[X-Machine]

Hey all.
I`ve heard bout this throttle thingy a lot of times since the past one week.One of my friend recently got a throttle installed in his Lancer,and said the performance has improved.
Now,i dunt really know wot this throttle does to the engine.
Also do u need a TC if u have a throttle??
Can sumbody help me out in understanding wot is it and how does it function.
Thanks.

X

[Rudra Sen]

According to Penguin dictionary throttle as a noun means the valves in the engine to regulate the supply of gas.
Throttle as a verb means to suppress shut off power of the engine and so lessen speed.....

Anybody (can use?) it as a name as you've experienced

[F50]

Originally Posted by [b

Quote[/b] (Rudra Sen @ Sep. 28 2004,22:07)]According to Penguin dictionary throttle as a noun means the valves in the engine to regulate the supply of gas.
Throttle as a verb means to suppress shut off power of the engine and so lessen speed.....

Anybody (can use?) it as a name as you've experienced

Now thats what I called Text Book stuff

[SLK]

.. all I know is...
every car has a throttle
its just a ... valve or shutter... or what ever u might call it.
its connected.. to the accelerator cable.. harder u push .. the more it opens.. and allows more air into the engine.

The complete thing is called a throttle body... its the whole system.

my alto's was changed by maruti for free .. without any complaint from our side (they said there was a problem with that batch).

my wagonR's throttle body has a deffective valve (not the main door, just a side valve)... b'coz of which the idle rpm is not completely smooth. (5% problem).... they say whole throttle body has to be changed... for 5k.... i say .. go to hell.

I think.. your friend must have got, say a modified throttle... for more .. performance... maybe..

[Domnic]

Hi,
Well a throttle as rudra mentioned is used to control the flow of gas, in a car this controls the amount of air entering the engine on the intake stroke, more air = more power and more revs, Its simply a butterfly valve. Now in Fuel Injected cars we have something called a throttle body.
The throttle body is a housing where the valve (butterfly) is housed. It also has added sensors like the TPS (throttle position sensor) and a IAC valve ( Idle Air Control).
Now, Most cars out from the company have preset butterfly sizes, like an MPFI Zen has a 47mm or so body and a Esteem 51mm. By increasing this butterfly size you can increase engine response and inturn get a bit of power too as it reduces restriction. The Lancer responds very well to this mod, you can increase a lancers upto 66mm (requires a bit of modification). You can expect upto 14hp by this mod. And by doing this other mods like NOS, Filter and TC etc will work better.
Hope this answers your q.

CHeers
Dom

[X-Machine]

Thanks for the response guys.
Dominic got ur explanation perfectly.But i have a few querries regarding this.

1. Will the increase in buttefly size affect the performance in any other way??Like a drop in FE or performance over the time.
2. And also,if this mod is done with just the free flow and air filter in the car,will it respond well?
Thanks.

X

[SLK]

Hey Domnic.. thanks for that explanation....

I also would like to know a bit about the IAC valve.
Since my car's IAC valve is not functioning properly, would it affect the engine in any other state i.e. while its running and not idleing

See my car has a knocking probelm... and after all types of tuning and fuel it doesn't go away. So is there any role an IAC value could play in knocking?

Thanks
SLK

[Domnic]

Hi,
First to answer Xmachine:
1) Yes FE will drop in extreme conditions. As engine breathing will be easier, more air means more fuel.
2) With just the free flow and air filter i will respond pretty good, but it will be better if good porting has been done, over size valves etc.

SLK
Strange that the IAC is not functioning properly. Does the car idle at all? what are the exact symptoms?.
The IAC's work is just to keep enough air flowing to idle the car well when the throttle body (butterfly) is not open. Once accelerating (pressing the throttle) the IAC has no work. So its not of any concern when running.
Now on the knocking part : .... The IAC wont play any role in this at all... but if the valve is not opening correctly it can create a huge restriction, which will lower the idle dramatically which you will feel by heavy vibration. Get the IAC repaired else go to the local scrap yard and pick up one from a throttle body assembly etc. WHich car do you have?. Does the engine pink only on hard acceleration or always?. What is the ignition timing set at?

Cheers
Dom

[X-Machine]

Ahhh.Got it perfectly.
Thanks Dom.
X

[SLK]

I have a wagon R 2000 model

My IAC valve had failed (according to MASS) 1.5 years after buying the car. It was already out of warranty by then.

My Car idles almost perfectly.... with very slight vibrations. But the problem comes when you suddenly switch on something... like the a/c The engine vibrates badly for a while and then feels a bit better.. but still not very smooth.
Well its not just the a/c ... every electrical equipment makes the engine vibrate... but of course not as bad as the a/c.

My point is.. the engine is at the 900rpm alright, but weak.

Remember in Wagon R the a/c doesn't open the throttle for running ... it runs at idle rpm only.

well.. knocking...
it knocks only under hard acceleration.... rather say it knocks the moment you cross 3500rpm mark (approx).
Its like.... 5th gear ... it starts knocking .. if u go over 115km/h.

.. I don't really know about the ignition timing... but I believe its perfect as per maruti!... I make it a point to remind those guys to set it properly.

One more point.... there is certain valve noise from the engine, which doesn't go no matter how many times I get the clearances adjusted (maybe its normal).

thats about it all

[auto]

reading the postings, my experience has been that a lot of vibration issues on acceleration are due to the poor quality air filter used in indian cars (incl legal imports). to solve the problem on the GTX Palio, i switched to the standard K&N filter replcament - and made a big difference to the ride. the clean aceleration, no idling/running jerks, low resistance allowing longer roll. check it out before you make major changes on mechanicals. cheerz

[Domnic]

Hi SLK,
* * No performance filters aint goin to solve your problem. You say the car idles perfect. When you switch on the ac, the iac valve is supposed to open further and increase idle to support the accessory. But in your case this is not happening. Im not sure of the wagon r system, as i mentioned either the IAC should open to a further extent raising the idle, but there are systems on older cars where a air solenoid valve is present which opens when the ac is switched on, allowing more air enter the engine and thus increasing idle. where are you located slk??
About your knocking.... really strange that your car knocks, just check if the vaccum line running to the distributor is not blocked. Also have your distributor checked as the problem may lie in it. As these cars will automatically advance on acceleration. I feel somehow this mechanism is not working in your case and your distributor is not pulling timing causing the knock after a particular rpm. Have the MASS check this and i think the problem will solve.

Cheers
Dom

[SLK]

Thanks Dom...

I will get it checked at a workshop owned by Maruti for one last time at the next service... .. BTW I am in Delhi.

The problem.. is... Wagon R .. has got too complex for the MASS guys to understand ...LOL

16 valves .. they are scared to even touch the clearances.
There's no distributor... its digital ignition.

I don't quite understand why does it knock!... and neither do MASS guys!! (they have no clue)

Since we also own an Alto Vxi... exactly same engine... and it doesn't knock.. or vibrate.... I give this e.g. to MASS ... and they just don't seem to get it.

Well in day-to-day running.. i don't go more than 3500 rpm.. so knocking is not an issue... but i have to get rid of it.. anyways.

I would have got the IAC changed if it was available separately..... they say .. u got to buy the whole throttle body for 5k. And that would be a gamble as i can see their capabilities.

[Rtech]

Hey SLK,

what fuel are you using? Do you fill up from the same pump everytime? If so, try using 93 octane and see if there's a difference. Or else maybe its the knock sensor thats gone kaput! With the right scanners (which I hope MASS has), its really a simple job to check if these sensors are working. The problem lies with the person reading the screen! If he doesn't know what to look for, the scanner is not gonna be much help.

Another thing, You say when you turn your AC on, it vibrates badly and then smoothens out. How long does it take to smoothen out? Is it in an instant or are we talking a few minutes here? If its just a few seconds before it smoothens out, I don't think its much of a problem. Have you checked the AC compressor and engine mountings? Loose mounts or a couple of loose bolts could be the culprit here.

Rt

[SLK]

Hi rtech

I have used all fuels...... speed, power, josh, premium, Xtra premium, Speed 93.. .. and the regular

Speed 93 is the best with Xtra premium close second... i can feel the difference with 93. Again.. it reduces.. knocking.. but.. its still there on hard acceleration.

Yes my car vibrates for just a second or maybe 2 at most. and then back to normal (with a/c is slightly harsh)

I did get the compressor checked... it was fine.

Once I sat with the MASS guy with his palmtop plugged into my car. It shows a lot of information. BUT as you rightly said...

Originally Posted by [b

Quote[/b] ]The problem lies with the person reading the screen

The screen was displaying O2 sensor readings..... and the guy says... this shows how much your car is polluting right now and this is how we check pollution..

Anyways, I switched on the a/c and the rpm in the palmtop dropped to 650+ just for a sec.. and then back to 850-900.

Knocking... when they can't solve it they say ... some knocking is good for fuel efficiency.

I don't really expect much for MASS after so many of such instances at different service stations.