05:19 PM