Poor Dyno numbers... need suggestions
#16
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Thanks for the offer, I've got everything to build one now.
The AFR from the dyno sniffer was a lot different than my wideband, it was showing 11.2-10.8, but I don't have a way to datalog it.
About the sensor... when it is mounted (part# side up) do you know which side/blade is positive?
I've got some new bpr7es plugs, but I had them gapped to 026" I'll change that too.
Thanks for the suggestions guys, my roommate didn't have time to help me with checking the header/crossover for leaks tonight. I'll try and get to it Thursday afternoon as I work at 24hr shift starting tomorrow morning.
You are climbing up to 13 AFR at higher RPM...That isn't good.
The knock sensor is a Pizo element (like a mic) so it does have a polarity. You do need to torque them correctly and make sure the mounting surface is flat and clean, no washers. Also make sure that the connecting cable does not vibrate or flop around, that can effect the sensor. Lots of Bosch ECU units used the same knock sensor, Volvo 240 and Saab 900 to name a few.
The knock sensor is a Pizo element (like a mic) so it does have a polarity. You do need to torque them correctly and make sure the mounting surface is flat and clean, no washers. Also make sure that the connecting cable does not vibrate or flop around, that can effect the sensor. Lots of Bosch ECU units used the same knock sensor, Volvo 240 and Saab 900 to name a few.
About the sensor... when it is mounted (part# side up) do you know which side/blade is positive?
Thanks for the suggestions guys, my roommate didn't have time to help me with checking the header/crossover for leaks tonight. I'll try and get to it Thursday afternoon as I work at 24hr shift starting tomorrow morning.
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Such a helpful contribution to this thread. ![banghead](https://rennlist.com/forums/graemlins/banghead.gif)
Interesting - as Shawn mentioned, an exhaust leak will cause the O2 sensor's reading to be off... There should not be that much discrepancy between your WBO2 and the dynos, if everything is sealed up tight.
When idling and the car is warm, is your WBO2 reading ~14.7? If so, I would be more inclined to believe your WBO2 than the dyno.
Definitely check for leaks - both intake and exhaust.
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When idling and the car is warm, is your WBO2 reading ~14.7? If so, I would be more inclined to believe your WBO2 than the dyno.
Definitely check for leaks - both intake and exhaust.
#20
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vacuum and pressure leak are the same things on the 951. when off throttle, the engine is under vacuum, when on boost, everything that was under vacuum is now on positive pressure.
#21
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I wish you had the boost plotted on the dyno chart. No matter... it looks like it's boosting slow. It looks laggy for that turbo.
That said... Do you have a cat? What Tial wastegate do you have and what spring is in it? And how do you have it plumbed? Also... I'd try a different boost controller.
TonyG
That said... Do you have a cat? What Tial wastegate do you have and what spring is in it? And how do you have it plumbed? Also... I'd try a different boost controller.
TonyG
#22
Burning Brakes
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That is strange, went back to the post that needed the "NOT" inserted and I am locked out from changing it. Appears there is a time limit to change posts. That isn't a smart thing to.
#24
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I should have put a NOT in the sentence. The knock sensor does NOT have a polarity.
That is strange, went back to the post that needed the "NOT" inserted and I am locked out from changing it. Appears there is a time limit to change posts. That isn't a smart thing to.
That is strange, went back to the post that needed the "NOT" inserted and I am locked out from changing it. Appears there is a time limit to change posts. That isn't a smart thing to.
#25
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I wish you had the boost plotted on the dyno chart. No matter... it looks like it's boosting slow. It looks laggy for that turbo.
That said... Do you have a cat? What Tial wastegate do you have and what spring is in it? And how do you have it plumbed? Also... I'd try a different boost controller.
TonyG
That said... Do you have a cat? What Tial wastegate do you have and what spring is in it? And how do you have it plumbed? Also... I'd try a different boost controller.
TonyG
Such a helpful contribution to this thread. ![banghead](https://rennlist.com/forums/graemlins/banghead.gif)
Interesting - as Shawn mentioned, an exhaust leak will cause the O2 sensor's reading to be off... There should not be that much discrepancy between your WBO2 and the dynos, if everything is sealed up tight.
When idling and the car is warm, is your WBO2 reading ~14.7? If so, I would be more inclined to believe your WBO2 than the dyno.
Definitely check for leaks - both intake and exhaust.
![banghead](https://rennlist.com/forums/graemlins/banghead.gif)
Interesting - as Shawn mentioned, an exhaust leak will cause the O2 sensor's reading to be off... There should not be that much discrepancy between your WBO2 and the dynos, if everything is sealed up tight.
When idling and the car is warm, is your WBO2 reading ~14.7? If so, I would be more inclined to believe your WBO2 than the dyno.
Definitely check for leaks - both intake and exhaust.
I've gotta go take photos of my rommie's mustang then test for exhaust leaks.
#26
Burning Brakes
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I think I remember you saying you had the head off recently? If so, be sure your cam timing is set to TDC. I recently had my cam timing jump advanced 2 teeth Tensioner failure). Lag was horrible and power was down by 90HP. Check this to be sure it correct! The car will run fine, just laggy and down HP.
My old K27/6 would see 370lb tq at 3200 rpm.
My old K27/6 would see 370lb tq at 3200 rpm.
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I think I remember you saying you had the head off recently? If so, be sure your cam timing is set to TDC. I recently had my cam timing jump advanced 2 teeth Tensioner failure). Lag was horrible and power was down by 90HP. Check this to be sure it correct! The car will run fine, just laggy and down HP.
My old K27/6 would see 370lb tq at 3200 rpm.
My old K27/6 would see 370lb tq at 3200 rpm.
You can't have a significant vacuum leak if you're pulling 18in.....
#28
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2) Just because you have it in "dual port" doesn't mean it's plumbed properly.
3) Manual boost controllers generally suck. And a lot of that has to do with the wastegate plumbing and spring rate. A properly setup wategate can do a decent job with a manual bleed type boost controller... (the operative word here is "properly setup".
That said... where is your boost plot on the dyno chart? That will tell the story with respect to proper wastegate operation. If you don't have that... then you need to get it. Without it... you're shooting in the dark....
In short..... it's clear that some part of your config is not properly setup.... which is reflected by the laggy TQ curve.
TonyG
#29
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I think I remember you saying you had the head off recently? If so, be sure your cam timing is set to TDC. I recently had my cam timing jump advanced 2 teeth Tensioner failure). Lag was horrible and power was down by 90HP. Check this to be sure it correct! The car will run fine, just laggy and down HP.
My old K27/6 would see 370lb tq at 3200 rpm.
My old K27/6 would see 370lb tq at 3200 rpm.
1) There is no "base line spring". You specify what the spring should be (at least that's how I order the wastegates)..
2) Just because you have it in "dual port" doesn't mean it's plumbed properly.
3) Manual boost controllers generally suck. And a lot of that has to do with the wastegate plumbing and spring rate. A properly setup wategate can do a decent job with a manual bleed type boost controller... (the operative word here is "properly setup".
That said... where is your boost plot on the dyno chart? That will tell the story with respect to proper wastegate operation. If you don't have that... then you need to get it. Without it... you're shooting in the dark....
In short..... it's clear that some part of your config is not properly setup.... which is reflected by the laggy TQ curve.
TonyG
2) Just because you have it in "dual port" doesn't mean it's plumbed properly.
3) Manual boost controllers generally suck. And a lot of that has to do with the wastegate plumbing and spring rate. A properly setup wategate can do a decent job with a manual bleed type boost controller... (the operative word here is "properly setup".
That said... where is your boost plot on the dyno chart? That will tell the story with respect to proper wastegate operation. If you don't have that... then you need to get it. Without it... you're shooting in the dark....
In short..... it's clear that some part of your config is not properly setup.... which is reflected by the laggy TQ curve.
TonyG
Like I said before, I don't have a boost plot, the shop didn't do one and I have no way to log it.
I did find two possible leaks with the crossover last night, but didn't have time to tighten things up. I will be working on that this afternoon but I'm still waiting on my harness connector for the knock sensor.
Here's a question...
After getting those leaks taken care of, since the knock sensor is still not connected would I even notice a change in spoolup?
#30
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[QUOTE=Zeff;9442387]I will get that checked out, but that is lower on my list of things to verify.
It won't take long at all to verify. Set the flywheel to TDC and look through the inspection hole on the cam cover. If you are off by only 1 tooth, it can make a big difference. Unless you have a major leak or as Tony suggests, the waste gate, I would check this first. It's simple and easy and you can rule it out if it's ok.
I just went through this. My HP and TQ curves were shifted way to the right. Spool up sucked and power was down while still holding 17 PSI to red line. It may not be your problem, but it's an easy check.
It won't take long at all to verify. Set the flywheel to TDC and look through the inspection hole on the cam cover. If you are off by only 1 tooth, it can make a big difference. Unless you have a major leak or as Tony suggests, the waste gate, I would check this first. It's simple and easy and you can rule it out if it's ok.
I just went through this. My HP and TQ curves were shifted way to the right. Spool up sucked and power was down while still holding 17 PSI to red line. It may not be your problem, but it's an easy check.