Convertor woes

[Anonymous]

Running a 9" dynamic vertor/3000 stall , pretty loose on the street but i use a big cooler with built in cooling fan, so no issues with overheating.

60 fts on the motor only are 1.7 , with the spray it's 1.6 , bearing in mind the cam is ground on a tight lsa (108) , thinking this might not be helping , have tried launching @ 2500rpm , also stabbing the pedal , nothing seems to make much difference on the 60fts , maybe it's flahing the convertor pretty high on the gas?

Should i leave the 3000 stall in there bearing in mind i'm swopping the cam out to a 112lsa , or fit the 2800 stall i have?

I have to use one or the other , brasic @ the mo.

TIA.

[NaughtyAlan]

That aint no 3000 9inch thats waaaay to loose, more like a 4. Fit The 2800 10inch and you to could get 1.5 60ft times

[Pete]

I think a tighter convertor will hurt the 60 foot times.....

[Anonymous]

Sorry Al , but i can't take advice from my opposition , you could be steering me in the wrong direction.

[NaughtyAlan]

The more torque you have the looser the verta. When does your new cam come in at?

[Anonymous]

I would of thought a 9" convertor in a 4000lb car would be to small............. Does it blow the tires away on the line..................

[Mick]

Nitrous creates a lot of extra torque, that's why nitrous convertors are tight.
You have a lot of car to get moving, so your 60 ft's will never be stellar, what torsion bars do you run and are your shocks adjustable.
You need a close up vid of your launch, slow it down and you will see what the chassis is doing.
Mick

[Anonymous]

Ranchero 9000 adj shocks , also got the 1" torsion bars , been advised to go higher on the stall many times , really don't know whether to keep the 9" vertor in there & see if i get better results with the new cam , as the cam in there @ the mo makes great power mid track but Bananarama! off the line , don't wanna change two things @ once , also don't wanna pull the GV & box out again either.

Tis a heavy bitch to get movin.

Watcha reckon , flip a coin?

[Mick]

The problem is, the heavy torsion bars will stop the car reacting off the line but if you fit lighter ones your road handling will be compromised, have you got adjustables on the front?.
Mick

[Anonymous]

Standard shocks on front , thinking should i change them to adj?

Took off anti roll bar , did'nt see much difference.

[Mick]

Read this Adam
Mick


http://board.moparts.org/ubbthreads/sho ... o=&fpart=1

[Dave-R]

Your gears are too tall in the axle if I remember right?

You need some 4.30s or 4.56s in the axle to get that thing off its backside and moving. The rpms will come up better too. The 4.30s will still give you a decent top speed with the GV.

[MilesnMiles]

Adam, my usual disclaimer of being out of depth, but for what it's worth.. .I changed from 3.23 gears to 3.91 today. All other aspects remain untouched, but what i did note was that the (advertised 2800) convertor really liked the change of gears.
Much more immediate and none of that dragging feeling as if the convertor is pulling the motor down.

[Dave999]

sorry to hijack Adam

Miles

i'm guessin' that your gearbox has a 1:1 top most mopar seem to

whats the rpm like at 70

is the car reasonably driveable

is you motor set up for high rpm use or resonably standard.

just nosing

need to decide if i go for
option 1 3.5:1 (a factory option for an RT but not mine)

option 2 3.89:1 (set off an aussie nissan skyline that had 5 or 6 gears)

Dave

[MilesnMiles]

Dave, haven't put on enough miles to know for sure. That said, it wasn't the dramatic difference that i'd feared i.e too many revs at cruising.
I haven't got the correct speedo drive so can't cite figures.
The car has the right cam for the set up. As for drivability, the car felt really good, better than before. I'll let you know when i 've put some miles on it!
Despite the whine from the diff , it felt really good.

Sorry Adam