alrighty so basically went to the track today, tried every single possible way to launch the car and it was an epic failure.

best 60' was 2.405. it was consistantly between that and 2.489

best run was 2.413 60', 14.662 1/4. and 99.8mph, i can only imagine a 2.1 60' then i would be around high 13's.

car has no balls off the line, but once it gets going it takes off.

so now the big problem. i need to build up back pressure. i refuse to put the primary cats back. i just installed the rv6 v3 jpipe and v3 pcds but somewhere i need to make up for my MAJOR loss of torque.

i was thinking originally of putting a cat after the jpipe but that would be pointless since it would be too far away. other option was to redo the j pipe merge and make it alittle harsher. and final thought was to do a true xpipe and build a dual exhaust.

i am open to all educated opinions.

thanks!

heres a couple shots from the track today, kinda bad quality since i scanned them and the guy printed the pictures out there

 

ATCO! I used to go there as a kid!

 

do you really loose that much torque of the line ? thats the only thing keeping me away of getting PCD.

 

sadly yes. it pulls hard around 3500, then pulls like crazy 5k-redline.

i previously thought my torque converter was blown, but there were no signs, and i finally figured it out today that its the lack of back pressure, pretty sad it took this long being its such a simple thing.

if you dont care so much about the 1/4 mile times do the pcd's. if you do care about the 1/4 mile time get richies hi flow precats.

i am in the middle, i never race on the street but occasionally when no one is around i like to "have fun" thats why i love the pcd's because their power is high in the power band, which is where it counts on the "street." and on the other hand i want to put up semi respectable 1/4 mile times and i have not even come close yet. i was contemplating nitrous, but i kind of shot that down because of the unknown damage that could potentially be done.

edit: i haven't experienced a lot of torque steer since i was stock.

 

I dont track my car but i love to have fun when i can and when its safe, well it never is but ej

Im just afraid that i would actually feel the loss of low end torque while just driving around. The Tl isnt peppy as is, making it worse doenst appeal to me at all.

 

well like i said, once your rolling, its awesome and you do not feel the loss. you only notice it from a stand still

 

Unfortunately, shaving 3/10 off your short time isn't going to shave 7/10 off your ET if nothing else changes, although you do have the trap speed to be in the high 13's.

Something does seem off here though, and my first thought was also that it's torque converter related. Granted my car is a stick, but on the single run I made down the quarter in '08, when I just had intake and catback, I ran a 14.5 @ somewhere between 99-100, but on a worse 60' than you. Mine was somewhere in the low 2.60's (hey I spun badly on a shitty track...lol)

With your 2.4x 60' times and trap speeds, I'd expect you to be at ~14.2-14.3 as it stands. I still don't think it's back pressure you need though. How are you launching the car?

 

MDX Intake Manifold Spacer?

 

What was ur tire pressure? What tires r u running? Have u tried launching ur car at different rpms? 3500? 4k? 4500? 5000rpms? ... what was the weather like? Air density? Humidity? Tire temp? There are MANY factors that can affect ur ET.

 

I'm wondering if the ecu timing is also a factor in the 0 - 2500'ish rpm range. The 6 MT shouldn't have this issue since they can control where they launch from.

My 07 5-A/T ASM TL-S is also the same from the line.

I think the new J&R ecu has a launch control function, which could be an option and really, really sweet!

 

While it might be true that your car has no "balls" off the line, its NOT because of backpressure.

Backpressure does not help anything.

ETA: This is a pretty good explanation
http://www.hondacivicforum.com/forum...ts-wrong-3064/

 

What are all your mods?

 

+1
you do not need backpressure. That is a myth. Especially during overlap, the less backpressure the better. Unless you want lower load

 

That was a really good explanation.

 

my tires never spun, they did a good job with the traction spray

bridgestone potenza re11's, they are summer tires not radials, i did not lower the psi. can not launch car above 2k.... i tried:
hitting the gas
rev to 1000
rev to 1250
rev to 1500
rev to 1750
rev to 2000

weather ranged from 64-68, was mostly cloudly, some sun from here to there. humidity was 35-37

thats another debate in itself.

aem v2
ur underdrive pulley
v3 pcd
v3 jpipe
greddy exhaust
tein ss, althought i did not mess around with the dampening since my seats were in and didnt want to take them out

 

Buy them for sure, the less catalytic converters the better.

 

Less back pressure is better end of story. Most people have just been misinformed. Would you care to explain why you need back pressure?

 

Yeah with those mods you would think it would be at least in the high 13's.

I think a stock type-s from the factory was said to perform a 1/4 mile @ 14.1 sec @ 101 mph.

But like everyone said they're are many variables that can effect this time.

I think the best way to determine if your car is running right is finding a dyno.

Lots of these people here have opinions, hit the dyno with high flow cats then compare them to straight pipes and let the paper do the talking.

 

you dont need back pressure. in fact, your MPH indicates you may have too much backpressure. are you auto? i put down 103-104 in the 1/4

 

something is not right!! you were in good weather 64-68 and like everyone else said your trap speed is good for high 13's low 14's!!

just to show you an example i have pcd's,jpipe,test pipe,mid muffler delete and resonator delete

with some shitty tires that thread was about 20%life left, full interior and full tank of gas @ 80-85degrees I managed to run 14.5@98mph with 60' of 2.3 which is pretty bad still! My TL-S is 5at so if you 5at as well it's all on the launch. is your VSA on or off?

I will be going back shortly after my RV6 exhaust comes in and I have got new tires and changed my tranny fluid to Redline lightweight

but back to topic I would not worry about the backpressure so much, I would check else where for the problem!

 

try driving a car with credentials to drag....

 

only thing about the dyno is it is not real world data. the powerband starts at 3k on dynos.

im going to get a dashdaq or dashdyno and add on dual wide band readings. another thing i was thinking was my car is running way to rich. but that cant be confirmed untill i add dual widebands.

the jandr ecu is in my future but not that soon since its 1400.

i dont really understand how i have too much back pressure. there is only 1 merge and thats at the end of the jpipe, the rest of the exhaust is basically straight through.

 

while i am no expert, i did some research and found that there needs to be low back pressure to help with scavenging, but i have no idea how much back pressure is needed and how much i am actually running.

 

You do not want back pressure. It will not help with exhaust scavenging. Pressure is not going to help suck exhaust gases out of the cylinder.

 

Needing back pressure is a myth. It's even more of a myth when you consider the car is on the small cam during most of your 60'. Only 2-strokes and rotaries need back pressure.

Usually eliminating back pressure boosts the midrange and upper rpms more making the low end feel weak when in reality it is not.

Scavenging should not be real important since it's a vtec car and the exhaust ports are merged inside of the heads. You could try the Supertrap muffler for adjustable backpressure for testing lol. I wonder if they still make those. For a street car, you should be able to chop the exhaust off right at the heads and not see a loss of torque.

i agree that a 2.4 60' with the pedal to the floor and no tire spin is lacking and that 99mph should be good for high 13s with a great launch. Take 3/10 off the 60' and you're looking at a 14.1. I've found that mine is quicker shocking the converter and you have to let off the brake before you mash the pedal. Maybe try using the e-brake to hold the car still so that your brake lights are not on and the ECU won't play games with the launch. That's assuming the e-brake is not tied into the throttle cut also. I've also found that a little tire spin is quicker in the 5at, gets you in the powerband quicker as long as you don't overdo it.

 

I think this myth came from a time when people would over cam their cars and use exhaust back pressure as a way to bring back some low end. It can work if the car is severely over cammed but it's a band-aid and it's not going to happen on a stockish TL.

 

Try a front tire pressure of 22 lbs, and are you as light as you can be? Empty trunk, low on gas, system out, etc. Also, on the third yellow just hit it from idle, but take a second or a little less to floor it, some tire spin is OK. If you mash it all at once,you will spin too much. The 99.8 MPH tells me good horsepower.

 

i tried to use the e-brake to hold it but they were very generous with the traction spray since there were a lot of high hp cars and it just pulled the car past the line very slowly lol. that time i ran 15+ lol

it was very frustrating and i was very depressed to say the least. not 1 thing i tried worked.

one guy actually said my car would be awesome in bracket racing since it ran 14.66-14.75 like clockwork. made me feel alittle better lol.

 

thats the thing

i have NEVER spun off the line. i have spun once the car got to ~4k rpms but then it caught

i had half a tank, extra weight was maybe ~20lbs, backseats were in.

 

Sorry, I meant to use the e-brake to hold the car there while idling and then mash the gas at the same time you release the brake. I'm sure you already know the ECU will only let it see roughly 25% throttle with the brakes on.

 

i just read through that thread and im going to order the parts monday. $50 vs several hundred for rebuilding the exhaust, ill try to cheap way first lol

i hit the gas while holding on to the e-brake, and once i felt it go forward i released. im pretty sure i let it go too fast, and pretty sure i creep past the line and it started the time.

 

HOw much do you weigh?

 

6'5" . 265

 

That's a 6MT; big difference.






I'll never understand why some people think that a competitive person who takes their sport sedan to the strip to have a little legal fun is trying to imitate John Force.

With a 165 lb driver and 1/8 tank your trap would have just kissed 101, up from 99.8. You're making decent power for a 3600+ lb car, so your et, coupled with your 60' still doesn't make sense. If everything is fine with your torque converter, is it possible their timing equipment is off?

You did have VSA off, right?

 

:ouch:

If you didn't before, remove your spare, your floor mats and Owners Manual/book. Also any misc "junk" in the car. Lighten the load a bit.

 

Bearcat, what did you run, like 14.3-14.4 @ 97-98 with just an IM spacer?

 

Correct.


14.37 @ 98 with lowering spring and TB Spacer. Stock tires ( ).

 

i agree, who cares what car someone takes to the track. his comment is pure ignorance, just like the people that say imports suck. its all about being an enthusiasts, not about what make car you drive.

the extra weight in the vehicle along with myself definitely does not help at all.

funny thing, my friend with a new cts-v came, he was running 12.2-4 consistent, then out of no where he ran 10.97 which is not possible

turning vsa/traction off is the first thing i do when get into any vehicle

that was the original plan, but of course nothing goes according to plan. me and my buddy were working tilll 3am on a sl55 that was suppose to go, but we ran into problems with the rear and were up till 3am trying to sort it out but didnt even get close to having it apart as EVERYTHING has to come off. after that, got home at 330, slept from 4-6, got to shop, rinsed car, then headed out, i completely forgot about it. it was just a horrible track trip, another vehicle couldnt make it because it needs new spark plugs and apparently the boost is blowing the spark out, car has 105k and never did plugs...go figure...oh and 8 hours for a plug change, kill me now. a mb s600

 

i am assuming automatic OP?

and if so.....
i know on a friend's 04 base, when you try and torque load the trans to get a decent launch it will make you start in 2nd gear instead of first, killing any sort of launch (sport mode or auto mode)

also with the e-brake thing NOT going to work at all, rears will more then likely just drag as soon as you start pushing the throttle


MAYBE figuring out someway to temporary keep the brake switch depressed (pedal up) while still allowing you to hold the brakes engaged (something like tape would work if it was strong enough)
and when done you more then likely loose your brake lights too, BUT do you really need them at the track though , just gotta make sure to reenable them before you drive home though
and before you think just disconnecting the switch will do, remember most switches are dual circuited, and while one switch is off, the other is on, so as soon as it gets disconnected there is a very good chance the modern ecu will pick it up right away and throw a check engine light (and YES some ecu's are getting to that monitoring capability nowadays)

 

Not so on the 3G TL-S. There may be other electronically induced "restrictions", but a forced 2nd gear launch isn't one of them.