What torque dip?

[Opposed]

^^ Correct, they do have access to both port and direct injectors. That was one way they were able to improve low end torque as well with the tune.

[Gardus@Supersprint]

Never mind....
Well i guess it's something more complicated than just the A/F ratio.

[Burn]

Originally Posted by Gardus@Supersprint

Never mind....
Well i guess it's something more complicated than just the A/F ratio.

Perhaps that's where a standalone ECU like motec comes in..

[dabocx]

I wonder what effect a aftermarket intake manifold would have or cams.

Honestly its strange that its there from the factory, the car would be killer without it.

[draggin_az]

Originally Posted by Drift-Office

Could we at least see a dyno chart to quantify the above statement please?

Regards,


Bob @ Drift-Office, LLC

i personally dont have access to a dyno but this thread does a good job at showing what your asking for

http://www.ft86club.com/forums/showt...=FA20Club+tune

[Dimman]

Originally Posted by Gardus@Supersprint

Never mind....
Well i guess it's something more complicated than just the A/F ratio.

What else can affect AFRs? So far you've looked at fuel. Now look at air.

[Gardus@Supersprint]

There may be some restriction in the intake or the tune given to the intake wave pressure may be not optimized on the rev range of the "valley".

[Neziah]

Originally Posted by draggin_az

i personally dont have access to a dyno but this thread does a good job at showing what your asking for

http://www.ft86club.com/forums/showt...=FA20Club+tune

Just FYI - Those dyno charts in that thread, are from Bob's shop. ie: the guy you are replying too.

I am pretty sure he is asking for dyno charts to back up the claims of the OP.
:happy0180:

[Dimman]

Originally Posted by Gardus@Supersprint

There may be some restriction in the intake or the tune given to the intake wave pressure may be not optimized on the rev range of the "valley".

Right, so what are the two ways of affecting intake wave pressure?

[Danzzt231]

The power dip reminded me FD2R Civic Type R



Coming from zzt231 Celica, it too has a dip right before lift, i never feel it. Driving such car all i have to do is rev it and maintain speed at powerband the whole time. I cannot be lazy and unaware of what gear I'm at. Makes driving the car aggressive and rewarding, to me at least.

I haven't got my GT86 yet, but that power dip wont be a real issue i think. Most of the time in city driving don't you all shift at 3000rpm? And when you floor it the dip quickly passed anyway. If not, a couple of downshift would land you back to the powerband. The powerband of this car is looks to be overall much better than my Celica for sure, but i will find out soon in December if Toyota keeps its promised.

[Gardus@Supersprint]

@Dimman you can either change the shape/lenght/diameter of the intake or you can introduce resonator or other geomery variants to send a pressure wave at the desired rev range...
Are you testing me?
@Danzzt231 I used to have a Honda S2000 in 2002, so I know what you mean. I also used to have a Clio RS, which had a much flatter torque curve, and it was much easier to stay in the "good" power band. This engine seems to give you enough torque to have some guts while driving slow in high gears, but it's nice during spirited driving, so instead on concentrating on filling the "valley" we should think about incresing horsepower in the upper range.

This has revealed to be much harder than we thought, unless you work on the headers there's no way you get more than 3-5 hp.

I'm also really skeptic about intakes, on our tests they usually give less power than the stock setup, especially on NA cars.

[Razz]

It's been posted that the dip is caused by the intake manifold design.

[Dimman]

Originally Posted by Gardus@Supersprint

@Dimman you can either change the shape/lenght/diameter of the intake or you can introduce resonator or other geomery variants to send a pressure wave at the desired rev range...
Are you testing me?
@Danzzt231 I used to have a Honda S2000 in 2002, so I know what you mean. I also used to have a Clio RS, which had a much flatter torque curve, and it was much easier to stay in the "good" power band. This engine seems to give you enough torque to have some guts while driving slow in high gears, but it's nice during spirited driving, so instead on concentrating on filling the "valley" we should think about incresing horsepower in the upper range.

This has revealed to be much harder than we thought, unless you work on the headers there's no way you get more than 3-5 hp.

I'm also really skeptic about intakes, on our tests they usually give less power than the stock setup, especially on NA cars.

Lol, I'm trying to bring the thinking process on this out into the open a bit more, not 'testing' you. Different perspectives help me, too.

What about wave transfer from exhaust to intake during overlap? Also, low pressure returns during exhaust valve opening can help pull out more spent charge even without overlap.

Changing the exhaust primary lengths is what moved the dip lower in the rpm range. And the stronger drop is from wave transfer during overlap, since the AVCS haven't been adjusted to reduce overlap in that rpm range.

In my non-professional opinion.

[Gardus@Supersprint]

That came out wrong, I was kidding!

You're probably right about the overlap...we won't know till we test a slighly different design.