Lift timing

[DuGong]

since the sportivo kicks in at supposedly 6k. does lowering the lift kick in help the car perform bettter . example introducing a VAFC-2?

on paper it states that the sportivo has 141kw but low on torque and does 8.2s. is the correct figure? has any1 beaten this 8.2s claim?

comparing the sportivo to the DC2 type-r. does the sportivo have a chance in perfomance to keep up?

[Northy]

VAFC wont work, the only way to change the lift kick in would be an apexi power FC or some other replacement ECU

[shaohaok]

does lowering the lift kick in help the car perform bettter

←

where do ppl get this idea from??

not having a go at u in particular, but perhaps there is a reason y it kicks in at 6200rpm and not 5000 or 2000.

every cam profile has an optimal powerband that operates between a certain rev range.

"example introducing a VAFC-2?"

no. vafc doesn't work coz the v stands for vtec. afaik, lowering the vtec changeover point on a stock engine makes it worse, unless u have different cams put in.

"on paper it states that the sportivo has 141kw but low on torque and does 8.2s. is the correct figure? has any1 beaten this 8.2s claim?"

i think any owner who doesn't have the sticky shift problem should blitz those times easily, unless the test strip was up a steep hill.

low on torque? y not use the shorter ratio gearbox that comes with the car? :P

"comparing the sportivo to the DC2 type-r. does the sportivo have a chance in perfomance to keep up?"

very close. if both drivers are just as good with the stock car. the stock dc2r should only be but inches ahead.

[Blade Hunter]

on paper it states that the sportivo has 141kw but low on torque and does 8.2s. is the correct figure? has any1 beaten this 8.2s claim?

←

A little bit of clutch slip in the 1-2 change will hold you in lift and see you stomp that time into the sub 8 second area.

[DuGong]

"no. vafc doesn't work coz the v stands for vtec. afaik, lowering the vtec changeover point on a stock engine makes it worse, unless u have different cams put in."

got sites that have cams for the 2zzge?

[51EKA]

Cams haven't been released yet. TPR and a few other companies are making prototypes and should be release later this year. Check newcelica.com or everythingcelica.com for cam release. They talk alot about it over there.

And 8.2sec claim? Someone must be seriously messed up to pull out 8.2sec out of the sportivo. :P

[shaohaok]

"no. vafc doesn't work coz the v stands for vtec. afaik, lowering the vtec changeover point on a stock engine makes it worse, unless u have different cams put in."

got sites that have cams for the 2zzge?

←

nope, not that i know of

[Danthuyer]

Cams haven't been released yet. TPR and a few other companies are making prototypes and should be release later this year. Check newcelica.com or everythingcelica.com for cam release. They talk alot about it over there.

And 8.2sec claim? Someone must be seriously messed up to pull out 8.2sec out of the sportivo.  :P

←

check any celica site...there are a few places doing cams but its all very hush hush...and as of now i dont think anyone has even started on the exhaust cam yet?...or am i wrong????

[51EKA]

Cams haven't been released yet. TPR and a few other companies are making prototypes and should be release later this year. Check newcelica.com or everythingcelica.com for cam release. They talk alot about it over there.

And 8.2sec claim? Someone must be seriously messed up to pull out 8.2sec out of the sportivo.  :P

←

check any celica site...there are a few places doing cams but its all very hush hush...and as of now i dont think anyone has even started on the exhaust cam yet?...or am i wrong????

←

Yeh.. everything is apparently hush hush. But on some of the threads. TPR has leaked abit of info. Can't remember where or what. None of the company is ready to release the cams yet as they aren't getting the gains they want.

[Danthuyer]

here is a pic of the intake cam that TPR have done....do results or anything as yet as 51EKA commented they didnt like the gains or lack there of :(

[MR22ZZ]

here is a pic

←

???????????

[Blade Hunter]

here is a pic of the intake cam that TPR have done

←

Where??

[Danthuyer]

um i have an issue here boys soz...it says my global space left is 0 bytes?????

Help steve!!!

[Blade Hunter]

um i have an issue here boys soz...it says my global space left is 0 bytes?????

Help steve!!!

←

LOL Thats classic, this forum can be quiet for hours at a time, and in the 2 mins that you have technical difficulties, 2 of us reply LOL

[MR22ZZ]

PMSL....

You payed extra for the SILVER membership and now have no global space, where we plebs get unlimited... ???

and Steve, I'll be sure to join soon...

Edited April 5, 2005 by Blue_Stivo

[Danthuyer]

pleb's is an understatement for some of you guys :P *jokes*

this isnt bloody fair i tell you :(

I want my money back with interest :P

[51EKA]

Go to reg.imageshack.us or photobucket.com

[Danthuyer]

[DuGong]

i c i c.

i thought that altering the lift point to suit to the box would be better than waiting for the lift to come you. As the power band is not high on the rpm, the acceration is there earlier.

has anyone tested this out yet on the 1/4mile track, NOT dyno. the power maybe down but it may improve the time.

[51EKA]

i c i c.

i thought that altering the lift point to suit to the box would be better than waiting for the lift to come you. As the power band is not high on the rpm, the acceration is there earlier.

has anyone tested this out yet on the 1/4mile track, NOT dyno. the power maybe down but it may improve the time.

←

Do you mean, altering the lift to kick in earlier so you could stay in lift when changing gears? You'd most deffinately lose power. And be slower on the 1/4mile than a driver that can stay in lift without changing lift engagement. If you think that way, you might want to change the rev limiter up a couple hundered instead so you can land lift easier.

[DuGong]

i c i c.

i thought that altering the lift point to suit to the box would be better than waiting for the lift to come you. As the power band is not high on the rpm, the acceration is there earlier.

has anyone tested this out yet on the 1/4mile track, NOT dyno. the power maybe down but it may improve the time.

←

Do you mean, altering the lift to kick in earlier so you could stay in lift when changing gears? You'd most deffinately lose power. And be slower on the 1/4mile than a driver that can stay in lift without changing lift engagement. If you think that way, you might want to change the rev limiter up a couple hundered instead so you can land lift easier.

←

getting to kick in earlier. i noe that u would lose power. but how do u noe that u be slower in the mile? in the sportivo. u change gears and it drops below the magic 6200. say u change the lift to 5000 where the gear change is. then lift is always there on the upshifts. u would get better pull. wouldnt the torque be more earlier?

[51EKA]

i c i c.

i thought that altering the lift point to suit to the box would be better than waiting for the lift to come you. As the power band is not high on the rpm, the acceration is there earlier.

has anyone tested this out yet on the 1/4mile track, NOT dyno. the power maybe down but it may improve the time.

←

Do you mean, altering the lift to kick in earlier so you could stay in lift when changing gears? You'd most deffinately lose power. And be slower on the 1/4mile than a driver that can stay in lift without changing lift engagement. If you think that way, you might want to change the rev limiter up a couple hundered instead so you can land lift easier.

←

getting to kick in earlier. i noe that u would lose power. but how do u noe that u be slower in the mile? in the sportivo. u change gears and it drops below the magic 6200. say u change the lift to 5000 where the gear change is. then lift is always there on the upshifts. u would get better pull. wouldnt the torque be more earlier?

←

I'm pulling figures out of my a*s now..

But say.. Change lift engagement down just say 500rpm and have it kick in 5700rpm. You'll have 130kw instead of the 140kw. You'll have that 130kw 1st gear, 2nd gear, 3rd gear and 4th gear. That means your 10kw behind through each gear change.

So say two sportivo were at the track. One with 140kw and crappy driver that can't stay in lift. And one with 130kw that can stay in lift. Take off both the same but the 140kw stivo leaps ahead abit before gear change. Change gears, 140kw stivo lags abit and go back in line wif the 130kw sportivo. It'll then have 10kw more than the 130kw sportivo through 2nd, 3rd and 4th gear.

And that's with a driver that can't stay in lift. Most drivers can stay in lift. You understand? Unless you can alter lift and still keep the power. Then you'll be faster.

But yeh, all that just came out of my b*tt so i may not be right.

Edit: Someone's bound to have a better more correct explaination than mine.

Edited April 5, 2005 by 51EKA

[shaohaok]

i c i c.

i thought that altering the lift point to suit to the box would be better than waiting for the lift to come you. As the power band is not high on the rpm, the acceration is there earlier.

has anyone tested this out yet on the 1/4mile track, NOT dyno. the power maybe down but it may improve the time.

←

Do you mean, altering the lift to kick in earlier so you could stay in lift when changing gears? You'd most deffinately lose power. And be slower on the 1/4mile than a driver that can stay in lift without changing lift engagement. If you think that way, you might want to change the rev limiter up a couple hundered instead so you can land lift easier.

←

getting to kick in earlier. i noe that u would lose power. but how do u noe that u be slower in the mile? in the sportivo. u change gears and it drops below the magic 6200. say u change the lift to 5000 where the gear change is. then lift is always there on the upshifts. u would get better pull. wouldnt the torque be more earlier?

←

u'd just be waiting longer to get back into the powerband

Edited April 5, 2005 by shaohaok

[51EKA]

I missed that bit. I have no idea what your asking.. Sorry.. :(

[MR22ZZ]

To put this one simply guys, if you extrapilate the power / torque (torque is simply an integration of the power) curves from the 2 cams and you will see the intersecting point is the magic 6200 RPM figure. Toyota did not just guess this figure, there is real science behind it... Lotus have adjusted the cut in point to 6000 for the Exige in 1st and 2nd gear but this is still within the tollorences if the 2 cams... if you extend the lift point either way you will create a hole in the torque curve..

I hope Craig won't mind me discussing this but I chatted to him a while back about this issue and my POV was that the best solution was to engineer a 'progressive lobe' cam which gradually shifted from a low RPM setting to a high RPM setting, rather then being on 2 seperate lobes. This would produce a smooth transition everytime, as you don't swap cams, and could also be extended to a much higher RPM by continuing the cams size progression (and stiffening the valves and springs, refined pistons and rings, etc, etc)... I think a similar method is used in F1 engines but I could be wrong. The down side is that these need to be precission engineered by hand making them extremely expensive, and the research that needs to go into it, well you may as well design a whole new engine around the cams as well..