N/A 8v and 16v Tuning

  1. Established Member Joined: Oct 2008 Washington Posts: 1232 MK5 Ibiza Cupra
    #1
    Hi all,
    First of all,
    i know the differences between the 8 and 16v engines, but would a 160bhp 8v engine with lairy cam, forged pistons and bodies be as fast over the rev range as a cam'd 160bhp 16v engine?
    Would they be evenly matched?
    The reason i ask is that in my situation both specs would cost about the same to build and at the moment i already have an 8v engine and if that could be a well matched engine to a cam'd 16v, id be very tempted to do it.
    Thanks
  2. Saxperience Addict Joined: Nov 2006 A farm shed in Aylesbury Posts: 14916 Corolla AE86 Peugeot 205 B18C (in bits)
    #2
    they'd have different characteristics .. the 8v would be more peaky and thus more difficult to drive well.

    the 8v engine would struggle on emmissions too
  3. Saxperience Forum Bum Joined: Jun 2005 Potters Bar United Kingdom (England) Posts: 2749 T/B'd VTS
    #3
    you'd need to do a lot more work to the 8v to get it to 160bhp than to sell the 8v and get a 16v to get it to 160.

    the powerband would also be pretty narrow with the 8v and you'd need a decent gearbox to keep it in check.
  4. Frequent Poster Joined: Nov 2003 Tayside Posts: 893 S/c VT!?
    #4
    If they'd both cost roughly the same from the point you're at - then would it not make sense to go for the 16v route, which would leave more options open in the future for extra power. Instead of doing all the work to the 8v, and spend a fortune on either starting from scratch with 16v or further developement on 8v.
  5. Saxperience Forum Bum Joined: May 2007 Posts: 4857
    #5
    It would really depend on how well it was tuned and the rest of the car not least the gearing. There are plenty of 1.3 and 1.4 8v that run rings round 1.6 8v and 16v claiming the same sort of power. I recall a guy who raced a 106 cup car came to buy my 1360cc 8V AX and commented how much better it pulled right across the rev range than his 1.6 16v ~155/160bhp cup engine.
  6. Established Member Joined: Oct 2008 Washington Posts: 1232 MK5 Ibiza Cupra
    #6
    the reason i fancied stayin with the 8v engine, is that to achieve the power that i wanted i would need tb's and i would love that presence and noise.
    Obviously dont need them to run a 160bhp 16v.
    A lot of people have commented on the reliability and driveability of a cam'd vts engine and it seems to be the way to go.
    With 160bhp, are they reasonably quick?
  7. Saxperience Forum Bum Joined: May 2007 Posts: 4857
    #7
    Quote:
    Originally Posted by gd16 View Post
    If they'd both cost roughly the same from the point you're at - then would it not make sense to go for the 16v route, which would leave more options open in the future for extra power. Instead of doing all the work to the 8v, and spend a fortune on either starting from scratch with 16v or further developement on 8v.
    May just be better boosting his 8v then. Value per bhp boost is a very good way to go. To put it in perspective you can boost a 1.6 8V to a point it starts braking gearboxes for a thousand or two. Fair few people have even done it on 1.4s as well. Then it starts getting really expensive for much more power than that remotely reliably.
  8. Established Member Joined: Oct 2008 Washington Posts: 1232 MK5 Ibiza Cupra
    #8
    boost gets complicated though
    id love to turbo it but just getting my head round it drives me mad.
  9. Established Member Joined: Oct 2008 Washington Posts: 1232 MK5 Ibiza Cupra
    #9
    160bhp 16v should be pretty quick shouldnt it?
    thinking of gutting the back and putting a cage in too.
  10. L-plater Joined: Nov 2006 Posts: 80
    #10
    yeah mate go for the 1.6 16v the 8v aint worth that sorta money cos your gonna be limited to the power output more than the 16v lump. if you like throttle bodies get them on the 16v lump and youll be looking about 180bhp without a turbo! turbo or supercharge it then itll be well over 200!
  11. Saxperience Hardcore! Joined: Oct 2005 Aycliffe Posts: 32205 Saxo VTS
    #11
    8v will be more torquey... so better pull.. but the rev range will limit you (i.e. shorter in gear time) so technically zip all difference
  12. Saxperience Forum Bum Joined: May 2007 Posts: 4857
    #12
    Boost is not that complicated. Its easer to get 150/160bhp from turbo charging a VTR engine than going the normally aspirated path.

    Even to get usable 150/160bhp out of a VTS your still talking cam belt, inlet cam, exhaust cam, high flow fuel reg, free flow exhaust, free flow manifold, free flow induction kit and a remap of the standard ecu.

    If you wanted to get 150/160bhp from a turbo charged VTS the list of parts are basically the same apart from you do not need the Cams, or cam belt but you do need a small turbo, a oil pipe for the turbo and to drill a hole in the sump to screw the oil pipe in to. Its not really any harder to do.

    Though most people complicate turbo setups with high boost, low compression, dump valves, inter coolers and so on but you don't have to have any of that to start with.
  13. Established Member Joined: Oct 2008 Washington Posts: 1232 MK5 Ibiza Cupra
    #13
    if i was to use boost.
    i think i would supercharge it as it seems easier to do, easier to map etc.
    would definatly do it properly, forged internals, intercooler etc.
    To spend the money on a charger, i might aswel aim for more than 160bhp. Maybe 180+?
  14. West Midlands Joined: Dec 2007 West mids Posts: 23149 Supra,civic GL
    #14
    looking into this too
    what dya rekon to an xsi engine running a 280 cam n bodies with a 1.1 box would be like (I know the 1.1 box isn't ideal but it's all I have)

    I know it would be very revvy and quite happy high end
    but what about low down in the revs
    purely an idea atm


    ps sorry mini hijack
  15. Frequent Poster Joined: Aug 2007 Rugby Posts: 756 Zetec S
    #15
    Quote:
    Originally Posted by adsayer View Post
    8v will be more torquey... so better pull.. but the rev range will limit you (i.e. shorter in gear time) so technically zip all difference
    i agree,


    be different and go down the 8v route mate ..i havnt seem many tuned 8v engines to that extent.
  16. Established Member Joined: Oct 2008 Washington Posts: 1232 MK5 Ibiza Cupra
    #16
    what kind of box would be needed to make the power accessible in a tuned 8v engine?
  17. Saxperience Post Whore Joined: Sep 2007 North London Posts: 6170 Land Rover Discovery
    #17
    throttle bodied 16v engine would be rapid

    not slow at all 0-60 in round 6secs or so and reach 100 in less than 14sec and top end ... no idea

    its a tincan, with 180bhp
  18. Established Member Joined: Oct 2008 Washington Posts: 1232 MK5 Ibiza Cupra
    #18
    i do fancy the 16v engine, its just the appeal of the 8v thats stopping me.
    iv been thinking that if 160bhp on each engine are equally matched then i would go for the 8v as i already have the engine but if its going to be too peaky and hard to drive, then il go 16v...
  19. Saxperience Hardcore! Joined: Mar 2005 Pompey/Darlo Posts: 31546 MK1 - 1.1 Animal
    #19
    check somers on ssc, think thats his username, he has/had a s/c vtr i believe, could be worth reading
  20. Established Member Joined: Oct 2008 Washington Posts: 1232 MK5 Ibiza Cupra
    #20
    i will do mate.
    if i supercharged the 8v, would i have any issues with driveability etc, would the power be all the way through the standard rev range? and even if i put a boost spec cam in, its very mild isnt it?
  21. Saxperience Post Whore Joined: Jan 2007 Shropshire Posts: 9994 Moonstone Blue 106 GTi
    #21
    8v turbo easy
  22. Established Member Joined: Oct 2008 Washington Posts: 1232 MK5 Ibiza Cupra
    #22
    have to tap the block for oil feed, move the oil filter, remote oil filter kit, different lines for oil cooler, modify sump etc. dont get me wrong, im much more of a turbo person but it just seems a lot of hassle.
    any ideas on the driveability questions that i posted before?
    thanks
  23. Established Member Joined: Oct 2008 Washington Posts: 1232 MK5 Ibiza Cupra
    #23
    bump...
  24. Saxperience Forum Bum Joined: May 2007 Posts: 4857
    #24
    Just screw oil feed in to oil switch or side of head. Oil cooler is not essential on basic kit but very easy to fit. You don't have to move the old filer but many off the shelf manifolds to require it moving. Its not car or expensive to move. Sump mod involved a drill and a nut, VERY easy to do. But if you don't want to go boost practically speaking you should go 16V. 160Bhp from a 8V through normal aspirated tuning would cost you a small fortune and require a lot of TLC. You would also struggle to pass a MOT.
  25. Established Member Joined: Oct 2008 Washington Posts: 1232 MK5 Ibiza Cupra
    #25
    If i do go for boost, i wouldnt want it to be a basic kit.
    Id do everything properly, forged internals etc. Basically i would use the car for straight line speed, a thrash through the gears every now and again, so would i need an oil cooler?
    180bhp + possible?
  26. Saxperience Forum Bum Joined: May 2007 Posts: 4857
    #26
    If your going to the work of forged internals then 300+ bhp is perfectly possible. Though your gearbox will not like it one bit. I know people running up to 200bhp without a out cooler but I would fit one just to be on the safe side.
  27. Established Member Joined: Oct 2008 Washington Posts: 1232 MK5 Ibiza Cupra
    #27
    If i aim for 200bhp at the flywheel and around 160bhp at the wheels...will the power be accessable with the vtr gearbox as the power band is not really moving higher up?
    Will it be pretty quick? 0-60 around 6 seconds or so?
    And most importantly, if done right will it be ok as an everyday car?