I did a search, found a few posts but nothing that answered my question specifically... I'm finally doing some engine work and will be at the track later this summer, now I'm getting told by a lot of people to not even bother modding an automatic car (F-them hahaha)...my question is, how much faster is a manual-equipped car with a stock or stage 1 clutch compared to a 4t40E tranny w/ interceptor at 100% LP. (Et's in decimals please) just a rough idea. Or an idea of the driveline losses of a auto compared to a manual would help too.
The mods will be done before I race it will be: wai, LZM tri flow cams, 2.4L intake man swap, balanceshaft delete kit, cobalt ss/sc green top injectors, professional HPT tune including transmission tuning/optimizing/torque management/shift points, 4-2-1 header and 2.5" full exhaust system..... high 14's doable at sealevel?
Don't buy from MANTAPART!!
There is no easy ways to get HP, no magic box or gizmo... And if you get more hp, there's no way to make your car still behave and sound like a stock one. More hp usually makes your car louder, more vibrations and harder to drive...but still people hope or think maby there's some magic way to have it all, comfort, stock sound and drive.
Should also mention the car is 4 speed auto base model, no AC or ABS, motor mounts and lots of suspension mods which have added some weight...4597 is the weight without driver.
Don't buy from MANTAPART!!
There is no easy ways to get HP, no magic box or gizmo... And if you get more hp, there's no way to make your car still behave and sound like a stock one. More hp usually makes your car louder, more vibrations and harder to drive...but still people hope or think maby there's some magic way to have it all, comfort, stock sound and drive.
Meant to say 2597 vehicle weight, lol..
Don't buy from MANTAPART!!
There is no easy ways to get HP, no magic box or gizmo... And if you get more hp, there's no way to make your car still behave and sound like a stock one. More hp usually makes your car louder, more vibrations and harder to drive...but still people hope or think maby there's some magic way to have it all, comfort, stock sound and drive.
Numbers wise, don't know, but it really comes down to the driver for the 5 speed, a good 5 speed driver who can shift correctly (and keep in the rpm for most power) should be a tad faster.
That's really light. Are you sure you're not around 2800?
Yup, sure.... well relatively..weighed on a truckscale and subtracted my weight....2800 is a fully loaded Z24's weight, and I don't have sunroof/AC/ABS/etc.
Don't buy from MANTAPART!!
There is no easy ways to get HP, no magic box or gizmo... And if you get more hp, there's no way to make your car still behave and sound like a stock one. More hp usually makes your car louder, more vibrations and harder to drive...but still people hope or think maby there's some magic way to have it all, comfort, stock sound and drive.
Ive read threads on thos before and the general concensus is that stickshift cars are about a half second faster in the quarter mile stock for stock. Course the more power you make the easier it willbe for the engine to turn the auto. Thats why all the old mucle cars use autos....cant shift faster than a built auto no mater what. just have to have the power to turn it and make up for the parastatic loss an auto gives.
Find a high stall torque converter and the automatic will really wake up. Generally, Automatics are better for drag racing and that shouldn't be any different for J bodies once you get some power behind it. And yes with those mods, you should get 14's.
Zs Z wrote:Ive read threads on thos before and the general concensus is that stickshift cars are about a half second faster in the quarter mile stock for stock. Course the more power you make the easier it willbe for the engine to turn the auto. Thats why all the old mucle cars use autos....cant shift faster than a built auto no mater what. just have to have the power to turn it and make up for the parastatic loss an auto gives.
Yikes, a half second is a LOT faster...it would take a number of extra mods then to have a auto car be as fast as a manual with good driver.
Don't buy from MANTAPART!!
There is no easy ways to get HP, no magic box or gizmo... And if you get more hp, there's no way to make your car still behave and sound like a stock one. More hp usually makes your car louder, more vibrations and harder to drive...but still people hope or think maby there's some magic way to have it all, comfort, stock sound and drive.
Green96 wrote:Find a high stall torque converter and the automatic will really wake up. Generally, Automatics are better for drag racing and that shouldn't be any different for J bodies once you get some power behind it. And yes with those mods, you should get 14's.
I definitly want to get a higher stall torque converter, but if doing that I would prefer to build the whole tranny up at once...the bands, clutch packs, valve body, etc.
Don't buy from MANTAPART!!
There is no easy ways to get HP, no magic box or gizmo... And if you get more hp, there's no way to make your car still behave and sound like a stock one. More hp usually makes your car louder, more vibrations and harder to drive...but still people hope or think maby there's some magic way to have it all, comfort, stock sound and drive.
Speaking of stall Convertors, I have yank. I think its 2800. Does the 2800 mean the launching point I should launch at? Or am I way off? lol
~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ
FastFireTwoTwo wrote:Yup, sure.... well relatively..weighed on a truckscale and subtracted my weight....2800 is a fully loaded Z24's weight, and I don't have sunroof/AC/ABS/etc.
My Z weighted in at 3002lbs with me not in it....
WHITECAVY wrote:Speaking of stall Convertors, I have yank. I think its 2800. Does the 2800 mean the launching point I should launch at? Or am I way off? lol
David it should stall to 2800RPM before the converter states to move the car withe the brakes on.
Edited 1 time(s). Last edited Tuesday, May 26, 2009 4:32 AM
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
3002 lbs. seems alot,that's as much as my vert was.To the OP,I always say that,stock for stock,a 5 speed J will beat an auto,but not by much and I think a fwd auto will always have the more consistent launches.Built auto vs built 5-speed,I have to say you'll see better ET's with the auto,some will argue but IMO you cannot shift faster than a computer
15.2@89mph 2.171 60ft. 9.830 1/8 R.I.P. "LULU"
Thx Mike, it would be ok to launch above 2800?
~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ
If it's one of the Yank, like I got, It stalls at 3000 rpm. Stock is 2375 rpm, so lauch rpm is considerably higher.
Ideally the stall should be between 600 and 1000 rpm below your torque peek, to make full use of the launching ability of the transmission.
I havnt weighed my Sunfire in awhile but it used to weigh just over 3 grand with a full tank, my heavy ass stereo system, and me in it.
I think the car weaights about 200lbs less now.... I need to re weigh it.
Zs Z..... all the old muscle cars have not gone to automatic.... its just that more of them where built and there more common...... you see quite a few (50/50) sometimes with manuals at the strip.
Trans brake vs correctly set launch limiter an a manual on high power cars? It pretty much comes down to the driver.... although the auto is much easier to launch correctly.
Our cars with minimal mods.... 5-speed is a little faster.... but you have to know how to drive it..
Also.... are you going to be bracket racing or "real" racing?.... Because if your going to be bracket racing.... it doesnt matter and the auto will prob end up being a good thing for its consistency.
As for the High 14's your shooting for... assuming your running an L61 or LD9.... if you cant hit that with those mods theres something wrong.... I'm running that with less mods (although I have a 5-speed)
My bone stock best with 5speed ecotec was 15.7. It was rather hot out that night....
And to compare apples to oranges, an auto base cobalt was running 16.4. Not sure how much they weigh though
my auto is faster then all the five speed cars that i have raced, my cav ran mid 15s stock no clue wat it runs now.
jeff stone wrote:my auto is faster then all the five speed cars that i have raced, my cav ran mid 15s stock no clue wat it runs now.
Could you please verify what you just said?
because taking that at face value......... well...... I cant think of anything nice to say LOL (assuming you meant what you typed)
cav vs. cav maybe 3 tenths
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
OK, to clear up some junk in this thread here:
At low power levels (below 300whp) a 5spd is always faster than an auto. Now later on in the higher HP ratings people switch to an auto for consistency not speed of shifts like mentioned. Above 350whp the auto will be faster. But, above 350whp isn't a street J
As for power loss through the different trans, it's generally about 20% with a 5spd and 30-35% with an auto. So, for the 180 CRANK HP cars on here w/ autos, That's why you are only making 125 whp at the dyno
Vitamin E has the right idea. Its not just all about how fast you can shift, its drive train loss. Not only is the auto heavier but the engine has to spin a lot of that weight and it robs power.
I've heard about the same numbers as posted above and have raced cars with autos on an oval and they are always significantly slower than the 5 speed cars. The entire field is made up of manual cars for a reason. the only time anyone ever has an auto is when they are new and they learn quickly and within a few weeks they have swaped it out for a 5 speed.
Plus the fact a 5 speed is 100 times more fun to drive.
OK if we are talking an actual race track and not a drag strip... then ya.... manual tranny no questions asked..
But if you drive it around as a dd or just every-so-often, there is nothing more fun than a manual trans. =P
Drag strip does not make a automatic any more appealing when it comes to a cav, the cav auto trannies are @!#$
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
