Bhp!!!!

Ems

Ems

Ex. Club Member
Ok i need an argument sorted!!!!

I was told by a mechanic when my wheel's were being balanced, that a backbox, say the same size as a lot of you lot have, will increase the bhp by 10-15 obviously depending on which one you fit. His mate who worked with him was a bit shocked too and said 'how come' and he said have a look inside the box and you can see the diff between them!!!!! Sorry i don't know what diff exactly!!!

Is this true?, or do u need a full exhaust fitted for increased performance?!!!
 
well considering that when you put a full system in you get about 20bhp increase then its doubtfull. however in this months practical performance car this guy actually proved that even a filter bolted on top of a throttle bottle will give a slight increase in power and torque.
 
there is different designs of internals of a back box but on a k10 you wont get much more bhp if any from just a backbox as the manifold and piping to the back box are very small and restrictive
 
i got told on rollin road that induction kit cone filters REDUCE THE BHP by about 10%.

Mine was about high 40's before it cocked up and shot upto 324.2BHP lmao :)
 
Fordy said:
there is different designs of internals of a back box but on a k10 you wont get much more bhp if any from just a backbox as the manifold and piping to the back box are very small and restrictive
Click to expand...

I would say that this is totally correct, a backbox can only flow as much air as the piping before it will allow (of course he exhaust gasses will be cooler at the backbox, but the front half of the exhaust is the place where most ofthe powr is lost).
 
depends if a cone filter has a cold air flow really, over a standard airbox with a standard filter its probably better. Could lose 10%, thats like a 7.5bhp loss on a 1.3 :s
 
I use the standard airbox with a K&N panel filter in it, people seem to say its a better way to go than the 57i kit. I plan to create a second feed for the box though (a bit like Davey Cs) so the airbox has cooler air :)
 
James said:
I plan to create a second feed for the box though (a bit like Davey Cs) so the airbox has cooler air :)
Click to expand...

Actually its mine now :p lol.
I do have something in mind with my old one though :)

I doubt a backbox can give 15bhp, if your running a standard system infront of it, your probably loosing power if its a big bore thing.
 
Craig said:
I would say that this is totally correct, a backbox can only flow as much air as the piping before it will allow (of course he exhaust gasses will be cooler at the backbox, but the front half of the exhaust is the place where most ofthe powr is lost).
Click to expand...

Thats exactly what i said to you ems!! Tell your mechanic he's talking crap :p

The manifolds on a K10 are the most restrictive part, and the front pipe is generally narrow too. You'd need to get a thicker system from the front back to get any gains at all.
 
contrary to what ive been told on a RR...

a simple conefilter placed on top of TB... is as good as it gets on a mildly modified NA 1300cc.... 4,2,1, upped fuel pressure etc..
 
James said:
I use the standard airbox with a K&N panel filter in it, people seem to say its a better way to go than the 57i kit. I plan to create a second feed for the box though (a bit like Davey Cs) so the airbox has cooler air :)
Click to expand...

i noticed big gains by just sawing off the resonator pipe tip on the standard air box.

i may have noticed big gains due to 1.3 cams going in a month or so before and the car was starved of air... bit its a free, quick mod that imo is worth doing ;) unless you want to go 'hardcore' like james and create another feed.
 
Your all missing the point! The standard K10 back box has BAFFLES in it. It is not a straight through design. This is what I mean..

backbox.jpg


A design like this is about as bad as it gets for airflow. So changing this WILL HELP but its hard to say how much. FYI the ST backbox (stock) is a straight through with no baffles.
 
Ah, never knew baffles were spiral like that, had been told previously that you could just smash them out, assumed thatthey were similar to a cat in structure
 
Ed said:
Your all missing the point! The standard K10 back box has BAFFLES in it. It is not a straight through design. This is what I mean..

backbox.jpg


A design like this is about as bad as it gets for airflow. So changing this WILL HELP but its hard to say how much. FYI the ST backbox (stock) is a straight through with no baffles.
Click to expand...

I never knew that either. How would you get inside the box to smash them out tho craig, arent backboxes sealed?
 
Yes you wont be smashing these ones out, youll have to change the type of backbox.
 
Ed has already suggested a company to me babe, i was going to ring them up but with recent events, i think my money could be spent on sorting her out first!

There's a place not far from mine called Longlife, its where he got his done too.
 
Oh ok!!! Cool!!!! Was just wanting price ideas etc!!!!

Y not put it on here for other k10 owners to see!!!! :p
 
Their site is quite nice. Shame most of the outlets are like normal chavvy barry exhaust centers. lol
 
Ed said:
Their site is quite nice. Shame most of the outlets are like normal chavvy barry exhaust centers. lol
Click to expand...


Cool!!! When i get round to looking at exhausts i run them by u Ed (if that's ok)!!! Don't want to end up buying a piece o poo!!!
 
Ems said:
Cool!!! When i get round to looking at exhausts i run them by u Ed (if that's ok)!!! Don't want to end up buying a piece o poo!!!
Click to expand...

You'd have to go to the center itself babe and ask them what you want, most likely it'l be the same as mine (we both want the same style etc). We could just go and get them done together as it's really not that far away at all!
 
on my k11 super s i have a k&n cone filter(with an air scoop over the top),janspeed mannifold, f.s.e fuel valve and a stainless steel powerflow de-cat exhaust system. before i got the exhaust system i had a universal back box and the standard exhaust, i don`t know what bhp i get from these parts but i can feel alot of difference between the two
 

Similar threads

F
  • Locked
104.1 BHP - What Next?
Replies
16
Views
4K
airmike
A
F
My 1.3 K11 Si - Over 104 BHP!
2
Replies
74
Views
24K
Agent_Sm1th
Agent_Sm1th
F
  • Locked
1999 1.3 Si - MANY MODIFICATIONS - OVER 100 BHP!
Replies
3
Views
3K
FH-5
F
M
BHP I need more lol.
Replies
22
Views
2K
Stani1029
Stani1029
D
Tuned 371.4 BHP Mitsubishi C5 RVR X3 Hypersport
Replies
1
Views
3K
joshbl
joshbl
Back
Top