Jump to content

Cooper_GTI

Members
  • Posts

    875
  • Joined

  • Last visited

  • Days Won

    5

Posts posted by Cooper_GTI

  1. You can't use reground cams in this engine due to the rocker design, and you can't fit carbs either as they won't pass emission regs.

    Tuning this type of engine is very expensive.

    A chap i know has got a polo gti running bike carbs and reground cams (using a 1.4 head)

  2. Thats how it goes with small N/A engines i guess, unless you have the knowledge and time to turbo/supercharge yourself etc.

    Yes, i agree, but in this instance it seems daft to spend that kind of money for 10bhp.

    On my old C20XE redtop engine (150bhp), i fitted some reground cams (£165), then some weber 45's and a 4-1 manifold with decat. This got me 187bhp. That came to approximately £1000, but it was definitely worth it! In an 1993 astra, it ran a 14.4 @96! B)

  3. ;)

    im tempted to get a bastuck for my arosa, except the fact that they are 380 quid!! or 500 odd from kam

    i mite get a scorpion but they are only a 50.8mm bore whereas the bastuck is a 63mm. but scorpions cost 300 quid.

    only thing is my de-cat section is about 50mm bore, and ive heard that if the bore changes in the exhaust then you can lose performance? in other words you should keep it the same all the way though?

    You're exhaust will be as resrictive as the smallest part of the system. You would gain nothing from having a 63mm diameter, being as there is a bottle neck in the decat section.

    This is why mandrel bent tubing is best, as the bends retain the original diameter and dont restrict flow as much as normally bent pipe, which shrinks by a few mill on every bend.

    2" is more than enough for 100bhp.

  4. Doesn't having no back pressure decrease torque though?

    No, but having an exhaust with too large a diameter pipe will effectively shift the power way up top, making it nigh on unuseable. It's a trade off.

    Bigger bore pipes shift the power band to the top, smaller bore pipes shift the power down the rev range. I think there is some confusion when people use the term "back pressure". The exhaust should be as free flowing as possible, but of a reasonable diameter to retain some low down power (perceived as torque).

  5. Simple method.

    Since you're running an SDI, you don't have standard rear speakers.

    If you're not running 6 x 9's and simply have the ones in the front, wire the second set up as rear speakers, head unit should cope with that fine.

    Thats not a bad idea.

    I really dont understand why you went to the hassle of fitting 2 pairs of coaxial door speakers though? It will be louder, but it'll sound awfull. The sound stage will be right down low and it will no doubt sound muddy and lifeless, like most coaxials do.

    You're best bet would be to invest in some 2 way components, amped up, for a far superior sound. Believe it or not, they would probably be much louder than your 2 sets of coaxials too!

  6. but I'm likely to do it anyway out of curiosity, and to check everything's running as it should, mainly back pressure. :shades:

    Thats a myth. The only engines that need back pressure are 2 strokes.

    Get them exhaust gasses out of that chamber as fast as possible!

    Please get some vids up of the Bastuck when it's on! Have you gone the decat route too?

    Also, how much was the chip and did it make any noticeable difference? Mines a 2001 as well you see! :)

  7. The simplest method would be to run one amp.

    If you run 2 amps, you will need to set them up to run perfectly in sync with each other using a machine called an ocsilliscope. You dont really want all that hassle for no real gain.

    Make sure you buy a 2 channel amp that is 2 ohm stable, with about 100w RMS per channel @ 2 ohms.

    When buying an amp, make sure it a brand you've heard of, and ALWAYS LOOK FOR THE RMS POWER RRATINGS! Max power means naff all! ;)

    Another option is, to buy a 4 channel amp and use the first 2 channels as i described above, and the second 2 channels bridged to run a sub.

  8. If i've understood you correctly...

    You have modded your door cards to accept 2 speakers in each one?

    If this is the case, you cannot simply wire them up together due to the different resistance (ohms) that you will load the head unit with.

    Let me explain!

    Each speaker is 4 ohms, if you wire 2 speakers together (in parallel), the resistance will drop to 2 ohms. Now there are only a select few head units that will happily run at 2 ohms. Most are only stable down to 4 ohms.

    If you wire them in series, you will be getting 8 ohms on each side, which will mean the power from the head unit is halved (i.e. if it kicks out 25w rms @ 4 ohms, it will only put out 12.5w rms @ 8), meaning that each speaker will be receiving a whole 6 watts!!! :confused:

  9. ...you also have a thread open regarding a performance fault with your GTI, so unless you have driven another, how can you compare?

    Had it in at VW yesterday, who said there was nothing wrong with it. It drives really nice.

    Apparently they can all be juddery at certain rev ranges.

    And suprisingly, they didnt charge me... :confused:

  10. Lightning audio aren't a bad budget brand to be honest.

    They were one of the better brands, once sold by halfods.

    They dont claim to handle tens of thousands of watts, instead give true RMS figures.

    I had an amp made by them (bolt 150.2) and it was great for the money!

    Stick ithe sub in a ported box and it should drop nicely.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.