PT54 am I running out of air?!?!?!

G

Grandnat

Member
Joined
May 26, 2001
I can only get 21-22 psi of boost out of this turbo.

I have run 127 mph in the 1/4 at that boost

with 21 psi and 22 degrees of timing.


the car weighs about 3750 with me in it.

am I out of turbo?

I heard Scott ATK
who weighs 3550 ran 128.8 at about 28psi


could it be I am just maxing this turbo out???
 
Originally posted by lazaris
What kinda of wastegate are you running? Are you sure its not opening?
Click to expand...

no I can't be sure.. it is a stock style HD wastegate.. I have ran 26 psi in the past on a TE44


what turbo do you have.


oh and by the way, if I add more timing the boost goes down....and if I lower the timing the boost goes up.

for example 24 degrees = 20 psi max boost


and 20 degrees = 23.5 psi max


this is not touching the wastegate..... I have the rod cranked down as far as I can and I have the bleeder valve wide open.

I do not THINK I have any exhaust leaks... but I need to really check again to be 100% sure
 
The lower timing generates more exh heat/energy which in turn spins the turbine wheel more, which is probably the reason for the boost change. a few years ago when I was running a THDP with the heavy duty actuator cranked all the way I couldnt get more than 24 -25psi out of my combination. I thought I might have been out of air too. Well i did a test and wired the wastegate door shut and immediately had 28 psi. after the run I looked under the hood and the wire I used had stretched some and alowed the flap to still open slightly so there was still more boost to be had. Needless to say I had allot of BP to do that, but found I still had more turbo.
 
Also try pulling the thdp away from the turbo far enough to get a look at the puck, to make sure the carbon ring is centered and at least 1/16" away from the edge.
 
so the concencus here is that the PT 54 will make more power?

what should it max out at in MPH with a car my weight?
 
What is your combo? On my car, I have seen it push 34psi....., but 30psi on a regular basis. (You know, trips to Walmart etc...lol)
 
I think that is the same turbo as a TE-61, 69 turbine wheel, 60 or 61 mm compressor. I get an easy 30psi out of mine with a stock block and heads. What is your motor's set-up.

Scott H.
 
WSLN 6, whats up with a 13 sec run at 121mph? I almost get into 10s with only 119mph? Are you using bicycle tires on the rear?:D
 
OK guys.... boost is irrelevant.


I do not care if I run 60 psi or 5 psi.....and you shouldn't either.

I am talking about HP!

I called precision and for those that would like to know..


127 mph on a 3700#+ with a PT 54 IS maxing out the turbo.


boost is a measurement of restriction. you want a turbo that makes 50 psi??? put a restrictor in your throttlebody and you're there.
 
"OK guys.... boost is irrelevant."

Ah I wouldn't go that far. Theres allot more involved than that. In "most" cars if you turn up the boost from 18psi to lets say 22psi, "most car will go faster'..................
 
Originally posted by lazaris
"OK guys.... boost is irrelevant."

Ah I wouldn't go that far. Theres allot more involved than that. In "most" cars if you turn up the boost from 18psi to lets say 22psi, "most car will go faster'..................
Click to expand...

true, but ONLY if that turbo is not already maxed out!

and that is exactly the scenario I am suggesting might be the problem with my turbo.

boost is only a measurement of restriction.. it is literally a measurement of the build up of air that cannot make it into your engine.


so 26 psi on your motor may be like 15 psi on mine.

I was just curious if I was maxing out the turbo. If I am then that explains why I can not get more boost out of it. If I am not, then theorhetically I should be able to increase the boost until I reach the power limitations of the turbo.

However after talking to Joe Lubrant I am quite sure that I have reached the HP limit of that turbo.

Thanks for the responses guys.
 
Turbotnr, I don't have a cage, so I tripped the lights and just sat there for a bit. 3.2 second 60ft...........:D
 
Originally posted by Grandnat
I can only get 21-22 psi of boost out of this turbo.

I have run 127 mph in the 1/4 at that boost

with 21 psi and 22 degrees of timing.


the car weighs about 3750 with me in it.

am I out of turbo?

I heard Scott ATK
who weighs 3550 ran 128.8 at about 28psi


could it be I am just maxing this turbo out???
Click to expand...
do you ran the car uncapped?
 
Originally posted by Grandnat
true, but ONLY if that turbo is not already maxed out!

and that is exactly the scenario I am suggesting might be the problem with my turbo.

boost is only a measurement of restriction.. it is literally a measurement of the build up of air that cannot make it into your engine.


so 26 psi on your motor may be like 15 psi on mine.

I was just curious if I was maxing out the turbo. If I am then that explains why I can not get more boost out of it. If I am not, then theorhetically I should be able to increase the boost until I reach the power limitations of the turbo.

However after talking to Joe Lubrant I am quite sure that I have reached the HP limit of that turbo.

Thanks for the responses guys.
Click to expand...

The only way to know for sure is to completely close the gate. You might be surprised at what you'll find.
 
Originally posted by lazaris
The only way to know for sure is to completely close the gate. You might be surprised at what you'll find.
Click to expand...


Lazaris.

our cars look pretty similar in power.

Let me ask you this.

What turbo are you running?

and

If you bolted on my pt54, do you think you would go faster or slower?
 
I was running a 3 bolt 72 with a stock MAF and a collapsed K&N filter with a real loose converter. Hard to say about the 54 in my situation but If I ran it in a non restricted intake track I believe it would have gone slower. You were looking for more boost out of that turbo so I would try making sure you not bleeding off boost at the gate first. You may have some more left in it if you ran 25-26 psi.
 
Originally posted by lazaris
Did you ever find out if you could increase the boost?
Click to expand...

I was going to take your suggestion and actually wire the puck closed and take it to the track, but it has been raining all weekend.

I will try and do it next weekend. and I will let you know.

If I can get this thing to hook and actually make 23# of boost or more I am shooting for mid 6's in the 1/8th at around 105mph.

I did 102.2mph on 20# a few weeks ago...but now the air is significantly cooler and with a few more pounds 105mph should be attainable.

I am thinking/hopeing low 10s in this lead-sled is possible.
 
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