What Stall with PTC NLU & DBB70GTQ

[Alaskabuick]

What stall are folks using with this combo? I recently decided to try a PTC non lock up and new NLU tranny. In the past I have always used a 3600 stall with 911 billet converter or vig lock ups.

I did not know much about PTC NLU so I went with their recommended 3000 stall for my combo.

I like the way the converter pulls and delivers the power once she has a head of steam built up, however It is a dog off the line. Is anyone running this 3000 stall converter with the DBB70GTQ and getting it to be lively on the spool? If so any recommendations on where I should have my timing at?

Please dont take me wrong, I a happy with the converter and PTC service so far, Im just curious if it is something I may not have right?

Can this converter work right with my combo or should I just bit the bullet and send back for restall?

Also want to mention that my new tranny from CK is shifting like silk, thanks Chris! But it did take some close attention to adjusting the TV cable, man that is touchy.

girdled 109, 212/212 roller, champ alum heads, 3.42 gears, fiberglass bumpers a bit lighter than stock, PTE front mount.

 

[Nick Micale]

Something is not right here? An advertised 3000 stall for a 70mm turbo sounds WAY too low to me?

Since converter stall numbers vary all over the place, it is best to get a baseline by finding at what RPM does the converter reach at 0 boost.

You should see a minimum of actual stall level of 3000 RPM with this test, and maybe more with that turbo.

I purchased a 3800 stall converter the other day for a customer's car, and the actual stall with a 67mm turbo was 3100 at 0 boost, which is what I wanted.

 

[forcefed3.8's]

Is this a 10" or 9.5"? I have never heard a 9.5" sold by stall rating. That turbo needs a 9.5" to couple.

 

[Dusty Bradford]

Check the stall rpm at 0-1# of boost and let me know what it is. Also if you can log or check your rpm drop at WOT on the 2-3 gear change it will provide more info on how much looser it can go. I have a restall policy that will cover this, all I need is some info from data logs to make the adjustment.

What are your et goals for the car?

 

[Alaskabuick]

Thanks for the reply's guys. Ill see if I can check the rpm on the 0-1# and the 2-3 drop. Snow is about to fly any time now, but might be able to find some dry patch of pavement.
Goals are probably like many, a 10.5 sec street car. I very rarely go to the track and most is just fun seat of the pant thrill rides on a sat night. With that said, I may have to much trubo for what I am doing with a street car.
Maybe I should think about a smaller faster spooling turbo that could reach my goals? recomendations?

10" or 9.5" ? feeling kind of silly on this cause took it in the box to installer and never checked. From what I remember it is a 9.5" but Ill check that as well.

Nick, the car has one of your motors that was built for Turbosam in 05 who I bought the car from.

Dennis

 

[bison]

If you want a 10.5 street car then you should sell that turbo and go with something much smaller.

 

[Alaskabuick]

What would you suggest? I do have a (what I was told) a GT67 that was on the car when I bought it. The guy told me it was a TE45 that had been upgraded to a GT67 by Jon Craig. Does that sound right? Sorry, for my lack of turbo knowledge.
Den

 

[bison]

Id suggest a small shaft small compressor wheel turbo. Like an old cast 60-1 or a newer 6262. Or a custom small shaft turbo with a 76p turbine. There was a 6265bb for sale cheap recently and that would spool at least twice as fast as what you currently have. You want something that will spool fast and support the power you are looking for. A 70 GTQ will cover you but is not a good street turbo and i wouldnt even consider using it unless the car i was building had a 9.50 or faster goal. The other turbo you mentioned is a good turbo too but is still a little more tan id want for a 10.50 goal. On a junk shortblock with crappy flowing iron heads i went 10.61 on 93/alky with an old cast 60-1 last year. The car never showed more than 515whp but still ran the number. This year on a stock shortblock with a 212/212 cam and ported GN1 heads it made 550whp@22-23psi again on 93/alky. I didnt run the car again and wont because no roll bar but its probably got a 10.40 in it. If i run it again im going to be switching to a custom compressor wheel (60mm inducer or less) and be looking for high 10.20's to 10.30 out of it. It will spool as fast or faster than it currently does. Its a lot of fun on the street.

 

[Dusty Bradford]

I do agree a 70mm is overkill for the street but the data from the 0-1# stall test and the 2-3 rpm drop at your current boost level will tell the story of what the converter is doing. There are variables in the transmissions that I can't account for all the time that can cause the stall speed to be off from what I'm shooting for. If you have excessive rpm drop the converter needs to be loosened. If the rpm drop is on target but spool-up is slow then the tune or wastegate system needs to be looked at. Considering it spooled faster with the other converter it could just need to be loosened which would also make the smaller turbo come alive faster.

With that said. There is no doubt a smaller turbo that will spool easier and be more suited to your et goals just makes a happier combo.

 

[TurboBuRick]

I like 9.5 sec power on the street.

I got the same deal a while back when I thought I would try the great ptc. Took it back out sold it (dirt cheap) put my art carr back in and it was back to almost instant spool. I have the same blow dryer btw. Being a big wheel turbo it will always be a little sluggish but no problem for the art carr and I can feel the car shift again too. That was another characteristic of the ptc I was not fond of.

What number ptc converter you put in?

 

[bison]

I like 9.5 sec power on the street.

I got the same deal a while back when I thought I would try the great ptc. Took it back out sold it (dirt cheap) put my art carr back in and it was back to almost instant spool. I have the same blow dryer btw. Being a big wheel turbo it will always be a little sluggish but no problem for the art carr and I can feel the car shift again too. That was another characteristic of the ptc I was not fond of.

What number ptc converter you put in?

A lot of people would like 9.5 sec power on the street. Very few will ever have it or even have the stuff that could produce it. The problem with that is there isnt an AC converter out there that i know of that will come close to coupling even 80% of what that turbo can do especially with a small hyd roller. Not even close. Every car ive put a PTC in went quicker/faster than it did with the old converter. When i see flash stall speeds over 5600 with an AC and the car is only trapping low 130's then i know its going to be a problem when its turned up. Ive seen them sit at 6000-6200 all the way down the quarter. You need an engine that can support mass flow or you will have crappy performance with a big heavy turbine like the one in the 70 GTQ.

 

[bison]

If you have excessive rpm drop the converter needs to be loosened.

Or the engine needs to produce more power.

 

[Dusty Bradford]

Or the engine needs to produce more power.

Exactly. The 0-1# rpm stall will tell me how close it is to spooling the turbo. I'm sure he has the boost backed down from a 10.50 tune-up so I expect to see some extra rpm drop but I'll wait for the data to see how things are working.

 

[TurboBuRick]

A lot of people would like 9.5 sec power on the street. Very few will ever have it or even have the stuff that could produce it. The problem with that is there isnt an AC converter out there that i know of that will come close to coupling even 80% of what that turbo can do especially with a small hyd roller. Not even close. Every car ive put a PTC in went quicker/faster than it did with the old converter. When i see flash stall speeds over 5600 with an AC and the car is only trapping low 130's then i know its going to be a problem when its turned up. Ive seen them sit at 6000-6200 all the way down the quarter. You need an engine that can support mass flow or you will have crappy performance with a big heavy turbine like the one in the 70 GTQ.

LOL! I hear ya!

It's funny because the ptc would do exactly as you described the Art Carr. It would flash to a mid 5000rpm's and stay there.

The closest thing I can compare ptc converter to is snowmobile clutch. The faster you go the more it wants to go but I did not like the way it felt down low. I'm not a big track guy. My car is to nice to beat the hell out of and gamble on a accident at the track. It's more a street warrior that does not see much above 100mph. That said the Art Carr works better for my needs.

 

[bison]

LOL! I hear ya!

It's funny because the ptc would do exactly as you described the Art Carr. It would flash to a mid 5000rpm's and stay there.

The closest thing I can compare ptc converter to is snowmobile clutch. The faster you go the more it wants to go but I did not like the way it felt down low. I'm not a big track guy. My car is to nice to beat the hell out of and gamble on a accident at the track. It's more a street warrior that does not see much above 100mph. That said the Art Carr works better for my needs.

Sounds like you had a bad converter or it wasn't filling for some reason. Usually they are a lot tighter under cruise conditions and super tight under full power. Adding 100hp to the input usually only results in 100-150rpm more flash stall. Other converters will flash 300rpm higher with that much added power. You should try a different turbo for what youre doing. I'd bet you can get even better drivability out of it.

 

[TurboBuRick]

I have a 6765 dbb I got from another member I want to try. I also have another 9.5-700-27-17 ptc converter sitting here to go with it but I'm worried it will be too tight. The car runs so good now with current combo I've been putting off the swap. Not to mention I been working on everyone elses cars all summer long.

 

[jasjamz]

Dusty/Bison, how is that converter going to work that TurboBuRick has for his combo? I believe it will be too tight. I say this because a 9.5" PTC I recently installed was a 19 blade behind a Champion iron headed 109 with a 6262 turbo. Perfect match! 3000-3100 at 0-1 psi. I had an 18 blade behind my 70gtq, way too tight. Went down to a 6765, still too tight. I can't see a 17 blade making anything larger than a 58mm turbo powered TR fun to drive.

 

[bison]

Dusty/Bison, how is that converter going to work that TurboBuRick has for his combo? I believe it will be too tight. I say this because a 9.5" PTC I recently installed was a 19 blade behind a Champion iron headed 109 with a 6262 turbo. Perfect match! 3000-3100 at 0-1 psi. I had an 18 blade behind my 70gtq, way too tight. Went down to a 6765, still too tight. I can't see a 17 blade making anything larger than a 58mm turbo powered fun to drive.

I ran a 6265 journal with a 17 blade and it was really quick. It didn't flash as high as it needed to though. It flashed to 5400 at almost 75lbs/min. It needed an 18 to get the flash stall up around 5500-5600 where peak power was. I recently put a 17 blade in a stock headed car with a journal 6262 after building the trans. It was a tire fryer even on the chip tune. With an xfi the ramp in could have been improved. The 6262 is too much for a stock headed application unless you're going to run boost in the high 20's though. A 70gtq needs a 10:1 engine with a 19 blade to spool fast and shouldn't be used for anything that will trap less than 140mph. It may need an 18 blade in a really high boost application with a small hyd cam. I'm going to be running a custom sub 60mm turbo on one of my cars this spring. I'm looking for 70lbs/min out of it and it should spool faster than a 60-1. It should be brutal with any 9.5" converter even with a .85 a/r ex housing. For anyone with a lazy spooling 6262,65,66, 6765,66 that isn't trapping more than mid 120's (which they should be) I'd encourage the use of a Garrett .63 ex housing. It makes a big difference on the roll in spool up and flat foot from vacuum street punch. Either that or just run a loose converter. But dont expect that converter to couple the power the turbo is capable of. Im sure dusty could spec a converter with a different pump that will slip more down low but won't deliver optimum et for guys running large turbos on small engines on the street or chip cars that don't have the tunability of other systems.

 

[NCTURBOS]

Engine cui., both static & dynamic compression, camshaft choices, turbo sizes, etc. all will make a converter behave differently. The 17-blade PTC is my "go-to" converter! I have them in mid 9-sec. TSM style builds, and IIRC forcefed3.8's 8-sec. Stage-2 build has one as well. (It might be a 18-blade though).

I'd throw a 17-blade in a car with a 6765 in a heartbeat... Although I'd want to know some other information as well first.

Dusty has been extremely helpful also!! Speaking of... I need to order (3) more converters from him very soon!


K.

 

[jasjamz]

Engine cui., both static & dynamic compression, camshaft choices, turbo sizes, etc. all will make a converter behave differently. The 17-blade PTC is my "go-to" converter! I have them in mid 9-sec. TSM style builds, and IIRC forcefed3.8's 8-sec. Stage-2 build has one as well. (It might be a 18-blade though).

I'd throw a 17-blade in a car with a 6765 in a heartbeat... Although I'd want to know some other information as well first.

Dusty has been extremely helpful also!! Speaking of... I need to order (3) more converters from him very soon!


K.

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!