is this right or am i being dumb lol

  1. Frequent Poster Joined: Jan 2009 northamptonshire Posts: 719 saxo furio/vtr
    #1
    i have a mk1 vtr wich is the blacktop obviously there 90bhp right?
    and silver tops are 98bhp ?

    but what makes the 9bhps differance?
    and also i heard someone say a decompretion plate adds 9cc of space
    i think he said a 2ml have no idea in this section of things lol so if i was to skim the head and put a decompretion plate on would i theoreticly have a 98bhp engine ???

    so confused hope someone could clear this up for me thanks in advance
  2. Infrequent Poster Joined: May 2008 Northampton Posts: 193 VX220 S/C
    #2
    The makeup of the blacktops is completely different to silvertops. To start they are rockers, not rollers.

    Head skimming reduces the gap in the head and thus increases compression. Adding a decompression plate is effectively just like adding a second gasket, therefore undoing what you just did on the head skim. It would do the huge amount of nothing.

    Increasing compression normally increases power on a naturally aspirated engine, doing the opposite and lowering compression often helps on boosted engines.
  3. West Midlands Joined: Dec 2007 West mids Posts: 23149 Supra,civic GL
    #3
    basically a decompression plate will effectively lose you power
    not gain

    the 90 and 98 are both the same at 1587cc (even the 16v is 1587)
    its in the head inlet and ecu where the difference comes from and tbh they wont fit the earlier car