Convertor chatters like hell going into OD
I follow these boards fairly closely (over 3000 posts on LS1.com over 3 years) and this is a new one on me.
As I understand it, the HPP III only boosts line pressure at WOT so I'm not going that route. Yes, it occurs at light throttle only. Full throttle blasts seem fine.
I'll put the stock ends back on but, to be honest, if this converter is toast due to this, it's a great big piece of **** and I'll never buy another Yank. The stock converter didn't 'glaze the clutch' with ported ends for 10k miles nor should a 'preformance ' one.
As I understand it, the HPP III only boosts line pressure at WOT so I'm not going that route. Yes, it occurs at light throttle only. Full throttle blasts seem fine.
I'll put the stock ends back on but, to be honest, if this converter is toast due to this, it's a great big piece of **** and I'll never buy another Yank. The stock converter didn't 'glaze the clutch' with ported ends for 10k miles nor should a 'preformance ' one.
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> I follow these boards fairly closely (over 3000 posts on LS1.com over 3 years) and this is a new one on me.
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I can't find the posts quickly, but here is a clear reference to it in another LS1.com post:
http://www.ls1.com/forums/showthread...ported+AND+MAF
The original discussions were before LS1.com upgraded servers.
Recent discussion of it at LS1Tech.com with the title being obvious:
https://ls1tech.com/ubb/cgi-bin/ulti...=001500#000000
https://ls1tech.com/ubb/cgi-bin/ulti...=001532#000005
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> The stock converter didn't 'glaze the clutch' with ported ends for 10k miles nor should a 'preformance ' one. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">The stock converter is bigger and has a les agressive clutch material and requires less force to keep the clutch on.
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> As I understand it, the HPP III only boosts line pressure at WOT so I'm not going that route. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Your understanding is incorrect. It changes it at part throttle. I only suggested that you borrow one and test it out. You are trying to diagnose the problem at this point.
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I can't find the posts quickly, but here is a clear reference to it in another LS1.com post:
http://www.ls1.com/forums/showthread...ported+AND+MAF
The original discussions were before LS1.com upgraded servers.
Recent discussion of it at LS1Tech.com with the title being obvious:
https://ls1tech.com/ubb/cgi-bin/ulti...=001500#000000
https://ls1tech.com/ubb/cgi-bin/ulti...=001532#000005
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> The stock converter didn't 'glaze the clutch' with ported ends for 10k miles nor should a 'preformance ' one. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">The stock converter is bigger and has a les agressive clutch material and requires less force to keep the clutch on.
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> As I understand it, the HPP III only boosts line pressure at WOT so I'm not going that route. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Your understanding is incorrect. It changes it at part throttle. I only suggested that you borrow one and test it out. You are trying to diagnose the problem at this point.
I posted this on LS1.com.
The last 2 times I've driven to work, the trans chattered like a s.o.b. going into OD under
light throttle. So bad that I got off the gas.
Not always, once when entering an entrance ramp and once doing 60 under light acceleration.
I drove it in D for awhile; that seemed to avoid the problem.
Yesterday, I checked the fluid level; it registered on the dipstick o.k. but added a pint anyway.
Then drove it in OD for 15 miles with no reoccurance of the problem.
The car has ported MAF ends, has not been driven hard and has around 3k on the converter.
The fluid is red; no signs of overheating.
Ragtop 99 suggested a glazed clutch in the converter. How does this happen and
what can be done to fix/prevent it? And, if this is the case, I'm going to be one pissed-off dude.
The last 2 times I've driven to work, the trans chattered like a s.o.b. going into OD under
light throttle. So bad that I got off the gas.
Not always, once when entering an entrance ramp and once doing 60 under light acceleration.
I drove it in D for awhile; that seemed to avoid the problem.
Yesterday, I checked the fluid level; it registered on the dipstick o.k. but added a pint anyway.
Then drove it in OD for 15 miles with no reoccurance of the problem.
The car has ported MAF ends, has not been driven hard and has around 3k on the converter.
The fluid is red; no signs of overheating.
Ragtop 99 suggested a glazed clutch in the converter. How does this happen and
what can be done to fix/prevent it? And, if this is the case, I'm going to be one pissed-off dude.
First you have to identify whether it occurs in 4th gear when unlocked or only when locked-up before it could be the converter.
The next step you can do to test it is to go back to stock MAF and see if that reduces the chatter. Alternatively, you could also borrow a HPP3 and test the car using the 50% line pressure setting, if that substantially cures it, then the problem was probably due to the ported MAF.
As was discussed on these boards, a ported MAF can reduce line pressure because the engine computer thinks the load is less, since it thinks less air is entering the motor than really is.
Normally the chatter occurs under light throttle. If it is occurring at all speeds it could your tranny clutches. Overfilling the tranny is not good either. Sometimes a friction modifier add to the tranny fluid will help, but it is probably too late for that.
The next step you can do to test it is to go back to stock MAF and see if that reduces the chatter. Alternatively, you could also borrow a HPP3 and test the car using the 50% line pressure setting, if that substantially cures it, then the problem was probably due to the ported MAF.
As was discussed on these boards, a ported MAF can reduce line pressure because the engine computer thinks the load is less, since it thinks less air is entering the motor than really is.
Normally the chatter occurs under light throttle. If it is occurring at all speeds it could your tranny clutches. Overfilling the tranny is not good either. Sometimes a friction modifier add to the tranny fluid will help, but it is probably too late for that.

