Exhaust cut outs

sublimemike · Post by **sublimemike** » Sat Jan 28, 12 8:04 pm

I know a lot of you run these - what's anyone reckon the percntage BHP gain is? Thinking about some - are the electric ones reliable or just a gimmick and the motors give up when you go through a puddle? - Stainless / mild - welded /clamped?

big block · Post by **big block** » Sat Jan 28, 12 8:44 pm

I welded a pair in,but didn't see any noticeable gain at the track.
3" exhaust and flowmasters,maybe a difference with a less free flowing system

sublimemike · Post by **sublimemike** » Sat Jan 28, 12 9:19 pm

mmm. thats what I'm running. Be good to hear what others say before I go to a whole load of cutting and shutting for just an increase in decibels.

Mick70RR · Post by **Mick70RR** » Sat Jan 28, 12 10:02 pm

Electric cutouts with 3" exhaust and Flowmasters. No difference in ET with them open or closed.
EDIT: Worth the money because they're great fun on the street.

Pete · Post by **Pete** » Sat Jan 28, 12 11:36 pm

Personally, I think they are Bananarama! - no gain in HP, reduced ground clearance and more hassle.

Drop the zausts at the track and save 50+ lbs,,,,,,

Les Szabo · Post by **Les Szabo** » Sun Jan 29, 12 12:00 pm

Pete wrote:Personally, I think they are Bananarama! - no gain in HP, reduced ground clearance and more hassle.

Drop the zausts at the track and save 50+ lbs,,,,,,

Pete · Post by **Pete** » Sun Jan 29, 12 1:48 pm

...Err, sorry about that, that was my "post whole bottle of Red wine" response

Still true, though

Blue · Post by **Blue** » Sun Jan 29, 12 2:13 pm

Calculating a BHP increase is tricky, it depends on how efficient your exhaust system is and the spec. of the engine. As with most things in racing, experimentation is the best way to find out what works for your particular combination. As a rule of thumb though, if you have less than a 3" system on a modified big block, you are likely to see a power increase on open headers, especially if you fit 15" long 3" collector extensions.

sublimemike · Post by **sublimemike** » Sun Jan 29, 12 2:48 pm

Don't worry Pete - done that myself plenty and thought about it in the morning. So... getting back to it . I'm running a tweaked 440, hooker comp. headers and 3 inch flowmasters through. So no gain bhp wise, cost to buy and fit, problems with ground clearance (thanks Pete). Upside seems to be a bit of fun on the street. Based on this starts to get harder to justify - I'm just a bit surprised that with no bends and boxes to go through at the rear axle there is no benefit....Still glad I asked.

Anonymous · Post by **Anonymous** » Sun Jan 29, 12 7:38 pm

Exhaust cutouts are a waste of space unless exhaust lobe is restricted.

BUDGIE · Post by **BUDGIE** » Sun Jan 29, 12 8:36 pm

Pete wrote:...Err, sorry about that, that was my "post whole bottle of Red wine" response

Still true, though

sublimemike · Post by **sublimemike** » Sun Jan 29, 12 8:47 pm

Budgies tucked you up there Pete

BUDGIE · Post by **BUDGIE** » Sun Jan 29, 12 8:52 pm

Our Pete has a wee problem with the old Claret ................

sublimemike · Post by **sublimemike** » Sun Jan 29, 12 9:08 pm

thanks all for the input - on the balance and for the messing about I'll give 'em a miss and get a new trolley jack instead so I can unhook and save 50lb.

BUDGIE · Post by **BUDGIE** » Sun Jan 29, 12 9:15 pm

sublimemike wrote:thanks all for the input - on the balance and for the messing about I'll give 'em a miss and get a new trolley jack instead so I can unhook and save £50.

They'd have cost ya more than 50 quid son