What Stall with PTC NLU & DBB70GTQ

[NCTURBOS]

Are you saying you would use one with one of your builds and a 6765 or recommend it to someone that already has a 6765? Thats a major difference in my book.

Here is what I'm am seeing happen in the TR community.
It's not common around here to find 231-235ci builds at 9.1:1 0r better(yet).
Not many using E-85 which changes spool up and low end torque.
Not many who spend a vast amount of time working on spool up tune in their stand alone or chips that have adjustability in that area.
The majority of complaints are foot brake spooled cars or stoplight brawlers.
Many do not know how to check their converter in the car to evaluate its performance.
There are many different opinions of what quick spooling is.
Stand still foot braking, flooring it from a stand still, and rolling along at 30+ mph. spool will all be different.
People have been sold Turbo/converter combos and told "this is whay you need" but isn't! It's what the seller liked.
A 9.1:1+ comperssion stroker, race ported aluminum head car owner should not compare his spool up to a basic bolt on car.

I hate to see someone spent $1000 on a turbo, then $1000 on a converter and not be happy. I have been there and do my best to help others avoid it. From the cars I have been working on I have had great results. You really need to get a good feel for the customers intentions and expectations. It may not be "ideal" in a drag racers world, yet perfect for a fun street car owner.
Sorry for the long winded reply!

I would never recommend any converter based on turbo size only. But I have used 14-blade through 19-blade PTC's in different combinations, and feel very confident when I choose the converters for the cars.

I do agree with everything else you say...

K.

 

[forcefed3.8's]

I have an 18 blade. I was worried it would be too loose behind this power, but I am able to get enough rpm to make it couple. I used the same 18 blade behind my 245" 8:1 109 with the same turbo. It spooled the 76 fine. It had lag, but when starting in 1st, it would still fry the tires. Both combos are at under 3% slip (maybe less than 2%). My boss has an 18 blade in a 2004r in his 8:1 274" Stage 2 with a 76GTQ, and it is brutal, I would say no more lag than a stock car, doesn't hit like my car though. He had the 18blade with a 235" 8.5:1 engine with a 66GTQ before, and it had 0 lag. He is running a Red's SLIC too, so that helps over a giant FM like alot of us are running. Ofcourse we had 0 pump Vigilantes before these PTC's. We got used to lag. I watched Red cut a 1.34 60' off 5psi in his car with a 25x" engine, less than 8:1, 76mm 3 bolt, and a 0 pump Vigilante. He can make big turbos spool!!!
A friend of mine is running a 6765 JB with a tired 235" engine and a junk converter that was spec'd for a TE44. Spools very fast, builds boost with throttle when driving. He is looking to get a PTC, and I figured a 17 blade would do the trick.

 

[Dusty Bradford]

What many people miss is the importance of a realistic et goal and the shift rpm. If I spec a converter for a 5400 shift and 10.20's but the car shifts at 5800 and run's 10.80 the converter will be too tight. I've fought this issue with the nitrous customers for years. I'm not saying any of my turbo Buick customer's are guilty of this but I'm giving an example to better help guys understand how a converter works. A converter stall will change with the amount of torque applied to it. In the nitrous case, those guys like to brag about how big a shot they are using. So I spec a converter for a 400 hit and they call to tell me the converter is way to tight. So I ask for the jet sizing info. Turns out it's a 125 shot..........well there's the reason the converter is to tight. One converter can work with any combo but it can't be perfect for 17psi and then perfect at 30psi. This is why I base a huge part of the stall speed on an et goal. Sure I can build a loose converter for that great seat of the pants feel but it won't be faster at the track which is what most guys want. There's been many times I have talked guys out of buying converters when they tell me what their plans are or give me the rpm drop info on their current converter.

Once I get the spec's nailed down from the info the customer provides I then have to take a very educated guess at what the car wants. There's no way to test stall speed, it's simply an educated guess. Once it's in the customer's hands all the other variables come into play. A converter is sensitive to cooler pressure. A change of 40psi in the cooler circuit can change the stall speed 400 rpm and there's no way for me to predict this. I've had 1 customer with a plugged trans cooler that installed a new cooler and changed his stall speed 1000 rpm! Then you get into the tune-up. Is the a/f ratio fat, is the timing too low, is the boost turned way down, is the alky coming on too soon?? All of these will also effect the end result stall speed and this is the purpose of a free restall. Since I can't predict what the final stall will really be the restall is to cover this and get the customer what he wants and paid for. I can't promise the converter will be dead nuts the first time but I've got a good track record of doing so. In some cases it is necessary to send it back to change it around to work with the entire customers combo. Once the customer has it in the car, drive it. If you don't like the way it works, get me some data and I can fix it so it will. I know most guys only want to pull the trans 1 time but in some cases for everything to work perfect, it will have to be restalled. I've pulled the trans 3 times in one night to get the perfect stall speed in my own car.

The whole reason this 9.5 non lock came around was because it's the only converter I could find anywhere that would spool quickly while at the same time put the max amount of power to the ground. I've used everything on the market today and once I got into the 10's I felt the converter options were severely lacking. Get it tight enough to couple, it won't spool. Get it to spool, it won't couple. This 9.5 was the only thing I could find that can do both once the car reaches a certain hp level.

 

[Dusty Bradford]

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[2QUICK2B6]

good info. I had a a/c lock up on my stock engine 3200 stall was a blast to drive on the street with the TE60 would 60ft 1.55 ... changed to a 6768 turbo an a lock up pts 3400 and it wouldnt spin the tires good to heat them up. An zero drop in rpm the whole 1/4

 

[NyBlankets]

2quick, is that the billet 6768. How fast have you gone with it?

 

[2QUICK2B6]

10.97 with only a 1.68 60ft its getting major changes now ... that was the old bone stock motor.

coulda shoulda went atleast 10.60 with the right converter.

yeah 6768 dbb billet 4 inch outlet

 

[Alaskabuick]

Ok, snowed tonight but got the car out to see where the car spools. Now I dont have a clue on the standard way to do this or any directions. However, cruzing along in 2nd and roll into it the car will start to move the needle from 0 at 3100 rpm. Stop and brake it and same results.. this turbo wants to start building boost at 3100. Roll along and stab it , 3100 it starts making boost, 3500 it has you back in the seat. I have not played with tuning, so alot is in question.
So should I just keep this converter and go with a smaller turbo? Im looking for the seat of the pants, scare the crap out of the passenger ride.......

Dennis

 

[we4Mateo]

Ok, snowed tonight but got the car out to see where the car spools. Now I dont have a clue on the standard way to do this or any directions. However, cruzing along in 2nd and roll into it the car will start to move the needle from 0 at 3100 rpm. Stop and brake it and same results.. this turbo wants to start building boost at 3100. Roll along and stab it , 3100 it starts making boost, 3500 it has you back in the seat. I have not played with tuning, so alot is in question.
So should I just keep this converter and go with a smaller turbo? Im looking for the seat of the pants, scare the crap out of the passenger ride.......

Dennis

Should be able to scare passengers with a quick spooling TA49/TE44.

 

[jasjamz]

The 44 and 49 are too small for a combo like his. The 70GTQ is a beast at 24 psi. The way it pulls up top will not be duplicated by a unit that small. Even the ramp into boost will feel awkward to him. The car will feel like its restricted. The turbos I would suggest you look at are the Te-45a with a Garrett housing and, the new and expensive Precision 6466dbb. The 6266 and 6262 are little monsters but need to be up around 28-30 psi to be enjoyable to someone use to the big boy units. The smaller units hit harder but dont have the same top end charge. Your converter stalls at like 3100 rpm.

 

[bison]

I would not recommend anything more than a 6262 based on what youre looking for. It will spool fast and support the mass flow needed to run 133mph and spoolup will be nice. It will complement the cam well too if the flash is in the low 5000's. Im going to have some nice forged milled 62's in a couple weeks and most likely be coupled with a t350 turbine. They will support 700hp easily and spool extremely fast. For guys looking for a little less right now but want more later and want an even faster spoolup they will be available with a .63 garrett ex housing.

 

[Alaskabuick]

Sorry Guy, I have been traveling for two weeks and now just getting back to a PC.
Would my current converter spool a 62 turbo?