[Drsagacity]

There was a discussion in another thread, so figured it was a worthwhile subject....anyone with LT4, Maggie, Whipple, or any other PD blower running a converter? If so, which one and what was the difference at the track?

On the other side, anyone running a Procharger, ecs, or Vortech without a converter?

If you are in either situation, please post your ET and MPH with the setup.

[wnta1ss]

As I recall, hogwild87 ran a 10.13 in his Procharged SS with the stock torque converter. He did more work to the car after that and therefore that time is not on the fast list anymore, however if you search through the old postings you should find it.

[Drsagacity]

Originally Posted by wnta1ss

As I recall, hogwild87 ran a 10.13 in his Procharged SS with the stock torque converter. He did more work to the car after that and therefore that time is not on the fast list anymore, however if you search through the old postings you should find it.

He's running the F1, right?

Sweet, maybe he will chime in.

[Drsagacity]

No responses...we saw one p1 blower in a different threat that ran 11.9 at about 116mph with no converter, anyone else?

We also have a few Magnusons running 10’a with no converter.

I am trying to gauge from real results:

1. Can the PD blower benefit from a converter?
2. Have things changed enough from my centri days that a centri blower can get away without the converter.

Times on the fast list lead me to believe that nothing has changed, but please, if you have numbers she’d some light on the subject.

[wnta1ss]

Originally Posted by Drsagacity

No responses...we saw one p1 blower in a different threat that ran 11.9 at about 116mph with no converter, anyone else?

We also have a sting of Magnusons running 10’a with no converter.

I am trying to gauge from real results:

1. Can the PD blower benefit from a converter?
2. Have things changed enough from my centri days that a centri blower can get away without the converter.

Times on the fast list lead me to believe that nothing has changed, but please, if you have numbers she’d some light on the subject.

You cannot really hold that 11.9 against the centri honestly, it was a crappy track. He said the stock Camaro ran 12.9 and we know that on a decent track they run low 12s or sometimes high 11s.

[Drsagacity]

Originally Posted by wnta1ss

You cannot really hold that 11.9 against the centri honestly, it was a crappy track. He said the stock Camaro ran 12.9 and we know that on a decent track they run low 12s or sometimes high 11s.

That isn’t what the fast list shows. We see stock ss Camaro running 12-13sec quarter mile times. Regardless, just looking for facts. My real purpose is to understand if a converter might make sense for my setup and just looking to understand facts not what the Internet researchers believe “should be the case”.

[KingLT1]

The stock converter is decent imo...guys are getting 1.5 60fts with it. So no you don't need a converter, but adding one might net you a couple tenths off your ET. The only setups that require a higher stall converter are Cam cars that have a fair amount of overlap and need increased idle rpm.

I'm not sure what fast list you are looking at but the slowest time on the list I see for a bone stock A8 is 12.3 and the fastest is 11.9.

[Drsagacity]

Thanks King.

I see another thread with the PD blown car, similar DA to centri, but running no converter deep 11’s in 125mph range.

I know it’s not “needed” on a pd car, but we are talking 10’s of a second improvement to make a cool number, right. I am kind of thinking about what it might take to run a vert into the 9’s. . .Pray is making it look easy with his setup...

[TEEZYSS]

According to Kevin aka hog his car did have a F1A on meth that went a high 9 second pass through manifolds and the stock convertor. According to Procharger the largest pulley or lowest psi on the F1A for our cars is 10-12psi and would 100% require 100% meth. Kevin did tell me that the stock motor let go because he was using the normal pre TB sprayer which did not distribute equally causing it to go lean. He ended up going to direct port meth with no issues.

[Drsagacity]

Originally Posted by TEEZYSS

According to Kevin aka hog his car did have a F1A on meth that went a high 9 second pass through manifolds and the stock convertor. According to Procharger the largest pulley or lowest psi on the F1A for our cars is 10-12psi and would 100% require 100% meth. Kevin did tell me that the stock motor let go because he was using the normal pre TB sprayer which did not distribute equally causing it to go lean. He ended up going to direct port meth with no issues.

Yeah. That makes a ton of sense because the F1 is a different animal all together. The F1 is a beast! I could for sure see running enough boost to grenade a motor, with meth, could result in great times while it lasts. Good info.

[toohighpsi]

This is what we ran with stock torque converter, stock engine, stock exhaust manifolds, and catalysts.

Video here:
https://youtu.be/bdJz6CJALtU

I don't think that this car would have gone any faster with a converter, the stock converter is pretty well suited to the 8 speed trans with a PD at this level. In the video you can hear the tires at their limit through first gear and in reality pulling a bit of timing at launch might have resulted in a slightly better pass.

We have gone as fast as 9.1@ 153 with the stock converter and 8 speed trans, but launching 1st gear at that level requires a well prepped track. I have just got home from Power Tour and none of the tracks could support a 1st gear launch with the really low first gear of the A8. (no real prep and lots of street tires running on the track)

With that in mind - the solution was to launch in second which resulted in:



Our 60' increased from a "prepped track" value of 1.39 to 1.52, but still a pretty respectable ET and MPH. Unfortunately after about 8-9 passes we began to notice some transmission problems, I think the transmission is still OK, but I believe that we have failed the lockup function in the stock converter. At least that is what the data looks like.

At this point I have no plans to continue to run the A8, we will be switching to a TH400 with a higher stall converter which I believe will ultimately be a faster solution in this car. Once the A8 is at this power level I don't think there is a good answer - it is near it's limit and shifts to much costing you precious time with every shift. Each shift requires 0.25 sec with ignition timing at about 0 - that's over a full second of a low 9 sec pass with heavily reduces power. The TH400 will happily shift under full power.

SO - with a PD you're in good shape with the stock converter up to the point that the transmission can't handle it anymore. I'm not saying that you won't be slightly faster with a higher stall, but as the car get faster it's less necessary.
The centri gets benefit from the converter, higher RPM at the line will allow it to get higher boost and further into is power range for better 60's.

Not sure if this exactly answers your question, but it summarizes my A8 learning to date...

[Drsagacity]

Originally Posted by toohighpsi

Attachment 941431

This is what we ran with stock torque converter, stock engine, stock exhaust manifolds, and catalysts.

Video here:
https://youtu.be/bdJz6CJALtU

I don't think that this car would have gone any faster with a converter, the stock converter is pretty well suited to the 8 speed trans with a PD at this level. In the video you can hear the tires at their limit through first gear and in reality pulling a bit of timing at launch might have resulted in a slightly better pass.

We have gone as fast as 9.1@ 153 with the stock converter and 8 speed trans, but launching 1st gear at that level requires a well prepped track. I have just got home from Power Tour and none of the tracks could support a 1st gear launch with the really low first gear of the A8. (no real prep and lots of street tires running on the track)

With that in mind - the solution was to launch in second which resulted in:

Attachment 941432

Our 60' increased from a "prepped track" value of 1.39 to 1.52, but still a pretty respectable ET and MPH. Unfortunately after about 8-9 passes we began to notice some transmission problems, I think the transmission is still OK, but I believe that we have failed the lockup function in the stock converter. At least that is what the data looks like.

At this point I have no plans to continue to run the A8, we will be switching to a TH400 with a higher stall converter which I believe will ultimately be a faster solution in this car. Once the A8 is at this power level I don't think there is a good answer - it is near it's limit and shifts to much costing you precious time with every shift. Each shift requires 0.25 sec with ignition timing at about 0 - that's over a full second of a low 9 sec pass with heavily reduces power. The TH400 will happily shift under full power.

SO - with a PD you're in good shape with the stock converter up to the point that the transmission can't handle it anymore. I'm not saying that you won't be slightly faster with a higher stall, but as the car get faster it's less necessary.
The centri gets benefit from the converter, higher RPM at the line will allow it to get higher boost and further into is power range for better 60's.

Not sure if this exactly answers your question, but it summarizes my A8 learning to date...

This is perfect and matches my experience running both setups. This is exactly what I expected (but opposite of some claims in a different thread). Net/net, until its time to change the transmission, the stock converter is just fine for the Maggie.

Just happy to have this put to rest by one of the most experienced on the forum.

[parbreak]

11.3 126 mph

Stock converter
PS4's at 24 psi

[Drsagacity]

Originally Posted by parbreak

11.3 126 mph

Stock converter
PS4's at 24 psi

Parbreak, great info. Do you recall your rwhp for that run?