[lrust]

I removed my TH400 and am putting in 200 to get overdrive capability for Dragweek next year.
Previous trans/converter combo went 11.4 at 117 MPH. 67 GTO, 3800 lbs, 455 w 670 heads, QJet, SD OF cam and 3.55 gears. Converter was a 9” ATI streetmaster that I had loosened up upon refresh.
I will attach the RPM profile from my LM2 when leaving from idle.
Goals:
1. Not go backwards in terms of ET and MPH
2. Make it through Dragweek next year.
I also changed rear to 3.31 vs the 3.55 previously installed. Gearing of the two is below for reference.
TH400: 2.48, 1.48, 1.0
TH200: 2.78, 1.57, 1, .67
I am looking at:

I sent my info to ProTorque and they recommend 9.5” with 2800 - 3200 range.
Art Carr 10” 2600-2800
http://cpttransmission.com/2004R_10converter.htm

Although the effective gear ratio is higher with the 200 and gear change vs the 400 I feel like I need a converter that is not as tight as the two above.

Thanks in advance, Lowell

[pastry_chef]

PTC - ptcrace.com

[77 TRASHCAN]

Call Cliff!!!

[Cliff R]

"Although the effective gear ratio is higher with the 200 and gear change vs the 400 I feel like I need a converter that is not as tight as the two above"

Do you plan on locking up the TCC once the trans makes the 1-2 upshift? Good plan and a nice feature of the 200's if you plan on using a TCC in the first place.

I agree that you need a converter with more flash stall for what you are doing. Regardless of the trans first gear ratio the hit is still the same, heavy car to get moving, etc. I'm thinking a 9.5" unit that flashes to about 3600-3800rpms but couples well for "normal" driving and has a billet cover with multiple disc TCC inside. A bit expensive but worth every penny.....IMHO......Cliff

[Steve C.]

I agree on your choice of a non -lock up converter.

See jakeshoe's post here (#4) :

https://www.chevelles.com/threads/20...ter-ok.339828/


Also I highly recommend the Bowtie Overdrives TV and Throttle Cable SYSTEMS.

http://www.bowtieoverdrives.com/

.

[Cliff R]

You can use a LU converter with high powered set-ups but it absolutely MUST have a billet cover and greatly increased apply area as it is a "shift" when applied at WOT. This instantly ceases all torque multiplication so you can use it to your advantage, or in other words have a decent amount of stall speed and torque multiplication for the launch, then lock the converter on the 1-2 upshift (or whenever you want to) for improved power transfer for the rest of the run.

We've spec'd them out in both ways, everyone always has an opinion on this sort of thing, but for sure you need a converter than manages Pontiac power and doesn't take a butt-ton of RPM's to get it to couple well.

Here is an email from a recent customer we spec'd out a converter for. He had already purchased and was using one from another vendor and thought there was more in his combo:

"Cliff


thought I would give you an update. last weekend was our first chance to get to the track this year.


converter is working great. only 250rpm more on the street than the old converter and it`s really woken the car up on the 60ft. before was normally 1.60 now it`s 1.52 and pulls the wheels up. ran into a head wind all weekend but car still went it`s quickest at 10.90. should see some 10.8`s without the wind.


thanks again for your help with this."




.........Cliff

[dragracerx2813]

Alan Pope racing. I was talked into trying him and I must say I was impressed.