No Power.
Not if there is a major boost leak. Impeller speed will be maxed out drastically increasing charge air heat and backpressure.
But my intake temps are low. The only leak I have is from the t-body shaft. How long should it take for it to leak down once pressurized? Mine leaks 10psi out in 10-15seconds. I can't get more pressure in it because the rig up I have on the intake side of the turbo to pressurize it keeps blowing off.
TECH Apprentice
Joined: Nov 2005
Posts: 304
Likes: 0
From: Newmarket, Ontario
If it takes 10-15 secs to leak 10psi, that is not your problem. I blew a coupler (1" X 0.5" hole) and still made boost and power, and that would bleed off 3000psi on 0.0001s (slight exageration but you get the point). Higher intake temps will effect air density, BUT if you AFR is good and the timing was not being pulled by computer you should still make power provided you are not choking the engine on the exhaust side. Two things must still be checked..
1) Why is you air temps only going up a couple deg. at 15psi i.e. is the boost gauge working / are you actually making boost in the intake.
2) Is the exhaust acting like a restrictor - if you are not sure about your backpressure measurements - find a way to be sure - check without the turbo downpipe. Also what size collector are you using i.e. you have truck manifolds that go into what before the turbo? Another way is to check your fuel map, if your engine has a very low VE in the higher RPM range, perhaps your exhaust is too restrictive.
3) Is your AFR ratio correct - could your gauge be giving you the wrong numbers? Connect a narrowband lambda and check near your 14.7 to see if the wideband is correct.
4) Try the sparkplug check thing that was previously mentioned.
If you have compression, air, fuel and spark you will make power - you know your car better then anyone else, narrow down what could be limiting any of these and run tests.
1) Why is you air temps only going up a couple deg. at 15psi i.e. is the boost gauge working / are you actually making boost in the intake.
2) Is the exhaust acting like a restrictor - if you are not sure about your backpressure measurements - find a way to be sure - check without the turbo downpipe. Also what size collector are you using i.e. you have truck manifolds that go into what before the turbo? Another way is to check your fuel map, if your engine has a very low VE in the higher RPM range, perhaps your exhaust is too restrictive.
3) Is your AFR ratio correct - could your gauge be giving you the wrong numbers? Connect a narrowband lambda and check near your 14.7 to see if the wideband is correct.
4) Try the sparkplug check thing that was previously mentioned.
If you have compression, air, fuel and spark you will make power - you know your car better then anyone else, narrow down what could be limiting any of these and run tests.
Well I took my exhaust off and am running a open DP and that helped some. What is really interesting is it decided to come alive a little one of the times I got on it. Luckily I was logging this time and was able to review the data. When it came alive it had 32* timing for a brief moment at the beginning of the run. I was running 9#'s. So I went and thew a additional 10* timing in the boosted region. The engine got significantly stronger. I am seeing some knock but I am pretty sure it is false.( spikes a couple degrees but falls off quickly.) Beleive it or not when it was up at 32* I had no knock! Now for the new questions. Why?
Is my compression not what we have calculated it to be?
Is my timing off? Not what the computer thinks it is?
I am going to start by looking up the part# on the pistons and gaskets to do a recalculation. If the timing is out of whack what is the right way to check it/make it right?
Thanks guys I am finally getting somewhere.
Is my compression not what we have calculated it to be?
Is my timing off? Not what the computer thinks it is?
I am going to start by looking up the part# on the pistons and gaskets to do a recalculation. If the timing is out of whack what is the right way to check it/make it right?
Thanks guys I am finally getting somewhere.
TECH Apprentice
Joined: Nov 2005
Posts: 304
Likes: 0
From: Newmarket, Ontario
32 deg's seems WAY to advanced to be right. I would bet you timing is off, use a timing light, mark your crank at TDC (relative to something on the block that doesn't move) and check from there. Looks like you are onto something...
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Verdad Gallardo Well I double checked and I have 29cc dish ,70cc heads, and .060 gasket. The only thing we are not sure about is how far the piston is out of the hole or if it is out at all. So more than likely the compression is fine.
I will check the timing tomorrow. If it is off then what? The only thing I can think would cause it is the reluctor wheel.
I will check the timing tomorrow. If it is off then what? The only thing I can think would cause it is the reluctor wheel.
Glad to hear you are making progress.
I have seen many people chase the tune forever just to find out there was a failed intake or head gasket causing all the trouble.
The compression ratio seems normal, but you could do a compression test on all cylinders to make sure that you don't have any mechanical issues.
I seems like the timing is pointing you in the right direction, but I would still
get an exact backpressure reading just to make sure that the additional timing
is not covering up an underlying backpressure problem.
Keep us posted!
I have seen many people chase the tune forever just to find out there was a failed intake or head gasket causing all the trouble.
The compression ratio seems normal, but you could do a compression test on all cylinders to make sure that you don't have any mechanical issues.
I seems like the timing is pointing you in the right direction, but I would still
get an exact backpressure reading just to make sure that the additional timing
is not covering up an underlying backpressure problem.
Keep us posted!
Glad to hear you are making progress.
I have seen many people chase the tune forever just to find out there was a failed intake or head gasket causing all the trouble.
The compression ratio seems normal, but you could do a compression test on all cylinders to make sure that you don't have any mechanical issues.
I seems like the timing is pointing you in the right direction, but I would still
get an exact backpressure reading just to make sure that the additional timing
is not covering up an underlying backpressure problem.
Keep us posted!
I have seen many people chase the tune forever just to find out there was a failed intake or head gasket causing all the trouble.
The compression ratio seems normal, but you could do a compression test on all cylinders to make sure that you don't have any mechanical issues.
I seems like the timing is pointing you in the right direction, but I would still
get an exact backpressure reading just to make sure that the additional timing
is not covering up an underlying backpressure problem.
Keep us posted!