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[feeutfo]

Let me ask you a q or two then.

Why mess with something that ain't broke?

Why assume I five minute fiddle would make it better, over god knows how many hours of development to tune an engine to a certain size and weight car designed for carrying passengers in comfort as quickly as possible?

Why does the " slap on a cone filter "(I realize that's not the question but the mentality is the same) approach automatically mean it must be better?

Why not take the approach that GM must have put it there for good reason.

What I really want to know is, why does re connecting the two sides of the previously split intake post maf affect the power delivery?

I suspect it's to do with intake flow rates at high and low rpm. Why exactly that is I'm not sure. Knowing the positions of the m.ram valves at certain rpm would give a clue I suppose. Difficult to tell when it's all fitted together though.

 Awaits a post from master DTM... And runs off to look at the guide in maintenance. 

In simplistic terms, you tune the engine power with the length of the intake (eg, remember YPVS on 1980s Yamahas).  The multirams, in effect, are adjusting the intake length.

Aeye. Was trying go remember what length gives better flow at high and low rpm and all the malarky. Although ypvs and exup are all exhaust tune related. 

Yamaha now have a system for raising or lowering bell mouths to suit rpm too.

[mr carl]

Let me ask you a q or two then.

Why mess with something that ain't broke?

Why assume I five minute fiddle would make it better, over god knows how many hours of development to tune an engine to a certain size and weight car designed for carrying passengers in comfort as quickly as possible?

Why does the " slap on a cone filter "(I realize that's not the question but the mentality is the same) approach automatically mean it must be better?

Why not take the approach that GM must have put it there for good reason.

What I really want to know is, why does re connecting the two sides of the previously split intake post maf affect the power delivery?

I suspect it's to do with intake flow rates at high and low rpm. Why exactly that is I'm not sure. Knowing the positions of the m.ram valves at certain rpm would give a clue I suppose. Difficult to tell when it's all fitted together though.

 Awaits a post from master DTM... And runs off to look at the guide in maintenance. 

if it isnt broke, then brake it....and then fix it lol

i dont know, i like to know the ins and outs of everything. i like to know how stuff works, how it can be improved, if it can be improved at all that is.

its just the way my mind works 

[Broomies Mate]

One word - Turbulence.

I shant bother going into detail, because for one, it's boring, for two, it's not easy to explain without a wind tunnel to give a visual reference.

The Multi-Ram setup is there for a reason.

The reason it is not fitted to the Cav/Calibra is because it wouldn't fit...... Oh, and if you have driven a 3.0 V6 Cavalier/Calibra, it doesn't work fine at all.  The torque curve is terrible (even for a V6) and the usable power is limited to say the least.  Fortunately the small weight of the Cav/Calibra makes the engine output enough.  Remove the Multi-Rams from an Omega and you'll be wondering if you're driving a V6 at all! 

[albitz]

Everything can be improved upon, but its usually not as easy as we would like it to be.

[mr carl]

 

http://www.omegaowners.com/forum/YaBB.pl?num=1153840176

that writing leaves a lot to question....and says "flattens out the torque curve" the only part that bothers me is why? why would they want to flatten it out?

[TheBoy]

 

http://www.omegaowners.com/forum/YaBB.pl?num=1153840176

that writing leaves a lot to question....and says "flattens out the torque curve" the only part that bothers me is why? why would they want to flatten it out?

By 'flatten' that doesn't mean 'squash' or 'lower', but remove the troughs (flatspots) that plague the chavalier and calibra.  Does that make sense?

You are right to want to try to improve things, thats how progress happens.  But you'll struggle to improve on whats there easily

[mr carl]

I see enough Omegas with non-functional multirams, and they are gutless.  Owners are always amazed at the difference when you fix it.


To test, simply remove the vac pipe between the solenoid and the actuator. Flat as a Witch's Tit will be your conclusion.


The intake on the Omega is actually not that limiting. Far from it. Every single attempt I've seen to 'improve' it, staying normally aspirated, has been a downgrade.


Lastly, just because the likes of those retards at Courtney Sport say something will improve things, that doesn't make it so.  A proper tuning company is a different story, but note that no proper tuning company has made a new intake for the Omega

sweet, i will give it a go.....but also note, no one makes a simple back box for a omega either 

What, decatted with no silencers?  I'll think you find they do  .  In fact, I know someone looking at getting rid of one, and putting a normal, cheap exhaust on in order to recover a whole heap of lost power from the car caused by 'upgrades'.

no i meant what i said, back boxes...i cant find any online....anywhere  i can find std ones where the exit pipe is the same diameter as a single pipe going in to the backbox...that must be some what restricting when you are taking two of the middle pipes and reducing the size to the single exit hole?

[mr carl]

 

http://www.omegaowners.com/forum/YaBB.pl?num=1153840176

that writing leaves a lot to question....and says "flattens out the torque curve" the only part that bothers me is why? why would they want to flatten it out?

By 'flatten' that doesn't mean 'squash' or 'lower', but remove the troughs (flatspots) that plague the chavalier and calibra.  Does that make sense?

You are right to want to try to improve things, thats how progress happens.  But you'll struggle to improve on whats there easily

yes that does make sense, although tbh i dont really know the problems the cav/calibra suffer with.

thats cool, now i am getting somewhere, knollage is power and all that 

[TheBoy]

I see enough Omegas with non-functional multirams, and they are gutless.  Owners are always amazed at the difference when you fix it.


To test, simply remove the vac pipe between the solenoid and the actuator. Flat as a Witch's Tit will be your conclusion.


The intake on the Omega is actually not that limiting. Far from it. Every single attempt I've seen to 'improve' it, staying normally aspirated, has been a downgrade.


Lastly, just because the likes of those retards at Courtney Sport say something will improve things, that doesn't make it so.  A proper tuning company is a different story, but note that no proper tuning company has made a new intake for the Omega

sweet, i will give it a go.....but also note, no one makes a simple back box for a omega either 

What, decatted with no silencers?  I'll think you find they do  .  In fact, I know someone looking at getting rid of one, and putting a normal, cheap exhaust on in order to recover a whole heap of lost power from the car caused by 'upgrades'.

no i meant what i said, back boxes...i cant find any online....anywhere  i can find std ones where the exit pipe is the same diameter as a single pipe going in to the backbox...that must be some what restricting when you are taking two of the middle pipes and reducing the size to the single exit hole?

THe 3.0 backboxes have twin outlets. Though ones I've driven with single outlet didn't seem down on power  :-/.  Probably because the 2.5/3.0 manifolds are so restrictive anyway

[Broomies Mate]

 

http://www.omegaowners.com/forum/YaBB.pl?num=1153840176

that writing leaves a lot to question....and says "flattens out the torque curve" the only part that bothers me is why? why would they want to flatten it out?

I think you are mistaking the wording.  A Torque Curve should be as balanced as possible (something that a V6 does quite nicely in most applications).  GM, however used the Multi-Ram setup to further BALANCE the torque/power.

GM arent the only ones to use this, other manufacturers do too under different names.

It's a very impressive way to 'in layman's terms' create the effect of Variable Valve Timing without the associated mechanical workings.

[mr carl]

 

http://www.omegaowners.com/forum/YaBB.pl?num=1153840176

that writing leaves a lot to question....and says "flattens out the torque curve" the only part that bothers me is why? why would they want to flatten it out?

I think you are mistaking the wording.  A Torque Curve should be as balanced as possible (something that a V6 does quite nicely in most applications).  GM, however used the Multi-Ram setup to further BALANCE the torque/power.

GM arent the only ones to use this, other manufacturers do too under different names.

It's a very impressive way to 'in layman's terms' create the effect of Variable Valve Timing without the associated mechanical workings.

so they are maniulating the torque curve to use it more effectively at different stages in the rpm range?

[mr carl]

I see enough Omegas with non-functional multirams, and they are gutless.  Owners are always amazed at the difference when you fix it.


To test, simply remove the vac pipe between the solenoid and the actuator. Flat as a Witch's Tit will be your conclusion.


The intake on the Omega is actually not that limiting. Far from it. Every single attempt I've seen to 'improve' it, staying normally aspirated, has been a downgrade.


Lastly, just because the likes of those retards at Courtney Sport say something will improve things, that doesn't make it so.  A proper tuning company is a different story, but note that no proper tuning company has made a new intake for the Omega

sweet, i will give it a go.....but also note, no one makes a simple back box for a omega either 

What, decatted with no silencers?  I'll think you find they do  .  In fact, I know someone looking at getting rid of one, and putting a normal, cheap exhaust on in order to recover a whole heap of lost power from the car caused by 'upgrades'.

no i meant what i said, back boxes...i cant find any online....anywhere  i can find std ones where the exit pipe is the same diameter as a single pipe going in to the backbox...that must be some what restricting when you are taking two of the middle pipes and reducing the size to the single exit hole?

THe 3.0 backboxes have twin outlets. Though ones I've driven with single outlet didn't seem down on power  :-/.  Probably because the 2.5/3.0 manifolds are so restrictive anyway

this is what i mean, the diameter of the backbox exit pipe is the same size as a single pipe going into the backbox





do you see what i mean, its like a funnel....gasses going in fast, but exiting slow due to the single bore

[Broomies Mate]

 

http://www.omegaowners.com/forum/YaBB.pl?num=1153840176

that writing leaves a lot to question....and says "flattens out the torque curve" the only part that bothers me is why? why would they want to flatten it out?

I think you are mistaking the wording.  A Torque Curve should be as balanced as possible (something that a V6 does quite nicely in most applications).  GM, however used the Multi-Ram setup to further BALANCE the torque/power.

GM arent the only ones to use this, other manufacturers do too under different names.

It's a very impressive way to 'in layman's terms' create the effect of Variable Valve Timing without the associated mechanical workings.

so they are maniulating the torque curve to use it more effectively at different stages in the rpm range?

Yes and No.

Yes, because the literally wording you have used is correct.

No becuase you'll take it that more torque could be had at 'a given point'.

Torque is an extremely difficult force to explain (Clarkson esq) lol.

Do me a favour if you would...... go and unplug your rear mult-ram.  Take your car around the block and notice it will be less than before under 4k revs.

Then reconnect it and disconnect the front multi-ram. This will make it less powerful above 4k revs.

Then come back and ask WHY they are there!

Or, add a couple of resisters to the plugs, remove the whole lot and see what happens.

You'll have a nigh on 2tonne Cavalier.

Good luck! 

[feeutfo]

Yep. As Mark says...

You need to consider that for optimum torque you need high air speed in the inlet........so if the inlet is small and long you get high inlet airspeed at low revs but a restriction at high revs (good bottom end torque but nothing higher in the rev range), if its short and large you get low inlet air speed at low revs and good inlet air speed at high revs (no bottom end torque)......the multiram allows a good compromise on both i.e. high air speed at low revs and high air speed with low restriction at high revs.....its a dam good system.

[Broomies Mate]

I see enough Omegas with non-functional multirams, and they are gutless.  Owners are always amazed at the difference when you fix it.


To test, simply remove the vac pipe between the solenoid and the actuator. Flat as a Witch's Tit will be your conclusion.


The intake on the Omega is actually not that limiting. Far from it. Every single attempt I've seen to 'improve' it, staying normally aspirated, has been a downgrade.


Lastly, just because the likes of those retards at Courtney Sport say something will improve things, that doesn't make it so.  A proper tuning company is a different story, but note that no proper tuning company has made a new intake for the Omega

sweet, i will give it a go.....but also note, no one makes a simple back box for a omega either 

What, decatted with no silencers?  I'll think you find they do  .  In fact, I know someone looking at getting rid of one, and putting a normal, cheap exhaust on in order to recover a whole heap of lost power from the car caused by 'upgrades'.

no i meant what i said, back boxes...i cant find any online....anywhere  i can find std ones where the exit pipe is the same diameter as a single pipe going in to the backbox...that must be some what restricting when you are taking two of the middle pipes and reducing the size to the single exit hole?

THe 3.0 backboxes have twin outlets. Though ones I've driven with single outlet didn't seem down on power  :-/.  Probably because the 2.5/3.0 manifolds are so restrictive anyway

this is what i mean, the diameter of the backbox exit pipe is the same size as a single pipe going into the backbox





do you see what i mean, its like a funnel....gasses going in fast, but exiting slow due to the single bore

NO NO NO NO NO!

The boxes are resonance boxes.  They are there to remove the sound only.  GM put a twin exit exhaust on the 3.0 and a single exit on the 2.5.  Why?  I dont really know as both work just as well with either back-box on.

Why do little boys put baked bean cans on the back of a 106?  MORE POWAHHHHHH! Obviously!