Jays BOM DC5s

[butter]

Is there much benefit in getting ITB's then bottle necking it with a GruppeM?

[BOMDC5]

I will be doing a proper write up soon once I get my car back to its old self.. with more little goodies to go on.

[BOMDC5]

Is there much benefit in getting ITB's then bottle necking it with a GruppeM?

Of course. Even though it's still being funneled through an enclosed box, each cylinder is now being fed individually with its own throttle. There's no "bottlenecking" from a singular throttle body feeding into 4 runners. The box doesn't affect anything in the way you're assuming. As long as there is an air supply no issue. Advantage is greatly enhanced throttle response. Not to mention low and mid range torque benefits. The peak power is affected by trumpet length. The idea is to get the right balance of power and torque with this setup.

[butter]

Sorry, my real question was - why would you go ITB's if you're going to bottle neck it with a GruppeM?
Why not just have open ITB's to get the most out of that very expensive setup, or why didn't you go all that way, and then end up with a GruppeM.

Craig from PSR, a well known Honda Tuner here in Melbourne, discovered that the GruppeM on my DC5 was actually very restrictive air-box. We tested it on the dyno and it was proven to be more restrictive than say a cold air intake.

[MYDC5R]

Who done your tune ?
Looks really good mate, keep it up!

[LiteX]

That Toda airbox, IMJ37LY.

[BOMDC5]

Sorry, my real question was - why would you go ITB's if you're going to bottle neck it with a GruppeM?
Why not just have open ITB's to get the most out of that very expensive setup, or why didn't you go all that way, and then end up with a GruppeM.

Craig from PSR, a well known Honda Tuner here in Melbourne, discovered that the GruppeM on my DC5 was actually very restrictive air-box. We tested it on the dyno and it was proven to be more restrictive than say a cold air intake.

It won't respond anything like what your setup would though unless you had ITB's.
ITB's respond to free floating, uniform air better than forced, turbulent air so a box which acts as a collector can work to ITB's favor. Running open trumpets is not the goal of ITB's and not advantageous over this setup.
Example. Toyota have produced engines with factory ITB's since the 90s. 4AGE 20v for example being their first. They run an enclosed box, yes for sound deadening but also because they respond better and produce a smoother torque curve with a more controlled air source. More recently. The Lexus LFA. They run 10 ITB's fed through a covered air box. It's possible you could pull a few more kW's with wide open trumpets but it's also far more reactive to air temp, pressure and density changes and how each cylinder is fed is much more unpredictable. A controlled air source just allows a more much smoother running at a much more constant rate. Not to mention open trumpets causes exposure to debris and other pollutants flying around.

Who done your tune ?
Looks really good mate, keep it up!

Adrian from SAS did my tune! Thank you sir

[BOMDC5]

That Toda airbox, IMJ37LY.

Lol thank you ^.^

[butter]

It won't respond anything like what your setup would though unless you had ITB's.
ITB's respond to free floating, uniform air better than forced, turbulent air so a box which acts as a collector can work to ITB's favor. Running open trumpets is not the goal of ITB's and not advantageous over this setup.
Example. Toyota have produced engines with factory ITB's since the 90s. 4AGE 20v for example being their first. They run an enclosed box, yes for sound deadening but also because they respond better and produce a smoother torque curve with a more controlled air source. More recently. The Lexus LFA. They run 10 ITB's fed through a covered air box. It's possible you could pull a few more kW's with wide open trumpets but it's also far more reactive to air temp, pressure and density changes and how each cylinder is fed is much more unpredictable. A controlled air source just allows a more much smoother running at a much more constant rate. Not to mention open trumpets causes exposure to debris and other pollutants flying around.

Thanks for the response. I'm not expert on the matter so I can't argue with you there, however I was just under the impression that ITB's worked on a principle that of more air + more fuel = bigger bang = more power.
I was commenting on how a the GruppeM is a more restrictive airbox, as it doesn't allow a lot of volume of air to be sucked in from its opening, than say a cold air intake. Why not have a cold air intake instead?

Also, what is "free floating, uniform" air? Air sitting inside the GruppeM? Isn't GruppeM a cold air + ram air intake? So the air would be forced and turbulent inside the box?

I never considered that open trumpets would have the issue of having individual cylinders having different air. Is that a likely concern to have with it setup on the DC5?
And you can just get sock filters for the open trumpets, right?

I was considering ITB's at one point as well, but I didn't see the gains being worth it.

[BOMDC5]

Thanks for the response. I'm not expert on the matter so I can't argue with you there, however I was just under the impression that ITB's worked on a principle that of more air + more fuel = bigger bang = more power.
I was commenting on how a the GruppeM is a more restrictive airbox, as it doesn't allow a lot of volume of air to be sucked in from its opening, than say a cold air intake. Why not have a cold air intake instead?

Also, what is "free floating, uniform" air? Air sitting inside the GruppeM? Isn't GruppeM a cold air + ram air intake? So the air would be forced and turbulent inside the box?

I never considered that open trumpets would have the issue of having individual cylinders having different air. Is that a likely concern to have with it setup on the DC5?
And you can just get sock filters for the open trumpets, right?

I was considering ITB's at one point as well, but I didn't see the gains being worth it.

I honestly don't know how restrictive the Gruppe M compared to say the Injen CAI is. But Adrian who tuned the car suggested that the Gruppe M would be as good if not better than the Injen.

With the enclosed box on the ITB's it also prevents hot air from the engine bay being sucked in.
Having socks over it would still not address this issue.

The box provides a more stable air flow and supply this allowing the tuner to be able to modify the car in a consistent environment not to mention the temperatures from the air box will be a lot cooler than the ambient air in the engine bay.

Again I don't know too much about the restrictiveness of the Gruppe M compared to a cold air intake.

But I can tell you one thing throttle response is amazing plus it sounds better than any rbc/rrc in my opinion

[PG_DC5]

Do you know how much the power difference would be vs a supercharger kit? I'm assuming the price would be almost similar factoring in the gruppM. Would be interesting to know since these cars are almost peaking their N/A power stock

[BOMDC5]

Do you know how much the power difference would be vs a supercharger kit? I'm assuming the price would be almost similar factoring in the gruppM. Would be interesting to know since these cars are almost peaking their N/A power stock

Overall power will always be in favor of forced induction. But I'm not hunting overall power.
I was after throttle response plus the Gruppe M wasn't brand new hehe.

[Paulieee_R]

Remember what I said this afternoon? If your car isn't in your driveway, when I get home at 6am...

[BOMDC5]

Remember what I said this afternoon? If your car isn't in your driveway, when I get home at 6am...

She's sitting there lol

[Paulieee_R]

She's sitting there lol

Indeed she is. Welcome home.