topping out???

[71_dart_swinger]

well i have a 71 swinger w/ a 360 and 727. mods are as follows...
360 ci purple shaft .509 292 duration torker intake edelbrock 750 headers tranny work is 2800 stall tci tci shift kit 8 3/4 w/ 3.55s rear tires are 24 inches tall and 7 inches wide my question is y is my car topping out at about 80 mph at 6000rpm

 

[340mopar]

If you are saying it won't go any faster it could be a fuel supply problem. If you have exhaust manifolds it could also limit rpm.


Chuck

 

[71_dart_swinger]

well i have a realy good fuel pump and 3/8s fuel line from tank to carb and full length headers its just doin like 75 80 mph at 6000rpm and i only have 3.55s

 

[63dartman]

Something doesn't sound right with those numbers. I have a 360 in my dart with a 904 and 3.23 8 3/4. with a stock converter.At 5000 rpm in 3rd gear i am over a 100mph. I am running 235-60-15 tires. I wouldn't think that 3.23 to 3.55 would be that much of a difference on the top end. Are you sure it's going into 3rd? Almost sounds like it's in second gear.

 

[GoodysGotaCuda]

you sure your in third? lol, secondaries opening? check if your getting wide open throttle?

 

[71_dart_swinger]

yeah its going into 3rd i can count the shifts yeah it doesnt make any sense to me either i have no idea. its pretty frustratting

 

[340mopar]

Your tach has got to be wrong, what kind of tach? To be at 6000rpm @ 80mph and a 24" tall tire you would have to have a 5.00 gear.

With a 3.55 gear your rpm should be 4200. Does your tach have a switch for 4,6 and 8 cylinders? if it does I would say it is set at 6 cylinders

Chuck

 

[ValiantMike]

I'm no expert, but if you're turning 6000rpm with 3.55s you should be doing more than 80mph. A taller tire would help top end, but there must be a power loss somewhere in between engine and pavement if your numbers are correct. Are you sure that speedometer is correct. If rearend gears or stock tire height has been changed, speedometer will read incorrectly. You have to change gear going to speedometer cable to correspond with gear or tire height change. Mike

 

[71_dart_swinger]

lol im hoping ur right its a sunpro 5inch w/ shift light

 

[63dartman]

340mopar is right, Have you verified your rpm and mph to known good? Tach would be the first to check. Are you sure you got the right speedo gear for your combo?

 

[71_dart_swinger]

i know that the speedo is off cuz i have gotten diff gears. i know they are about 15 20 mph off. but even w/ the speedo off the speed is only reading about 90 100 mph at 6000 rpm and w/ the lower gears i know im goin slower than what the speedo says

 

[340mopar]

If it's this one here it has an internal setting for 4,6 or 8, my money is on that it is set on 6.

http://www.sunpro.com/product_detail.php?pid=16379

Chuck

 

[71_dart_swinger]

no its not that one. its the one that looks just like the autometer. and it does have the 4 6 8 cyl adjustment in back how do i know were to move those little markers lol

 

[340mopar]

It should tell where the switches are what arrangement it should be.


Chuck

 

[71_dart_swinger]

it has little switches that go from 1 through 6

 

[63dartman]

SUNPRO has user manuals listed under customer service for their tach's. fyi

 

[340mopar]

They are called dip switches, try this.

http://www.sunpro.com/publish/2004/08/05/pdf_english_16331.pdf


Chuck

 

[71_dart_swinger]

hey thanks for the help guys thanks

 

[demon seed]

The quickest way to find out if your speedo is accurate is find someone with one of those handheld GPS that also show speed and take it for a ride. That's what I used. If your speedo and tach are accurate then either your tranny or converter are slipping like crazy.

Terry

 

[71_dart_swinger]

yeah well i just got the pics of how to set the things on back of tach and like a dumb dumb i had them off so i have adjusted to way it says and now i can tell the diff lol i feel like an idiot but thanks anywho guys thanks

 

[340 Dart]

So how fast are you going at 6,000 rpm's now?

 

[71_dart_swinger]

lol i have no diea my tranny is still bein way dumb i have no clue what it is and it sucks cuz im so eagor to get out and see my mph vs rpms now, ill just have to have it hauled over to the tranny placee who put in my shif kit on monday and see what they can do. ive tested pump by takin of the line and starting engine, spits out trany fluid real good, i have adjusted bands and the kickdown lincage is still fine and i have let it sit in nuetral for 1o mis to build pressure i have no idea why i i am barely moving in gear....????

 

[mullinax95]

well i have a 71 swinger w/ a 360 and 727. mods are as follows...
360 ci purple shaft .509 292 duration torker intake edelbrock 750 headers tranny work is 2800 stall tci tci shift kit 8 3/4 w/ 3.55s rear tires are 24 inches tall and 7 inches wide my question is y is my car topping out at about 80 mph at 6000rpm

336 X 3.55 X 80 / 24 = 3,976 RPM

By doing the math you should be running 3,976 RPM at 80 MPH.

 

[340 Dart]

That sucks, but it's going to be nice when you have it all fixed.

While you are there have them put in the correct plastic gear so your speedo is correct also. They are still available at the dealer and only a $3-$4 apiece.

 

[get dustd]

I would guess your not on third. my charger with a 26" tall tire would top out about 90 in second. I remember because the car would trap like 99 at high 13's and it was frustrating that i had to shift to third. If your engine is at 6grand you can hear it. If you think it seems like its revving fast then the tach might be off. make sure your kickdown isnt doing anything wierd or something like that.