i want more power!

si.c1978

si.c1978

Senior Member
hi,
im relatively new to this site and im after getting some more oomph out of me astra, i have been told to remove my pre cat, is there any kind of kit you can buy for this?
is a remap a worthwhile excersise? if so where is best?
also any tips on squeezing a bit more out of him ll be gratefully recieved. (im already running a piper cross viper air filter and power flow exhuast)
Great site and thanx!
 
JohnnyN

JohnnyN

Former Staff
Senior Member
Righty then!!!!

1. Precat removal is a simple enough task. Remove the downpipe away from the manifold and the catback. Don't forget to unclip the sensors in the downpipe. Use a vice to hold the downpipe and remove the precat with a lump hammer and a cold chisel. You can also make a start on it by drilling some of it out. Remember to tip the downpipe upside down when you have finished to get any of the crap out of the downpipe before refitting. Leaving particals of precat to get blocked in the main cat is bad. Make sure that you order yourself a new gasket to fit back on between the downpipe flange and manifold.

2. You say that you have a Powerflow exhaust. What diameter? Was it just a normal 2 inch replacement in stainless or have you gone upto 2.5 inch. A 2.5 inch catback system will give you more power and torque especially if its coupled together to a 2.5 inch custom stainless downpipe. Also a 200 cell sports cat will help things flow better.

3. Its worth upgrading your intake side of things too. The dbilas above would be a good addition. Other than that, a larger bore custom aluminium intake tube with silicone elbows will do the job especially if you've already spent money on the Viper.

Only after the above has been done would it be worth having a remap. You would be able to make the most from your mods then. If you intended on going further with head and cam work then it would be advisable to wait.

See this link for custom downpipes and 2.5 inch catback systems from Piper for the Astra G. Well worth spending a bit of money I think.

Scroll halfway down the page once its loaded up.

http://www.courtenaysport.co.uk/

;-)
 
si.c1978

si.c1978

Senior Member
so am i to presume the pre cat is inside the down pipe and thats all there is to it????
and i shall start on all the above as soon as the mrs is at work on sunday!
what sort of power gain would i achieve? i know some where i can get an inlet so many thanks!
 
B

blue se2

Senior Member
like a said on a previous post dont expect much maybe 3bhp out of removing the precat (if it has one) these little mods just seem to improve the drive of the car rather than the power.
 
H

Huskyman

Member
Don't forget to wear a really good dust mask when you remove the pre-cat. These things contain Platinum, which is really really bad for your health if you breathe the dust!! :(
 
si.c1978

si.c1978

Senior Member
Im running at around 160bhp at the mo, im after what ever increase i can get,
im fairly handy and know my way around an engine so im open to suggestions.
 
dunowt

dunowt

Regular Member
its running sweet as a nut now thanks daniel, thinking of getting a stainless cat back next but need to save some pennies first and theres a risk of redundancy at work so our lass does'nt seem to think it's a necessity!!! lol (n)
 
D

Daniel

Senior Member
thats a shame m8 but can see here point lol if you got loads of money to spend feller you can do loads to the z22se but if ya want a faster car i would get a car that is faster works out cheap astra turbos have right down in prices ????
 
dunowt

dunowt

Regular Member
i know mate but its hard to find a good one thats not been to the moon and back or is seriously overpriced compared to the coupe that ive got it was a bargain,So got to stick with the one that ive got "for now"......
 
dunowt

dunowt

Regular Member
im lucky mate am an oldie....well i say old am only 32 but it doesnt half make a difference with the insurance and its even cheaper to have our lass as a named driver fully comp, it dropped by about £100 (y)
 
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