2.5" exhaust for bodies?

27th October 2012, 17:27

I had one made for my turbo project, the quality is amazing and i dont really want to sell it.
Would it loose power with this system using jenvey bodies, sandy big valve head and 4branch?

27th October 2012, 19:03

Ai mate, it's far to big or your set up tbh

It's a shame tbh it's a nice exhaust

27th October 2012, 19:12

Even the cars over 200bhp have 2 inch systems.
I think if you was going for some mental 10krpm making 230bhp+ then yes 2.25 or 2.5 , then I'd stick to 2inch exhaust for any less.

27th October 2012, 19:29

As above, 2.5" is far too big for a high comp n/a tu5 engine, I think even JP is only running a 2" saxsport and his is one of the most powerful ones out there

27th October 2012, 19:35

Quote:

Originally Posted by jones91

As above, 2.5" is far too big for a high comp n/a tu5 engine, I think even JP is only running a 2" saxsport and his is one of the most powerful ones out there

jps not got a saxsport he has a full custom iirc 2.25" system by mike edwards

i ran a 2" on my 185hp 106gti
you really dont need more than that on n/a in most cases

27th October 2012, 19:43

you probs werent far off the limits of what 2" will be useful for with yours alex

27th October 2012, 19:45

2.5" on a 240bhp Supercharger would be about right

27th October 2012, 22:00

Quote:

Originally Posted by blackie_2k5

you probs werent far off the limits of what 2" will be useful for with yours alex

yea i know that one
ive seen a few cars higher on 2" but i think much more id want a 2.25"

27th October 2012, 22:57

Are all btb systems 2.5"?

Also would you need another map session after changing from 2.5" to 2"?

27th October 2012, 23:14

for a stock vtr or vts can both run 2.25" exhaust systems. a 160bhp+ can easly run 2.5" ehxaust without any problems or loss... (i ran a 2,5" on a 130bhp engine with other breathing mods and gained close to 20bhp over all)

27th October 2012, 23:20

^^ really?^^ awaits difference of opinion. Only reason ask about the btb is that a btb was fitted when I bought the car so I though I'd go with it.

27th October 2012, 23:54

On an na car 2" should be more then enough for about 190-200,

Then 2.25 would've better,

2.5" should cope with up to 300 boosted really, if not a little more, (some say up to 350)

2.5" on a 160bhp 1.6 na car is just silly really

It's not just about peak figures, exhaust size has a big impact on low/mid range power

28th October 2012, 00:20

I made over 400 on a 2.5 system, but that was one of the things limiting power

28th October 2012, 00:22

So would you say 2.5" would be bogging down the pick up through the rev range?

Are btb's 2.5", may possibly look at changing next year if so, would I need a Map again, or would it simply free things up a bit?

28th October 2012, 00:25

Quote:

Originally Posted by Old_School_Saxo

for a stock vtr or vts can both run 2.25" exhaust systems. a 160bhp+ can easly run 2.5" ehxaust without any problems or loss... (i ran a 2,5" on a 130bhp engine with other breathing mods and gained close to 20bhp over all)

guessing from your other posts that wont be on a saxo though i bet as youve mentioned youve played with a lot of foords and no saxos yet apart from the one youve just bought

im with blackie on the fact it alters more than just power
exhaust tuning can move the power around the rev range and a good setup will give a very good mid range and aid driveability

back pressure and pulse tuning and all things i dont fully understand enough to go into details on personally but the guys who do allways seem to come to the conclusion that a 2" system is more than ample for 90% of n/a setups on saxos its the details that matter more (primary lenths, 4-2-1 or 4-1, boxed or not and how far up the system the box is ect all matter)

btb are a 2.5 as questioned above and personally i see little point in them on an n/a car they are really imo an off the shelf boost system
also they weigh a fucking ton for some reason
on a stock vts the gain is so small on a btb id bet the weight gain allmost cancells it out lol!!

and ideally if your swapping exhaust get your map looked at but it wont be miles out tbh
look at fitting breathing mods on a stock ecu
you can remap and see 1-2 hp and a better run but lots dont due to cost
for a few hours mapping a standalone its much cheaper so its a better option then tbh

28th October 2012, 00:32

Thanks for the detailed reply alex! Your right the btb does weigh a ton! Surprising!!

I'll look to change early next year maybe, after driving it! Not really sure what the 2" options are! I'll have to look into it

28th October 2012, 01:22

Quote:

Originally Posted by AlexB

guessing from your other posts that wont be on a saxo though i bet as youve mentioned youve played with a lot of foords and no saxos yet apart from the one youve just bought

im with blackie on the fact it alters more than just power
exhaust tuning can move the power around the rev range and a good setup will give a very good mid range and aid driveability

back pressure and pulse tuning and all things i dont fully understand enough to go into details on personally but the guys who do allways seem to come to the conclusion that a 2" system is more than ample for 90% of n/a setups on saxos its the details that matter more (primary lenths, 4-2-1 or 4-1, boxed or not and how far up the system the box is ect all matter)

btb are a 2.5 as questioned above and personally i see little point in them on an n/a car they are really imo an off the shelf boost system
also they weigh a fucking ton for some reason
on a stock vts the gain is so small on a btb id bet the weight gain allmost cancells it out lol!!

and ideally if your swapping exhaust get your map looked at but it wont be miles out tbh
look at fitting breathing mods on a stock ecu
you can remap and see 1-2 hp and a better run but lots dont due to cost
for a few hours mapping a standalone its much cheaper so its a better option then tbh

Yeah hands up i am a ford man lol but the std exhaust upgrade for the fiesta mk5 zs from miltek or piper is 2.25 bore and thay have what 30bhp less than than the saxo vts but the same engine size :? and the std bore size for the focus st170 (which really only have 160bhp lol) is 2,25" and the upgrade is 2,5" :? which all these make good gains even when stock :?

28th October 2012, 08:23

Quote:

Originally Posted by Mathias

Thanks for the detailed reply alex! Your right the btb does weigh a ton! Surprising!!

I'll look to change early next year maybe, after driving it! Not really sure what the 2" options are! I'll have to look into it

iirc your on 708s and bodies id look at saxsport or kam boxed systems tbh
track legal volume and good for the power you want

Quote:

Originally Posted by Old_School_Saxo

Yeah hands up i am a ford man lol but the std exhaust upgrade for the fiesta mk5 zs from miltek or piper is 2.25 bore and thay have what 30bhp less than than the saxo vts but the same engine size :? and the std bore size for the focus st170 (which really only have 160bhp lol) is 2,25" and the upgrade is 2,5" :? which all these make good gains even when stock :?

different engine designs require different things was my point i was trying to say in the above post

a for may require a 2.25 system due to how its designed a pug/saxo a 2" is a better option in most peoples eyes

28th October 2012, 10:26

they may make an oversized exhaust simply because that's what the customers want.
Whether its best for the engine is another matter entirely.

28th October 2012, 13:00

Most tuning seems t follow trends... And if on or two do it, everyone seems to do it where he its right or wrong

Take the vauxhall lads.. All seem to want to run 3" systems.. Most of them aren't even at 300bhp and vast majority are sub 250bhp

But be its a "normal" mod to do, ppl just do it