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Old 15th July 2013, 23:30   #16
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Default Re: Building a Harder, Better, Faster Chevy Spark | Includes Automech FFE Review

Congrats on the ffe.I have a automech on my 800 but had to change the muffler back to stock sound as i got pulled over by cops.The dead giveaway was the exhaust tip.I hope the tip is not clearly available in your case.God i still remember having so much fun with the car that i just didn't wanted anything else.Wishing you tons of joy and fun with your car.
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Old 16th July 2013, 07:16   #17
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Default Re: Building a Harder, Better, Faster Chevy Spark | Includes Automech FFE Review

Thanks for the info but on what basis did they pull your car? Noise? PU Check?
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Old 16th July 2013, 08:29   #18
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Default Re: Building a Harder, Better, Faster Chevy Spark | Includes Automech FFE Review

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Originally Posted by Eminenttismo View Post
Well, I asked Mr.VivekBhat on how the diameter is calculated and he said they have a formula(which he apparently cannot share) depending on Engine Displacement.

So far, the vehicle has been so good. I'm enjoying the ride.
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Originally Posted by Eminenttismo View Post
Got a reply from automech:



How is the size of the pipe determined? Sankar can you please help?


Thanks!
Pipe diameter and length are calculated based on the peak rpm, volumetric efficiency, bore, stroke, timing (valve opening closing) etc.. If the pipe is based on these calculations well and good. Btw this formula is available to anyone who is into tuning, its been published in respective books.

But there is no excuse for the poor workmanship on the header flange entries. This shouldn't be based on the size of the pipe used what the header is doing is creating a step and masking some of the port area on the head and it IS not the best for the flow. Those who built the pipe know that, and they know that a typical customer wouldn't care.

What they have done is take the easy way out and keep the entry the same size as the pipe since it will keep the labour costs down. It is possible for a pipe builder to make the header entries the same size and shape as the port but use the correct diameter piping from there onwards. Its takes more time and effort.

If your pipe was built like that you would be seeing even better performance gains than what you are getting now.
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Old 16th July 2013, 09:33   #19
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Default Re: Building a Harder, Better, Faster Chevy Spark | Includes Automech FFE Review

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Originally Posted by Sankar View Post
Pipe diameter and length are calculated based on the peak rpm, volumetric efficiency, bore, stroke, timing (valve opening closing) etc.. If the pipe is based on these calculations well and good. Btw this formula is available to anyone who is into tuning, its been published in respective books.

But there is no excuse for the poor workmanship on the header flange entries. This shouldn't be based on the size of the pipe used what the header is doing is creating a step and masking some of the port area on the head and it IS not the best for the flow. Those who built the pipe know that, and they know that a typical customer wouldn't care.

What they have done is take the easy way out and keep the entry the same size as the pipe since it will keep the labour costs down. It is possible for a pipe builder to make the header entries the same size and shape as the port but use the correct diameter piping from there onwards. Its takes more time and effort.

If your pipe was built like that you would be seeing even better performance gains than what you are getting now.
Thanks for the info... Although there is nothing I can do about it, I feel a little sorry. Anyway, I will take care of it with time.

Lets keep the workmanship of Automech out of the equation for now, does this poor execution cause a immediate serious effect on the engine?

PS: Sankar, do you know who can get these headers right?


Thanks!
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Old 16th July 2013, 09:45   #20
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Default Re: Building a Harder, Better, Faster Chevy Spark | Includes Automech FFE Review

Quote:
Originally Posted by Sankar View Post
But there is no excuse for the poor workmanship on the header flange entries. This shouldn't be based on the size of the pipe used what the header is doing is creating a step and masking some of the port area on the head and it IS not the best for the flow. Those who built the pipe know that, and they know that a typical customer wouldn't care.

What they have done is take the easy way out and keep the entry the same size as the pipe since it will keep the labour costs down. It is possible for a pipe builder to make the header entries the same size and shape as the port but use the correct diameter piping from there onwards. Its takes more time and effort.

If your pipe was built like that you would be seeing even better performance gains than what you are getting now.
+1

But even if they spend more on machine+labour it is difficult to achieve something close to stock (Cast vs fabricated). If they could make something closer performance could have been even better as you said.

The gasket used there is going to be the first victim in this new design. Ocassional visual inspection is required to check any leakage due damage.
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Old 16th July 2013, 10:02   #21
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Default Re: Building a Harder, Better, Faster Chevy Spark | Includes Automech FFE Review

What it will do is cause a LOT of exhaust reversion which consequently causes contamination of the air+fuel mixture in the bore for the next power stroke. Instead of a mixture of fresh air and fuel, some of that fresh air will be replaced by the gases that are supposed to be thrown out through the exhaust but they're not; in essence causing a lack of fresh oxygen which reduces power.

The difference you are seeing is due to the smaller-than-stock-diameter piping that is effectively moving the powerband to the low-mid RPM range, which happens because smaller diameter piping produces peak exhaust velocity much faster than a bigger pipe. No real harm to the engine other than the exhaust reversion turning the intake ports black with carbon and less outright power. Production engines are stout enough to not get damaged due to this (most people run their car on clogged filters which produces a similar effect minus the exhaust reversion).
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Old 16th July 2013, 10:34   #22
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Default Re: Building a Harder, Better, Faster Chevy Spark | Includes Automech FFE Review

Thanks for the detailed report.

One question which always comes to my mind regarding FFE. Will the cops trouble always for the sound? And how much they can fine if caught?

Probably memebers having FFEs installed might put in 2 cents.
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Old 16th July 2013, 10:50   #23
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Default Re: Building a Harder, Better, Faster Chevy Spark | Includes Automech FFE Review

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Originally Posted by Eminenttismo View Post
Thanks for the info... Although there is nothing I can do about it, I feel a little sorry. Anyway, I will take care of it with time.

Lets keep the workmanship of Automech out of the equation for now, does this poor execution cause a immediate serious effect on the engine?

PS: Sankar, do you know who can get these headers right?


Thanks!
In the short term nothing much, but in the long term the combustion chamber, valves, intake manifold, tb can see some excess carbon buildup than normal. Its like having some extra EGR, can possibly increase your FE.

You need to get in touch with people who build pipes for race engines, you may be able to find some in Coimbatore/Bangalore. I too am on a mail order pipe now, i know Joel can build good headers he's in Bangalore, if i were there i would have got mine done by him if he has the time.

All is not lost, if you can find an exhaust guy try to salvage this one by making the flange and the entries correct. It will work better than now.
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Old 16th July 2013, 15:28   #24
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Default Re: Building a Harder, Better, Faster Chevy Spark | Includes Automech FFE Review

Quote:
Originally Posted by Latheesh View Post
+1

But even if they spend more on machine+labour it is difficult to achieve something close to stock (Cast vs fabricated). If they could make something closer performance could have been even better as you said.

The gasket used there is going to be the first victim in this new design. Ocassional visual inspection is required to check any leakage due damage.
Yes, the OEM Manifold have the perfect build. From the looks of it, it takes a lot of equipment and effort to make those.

Quote:
Originally Posted by pranavt View Post
What it will do is cause a LOT of exhaust reversion which consequently causes contamination of the air+fuel mixture in the bore for the next power stroke. Instead of a mixture of fresh air and fuel, some of that fresh air will be replaced by the gases that are supposed to be thrown out through the exhaust but they're not; in essence causing a lack of fresh oxygen which reduces power.

The difference you are seeing is due to the smaller-than-stock-diameter piping that is effectively moving the powerband to the low-mid RPM range, which happens because smaller diameter piping produces peak exhaust velocity much faster than a bigger pipe. No real harm to the engine other than the exhaust reversion turning the intake ports black with carbon and less outright power. Production engines are stout enough to not get damaged due to this (most people run their car on clogged filters which produces a similar effect minus the exhaust reversion).
Wow, that's quite some information. Thanks!


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Originally Posted by Dodge_Viper View Post
Thanks for the detailed report.

One question which always comes to my mind regarding FFE. Will the cops trouble always for the sound? And how much they can fine if caught?

Probably memebers having FFEs installed might put in 2 cents.
+1, same question can anyone else please about these?

GTO? Sankar? Sumeeth?

Quote:
Originally Posted by Sankar View Post
In the short term nothing much, but in the long term the combustion chamber, valves, intake manifold, tb can see some excess carbon buildup than normal. Its like having some extra EGR, can possibly increase your FE.

You need to get in touch with people who build pipes for race engines, you may be able to find some in Coimbatore/Bangalore. I too am on a mail order pipe now, i know Joel can build good headers he's in Bangalore, if i were there i would have got mine done by him if he has the time.

All is not lost, if you can find an exhaust guy try to salvage this one by making the flange and the entries correct. It will work better than now.
Thanks for your support and guidance.

I see the rule of thumb is Oval Headers for low end power and Rectangular for high end power - Read it in various forums

EDIT: Just now, I happened to see if there were others who had Round Headers on Rectangular Heads, they seem fine. So I'll hold my breadth, be happy with what I have now.

Will keep a keen eye on other aspects which you guys have mentioned(gaskets, carbon etc) and update the same.

Last edited by Eminenttismo : 16th July 2013 at 15:50.
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Old 16th July 2013, 16:25   #25
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Default Re: Building a Harder, Better, Faster Chevy Spark | Includes Automech FFE Review

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Originally Posted by Eminenttismo View Post
I see the rule of thumb is Oval Headers for low end power and Rectangular for high end power - Read it in various forums
There is no such rule.
The rule of thumb should be smaller diameter for low end power and larger diameter for more top end performance. Again its just a rule of thumb, the headers should be built to spec.
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Old 16th July 2013, 16:33   #26
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Default Re: Building a Harder, Better, Faster Chevy Spark | Includes Automech FFE Review

Congrats on the Faster Spark Eminenttismo!!

I too had a headers, free flow exhaust and BMC cold air intake (initially BMC conical), iridium plugs & running fully synth oil, on my 2010 Spark. Got the mods at 9000kms on the Odo. Ran it till 30,000kms. The work was done by enginecal in B'lore. Flawless work.

Since the spark already has good low and mid end, i requested for better top end without much change to low end grunt. It was awesome to feel the spark revving so freely in each gear which was impossible when stock.

In B'lore for nearly the 2.5 years that I used the car with mods, i was never pulled over for sound. Of course, i would not revv the nuts off the car when i see cops in the vicinity. The FFE was also designed to give out a bassy growl when not revving which helped matters. But in case you are pulled over in B'lore, it depends on the cops mood what the amount is going to be. Ideally it should be around Rs. 300 i am thinking. Not very sure.

Quote:
Originally Posted by Dodge_Viper View Post
One question which always comes to my mind regarding FFE. Will the cops trouble always for the sound? And how much they can fine if caught?
Quote:
Originally Posted by Eminenttismo View Post
+1, same question can anyone else please about these?
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Old 16th July 2013, 20:55   #27
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Default Re: Building a Harder, Better, Faster Chevy Spark | Includes Automech FFE Review

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Originally Posted by abhinav.s View Post
Congrats on the Faster Spark Eminenttismo!!

I too had a headers, free flow exhaust and BMC cold air intake (initially BMC conical), iridium plugs & running fully synth oil, on my 2010 Spark. Got the mods at 9000kms on the Odo. Ran it till 30,000kms. The work was done by enginecal in B'lore. Flawless work.

Since the spark already has good low and mid end, i requested for better top end without much change to low end grunt. It was awesome to feel the spark revving so freely in each gear which was impossible when stock.
Hey abhinav.s, I know your Spark. I've read your thread sometime ago. Glad that your are enjoying everybit of your Spark. Do you still run the same setup?

Do you see major difference after iridiums and fully synth oil?

Thanks!

Quote:
Originally Posted by abhinav.s
In B'lore for nearly the 2.5 years that I used the car with mods, i was never pulled over for sound. Of course, i would not revv the nuts off the car when i see cops in the vicinity. The FFE was also designed to give out a bassy growl when not revving which helped matters. But in case you are pulled over in B'lore, it depends on the cops mood what the amount is going to be. Ideally it should be around Rs. 300 i am thinking. Not very sure.
Thanks for the clarification. I was curious on which law cops can pull us down, except may be PUC(which I suppose we should clear).
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Old 16th July 2013, 21:05   #28
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Default Re: Building a Harder, Better, Faster Chevy Spark | Includes Automech FFE Review

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Do you see major difference after iridiums and fully synth oil?
Yes there was a major difference in the way the vehicle accelerated with the iridiums and the fully synth oil. I parted ways with the car after 2yrs 8months (32,000 kms). Got an Alto K10 and will plan something on it too in the near future

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Originally Posted by Eminenttismo View Post
Thanks for the clarification. I was curious on which law cops can pull us down, except may be PUC(which I suppose we should clear).
Yes we will certainly clear the PUC as my car had its PUC checked twice or thrice and it cleared it without any manipulation by the checking center. So that will certainly not be a worry. The only thing would be sound on which they can catch us but unless they can prove our cars are above a certain allowed db limit, they cannot charge us. And they generally dont carry db meters with them. But like i said, its on the whims of the cop who pulls you up and depends on your luck
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Old 16th July 2013, 21:11   #29
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Default Re: Building a Harder, Better, Faster Chevy Spark | Includes Automech FFE Review

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Originally Posted by abhinav.s View Post
Yes there was a major difference in the way the vehicle accelerated with the iridiums and the fully synth oil. I parted ways with the car after 2yrs 8months (32,000 kms). Got an Alto K10 and will plan something on it too in the near future
Nice, can you please share the price you got for your Spark? *smile*
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Old 16th July 2013, 23:25   #30
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Default Re: Building a Harder, Better, Faster Chevy Spark | Includes Automech FFE Review

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Originally Posted by Eminenttismo View Post
Thanks for the info but on what basis did they pull your car? Noise? PU Check?
As i mentioned the giveaway was the exhaust tip.It was big and looked sexy too .My car sounded normal at lower rpms so unless it's too loud you need not worry about the sound.I was infact pulled over by a couple of policemen who were on a motorcycle while i was waiting at a signal.They spotted the exhaust tip and decided to make a quick buck.

edit :if you do get pulled over for the sound just saythe exhaust needs repair.

Last edited by sumeethaldankar : 16th July 2013 at 23:27.
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