TU Question..

  1. Saxperience Post Whore Joined: Jan 2007 Posts: 7705 Saxo VTS
    #1
    To my knowledge this question hasn't been asked before..If it has i do apologise..

    The other day me and my brother were looking at cams etc for our 205 rally car and we discovered the piper 285 gives the 1.6 XU GTI engine a 30bhp increase whereas the same cam for the TU5 8V VTR engine only gives 12bhp iirc..

    I just wanted to know why there is such a difference? I know they are very different engines etc but that is a big difference! Also why is it induction modifications dont give as good power gains on the TU as alot of other engines?

    Only people with decent knowledge to answer please..lol

    Cheers..
  2. Saxperience Post Whore Joined: Mar 2007 Reading Posts: 8980 French tin can
    #2
    Very simple Mario. One engine has 16 vales, while the other has only 8. If you're going to increase the lift and duration for 16 vales, it will be more effective than doing the same on just 8...

    Also, are the camshafts really identical? Plus, those power figures aren't exactly set in stone.

    Not sure about your induction question. Who says so?

    EDIT: It's also woth metnioning about the percentage increase. The 8v has less BHP for starters, so the same proportion increase in comparison to the 16v engine will be a smaller figure.
  3. Saxperience Post Whore Joined: Feb 2006 northumberland Posts: 7693 pulsar gtir, mk4 astra sxi
    #3
    the TU engine is probably better designed to start with imo.
  4. Saxperience Post Whore Joined: Jan 2007 Posts: 7705 Saxo VTS
    #4
    Quote:
    Originally Posted by Toad View Post
    Very simple Mario. One engine has 16 vales, while the other has only 8. If you're going to increase the lift and duration for 16 vales, it will be more effective than doing the same on just 8...

    Also, are the camshafts really identical? Plus, those power figures aren't exactly set in stone.

    Not sure about your induction question. Who says so?

    EDIT: It's also woth metnioning about the percentage increase. The 8v has less BHP for starters, so the same proportion increase in comparison to the 16v engine will be a smaller figure.
    Cheers for the reply Toad but you must have mis-understood me..The XU GTI 1.6 engine is the 1.6 8v 205 GTI engine..I was comparing the VTR engine to the 205 1.6 GTI engine..lol

    As for the induction part, for example, Vauxhalls gain nice power from induction modifications..

    Quote:
    Originally Posted by williamsvts View Post
    the TU engine is probably better designed to start with imo.
    True..
  5. Saxperience Post Whore Joined: Feb 2006 northumberland Posts: 7693 pulsar gtir, mk4 astra sxi
    #5
    so its harder to improve something which is better to start with. like the equivelant corsa gsi 1.6 16v has less power than a vts, and responds well to inlet manifold improvements as this is a bad design on them.
  6. Saxperience Post Whore Joined: Mar 2007 Reading Posts: 8980 French tin can
    #6
    Quote:
    Originally Posted by MaRiO89 View Post
    Cheers for the reply Toad but you must have mis-understood me..The XU GTI 1.6 engine is the 1.6 8v 205 GTI engine..I was comparing the VTR engine to the 205 1.6 GTI engine..lol

    As for the induction part, for example, Vauxhalls gain nice power from induction modifications..



    True..
    I did indeed. I read it as a 106 GTI engine, sorry mate.
  7. Saxperience Post Whore Joined: Jan 2007 Posts: 7705 Saxo VTS
    #7
    Quote:
    Originally Posted by williamsvts View Post
    so its harder to improve something which is better to start with. like the equivelant corsa gsi 1.6 16v has less power than a vts, and responds well to inlet manifold improvements as this is a bad design on them.
    I see..Makes perfect sense..

    Still cant get my head around why the XU 1.6 8v responds soo much better to a cam..It even has more power standard than the VTR engine..

    I know the TU is more modern and is probably more restricted due to emissions etc but the XU's seem to improve on power very easily..

    Quote:
    Originally Posted by Toad View Post
    I did indeed. I read it as a 106 GTI engine, sorry mate.
    lol, thought you did..

    I'm not that dumb..I know the differences in the VTS and VTR engines..What an insult..
  8. Saxperience Hardcore! Joined: Oct 2005 Aycliffe Posts: 32205 Saxo VTS
    #8
    what about those timings and durations james.... what are the differences on those?
  9. Saxperience Post Whore Joined: Mar 2007 Reading Posts: 8980 French tin can
    #9
    Quote:
    Originally Posted by MaRiO89 View Post
    I see..Makes perfect sense..

    Still cant get my head around why the XU 1.6 8v responds soo much better to a cam..It even has more power standard than the VTR engine..

    I know the TU is more modern and is probably more restricted due to emissions etc but the XU's seem to improve on power very easily..



    lol, thought you did..

    I'm not that dumb..I know the differences in the VTS and VTR engines..What an insult..
    Heh. Well, I wasn't explaining the difference in the engines, I was explaining why a 16v engine would respond with more BHP with wilder camshafts compared to a 8v engine. Although irrelevant, it wasn't a bad comment. Heh
  10. Saxperience Post Whore Joined: Jan 2007 Posts: 7705 Saxo VTS
    #10
    Quote:
    Originally Posted by adsayer View Post
    what about those timings and durations james.... what are the differences on those?
    They look pretty similar..lol

    Quote:
    Originally Posted by Toad View Post
    Heh. Well, I wasn't explaining the difference in the engines, I was explaining why a 16v engine would respond with more BHP with wilder camshafts compared to a 8v engine. Although irrelevant, it wasn't a bad comment. Heh
    It was a good comment..Just irrelevent..
  11. Saxperience Hardcore! Joined: Oct 2005 Aycliffe Posts: 32205 Saxo VTS
    #11
    any link to lift and duration?