TA49 To PT61Woes

[AKTURBOTA]

Previously my TTA with a TA49 and 36# fuel injectors ran a best of 11.79 @ 114.7 with a 60' of 1.61. Usually the car ran in the 12.0’s to 11.90's. In my quest to better my ET and MPH I purchased a PT61 turbo with 60# injectors. The following are the mods to my TTA:

Extender Chip - 23/19 timing
MAF Translator Plus
PT61 P-Trim Turbo
60# Mototroininjectors
Walbro 340 Fuel Pump
Action Fab 3” downpipe
freeflowing exhaust with testpipe
62mm throttle body
ported plenum
1" plenum spacer
adj fuel pressure regulator
ATR bleed valve to control boost
PTS 9/11 Torque Converter (Advertised 2800 stall)
LT1 MAF Sensor
Translator Plus
K&N 8" Air Filter on 3" Stainless Steel MAF pipe
110# valve springs
BFG Drag Radials on the stock rims
Spohn Adjustable Torque Arm
Global West Subframe Connectors
Spohn Adj Panhard Rod
Spohn Lower Control Arms
On the street I run 92 Chevron unleaded premium
At the strip I run Sunoco NOS Supreme Racing Fuel (117 octane)
Turbo Link 4.0 used as my data logger


I have run the car twice with the PT61 and have lackluster results. The first time was with the ULTRA Chip and it was running very rich. It ran 12.40 to 12.50 at 113 mph with 60’ time in the 2.0’s. The car was running very rich so I purchased an Extender chip along with a MAF Translator Plus so that I can adjust the A/F ratio and ignition timing. I went to the track yesterday 6/26/05 it was equally unimpressive.
I was only able to turn a 12.50-60 at 113-114 with my short times in the 2.0-2.1's. I can understand the poor short times are attributable to the stall speed of the torque converter (2900 rpm) and that I need the stall to be 3400-3500 to properly spool the turbo, but the mph with this turbo should be in the 120 mph range. My boost was set at 22-24 psi and the O2 volts were in the 790's the end of the quartermile, so I feel that it may be a little on the rich side of the fuel curve. The T-Plus was set for 2 percent rich for the base fueling (this was done to get the cruise BLM’s close to 128) with no changed for WOT and 4 degrees retarded for the base spark with no change for WOT.

With the smaller 800CFM TA 49 the car was consistently producing low twelve/high eleven second time slips with a Caspers Ultrachip with the #4 chip selected (20 degrees of timing at WOT). I don't understand what is holding the engine from developing the horspower that the PT61 (900CFM and 600HP max horsepower) can generate. I am perplexed...any ideas on what is wrong would be most welcome.

 

[Russ Merritt]

With 117 octane, why are retarding timing at all? You should be running 24ish degrees in third with that low of boost and that good of fuel...... Your not doing it right...........

 

[AKTURBOTA]

Russ,

Previoulsy to get less than 5 degrees of spark rtd even using the 117 racing fuel required running low timing. I can't exactly say why but running 24 psi with the 23/19 extender chip retarded 4 degrees resulted in two frames of spark retard at only 2 degrees. I ran out of time yesterday, otherwise I would have eliminated the base spark retard of 4 degrees. My feeling now is that part of the problem is that my timing is too low...but low timing should have increased EGT's right...thereby increasing turbo spool correct?

Mark

 

[Russ Merritt]

No way is that thing pingin with 117 and 19 degrees timing........You have false knock happinin. You'll need more timing to wake up that turbo on 117. Unless you have an ignition problem.........Change plugs lately? Gap em tight, unless you have MSD. EGTs are a pain, wide band is for more accurate.

 

[AKTURBOTA]

Russ,

Like I mentioned previously, I ran out track time, otherwise I would have proceeded to raise my timing. In reality with the 24/19 Extender chip, I had the base timing retarded 4 degrees, so at WOT in 3rd gear the timing would have been only 15 degrees, so if my timing was set to 24 degrees WOT at the top of 3rd gear the MPH would probably have been in the 120's...what do you think?

Here is an academic question... how much boost can be run given 24 degrees of timing with Sunoco 116 fuel? I realize that there are other contributing factors that have a bearing on the answer, but if all things remain the same and you just vary boost how much PSI of boost can you reasonably run with the aforementioned timing and racing fuel.

Mark

 

[1BADDAM]

Last time out into a headwind I went times in sig.

Ran on 112 octane
T+/Extender settings were -- 29/25, +6% fuel WOT, -4% Fuel 1st & 2nd gear.
Launch assist enabled, spool fuel was at setting 6 (-4%)

Boost was at 27 psi and creeping thru the traps, KR was 0.0

Sounds like some timing will help, plus that 61 is not gonna outperform a 49 in the 22-24 psi range, unless you increase flow via cam and/or ported heads.

I had spool issues when I got my 61, tuned them out the best I could. Then found the culprits, copper turbo/header gasket had a 3/4" section literally erroded away. Used the Riviera gasket, that blew first time boost was put to it. Found header flange to be somewhat warped, block sanded it, and put a 2 1/2" headergasket in there to take up some of clearance, has worked great ever since.

 

[Razor]

Octane is too high for timing run, converter is way too tight, turbo is a waste at that PSI, MPH has pretty much stayed the same(so the same HP is being made), and ET is a is a function of 60 foot. No 60 foot.. fugedaboutit.

So... your fix, get a higher stall converter. But careful its not too loose else you'll be at 5000+ RPM's all the way down the track. And the converter has to be of the 9 or 10 inch varieties.

On a stock longblock.. you have to run gobs of boost to make MPH. For running low 20's boost wise.. be doing that on C12/110.

Another fix.. put the 'ol 49 back on. Too many times bigger is not better if the rest of the supporting mods are not present. Want to slow down even further, put a 70 turbo.

HTH

 

[AKTURBOTA]

This was my first experience at the track with the Extender Chip and obviously my timing was set too low. I am going to stick with the base timing of the chip which is 23/19 as a place to begin and run 24+ psi and see what happens.

If memory serves me correctly I think that recommended stall for the PT61 is 3200, is that what people are using?

I hate to step back to the TA49, but it sure worked like a dream. With the 2800 stall 9/11 torque converter, the actual stall turned out to be approximately 3300-3400 and was getting 14PSI launches which translated to 1.6-1.7 60' times...those were the days. This was with the Caspers 7 position chip in the #4 position with 20 degrees of timing.

An

 

[turbojimmy]

But careful its not too loose else you'll be at 5000+ RPM's all the way down the track. And the converter has to be of the 9 or 10 inch varieties.

5000+ RPMs all the way down the track is a bad thing? I never gave it any thought until I saw this post. I have a 3600 RPM stall 9/11 converter with the PT61. I just checked a couple of DS runs and I'm at 4900-5400 (mostly at the low end of that range) the entire run. Car seems to run okay. Is my converter too loose?

Check this out:

http://www.turbojimmy.com/060604-2_files/chart001.htm

Jim

 

[AKTURBOTA]

Let me ask you this question...while the 3600 9/11 probably spools your turbo very well and launches hard, does your converter feel "loose" on the street in comparison to the stock torque converter. Speaking from my experience, in noticed a little bit of "loosness" going from the stock D5 to the 2800 stall 9/11 converter...it is very slight though...not enough to to bother me. I worry a little more about going to a 3200+ stall speed though.

Mark

 

[turbojimmy]

Let me ask you this question...while the 3600 9/11 probably spools your turbo very well and launches hard, does your converter feel "loose" on the street in comparison to the stock torque converter. Speaking from my experience, in noticed a little bit of "loosness" going from the stock D5 to the 2800 stall 9/11 converter...it is very slight though...not enough to to bother me. I worry a little more about going to a 3200+ stall speed though.

Mark

Honestly it feels great on the street. Driving 'normally' it isn't very loose at all. Only when you stomp on it and the turbo spools does it become obvious that there's a converter in it (RPMs shoot up).

Jim

 

[Razor]

5000+ RPMs all the way down the track is a bad thing? I never gave it any thought until I saw this post. I have a 3600 RPM stall 9/11 converter with the PT61. I just checked a couple of DS runs and I'm at 4900-5400 (mostly at the low end of that range) the entire run. Car seems to run okay. Is my converter too loose?

Check this out:

http://www.turbojimmy.com/060604-2_files/chart001.htm

Jim

Well I see a couple issues. One is when the converter was locked the rpm's didnt drop. Also you didnt mention the boost being run.

The more boost run the more it will slip. My 3600 9x11 would not see any RPM's under 5400 at 27 PSI. If I shifted at 5400.. it wouldnt drop.. and if I let it climb to 5800 and then shift it would drop to 5400 unlocked. Now locked it would drop into the 4000's.

The more TQ you make .. the higher the stall.

Yes 3200 is the rule of thumb for a 61. And on a stock longblock, the sweet spot is about 28-30 PSI. Any boost less, is a waste of turbo. Actually with your combo.. a PT51/TE44/TE60 would have been better.

HTH

 

[turbojimmy]

Well I see a couple issues. One is when the converter was locked the rpm's didnt drop. Also you didnt mention the boost being run.

The more boost run the more it will slip. My 3600 9x11 would not see any RPM's under 5400 at 27 PSI. If I shifted at 5400.. it wouldnt drop.. and if I let it climb to 5800 and then shift it would drop to 5400 unlocked. Now locked it would drop into the 4000's.

The more TQ you make .. the higher the stall.

Yes 3200 is the rule of thumb for a 61. And on a stock longblock, the sweet spot is about 28-30 PSI. Any boost less, is a waste of turbo. Actually with your combo.. a PT51/TE44/TE60 would have been better.

HTH

That does help - thanks.

I was running 25 PSI at the time. I guess if I turn it up I'll see more RPM. The TC lockup thing is interesting, though. Maybe it's slipping?

I got the PT61 to 'grow into'. It was used and a good deal so I couldn't pass it up. A couple of setbacks put me off-track with regard to planned mods - I had wanted to put heads on it by now.

Thanks,
Jim

 

[turbojimmy]

Just a point of clarification. Looking at my notes it appears as if my converter is a 3400 stall. I had 3600 in my head, but the notes don't lie. I had talked to CK about a 3500 stall and the box that arrived said 3400 on it.

Jim

 

[Razor]

By the looks of the rpm drops I would concur 3400. And if you do heads and cam and... run 25-27 PSI.. thats when you'll see it get stretched into the 5,000+.

As the TQ increases so does the stall. Flowing more air, making more power.... adds to the equation.

 

[turbojimmy]

By the looks of the rpm drops I would concur 3400. And if you do heads and cam and... run 25-27 PSI.. thats when you'll see it get stretched into the 5,000+.

As the TQ increases so does the stall. Flowing more air, making more power.... adds to the equation.

I have a fairly aggressive cam and P&P stock heads w/ a port-matched stock intake. No substitute for aftermarket heads, but still a bit better than stock.

EDIT: Messed up some assumptions about my own chart.

Jim

 

[turbojimmy]

Sorry 'bout the threadjack but....

One other question....based on the data, does it appear as if the TC is not locking at all? It locks up on the street pretty hard (like a 5th gear) but you can't see it impacting the RPM in the DS runs even though I can see the 'puter calling for the TCC to lock. Could it be slipping so bad that it doesn't even affect the RPM when it locks, or could it be something else (weak solenoid maybe?)?

Jim

 

[AKTURBOTA]

I have taken the plunge...I have ordered the PTS Billet Extreme 9/11 lockup torque converter with a stall speed of 3200. This should be the answer in getting the sorry 2.0-2.1 60' times back into the 1.6's.

 

[turbojimmy]

I have taken the plunge...I have ordered the PTS Billet Extreme 9/11 lockup torque converter with a stall speed of 3200. This should be the answer in getting the sorry 2.0-2.1 60' times back into the 1.6's.

Just an FYI....I posted my TC lockup question in the trans section:
http://www.turbobuick.com/forums/showthread.php?p=1113694#post1113694

Seems there's trouble with the 9/11s locking up at WOT.....

Jim

 

[AKTURBOTA]

Jim,

Not a good thing to happen.... I presently have a 9/11 torque converter in my TTA, but it has a stall of 2800 and that is why I am going to a higher stall speed. I have been running the torque converter since the summer of 2003 and have not experienced it not locking up at WOT.

Mark