I would say 4 to 5bhp at high revs in a Corsa.
After my Alterpower had broken I made another power run and the car gave 112 bhp with the adittion of Mantzel Group A,which is supposed to give +2bhp.
It's one of the last things to add but I had to experiment:lol:

so what power gains ya get, the alternatolr saps power, so how much power will it give the engine back once the load is taken off

Alterpower is now called freepower.
It's a product of racelogic.
You can buy it from GMC Motorsport two.
When the things starts there's a small boost in the torque/Power curve.

But it only work for three months:mad: I think it caught water:(

The new version works with a switch, vaccum in the inlet manifold or...

I have paid some 180 £ 3 years ago:!

I read this came from touring cars.

Interesting. Doesn't that drop the car's voltage/spark strength?

Ian/ffls

Where do you get the alterpower from? price?

Thing that cuts your alternator when you're gunning it to lessen the load.

Whats alterpower?

mucho £££'s :|

I have Mantzel + Superchips
It gave a power increase of 25bhp together with urated fuel pressure and alterpower fitted. The increase is visible from 5500 rpm till 7300 rpm. the car is much faster and you will need the chip to see the power hike from 6600rpm.
Very good mod:thumbs::thumbs:

Now I'm thinking in TB's:cool:

yeah I s'pose the inlet + chip is the best 'bang per buck' mod ya can do without spending masses of cash

I think Velos have stopped trading.

Raised rev limit does give more power, but you still get huge gains without it.

yesh ya sed bout the raised rev limit before.. I am finking maybe next year une the engine a bit... gotta get it running smooooth first :thumbs: ;)

mantzel is £585 not fitted £250 fitting at courteney, velos is about £280 and about £250 fitting i think.
Only velos do the tourqe tube and i think courtney only do the mantzel stuff. Shit i would fit it for £150
Carnt emphasise enough how much you need a raised limit with these mods, you would be loosing about 10BHP with out it,

cool, wots velos price? £250-300? Mantzel around £400-500?

the velos looks like a fat ugly bird (not nice) the mantzel look like it was made in the GM factory, plus the Plenum design is slightly different the mantzel one is better and you gain a few more horses due to it flowing more air

Wots the diff between velo's & mantzel Kris?

Mantzel gets better power gains over the velos, but the price is stupidly expensive, but if its second hand and cheaper you would be a fool not to go for it

mantzel is alot easier to fit and is more well built. id go for that if i was u

what the better of the two seen a mantzel with chip for sale but dont know if to go for it