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-   -   What's a free flow exhaust ? (https://www.team-bhp.com/forum/technical-stuff/2173-whats-free-flow-exhaust-7.html)

Wondering if anyone fitted a FFE on a TCIC Safari. I believe some place in Delhi offers that but would want to know more about performance enhancement before going in for one.

Any ideas?

Cheers,
AVR

Hi rehaan

i am having some doubts on the backpressure calibration, now that i have modifiedmy zen to be a free flow on straight pipe. should u shave in my cams on the exhaust valve to offset the backpressure calibration on my stock cams??

Hi Gopa99,

Unfortunately my knowledge on the subject is nowhere near extensive enough for me to be able to help you with your query.

I'm sure there are others on the forum who can help. Also, do try searching the forum some more just incase a similar query exists.

cya
R

Waiting for some long term reviews of the popular FFE's on TBHP. I think this will help others decide and make the right choice. Otherwise you may just end up buying a FFE which makes money flow freely out of your pocket.

True !

I dont have FFE yet, been planning for ages. Funds not an issue, but such mixed opinions and views from different tuners on all aspects including material , costs, gain in BHP.

I have removed my CAT and replaced with a straight pipe. I have seen a huge increase in power. On one tuner's website, it says headers add only 2bhp ! So is it worth going for FFE at 10-16K for just 2bhp increase, could rather, pay 200rs to a local exhaust guy and remove the CAT and replace with a pipe !

I dont know, still confused as ever..:Frustrati

I also had same fear till i installed FFE on my Ikon 1.3 ROCAM. one thing i am very sure is the over all driving experience have changed. its running on a K & N Stock replacement Filter also

1. I believe it have better drivability. ie better roll on rates in between gears

2. believe me my FE is between 15 -16 with 100% AC on

i am running on this setup for last 30k kms and i believe it worth 14k spending ( MS FFE)

Once a friend of mine asked about the performance mods he can do for his car. He is a Yoga expert and trains in Sudarshan Kriya at an AOL centre. So it was easy to explain it to him. I asked him what is the importance of breathing and how does good breathing practice like SK helps. He said it helps to improve blood quality as there will better supply of fresh Oxygen. Next I asked what do you think if we do something similar to the car. Improve the breathing, both in and out. (CAI and FFE). He is convinced and did it within a month and is a happy TBhpian now!

Actually it's like this:
CAI=Sudarshan Kriya
FFE=Pavan Muktasanalol:

Hi guys sorry for all the late replies to the earlier posts i was more involved in the vintage section than the other ones.Hopw its ok with everyone if i share something.


Well you can put in a free flow in a diesel car provided it does not have a turbo other wise you'll have to geta special type designed as mentioned earlier as the turbo works off the exhaust system.The thing with putting a free flow exhaust in a diesel car is that the sound wouldn't be as nice as compared to a petrol car,but well you could try it and see.

Well having free flow exhausts on four stroke engines are good for the engine as the pickup and performance and milage everything increase but would you like to have a loud car all the time.Instead you could have a semi loud car and put a straight through with the stock pipes which are fitted on the manbifold from before and chop off the Cat converter and then put an expansion chamber at the end.With this you would have a nice base noised and will have a loud noise in the initial gears during pickup.

Well you can get someone to design it and if it is designed well keeping everthing in mind then you should get a better one than the ready made ones.

well that's a better idea for a diesel vehicle.

how restrictive is the stock centre section ? will removing it add to performance? I am aware of the increase in sound.

Thanks

You can do without removing it. The microscopic gains that you might get, you will be used to it in a day's time.

With stock headers, no point, unless you can get a customised mid muffler fabricated (least restrictive).

I would like an answer for the same. A tuner just told me that a mid can (did he mean expansion chamber?) is essential and without this the car doesnt develop bottom and mid range powers, hence crucial

on a small 4 banger, its quite hard to squeeze "perceivable" performance from an exhaust. Most people hear it more :-) FE will improve as long as the engine load/speed characteristics dont change, but as we all know the noise makes ppl drive harder & faster.

FE will improve because the individual tube headers improve exhaust scavenging (process of exhaust leaving the cylidner) and also reduces the exhaust back pressure. On SI engines, the main criteria for improved performance is lower pumping work and reduced back pressure does help. THis doesnt mean that if you go from a 1" pipe dia to a 4" pipe dia that your performance will improve proportionally. there is a local maximum. A smaller pipe also has higher gas velocity and pipe friction is directly proportional to the velocity.

In most indian cars, the headers might not be the bottle neck. i used to have 1st gen city (many many many years ago) and the biggest break through was the mid pipes / end box that caused most resistance to the flow.

In V6 / V8's you have an option for an H-pipe or X-pipe config which basically have exhaust pulse interference and hence change the tone fo the exhaust. Some performance differences too. The Mugen exhaust for the 3.0V6 accord came with an X-pipe and sounded fantastic.

I have just started the mental math of doing a free flow (AutoMech) for my type - II City VTEC , wanted some advice from you guys who already have a FFE ...

1. How do you deal with PUC - i am pretty sure that the VTEC wont pass PUC with a FFE - happy to told i am wrong on this count though ..

2. Any recommendations from fellow BHPians on where to get the work done in Pune ? i have a auto accessory store next door who knows a fair bit about all this as he is into rallying and has modified a few cars but interested in peoples experiences in Pune especially with a Honda Type - II VTEC

Cheers !

I was wondering what is FFE and headers and all! Now after I read this thread I somehow have understood the basic principle and what it means. I guess I can survive without FFE and Headers etc.

Cheers!
-Z