cd.thomson
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| posted on 15/5/09 at 06:37 PM |
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c20xe power band and rev limit
bored with slow progress recently (waiting on parts from three different suppliers) ive been day dreaming.
The sump is currently off my engine and everything looks very tidy. I was going to leave as is apart from the changed induction but was thinking about
the ARP conrod bolt change. I know quite a few people will say to just do it, but, what is the normal power band on an XE? If I'm going to be
changing well before the limit then is there a need to increase that limit?
What is the standard and improved rev limit just by changing these bolts?
Craig
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GregSL75
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| posted on 15/5/09 at 06:40 PM |
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For £50 it's a sound investment.
IIRC it's upped from 6800 to 7200 officially, other components come into play then.
I'm running 8250 rev limit with a standard bottom end apart from the ARPs and it hits that regularly, not problems with it flying apart yet.
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cd.thomson
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| posted on 15/5/09 at 06:46 PM |
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are you "on cam" all they way up to that 8k redline greg?
Craig
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GregSL75
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| posted on 15/5/09 at 06:52 PM |
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No but in an Autograss car it's a sprint really, it's got a 2 speed dog box, but you're only at full throttle for around 2-3seconds,
let off for corner etc. so you'd be thrashing the gearbox otherwise. 2nd gear only comes in on longer tracks where it runs out of legs in
1st.
Official powerband for my cams is 2000-6500
2.0 XE on GSXR TBs and Megasquirt
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cd.thomson
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| posted on 15/5/09 at 07:04 PM |
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so on the road with normal cams I'd generally not look to stray too far past 6500 revs I guess?
So I understand £50 gets me another 500ish revs to play with, but not really usable revs?
Is it worth waiting until its on the road and I look into upgrading the camshafts, swapping out the bearings etc during winter time.
Craig
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GregSL75
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| posted on 15/5/09 at 07:19 PM |
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Probably not worth it on a totally standard engine on the road. If you've got £50 to spare it's a bit of insurance though.
2.0 XE on GSXR TBs and Megasquirt
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perksy
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| posted on 15/5/09 at 07:25 PM |
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I'd fit the ARP's as an 'insurance policy' to be honest
Also once this is done and you fancy some hotter cam's in the future you won't have to touch the bottom end unless going for some
Omega's or similar
Also Might be worth having a look at the SBD oil pressure releif valve mod' and also their Cam cover Mod'
(Details on their site)
HTH
[Edited on 15/5/09 by perksy]
[Edited on 15/5/09 by perksy]
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cd.thomson
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| posted on 15/5/09 at 08:05 PM |
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I've done the cam cover mod, sorry by "standard" i meant no performance modifications.
I wasnt aware of the pressure valve thingy? whats that?
Craig
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omega0684
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| posted on 15/5/09 at 08:21 PM |
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craig how old is your engine and how many miles has it done?
if it has done some excessive milage then whilst you have the sump off you could have a look at the shells for excessive wear and see if they need
replacing, also check the condition of the front and rear crank seals. if you check the shells check the crank and big end bearing for ovality!
[Edited on 15/5/09 by omega0684]
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GregSL75
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| posted on 15/5/09 at 08:22 PM |
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Replace the brass relief valve with a nylon one to stop it sticking open with disastrous consequences.
Although there's some debate as to whether it's better. Some people clean up the brass one instead.
I'm running the nylon one.
2.0 XE on GSXR TBs and Megasquirt
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cd.thomson
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| posted on 15/5/09 at 08:30 PM |
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quote:
Originally posted by omega0684
craig how old is your engine and how many miles has it done?
if it has done some excessive milage then whilst you have the sump off you could have a look at the shells for excessive wear and see if they need
replacing, also check the condition of the front and rear crank seals. if you check the shells check the crank and big end bearing for ovality!
[Edited on 15/5/09 by omega0684]
Everything has been checked and its okay, these engines are fairly bullet proof, but I will be rebuilding it after its on the road before any more
performance mods. Thanks for the advice as always.
I will look into this release valve thing. I'm not even sure if I've seen it while I've been working on the engine :S
Craig
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GregSL75
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| posted on 15/5/09 at 08:42 PM |
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It's under the big bolt on the oil pump next to the filter housing..
2.0 XE on GSXR TBs and Megasquirt
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GregSL75
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| posted on 15/5/09 at 08:45 PM |
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2.0 XE on GSXR TBs and Megasquirt
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loggyboy
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| posted on 15/5/09 at 09:43 PM |
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Not sure if it helps but heres the power chart of my standard (bar exhaust and filter) XE. (power at wheels BTW)
Good thing about the XEs is the nice smooth delivery  especially noticable in light cars.
However IMO raising the revlimit isnt really much of a benefit, its the shift point that counts, getting it just right to get most of the
power/torque, rather than trying to hit the highest point the engine will withstand, just because it can!.
[Edited on 15/5/09 by loggyboy]
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perksy
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| posted on 16/5/09 at 08:21 AM |
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If you do decide to fit the ARP's
when you drop the sump make sure the inside of the sump and the pick-up pipe gauze are nice & Clean
Also check condition of the big end shells
(the one furthest from the oil pump is usually the first to show signs of wear)
Main bearings are usually pretty good and ok on these unless its suffered from oil starvation
As has been said, their are different views on the SBD Nylon releif valve
Perhaps just check what you have already and make sure it is score free
Also check its Housing inside the oil pump as these have been known to score
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philw
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| posted on 16/5/09 at 10:21 AM |
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Also if you fit ARPs dont forget to countersink the caps.
Must try harder
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