GS455 Stage 1 Turbo 400 not kicking down

Just bought a 1971 GS Stage 1 hardtop drove the 500 miles home over 2 days.
Trans changes up seamlessly on medium throttle, but once in top gear wont kick down when I floor it...the engine just pings!, got forged pistons so itll handle it but its not good.
Rang a mechanic mate who reckons these cars have an electric kickdown switch?
any ideas?...dont wanna burn up the trans!
Starting out in Low itll lay 2 strips of rubber till I manually shift to second, gears are on the column but.
Gonna be on the dragstrip on the 21st of this month so Id like to have everything tip top by then.
Help!

 

Look at Larry's timing thread before you flat foot it again. The pinging is a warning and you could damage the engine.

Adjust the kick down switch under the accelerator pedal.

 

Could also be carburetor/vacuum related.

 

Looking through all the reciepts I got with the car it appears the car may have a 200 4R Trans fitted.
Whats the go with them?. why would it be fitted not a Turbo 400?
and is kickdown issue the same? switch under the pedal?
Thanks for your replys by the way, getting a few on my suspected overheating/bung gauge thread too

 

When your car was built there were no 200R trans in the world. The Th400 could have been replaced in order to get a 4th gear overdrive. Unless specially built it is not rated to handle the torque of your 455. I am unsure what is in there now for a kickdown.

http://www.superchevy.com/how-to/49798-th200-4r-transmission-swap/

Share:


Stock 200 4R Overdrive

Maximum HP Rating: 300
Maximum Torque Rating 275
Standard Gear Ratio: 2.75/1.57/1.00/0.71
Optional Gear Ratio: (none)

 

We should probably add, for the OPs benefit, that the 2004R can be built to handle the 455 with power adders. There are lots of Turbo Regals out there with built 2004Rs running 500-600HP. I had one. (Just noticed your statement "specifically built".

 

Good to know, and the guy that built this car went to extremes judging by all the reciepts and records, Im looking at one from Bowtie Overdrives right now that lists the trans of the vehicle as a 200 4R, for complete TCC brake kit, SBB UNI lasser bracket with kickdown stud and hardware. Inside snap ring yoke. $190+
thats all Ive got on it though I do have a phone number for the guy who did a lot of the work on the car, just tried ringing but its Sunday morning where you are I think.

 

That must be an awesome ride with the overdrive and big Buick power N torque we have a 200 4R for pops car that hopefully will get installed this summer

 

Overdrive hey...well its turning 3000 rpm at around 110kph (70mph) if the tach is correct, it goes a bit wild once past 3500 dances a bit, and the one big pull I did in second I was watching the road not the tach, being LHD on the wrong side of the road commands full attention, I could try ringing Bowtie Overdrives but Ill try the other guy again later as the receipt is dated late 2011

 

Congrats on the "new" ride. Show us some pics. Did you get a build sheet with your documentation?

 

no build sheet was found in the car but I got a good breakdown of all the original equipment.
Dunno how to post pics, well busy going thru papers on the car and tryna find stuff out at midnight here so Ill get it sussed in next 24 hrs or so..its triple black and a very nice car.

 

Here ya go, my 47 Hearse in the background.
On the road home.
Sunset in the hood.
Bad to the Bone.
Fill er up!

 

No GS Grille? Sharp looking ride.....git it sorted out before ya flog on it. Jim

 

Really nice GS. Enjoy it.

 

flog on it???speak strayan mate!....,
looks like a '71 GS grille to me mate, watcha talkin about?

 

Looks like a GS grille to me, too!

 

Ahh, misread ,thought I was looking at a 70. Jim

 

well its that smooth you cant really tell.
Now I was under the impression it still had the Turbo 400 fitted so now I know other wise I will count the shifts.
I managed to ring the guy on the receipt for the 200 4R bits, seems the trans was in the car when he got it there was quite a few things needed tidying up.
He said he finetuned the TV cable so it was operating perfect and also added the Grand National brake switch to cut out the lockup convertor and added an underdash switch to manually lock it up.
Just crawled under the dash at 2am and the switch is no longer there.
Ron said he was informed the trans was out of an 87 Grand National and they can supposedly cop the grunt factor of the 455.
Now I'm getting somewhere...also the original Turbo 400 has gone missing somewhere along the line, Ill see if I can track down its wherabouts...
I have a mate whos game is transmissions so Ill ring him when its daylight and a reasonable hour.
I need to get a roadworthyness check done in the morning too then pay the rego charges and stamp duty and get her on the road all legal, once the trans issue and temp gauge issue are sorted the game will be on!
Next weekend Im volunteer flag marshal at the historic motor racing at Morgan Park Warwick so I may drive the GS out there, as long as its all good, or I may ride the Victory if not.
Thanks everyone for your help, Im hitting the sack now but keep the ideas and comments coming iof you like, this is only the first chgapter of my V8 Buick!