Back from the track with the daily driver 9.88@144mph
So, this past couple of weeks we put a ported head on it with 1mm over sized valve. The head was flow benched here locally and the flow bench showed a 15cfm average gain, not much but it is some. However. The car is making no more power then it did before and has got me kinda stumped. It has a bottle neck somewhere.
Could be the turbo is just out of steam at this point or the stock throttle body is really holding me back. But I just can't see how the throttle body would be such a huge bottle neck.
I still have yet to make a turn down pipe off the downpipe and run open exhaust to see if that helps any. Last time I disconnected the cat back from the down pipe with the stock head it seemed it lost power, and I thought that was really odd. Put the cat back back on and the power came back..
I really need to bung the manifold and measure my back pressure to see where I'm at. But then again I would think if I was creating so much back pressure, taking the catback off the down pipe it should have gained power, not loose it. I dunno. I've tried adding timing, taking away timing, adding boost, taking away boost, leaning it out, riching it up and nothing. Just can't seem to make anymore power with this setup for some stupid *** reason!
Could be the turbo is just out of steam at this point or the stock throttle body is really holding me back. But I just can't see how the throttle body would be such a huge bottle neck.
I still have yet to make a turn down pipe off the downpipe and run open exhaust to see if that helps any. Last time I disconnected the cat back from the down pipe with the stock head it seemed it lost power, and I thought that was really odd. Put the cat back back on and the power came back..
I really need to bung the manifold and measure my back pressure to see where I'm at. But then again I would think if I was creating so much back pressure, taking the catback off the down pipe it should have gained power, not loose it. I dunno. I've tried adding timing, taking away timing, adding boost, taking away boost, leaning it out, riching it up and nothing. Just can't seem to make anymore power with this setup for some stupid *** reason!
The turbo is prob runnin out of breath, if that dyno is near accurate then u have one of the highest 3586 hp numbers ive seen, unless u put on a 3794 or 6765 u may not get much more power from this turbo
So, this past couple of weeks we put a ported head on it with 1mm over sized valve. The head was flow benched here locally and the flow bench showed a 15cfm average gain, not much but it is some. However. The car is making no more power then it did before and has got me kinda stumped. It has a bottle neck somewhere.
Could be the turbo is just out of steam at this point or the stock throttle body is really holding me back. But I just can't see how the throttle body would be such a huge bottle neck.
I still have yet to make a turn down pipe off the downpipe and run open exhaust to see if that helps any. Last time I disconnected the cat back from the down pipe with the stock head it seemed it lost power, and I thought that was really odd. Put the cat back back on and the power came back..
I really need to bung the manifold and measure my back pressure to see where I'm at. But then again I would think if I was creating so much back pressure, taking the catback off the down pipe it should have gained power, not loose it. I dunno. I've tried adding timing, taking away timing, adding boost, taking away boost, leaning it out, riching it up and nothing. Just can't seem to make anymore power with this setup for some stupid *** reason!
Could be the turbo is just out of steam at this point or the stock throttle body is really holding me back. But I just can't see how the throttle body would be such a huge bottle neck.
I still have yet to make a turn down pipe off the downpipe and run open exhaust to see if that helps any. Last time I disconnected the cat back from the down pipe with the stock head it seemed it lost power, and I thought that was really odd. Put the cat back back on and the power came back..
I really need to bung the manifold and measure my back pressure to see where I'm at. But then again I would think if I was creating so much back pressure, taking the catback off the down pipe it should have gained power, not loose it. I dunno. I've tried adding timing, taking away timing, adding boost, taking away boost, leaning it out, riching it up and nothing. Just can't seem to make anymore power with this setup for some stupid *** reason!
I honestly think that dyno reads a bit high. VDR shows my car making 770-780whp. And that would seem about right for my setup and the numbers it runs at the track with the weight of the car at almost 3400lbs.
I also think your right about the turbo just being out of poop
I also think your right about the turbo just being out of poop
No bent valves, the broken guide was on the intake side of #3 cylinder. Surprising enough, there was a broken guide on #4 cylinder intake side as well
Some of the guide did make through the motor as there were little nicks in the piston top, nothing too major or alarming enough to change the pistons.On another note. I went out testing on a side road today, put the boost at 38lbs and the wastegate went soft/quite at that boost level. So this leads me to believe the turbo is just out of steam at this point since the waste gate is staying more on the closed side to maintain the 38lbs of boost. So I guess it's time to go bigger. Not sure if I wanna try and push these eagle rods any further then I am though
I'm shocked these rods are taken it at this point (knock on wood)
Welp, I found my source of power loss. After 25k miles the exhaust housing bolts/shims that hold the center section to the exhaust housing backed out, one is completely gone and the rest are backed out. I started to hear a clicking noise today after a couple hard pulls trying to figure out why it was laggy and wasn't making the same amount of power as it was with the stock head..
So off the turbo comes tonight to fix it, hopefully it didn't do any damage to the back plate on the exhaust wheel side or the exhaust wheel itself.
I guess all of those passes I have made on this setup the bolts just rattled themselves loose lol.
So off the turbo comes tonight to fix it, hopefully it didn't do any damage to the back plate on the exhaust wheel side or the exhaust wheel itself.
I guess all of those passes I have made on this setup the bolts just rattled themselves loose lol.
Evolved Member
Joined: Aug 2006
Posts: 1,427
Likes: 4
From: Sag-Nasty, MI
Anything above 37-38lbs the car starts to make less power since the turbo is just out of breath at that point. I can actually feel the car nose over a tad anything above 38lbs.
And Patrick, next outing if everything goes well will be this Saturday. I degreed the cams last night then started to play around with the cam timing tonight. Going to finish up the cam tuning tomorrow if things go well.
It's amazing how much different the car feels with this new head. In some spots the car feels flat, and other spots the car feels stronger, kinda hard to explain, but I'm sorting out the tune now since things have changed a bit, not much, but some. Mostly timing has changed since the head has been shaved a lot and with the cams degreed it has moved the power band a bit.
Good god, I might as well go bracket racing with this thing! Ran today
run #1 1.53 60ft 9.90 @143mph
run #2 1.52 60ft. 9.89 @144mph
run #3 1.58 60ft. 9.92 @144mph
Everytime I go out to race it runs from 9.88-9.93 every single pass and every time I go out. I just can't seem to get it any faster ha. I need to go bigger turbo.
http://www.youtube.com/watch?v=hjU6lPQL49s
run #1 1.53 60ft 9.90 @143mph
run #2 1.52 60ft. 9.89 @144mph
run #3 1.58 60ft. 9.92 @144mph
Everytime I go out to race it runs from 9.88-9.93 every single pass and every time I go out. I just can't seem to get it any faster ha. I need to go bigger turbo.
http://www.youtube.com/watch?v=hjU6lPQL49s