Turbo won't spool at the line

[CliffyC]

Went to a two day race event at Madras Oregon, 1/8 mile track. Had on my newly rebuilt ($570) GT3161. Could hardly get the thing to spool for a burn out or at the line - mayby 1 to 2 lbs boost at best. I mean I was holding the brake for all I was worth , hoping the trans wouldn't tear apart and it would not come up! As a result my 60' times sucked, 1.9's & 2.0's. When the car starts rolling the boost seems to come up fine, my trap speed were good, 94 - 95 mph but ET's were only 7.7 - 7.8 sec.

Next day decided I'd had enough of that, put on an old stock turbo with 80k miles on it. The car fried the tires at the burn out and boost came up to 5lbs + in a couple seconds at the line. Turned some 1.6 sec 60'ers and ET's dropped to 7.4 sec. (Still not great, but I'll take it)

So what gives? Got a 3000 stall TC, that turbo should come up. Any ideas? Thanks.

 

[Sinful6]

Went to a two day race event at Madras Oregon, 1/8 mile track. Had on my newly rebuilt ($570) GT3161. Could hardly get the thing to spool for a burn out or at the line - mayby 1 to 2 lbs boost at best. I mean I was holding the brake for all I was worth , hoping the trans wouldn't tear apart and it would not come up! As a result my 60' times sucked, 1.9's & 2.0's. When the car starts rolling the boost seems to come up fine, my trap speed were good, 94 - 95 mph but ET's were only 7.7 - 7.8 sec.

Next day decided I'd had enough of that, put on an old stock turbo with 80k miles on it. The car fried the tires at the burn out and boost came up to 5lbs + in a couple seconds at the line. Turned some 1.6 sec 60'ers and ET's dropped to 7.4 sec. (Still not great, but I'll take it)

So what gives? Got a 3000 stall TC, that turbo should come up. Any ideas? Thanks.

Well since you're running a HD actuator, firstly, I would recommend a QSBC boost controller which should give you a noticable increase in spool(~500rpm quicker). It will especially help if your wastegate flap is opening prematurely(which is likely). I had an ad up for them in the FS section, but I still have one brand new if you want it, $50 shipped(normally $80). I would try that out first, and if its not enough for you, I would look into a looser(about 3600RPM) stall convertor. But, if its a street car, you don't want to go looser if you don't have to so that's why I suggest trying the controller first. Whatever you do, definitely don't run around with the stock turbo as a band-aid solution!

PM me or email: bullishness@gmail.com

Thanks, -D

 

[SCOOBY DOO]

Puck not sealing?

 

[CliffyC]

Boost at the line

Well since you're running a HD actuator, firstly, I would recommend a QSBC boost controller which should give you a noticable increase in spool(~500rpm quicker). It will especially help if your wastegate flap is opening prematurely(which is likely). I had an ad up for them in the FS section, but I still have one brand new if you want it, $50 shipped(normally $80). I would try that out first, and if its not enough for you, I would look into a looser(about 3600RPM) stall convertor. But, if its a street car, you don't want to go looser if you don't have to so that's why I suggest trying the controller first. Whatever you do, definitely don't run around with the stock turbo as a band-aid solution!

PM me or email: bullishness@gmail.com

Thanks, -D

Sounds like a good idea. I've thought about a boost controller before but just never got around to getting one. Not sure I want another gadget around my dash though with the alky controller, line lock, and gauge pods I have now. I'll get back to you on that.

Puck not sealing?

I think that may have been the main problem. Seems I may have extended the rod too much to keep the boost down. I'll 22lbs boost with no adjustment at all. Maybe this is another problem What say you?

 

[JDSfastGN]

Im willing to bet that the issue is the wastegate rod was not tight enough to hold the puck shut. One day I made an adjustment to my compressor housing and moved it higher, and it didn't click that I would be putting less tension on the wastegate. So I took it out and it spooled like a dog. I was confused at first, but then it finally clicked.

 

[La8agn]

I'm using the same turbo (Gt6131E), with that much stall and your engine combo your car should rock!!!! Did you run the car long enough to create a soot ring around the wastegate hole? Was the wastegate puck properly covering the wastegate hole? If the puck was covering the hole properly I'd have to go with JD's recommendation on the actuator rod adjustment. If you have ran this turbo before and it didn't have this problem it's got to be something simple. I've ran 1.55-60' 7.08@95+mph (best mph 96+) with an Edge Racing 9.5" 2800-3000 converter. I'm just waiting for cooler weather, I know that I've got a 6.99 et with some more boost. Good luck with your troubleshooting, let's know what you find.....

One more thing, I'm using a RJC boost controller.