dynoed today, questions???
08-08-05, 05:43 PM
#1
dynoed today, questions???
that run is at 9psi. fell to 7psi by 7500 (maybe even less)
mods are in sig. afr's around 10.8:1.
seems like a reasonable amount of power to me, but there was definatly much more potential.
as you can see the torque falls off REALLY huge after 5500... any ideas why? it's a pretty big compressor, the torque/boost shouldn't be falling off so badly....
08-09-05, 12:21 AM
#3
Senior Member
Join Date: Jan 2003
Location: Alberta
Posts: 430
Likes: 0
Received 0 Likes
on
0 Posts
Thats all you put down with a T04b? That seems rather odd. As stated in my sig. i put down 232 RWHP and 219 RWTQ with boost leaks and a turbo that was ready to be dumped into a garbage can. Now when i dynoed, my peak Hp was at 5800rpm as well and the boost did drop.
Did you get an A/F reading at all when you dynoed? You could be really rich and thats whats cuttin your power? But somehow i dont think so.......
Did you get an A/F reading at all when you dynoed? You could be really rich and thats whats cuttin your power? But somehow i dont think so.......
08-09-05, 10:14 AM
#7
as I posted above, AFR's are 10.8:1. The reason for the lack of power up high is most certainly the lack of boost up high (6psi at 7500!)
engine is stock, unknown s5 j-spec shortblock. 20" of vacuum at idle, ~110psi compression. Seems to be in really good shape.
2: turbine is STOCK.
3: exhaust system: 3" DP, 2.5" MP, 2.5" Y to dual 2.5". mufflers are 3" in and 3" out, straight through design.
not sure if this matters, I'm running the stock TMIC. going with water injection soon.
p/s and a/c are intact, but I'm sure that doesn't matter at all lol
engine is stock, unknown s5 j-spec shortblock. 20" of vacuum at idle, ~110psi compression. Seems to be in really good shape.
2: turbine is STOCK.
3: exhaust system: 3" DP, 2.5" MP, 2.5" Y to dual 2.5". mufflers are 3" in and 3" out, straight through design.
not sure if this matters, I'm running the stock TMIC. going with water injection soon.
p/s and a/c are intact, but I'm sure that doesn't matter at all lol
Last edited by Terrh; 08-09-05 at 10:19 AM.
Trending Topics
08-09-05, 10:32 AM
#8
Lives on the Forum
Originally Posted by Terrh
2: turbine is STOCK.
The stock turbine section is choking the flow.
This is why the torque peaks quickly, and why it plummets so quick approaching redline.
-Ted
08-09-05, 10:40 AM
#9
so the stock turbine isn't capable of spinning that compressor to more than 6psi at 7000RPM?
even though on the (stock) compressor it would spin it to ~17PSI by that time if I let it (aware that that's neither good nor healthy, just that it would happen)
even though on the (stock) compressor it would spin it to ~17PSI by that time if I let it (aware that that's neither good nor healthy, just that it would happen)
08-09-05, 10:46 AM
#11
no.
all I did with the wastegate was attach it to that compressor housing and put it on the actuator.
the wastegate is ported (very much). The arm seemed to be the right length allready, like, it fit right on the wastegate lever, with no hassle or anything. I'm using a strange vacum source for the WG, not sure if that matters.
I've got it plumed with a T into one of the lines from the I/C out the back (s4 intercooler). to the MBC, then to the WG. I'm using a pretty "big" (dia) vacuum line too, not sure if that matters or not as well.
all I did with the wastegate was attach it to that compressor housing and put it on the actuator.
the wastegate is ported (very much). The arm seemed to be the right length allready, like, it fit right on the wastegate lever, with no hassle or anything. I'm using a strange vacum source for the WG, not sure if that matters.
I've got it plumed with a T into one of the lines from the I/C out the back (s4 intercooler). to the MBC, then to the WG. I'm using a pretty "big" (dia) vacuum line too, not sure if that matters or not as well.
08-09-05, 10:49 AM
#12
Super Raterhater
iTrader: (6)
Join Date: Dec 2001
Location: NY, MA, MI, OR, TX, and now LA or AZ!
Posts: 10,624
Likes: 0
Received 2 Likes
on
2 Posts
You probably will want to modify the arm by drilling a new hole, so that there's more tension on the arm. A lot of us had problems with the wastegate opening on it's own. I usually drill about 1.5cm or so (been a while) higher, then reattach.
08-10-05, 12:15 AM
#14
1.5CM seemed a little extreme... I hammered the rod flat (boy was that a PITA lol) and then drilled a hole about 1CM further up, and put it on. the issue didn't TOTALLY disappear, but it did help significantly! I had to re-adjust the MBC after, of course... Boost is now 9.5PSI midrange and 8.5PSI at high RPM... car pulls about the same but MUCH better up high! feels like it's making peak HP in the low 7000's...
I had to take it off the car (that sucked
) ..... and I could have gone another 5mm at least I think, it doesn't have much tension on it really, just a tiny bit.. looking back, it was clearly too long in the stock position.
the lag seems to have cleared up a bit as well, though it still doesn't make 10PSI until 3500RPM...
I had to take it off the car (that sucked
) ..... and I could have gone another 5mm at least I think, it doesn't have much tension on it really, just a tiny bit.. looking back, it was clearly too long in the stock position.the lag seems to have cleared up a bit as well, though it still doesn't make 10PSI until 3500RPM...
Last edited by Terrh; 08-10-05 at 12:18 AM.
08-10-05, 12:23 AM
#15
Originally Posted by jacobcartmill
if you have a stock turbine and housing, you're choking your engine in the high rpms. thats why the power falls off so bad... why does no one realize that hybrid stockers suck?
did nobody catch this the first time i posted it?
08-10-05, 03:30 AM
#18
Super Raterhater
iTrader: (6)
Join Date: Dec 2001
Location: NY, MA, MI, OR, TX, and now LA or AZ!
Posts: 10,624
Likes: 0
Received 2 Likes
on
2 Posts
Originally Posted by jacobcartmill
if you have a stock turbine and housing, you're choking your engine in the high rpms. thats why the power falls off so bad... why does no one realize that hybrid stockers suck?
08-10-05, 09:31 AM
#21
Super Raterhater
iTrader: (6)
Join Date: Dec 2001
Location: NY, MA, MI, OR, TX, and now LA or AZ!
Posts: 10,624
Likes: 0
Received 2 Likes
on
2 Posts
Haha, yeah, I'm just giving Cartmill a hard time because he knows my car running on a hybrid would probably stomp his car at the moment.
However, is that turbine clipped, or 100% bone stock?
However, is that turbine clipped, or 100% bone stock?
08-10-05, 02:45 PM
#25
Originally Posted by jacobcartmill
if you have a stock turbine and housing, you're choking your engine in the high rpms. thats why the power falls off so bad... why does no one realize that hybrid stockers suck?
That is part of the equation, but his set-up can still be improved even with the stock exhaust turbine and housing.
Reducing intake restrictions (porting TB, better flowing IC and piping, ditching/re-locating AFM, etc) will help the top end as well reducing intake pressure drop means the exhaust side has to work less hard to power the compressor.
if you have a stock turbine and housing, you're choking your engine in the high rpms. thats why the power falls off so bad... why does no one realize that hybrid stockers suck?
That is part of the equation, but his set-up can still be improved even with the stock exhaust turbine and housing.
Reducing intake restrictions (porting TB, better flowing IC and piping, ditching/re-locating AFM, etc) will help the top end as well reducing intake pressure drop means the exhaust side has to work less hard to power the compressor.