ZRE - exhaust upgrade vs 1/4 mile times

[rolla91]

hey everyone,

so lately iv been taking my new zre corolla to the drag strip for a bit of fun, when it was completely stock i got a best of 17.7 sec and i was changing around the 6000 rpm mark but now i have a 2 1/4 inch catback exhaust from the stock resonator, i went again last night and could only get a best of 17.9 but mostly were 18.1 and it had a lot less fuel which inturn would be less weight but i realise it may make no difference what so ever, and the only way i could acheive that figure was to scrap every last rpm from the engine and shift around 6700 rpm but my trap speed is now quicker. if i shifted at 6000 rpm it would get around a 18.5.

so has the exhaust made the engine loose some power/torque as on the street i can no longer feel it pull from around 3500/4000 rpm where all the torque is. is the stock exhaust better and do you think a CAI would help to drop the times slightly back to what they were or better?

i know im only talking a small amount of time and i know its no performance car but its all good fun and i want it to be atleast running what it did whenit was stock.

just curious

cheers

[DJKOR]

How many separate occasions did you venture out to the drags while stock, and how many of those times were you able to replicate your best time or get very close to it? Reason being is that sometimes you may not always be able to replicate your best run even when all things remain the same on your car. Dealing with the level of power you have, your ET relies heavily on your your launch. Getting it just right makes all the difference, and getting it just right can be quite a tricky exercise.

[2204]

mate im trying to achieve a 15.9 pass on my zze122 and the best i have been able to get so far was 16.8 all i have is a injen cold air intake, and by all means i know that our cars are not performance cars but i agree with you were all just trying to have fun and set a few goals.

[rolla91]

thanks for the reply guys. im launching at around 2500 rpm doesnt bog down and no wheel spin. my reaction times are quit good and pretty consistent had a best of 0.034 last night but usually around the 0.08 mark. the time before last my quickest run was my first one but the others were very close behind same with last night but my best were the last 2 runs when i really pushed it as far as i could to get the most out of each gear. i have the tickets in the car but the times were fairly consistent went something like 18, 18.1, 18.5, 18.1, 18, 17.9, 17.9

every run i try to do the exact same thing to get the same time well try anyway. its all just good fun but i would like to get to atleast a 17 flat

do you reckon a CAI would help along with the exhaust upgrade?

i did look and last night was a tad hotter then last time so that may have made a difference.

should have bought a zze man haha thats a good time for only a CAI nah im happy with the ZRE but i want it to go a little quicker 15.9 should be achievable i reckon. id like to try stock exhaust with a CAI now but too much stuffing around to change exhaust again.

[DJKOR]

There is so much in terms of variables that even if you feel like you are matching what you can, it can still have an effect on your overall run. I wouldn't be going as far as to saying your exhaust could be the reason behind such a difference yet. After all, the difference you are dealing with here is only 200 milliseconds. It's not unrealistic to consider just your normal atmospheric or driving variables to be causing this difference.

Two things however:

1) Reaction time does not have any effect on your 1/4 mile time. Take advantage of that and use an extra second or two to put more focus into your launch. It can make a difference.

2) I would not be expecting a 0.7 second improvement from just an exhaust and intake alone unless your stock ones had some serious issues. To give you an example, from my experience, the fastest time on my TRD Aurion was only 0.76 seconds quicker than that of my Aurion Sportivo. These two cars had a measured power difference of 40kW at the wheels. That's not to say one or the other could have performed better, but when you are dealing with things like this, there is a fair amount of variable.

[rolla91]

yea thats true, gear changes could have been 0.2 sec slower etc i know its only a small difference just thought the exhaust maight have contributed to that slightly since you can no longer feel the toque kick in now. i reckon the temp had something to do with it as well.

i think a 17 flat would be a bit far fetched unless i spent big $$ but that would be a waste of money the main thing is that i have fun and when i go i always have fun, i doubt ill do anymore to it CAI wouldnt make a huge difference i dont think.

[ben yip]

use this http://www.torquesta...?pid=calculator

exhaust will have only 4kw increase at the wheel

If you want to be faster, use a light wheel, 16 or 17.. wheel does make

http://www.caranddri...nd-tires-tested

Take off all your seat, and use 1/4 of fuel, they should make another 0.1 or 0.2

Shifting from 2nd to 3rd lost so much time, keep practising it

For the exhaust , another memeber has done a dyno before and after a cat back (dutchie101), no evidence to prove that the torque has been lost

Edited October 11, 2012 by ben yip

[SuperDave]

my trap speed is now quicker.

If your trap speed is higher you have more power. The reason why you are slower is at the other end of the strip; as DJKOR says, there are quite a few variables for this. How do the 60' times compare?

[4ABHGE]

Another factor to include is variation in weather conditions (wind, humidity and temperature) and grip levels. Both can alter your times a fair amount.

[rolla91]

my trap speed is now quicker.

If your trap speed is higher you have more power. The reason why you are slower is at the other end of the strip; as DJKOR says, there are quite a few variables for this. How do the 60' times compare?

I actually thought my trap speed was higher but i just had a look at the slips and its only about 1-2 km/h more but 60 foot times are higher in my recent runs. time before last i was averaging 2.7 but this time i went it was averaging 3 so quit a bit slower.

iv got a feeling the exhaust has had an impact i know there are other facotrs but i reckon the max torque has been moved further along in the rev range? only because even on the street you can really feel nothing unless your well over 4000 rpm now unlike before thats why if i reved righ to redline i got the best time of the night.

Another factor to include is variation in weather conditions (wind, humidity and temperature) and grip levels. Both can alter your times a fair amount.

yea i did consider this, temp/humidity last time i went was around 18 deg and 55-60 but the most recent time it was 23 deg and 70-80 so quit alot different

[rolla91]

what rpm would you recommend i launch at? i hold it on 2500 rpm then take off and plant it

[SILVABULLIT]

Could be the exhaust is costing you low down torque.

Up the revs on the launch to about 4500-4800rpm and slip the clutch of the line a bit.

Gut the car and take some weight out of it! Zre's are a bit on the beefy side so get some weight out and go that bit quicker!!

Reset the ecu and throw some octane booster in with minimal fuel and then go and drive it hard to let ecu relearn with higher octane fuel.

[rolla91]

Could be the exhaust is costing you low down torque.

Up the revs on the launch to about 4500-4800rpm and slip the clutch of the line a bit.

Gut the car and take some weight out of it! Zre's are a bit on the beefy side so get some weight out and go that bit quicker!!

Reset the ecu and throw some octane booster in with minimal fuel and then go and drive it hard to let ecu relearn with higher octane fuel.

i think thats exactly what the exhaust has done its either taken torque away or moved it further up in the revs.

i was gonna do that one day might take rear seats out and carpet and other things i dont need in there haha

i was considering octane booster, does that hurt engines though running extra octane or is just like using 98 instead of 91? can i run 98 and octane booster? and how do i reset the ecu? im currently using 95 octane.

[ben yip]

octane booster give you no performance increase (dyno proven on a FTO I read a long time ago) if your engine does not support it, putting 98 in our car which is designed for 91 is usless, except for cleaning the engine. My car has been tuned to use 98, but guess how many kw I gain, 3kw at peak

Unless your engine is desiged for checking the octane level (such as the golf gti), no performance increase at all, the following 2 videos say it.. actually

using octane booster will drop power by 2%

before reset the ecu, make sure you know your audio security code, disconnect the battery for 20 minutes, reset the audio security code

I don't know why your exhaust will take away any torque, no torque should be lost across the whole rpm range

Read the following, it includes torque graph as well

http://www.importtun...10_mazda_3_atx/

Our car should yield similar result, if you are losing torque, there might be leaking in your exhaust

Edited October 12, 2012 by ben yip

[4ABHGE]

Other than removing weight why not try to add more mechanical grip to the car by a means of suspension modification to make it launch quicker?

Oh and I have to run 98 on my 4AGE im scared it will go ping otherwise :P

[rolla91]

Other than removing weight why not try to add more mechanical grip to the car by a means of suspension modification to make it launch quicker?

Oh and I have to run 98 on my 4AGE im scared it will go ping otherwise :P

im only currently using 95 but i prefer 98 and weather it gives you 'performace' gains i dont know but i do know its is alot better for your engine especially when your flogging it and its safer so id use that, might try octane booster though to see if it does anything just hope it doesnt hurt the engine.

do you think suspension mods will work? iv been thinking of lowering it but cant afford coilovers yet as thats what i want but was thinking of just using springs for a while? even that would go nicely with my rear swaybar for through the corners, i dont have any traction issues though atm when im at the drags.

also any opinions on the CAI option? would this go nicely with the exhaust or not worth it?

[Hiro]

Weight I think is a definite killer, you're getting the same sort of times as an AE102 which has ~15kw less at the flywheel and 1 less gear (but 200kg lighter).

[rolla91]

i know less weight will make a difference just wondering why the exhaust has made a difference in the wrong direction.

its actually disappointing the time im currently running yes its stock and yes i have a great time everytime i go but i thought it might get a low 17 or high 16 just from what iv seen with the old zze models i know these zre's weigh more but i had high hopes haha doesnt really matter though its fun and legal thats all that matters to me.

take some weight out soon and well see how i go, going on a track day on the 18th of novemeber so might take some weight out and leave it out for the drags too

so still no opinions on CAI???????

[SuperDave]

Skip the octane booster, you'd get more gains by running a 'thinner' oil.

[rolla91]

Skip the octane booster, you'd get more gains by running a 'thinner' oil.

ok sweet ill leave the octane booster alone

does thinner oil mean less protection? do you know what oil toyota run from factory? (havent looked in service manual)

whats a good oil you would recommend? id like to change it after the track day anyways as it will still be a while till the next service

[4ABHGE]

Thinner oil means less friction in the engine...

Run a raised solid bar or something sitting on the bump stop in the rear with any lowering spring on the front so it rakes and reduces weight shift to a minimum. It will give you a much better launch.

[DJKOR]

Thinner oil means less friction in the engine...

Run a raised solid bar or something sitting on the bump stop in the rear with any lowering spring on the front so it rakes and reduces weight shift to a minimum. It will give you a much better launch.

Also if you go back to the 1/4 mile while stock, you can get a couple of old bump stops, cut it down the side, and then cable tie them onto your rears to help reduce you car squatting when you launch.

But at the end of the day, you should be aiming to get these great times without aids like stripping out the car etc. You only end up cheating yourself.

[rolla91]

Thinner oil means less friction in the engine...

Run a raised solid bar or something sitting on the bump stop in the rear with any lowering spring on the front so it rakes and reduces weight shift to a minimum. It will give you a much better launch.

Also if you go back to the 1/4 mile while stock, you can get a couple of old bump stops, cut it down the side, and then cable tie them onto your rears to help reduce you car squatting when you launch.

But at the end of the day, you should be aiming to get these great times without aids like stripping out the car etc. You only end up cheating yourself.

thats exactly right, ill strip it out one day but for now ill just keep trying to get my best while its pretty well stock which it is apart from the exhaust so might try a CAI and a few other little things then just keep practicing (iv been plenty of times before just not in this car) and ill see how it goes. at the end of the day i only go to have fun if i want a car that runs 14s ill buy a different car but for now the rollas good for me ;)

[xoom]

slap a turbo on it ..... get urself under 13's ;) ;) ;) ;)

[Licky]

Remember as the days go by, its getting hotter.. hotter = slower