Max safe RPM on stock bottom-end

1. menmen L-plater Joined: Aug 2007 youtube.com/medelski Posts: 77 Saxo VTS 167hp

   #1 14th June 2008, 19:36

   Hi!
   
   Anyone knows how much RPM can the stock VTS bottom end take? I set my rpm limitter to 7800 and it feels not enough when the engine is cammed. I get max power at 75XXRPM - very close to the limitter. I have been told recently that the Citroen C2-R2 rally car kit sets the limitter to 8200 on stock C2 VTS bottom end. The C2 VTS bottom is same as in a Saxo, isn't it?
   Anyone tested more than 7800 on stock pistons and rods?
2. pjm300 Saxperience Forum Bum Joined: Jun 2005 Potters Bar United Kingdom (England) Posts: 2749 T/B'd VTS

   #2 14th June 2008, 19:43

   which cams are you running?
   should be able to go to 8k at least, but if your cams are dropping off power theres no point
3. Baz Saxperience Hardcore! Joined: Nov 2005 Coventry Posts: 17782 Fiesta ST150

   #3 14th June 2008, 19:47

   suposidly the saxo or vts is tested to 14k?
4. pjm300 Saxperience Forum Bum Joined: Jun 2005 Potters Bar United Kingdom (England) Posts: 2749 T/B'd VTS

   #4 14th June 2008, 19:49

   i might try it
5. carter Established Member Joined: Aug 2005 nailsea nr bristol United Kingdom (England) Posts: 2273 GOLF R32

   #5 14th June 2008, 20:46

   Quote:

   Originally Posted by Baz suposidly the saxo or vts is tested to 14k?

   14k!! thats nuts
   
   imagine how that would sound!
6. Baz Saxperience Hardcore! Joined: Nov 2005 Coventry Posts: 17782 Fiesta ST150

   #6 14th June 2008, 20:48

   might be 12k but was defo round that sort of mark
7. menmen L-plater Joined: Aug 2007 youtube.com/medelski Posts: 77 Saxo VTS 167hp

   #7 14th June 2008, 21:20

   Quote:

   Originally Posted by pjm300 which cams are you running? should be able to go to 8k at least, but if your cams are dropping off power theres no point

   Well, if there is point or not depends on gearset and what the car is used for.
   I am using my Saxo for rally events on a standard gearset (shortened 59/13) The standard gearset is not a close-ratio one and is slow (dog-gears would make a world of a difference). Very often it would pay to rev a bit higher rather than to shift up 10 meters before next corner...
8. rushy_23 Saxperience Hardcore! Joined: Aug 2004 West Mids Posts: 15392 '98 EK9 N1

   #8 14th June 2008, 21:28

   I remember hearing that too Baz. Or was it you stating the same thing a while ago?..
9. Baz Saxperience Hardcore! Joined: Nov 2005 Coventry Posts: 17782 Fiesta ST150

   #9 14th June 2008, 21:36

   nope i havent stated that before Rushy
10. rushy_23 Saxperience Hardcore! Joined: Aug 2004 West Mids Posts: 15392 '98 EK9 N1

    #10 14th June 2008, 21:48

    You sound like an automated Robot! What did you do with Baz
11. Baz Saxperience Hardcore! Joined: Nov 2005 Coventry Posts: 17782 Fiesta ST150

    #11 14th June 2008, 22:01

    sorry Rush lol i'll try better next time to sound like robot-like
12. jason2003 L-plater Joined: Nov 2007 Taipei Posts: 63 98 Saxo VTS

    #12 16th June 2008, 16:58

    9k on gear 1~3 was ok to my stock VTS bottom end
    , if your peak hp@75xxrpm, I think set rev limit to
    around 8500 will be fine.
    
    but once your peak @75xx, you should enhance all
    the stuff to meet the power.
13. vtr130 Established Member Joined: May 2006 Posts: 2279

    #13 16th June 2008, 20:32

    Id say 8k safely!
14. menmen L-plater Joined: Aug 2007 youtube.com/medelski Posts: 77 Saxo VTS 167hp

    #14 18th June 2008, 07:49

    Thanks guys, I think I will set the limmiter to 8200 then, as in the C2-R2 rallycar
15. menmen L-plater Joined: Aug 2007 youtube.com/medelski Posts: 77 Saxo VTS 167hp

    #15 18th June 2008, 07:51

    Quote:

    Originally Posted by jason2003 but once your peak @75xx, you should enhance all the stuff to meet the power.

    Like what specificaly? (Sorry for the dumb question)
16. jason2003 L-plater Joined: Nov 2007 Taipei Posts: 63 98 Saxo VTS

    #16 18th June 2008, 11:24

    forged rod, piston, balanced crankshaft, proper final
    drive...
    
    one Saxo VTS here hit 19xhp@75xx on dyno, and
    broken the rod at the way home, there are rebuilding
    now.
    
    you mention peak hp @75xx, so I suppose the hp
    will reach 170+
17. menmen L-plater Joined: Aug 2007 youtube.com/medelski Posts: 77 Saxo VTS 167hp

    #17 18th June 2008, 13:40

    Quote:

    Originally Posted by jason2003 forged rod, piston, balanced crankshaft

    By saying "stock bottom end" I meant stock pistons and rods... How much RPM can they take?
18. MaRiO89 Saxperience Post Whore Joined: Jan 2007 Posts: 7705 Saxo VTS

    #18 18th June 2008, 14:47

    Stock rods and pistons were tested to around 14k iirc..But that was like a one off thing, you wouldnt run a rally or road car revving like that all the time as it wouldnt last 5 minutes..
    
    The engines were designed to take a certain amount of revs which with the TU's was around 14k then put into production and fitted only to rev to 7250rpm on the VTS and 6250rpm on the VTR, this makes them ultra reliable at normal revs..Most car companies do it, its called over engineering..
    
    I have heard though that the stock bottom end will take around 8k rpm as an every day car and not have any problems..
    
    Also do remember that although the C2 R2 is a stock bottom end, they are scheduled by Citroen Sport to be rebuilt every 3500km..Thats new rods, pistons, rings and bearings..
19. leeroybrown Saxperience Hardcore! Joined: Nov 2006 Durham Posts: 16000 Clio Trophy 025/500

    #19 18th June 2008, 15:24

    Thought you needed solid lifters to rev to 8k standard ones wont last that long I wouldnt think at 8k
20. pjm300 Saxperience Forum Bum Joined: Jun 2005 Potters Bar United Kingdom (England) Posts: 2749 T/B'd VTS

    #20 18th June 2008, 15:36

    he asked about bottom end
    
    hydraulic lifters will take 8k, but not much more
21. leeroybrown Saxperience Hardcore! Joined: Nov 2006 Durham Posts: 16000 Clio Trophy 025/500

    #21 18th June 2008, 15:41

    Pushing it tbh on 8k... would never run hydraulic lifters on a 8k limit
    
    Would change, better of being safe then sorry
    
    Mates old TB vts just to Rev to 7800 never had a bottom end problem
22. pjm300 Saxperience Forum Bum Joined: Jun 2005 Potters Bar United Kingdom (England) Posts: 2749 T/B'd VTS

    #22 18th June 2008, 15:42

    ive been running 7800 for about 2 years with no problem on hydro's, 8k will be fiiiiine
23. leeroybrown Saxperience Hardcore! Joined: Nov 2006 Durham Posts: 16000 Clio Trophy 025/500

    #23 18th June 2008, 15:48

    Being sensible
    
    I know its only another 200 revs but me personally I would have changed to to solids…not worth the risk
    
    Any how cant see there being much power being made at 8k revs lol
24. pjm300 Saxperience Forum Bum Joined: Jun 2005 Potters Bar United Kingdom (England) Posts: 2749 T/B'd VTS

    #24 18th June 2008, 15:51

    depends on your cams and how well worked your head is, but yeah, for someone who is saving money and will not be running stupid cams, set the limiter at 7800
25. leeroybrown Saxperience Hardcore! Joined: Nov 2006 Durham Posts: 16000 Clio Trophy 025/500

    #25 18th June 2008, 15:52

    Are you making an apperance at FCS with your TB vts?
26. frankie Saxperience Addict Joined: Apr 2006 Frome, down deepest, darkest zummerset Posts: 12971 VTRallye

    #26 18th June 2008, 15:53

    the limiter on my S was rasied to 8k....
    
    no 3 conrod came out to play
27. pjm300 Saxperience Forum Bum Joined: Jun 2005 Potters Bar United Kingdom (England) Posts: 2749 T/B'd VTS

    #27 18th June 2008, 15:55

    Quote:

    Originally Posted by leeroybrown Are you making an apperance at FCS with your TB vts?

    unfortunately not wont be ready in time
28. jason2003 L-plater Joined: Nov 2007 Taipei Posts: 63 98 Saxo VTS

    #28 18th June 2008, 18:38

    my engine got DP short inlet manifold, Cat 708,
    lightweight flywheel, port & polish only, others keep
    stock.
    
    ever run 8xxx at gear 4 for several seconds, but I
    won't do it again, because my peak hp are around
    7k-, and then drop quickly, higher rpm=lower power.
    
    beside the stock engine had its limit.