Can't keep boost lower then 19lbs (Ta-61)

[ZMIKEMAN]

Hey guys,

Ben having a problem for a while on my 87GN. Setup specs. can be found below the post. The cars running an internally gated Ta-61 (.63A/R) with a 14psi wastegate spring.

Currently the LEAST amount of boost I can run is 19lbs. Waste gate hole has been ported as large as possible and the wastegate has been tested to be a good unit. Even with the gate fully opened the car creeps up to 19lbs. I'm having to run 100 octane gas in it to keep it from pinging on the street and need to find a solution to get the boost down to a more reasonable 16-17lbs for the street. Anyone else ever have this problem? Suggestions, thoughts, ideas? I've thought about needing an External gate but then againg I've seen others on this setup and several with even larger turbos that where internally gated.

Here are the specs on the build.

Engine:
-Limit Engineering - Arizona Ta-61 (.63A/R)
-Weisco Forged Pistons
-Re-conditioned Rods
-Comp. Billet roller camshaft 206/206 .512 intake/exhaust w/ 109 lobe seperation
-Durabond performance cam bearings
-Comp. Roller lifters
-Fedeeral Mogul Main/Rod Bearings

-ARP Hardware
-Billet center caps
-Resurfaced Crank
-Brass Freeze plugs
-Balanced assembly
-Xtream Duty roller timing chain set 1013-4
-Stainless steel fuel rail feed and return lines

Heads:
-Port & Polished heads
-Ferra Valves 1.77 Intake / 1.55 Exhaust
-Comp roller springs / titanium retainers / 10* locks
-New springs / Seals / Machined pedestals
-Champion Valve covers
-Harland Sharp 1.60 roller rockers

Intake:
-Tin Man cold air kit
-Aftermarket Stock location extended intercooler
-Removed screens from MAS
-Larger inlet bell for Turbo
-Ported $ Polished Intake

Exhaust:
-Terry Houston DP & Cat-back
-High Flow cat
-Repaired driverside exhaust header crack
-Stock manifolds

Fuel:
-High Flow in-tank pump
-60-61lb mototron injectors
-High flow in tank pump
-Hot wired
-Volt Booster

Currently running a Turbo Tweak chip with DirectScan / TurboLink / and an Innovate wideband for monitering.

 

[turbojimmy]

Was it ever working (i.e., are you sure you have a 14 lb. spring)?

Make sure you have the "y" restrictor installed properly. If you have the restriction between the solenoid and the wastegate this could be your problem. The restriction should be between the turbo and the solenoid, if memory serves.

If your wastegate hole is ported as large as possible then you shouldn't have any creep problems. Is it 'creeping' (shoots up to where you set it and then slowly creeps higher) or can you not 'set' it?

Jim

 

[foreveryoung]

Boost can't get lower than 19 lbs.

I am familiar with this car and can add some more detail. We do not believe the engine boost has been right since the rebuild. Could not get the RA chip to work without some knock and it would not idle good. Changed to Turbotweak chip and idle problems went away. Now running 100 octane until we find the problem. Looking back, I think we were boosting more than gauge was saying. Installed FP gauge so we could see it from inside of car and compared with boost on boost gauge. Boost gauge was low so we changed it out. Boost gauge and FP are now in sync.

Tried taking the boost control away from the car by plugging up the hose. Still too much boost. Put regular hose on the compressor housing and ran direct to the waist gate, still getting too much boost. Replaced the wastegate with another new stock one, still too much boost. Bored the waste gate hole out from .9 +/_ to 1.1 inch. Seemed to help a little, but will still go to 19 before I have to let off on the highway.

The car now has a data logger on it. Looking at boost curve, it will got to 14 very quickly, then flatten out SOME, but continue to climb more slowly to ?. We have always needed to let out by the time we get to 19 lbs due to traffic problems. No knock with 100 octane, but would like to get to 16 ish to start tuning back up.

Any suggestion for this car would be appreciated.

 

[turbojimmy]

Looking at boost curve, it will got to 14 very quickly, then flatten out SOME, but continue to climb more slowly to ?

That's creep. You should be able to port the exhaust housing on the turbo enough to eliminate it. I'd open it up as much as you can. I have used a 3" THDP with both a PT61 and now a T70 turbo (w/ a Precision housing) and by porting the exhaust housing I eliminated creep on both.

I'm not sure what you mean by 'plugging up the hose', but if you plug the hose between the turbo and the wastegate you will get max boost (wastegate won't see any boost and thus won't open). By connecting the compressor housing directly to the wastegate you should only get boost within a couple of lbs. of the spring. It should be solid - shoot right up to 14-16 PSI and STAY there. If it creeps up at WOT then you have more porting to do on the exhaust housing.

Jim

 

[foreveryoung]

Thanks for the reply TurboJimmy.
This has been baffling me for a long time now. Ready to get it fixed and enjoy the car.
By "plugging" I ment we took the car waste gate control out of the picture. This basically routed the "Y" hose from turbo to waste gate actuator. When that did not help, we took the waste gate hose "Y" completely off and replaced it with a straight hose going directly from the trubo to the waste gate actuator.
This still gave me a quick 14 psi and then more gradual to 19 lbs. when I had to let off the gas.
When I talked with my engine builder who did the porting of the waste gate hole, he indicated that he thought it was ported as much as he could do it and still have a seal. I think about 1.1". I will talk with him again and see if he can stretch it some more. If not, I do not know where to go from there. Anyway, thanks for the reply post always good to talk with other Turbo guys.

 

[turbojimmy]

Thanks for the reply TurboJimmy..

You're welcome. It sounds to me like that needs ported some more. Your THDP puck will have left a nice carbon ring around the hole by now - he should port out close to that. He should also make sure he's porting into the housing, NOT just just the hole itself. If you look at it you can see what I mean. You're not just making the hole bigger, you're opening up the passage.

Jim

 

[foreveryoung]

I will relay the info. to the builder and see what he says.
Thanks again for the help!

 

[RUQWKNF]

One more thing you can verify would be to write down all the numbers on the wastegate actuator (if memory serves me correct it should be a 4 digit number) and either call PTE or Limit and verify if it is a Standard Spring actuator or a Heavy Duty spring actuator. From what I've read, it sounds like you might indeed have a Heavy Duty Spring actuator, especially with you hooking it up tuner style and it stills goes past 19psi. The low setting on a HD actuator is typically no lower than 18psi. The Standard Spring actuator starts to open at around 10psi. Have you tried adjusting the rod length back to static setting? IE: adjusting it so that you don't have to pull it over and onto the swing valve?
Hope this helps a little.

Patrick

 

[foreveryoung]

Thanks for the thoughts and reply Patrick.
I actually thought of the same thing on the actuator. I looked on the stock one I pulled off and could not find any numbers on it. I will look better, but did not see any. I thought if it had numbers on it I would check it out for maybe a HD actuator they sent instead of a stock. It is however doing the same thing as the stock one I pulled off.
I have the actuator arm adjusted all the way out so that I just barely pull on it to get it over the puck pivot arm, so I think I have maybe covered that one. Good thoughts though. Thanks for keeping the thought juices going on this one.
Best regards,

 

[foreveryoung]

Can't find any numbers on the wastegate actuator. Should there be some on it???

Thanks

 

[NCTURBOS]

Engine builder here:

1.) The wastegate hole was .930" before the porting was done, and at that time the boost would very rapidly swing well past 20psi and continue until you let out. It was supposed to be @ 1.000" from Limit.

2.) The wastegate hole is now approx. 1.150" and is radiused into the housing. The car now hits 14psi rapidly but continues to approx. 19psi slowly and seems to level out around there, but it's hard to tell if it will continue to rise from there or not. At that point the car is already well over 100mph on the highway!

3.) I've had this same combination on other cars as well, and they yield approx. 14psi with the wastegate hooked up "tuner style".

Other than double checking the part# on the actuator are there any other thoughts?? Maybe we're missing something real simple here...


K.

 

[turbojimmy]

Engine builder here:

1.) The wastegate hole was .930" before the porting was done, and at that time the boost would very rapidly swing well past 20psi and continue until you let out. It was supposed to be @ 1.000" from Limit.

2.) The wastegate hole is now approx. 1.150" and is radiused into the housing. The car now hits 14psi rapidly but continues to approx. 19psi slowly and seems to level out around there, but it's hard to tell if it will continue to rise from there or not. At that point the car is already well over 100mph on the highway!

3.) I've had this same combination on other cars as well, and they yield approx. 14psi with the wastegate hooked up "tuner style".

Other than double checking the part# on the actuator are there any other thoughts?? Maybe we're missing something real simple here...


K.

It sounds like it's still creeping - it would probably continue to rise if you stayed in it. The wastegate is doing its thing if it shoots up to 14 and then slowly creeps. It really sounds like you've exhausted the possibilities - I'm not sure what else would cause it to creep.

Jim

 

[foreveryoung]

Engine Builder, Any more room to port out the wastegate hole?

 

[trbojo]

having the same problem with a new te 62 from limit e. 'cept i'm creepin up to 27- 28! tryin' to get it set at 23. never had a problem with the te 60. set it and it held rock solid, now i can't get it under control. still waiting to hear back from chopper. he was supposed to discuss it with John Craig and get back to me??????

 

[Ed Valvo]

Unhook the wastegate rod and let the thing flop open. You'd think it will never build boost but it will eventually. Go WOT the car and see if it still goes to 19 PSI. It will feel like a pig but will probably fly to 19 PSI once you hit 10-12 PSI. If this is the case, you'll need a larger aftermarket gate since your stock setup isn't doing the job. Deltagate, two of them at times, on the crossover worked well for me but too loud for the wife.

You can only open up the wastegate port so much forthe THDP. I had a TE-50 which has the same exhaust wheel as your turbo. When I switched turbos, my problem went away so I switch back to the stock wastegate setup. It has something to do with intake/exhaust ratio of the turbo and your particular engine combo. The vendor I got it from was no help so I ended up buying another turbo.

 

[NCTURBOS]

Unhook the wastegate rod and let the thing flop open. You'd think it will never build boost but it will eventually. Go WOT the car and see if it still goes to 19 PSI. It will feel like a pig but will probably fly to 19 PSI once you hit 10-12 PSI.

That was going to be the next test.

If this is the case, you'll need a larger aftermarket gate since your stock setup isn't doing the job.

I disagree here. I've used the Ta61/Te61 on many cars with THDP's and never had this problem before. I've run a Te45a P-trim, Te45a Q-trim, and a Te70 Q-trim also with a THDP and never had a problem. Then there's this car???


K.

 

[NCTURBOS]

Engine Builder, Any more room to port out the wastegate hole?

Some, yes... But it shouldn't need to go any bigger...


K.

 

[foreveryoung]

OK, any idea where we go from hear? Should I un hook my wategate rod and see what happens? If it does not get high (19+) as before, does that indicate the new waste gate actuator may be bad?

If it still goes up to 19+ what then?

Sure would like to get it down in the 16 range so I can start doing some tuning.

 

[turbojimmy]

OK, any idea where we go from hear? Should I un hook my wategate rod and see what happens? If it does not get high (19+) as before, does that indicate the new waste gate actuator may be bad?

If it still goes up to 19+ what then?

Sure would like to get it down in the 16 range so I can start doing some tuning.

I would port the exhuast housing out as much as possible. If you've hooked the compressor directly to the wastegate and it still creeps, and you've tried multiple wastegates, then the only explanation is that not enough exhaust is bleeding off through the wastegate hole, which means you need to make the hole bigger (or move to a different wastegate arrangement, but you shouldn't have to).

I would try unhooking the rod completely and see how much boost you get. Theoretically you should ultimately get 19 lbs. Also make sure the puck isn't binding for some reason.

I understand wanting to control your boost, but with your mods you should be tuning with more boost anyway. I can't remember the last time my car saw less than 23 lbs. I start there and work my way up!

Jim

 

[foreveryoung]

Thanks for the reply Jim. I will talk with engine builder about making waste gate hole larger if possible. I will try un hooking the waste gate rod tomorrow and see what I get. I wanted to start tuning around 16 lbs because I would like to run 93 octane on a regurlar basis with possible alky later on.
Thanks again,
Mike