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**Prabhakar** · 02-02-2010, 03:38 PM

I would like to add something about the Fuel efficiency part.
If the Tuning is Right then The Fuel efficiency wont drop.
As a matter of fact it increases for the same kind of riding.
To elaborate a simple example -
If the Bike does 80kmph in fifth gear at 6000 rpm before the tuning consuming 1 litre of petrol for 37kms then after tuning it does 80kmph at 5700 rpm consuming 1 litre to travel around 39kms ( It does 89kmph at 6000 rpm).
The Stock 220 was giving 35-36 with speeds upto 120.
After the tuning (Read all the changes in my earlier post) it was giving around 37-38 for similar speeds.
Reason - U need to ride at a lower RPM for the same speed.
However the moment we hear the sweet sound of the Exhaust we tend to rip it harder than normal which results in lesser Fuel efficiency.
SO its not the machine which makes the FE lower, But its we who make it lower.
The bike now burns the fuel better than before due to the tuning.

**Grease Monk** · 02-02-2010, 04:56 PM

Originally posted by Prabhakar View Post

If the Bike does 80kmph in fifth gear at 6000 rpm before the tuning consuming 1 litre of petrol for 37kms then after tuning it does 80kmph at 5700 rpm consuming 1 litre to travel around 39kms ( It does 89kmph at 6000 rpm).

You cannot change the RPM to speed ratio without altering your gearbox.

Yes, it is possible that since it is developing more power due to better combustion, you will have to use less throttle to accelerate to that speed and hence possibly reduce the fuel consumed. And for the same reason it is possible that it requires less fuel to maintain that speed (again, due to better combustion). But you cannot get higher speed from the same RPM just by tuning.

**Joel** · 02-02-2010, 07:37 PM

Originally posted by Grease Monk View Post

Yes, it is possible that since it is developing more power due to better combustion, you will have to use less throttle to accelerate to that speed and hence possibly reduce the fuel consumed. And for the same reason it is possible that it requires less fuel to maintain that speed (again, due to better combustion). But you cannot get higher speed from the same RPM just by tuning.

Yes, that makes it so clear!

Improving the volumetric efficiency of an engine will enhance the throttle response and proportionally improve the fuel efficiency as well.
Gearing is a variable which transmits the torque to the wheel. If the gearing is kept constant, there will not be any change in the rpm v/s speed.

**diehard** · 02-02-2010, 07:54 PM

Originally posted by Joel View Post

Yes, that makes it so clear!

Improving the volumetric efficiency of an engine will enhance the throttle response and proportionally improve the fuel efficiency as well.
Gearing is a variable which transmits the torque to the wheel. If the gearing is kept constant, there will not be any change in the rpm v/s speed.

yes this makes a lot of sense , so when is the prototype ready ?? with all the aesthetics ??????

and will u install it if v are in bangalore ?? so many questions ! sorry mate my patience is a tad run out

**Prabhakar** · 02-03-2010, 12:47 AM

I mentioned in the post to refer my earlier posts.
Sorry I did not mention which posts they are.
They are in 3rd page 32nd post & some 35th post.
There I mentioned all the changes made.
Yes there was a change in the gearing too for achieving the above speeds.

**Joel** · 02-03-2010, 02:09 AM

@diehard - The installation of the pipe is a simple DIY job. Nothing rocket science.
I just finished my first prototype today. Will do a final finish and post the pics.

**diehard** · 02-03-2010, 03:09 PM

Originally posted by Joel View Post

@diehard - The installation of the pipe is a simple DIY job. Nothing rocket science.
I just finished my first prototype today. Will do a final finish and post the pics.

tere mooh meh ghi shakar

!!! (if u understand it) lol ! waitin for the pics

**kk_RTR** · 02-03-2010, 10:43 PM

@ joel

will we be seeing any dyno-charts comparing the original power curves to the modified ones ????

**rahul9985** · 02-03-2010, 11:03 PM

@ Joel

Hey,
I had tried the bike done by Prabhakar for one whole day. Ripped it like crazy! Did some crazy drags on it!

I feel that on stock fuelling the power bump with the exhaust wasnt noticeable much & there were lots of backfires. With a better tune the bike was performing way better! The bike was revving much better than before. It had an awesome mid-range power. Much better than P220 FI. At higher rpms there was considerable loss of power which could be felt. If upjetted, to say 150mm+ main jet, i feel much more power can be generated at high revs.
But did not try it much after the final tuning. So no comments on the final product.

+10000 for the exhaust.. A MUST buy for every crazy revver!!!

PS- What about my fire spitting exhaust?

**freekoo** · 02-03-2010, 11:34 PM

Originally posted by Joel View Post

The p180 can also be worked on. But it will need more work inside the engine than merely an exhaust. Nevertheless the exhaust alone will still give you good gains.

What about the FZ16 joel? How does the bike perform with the exhaust and will it require any modification to the engine? Does the exhaust have tappered header?

**diehard** · 02-04-2010, 12:30 AM

Originally posted by rahul9985 View Post

@ Joel

Hey,
I had tried the bike done by Prabhakar for one whole day. Ripped it like crazy! Did some crazy drags on it!

I feel that on stock fuelling the power bump with the exhaust wasnt noticeable much & there were lots of backfires. With a better tune the bike was performing way better! The bike was revving much better than before. It had an awesome mid-range power. Much better than P220 FI. At higher rpms there was considerable loss of power which could be felt. If upjetted, to say 150mm+ main jet, i feel much more power can be generated at high revs.
But did not try it much after the final tuning. So no comments on the final product.

+10000 for the exhaust.. A MUST buy for every crazy revver!!!

PS- What about my fire spitting exhaust?

errrr will there be loss of power at high revs on the 220 fi too ??? wat abt backfire etc ?????

**Joel** · 02-04-2010, 01:27 AM

Originally posted by kk_RTR View Post

@ joel

will we be seeing any dyno-charts comparing the original power curves to the modified ones ????

show me one manufacturer in the country that sells performance with dyno chart as a reference. I have done dyno testing for my own bench marking and there is V-box testing done to further get real world figures. If anybody else is doing this much, we can take it from there.

@rahul - A race exhaust (like in the case of prabhakar) will lean the mixture quite a lot and hence will need to be backed with more fuel to get back to stoich. Backfire is a clear sign of lean out. In the case of normal street pipes, that wont happen as it wont let the mixture lean by that much.

@freekoo - FZ will gain quite a lot with an exhaust. Wont quite any figures, but its easily over 10%. No engine mods required unless you feel the need

. Tapered headers are for 2-strokes man. However tapered sections will follow at other places.

@diehard - Thats a race pipe, will not matter to anyone else.

**GP_freak** · 02-04-2010, 02:09 AM

Joel, All the very best man. I was sure that you will come this way

And what about the back fires during engine braking ? Say a thud thud(mild decelaration)or a loud clapping noise(heavy engine braking).

**Prabhakar** · 02-04-2010, 09:06 AM

There will be back fire when U leave the throttle in High RPMS.
This is a sign of a properly Tuned engine.
The reason for this is that the Fuel Supply is almost negligible when compared to the RPM.
I'll provide U a link please check it.
It'll provide U a better idea why it happens.

Mikuni American Corporation

**kk_RTR** · 02-04-2010, 12:19 PM

Originally posted by Joel View Post

show me one manufacturer in the country that sells performance with dyno chart as a reference. I have done dyno testing for my own bench marking and there is V-box testing done to further get real world figures. If anybody else is doing this much, we can take it from there.

everybody over here believes that you are not one among those manufacturers who make false claims about the performance of their products. So i thought that you wont have any problems in sharing the results with us.

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4-stroke Performance - Tuned Free-Flow Exhaust

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