View Full Version : gaining performance
stockcar racer
21-06-10, 11:59 PM
hi guys, as you can tell from my name i race nova's in stockcar racing, Just wondering if any of you know any small mods that can gain some extra performance. Its a 1.2st engine, i've had the head skimmed to the minium allowed by the rules, new hydralic lifters, the cam has to be standard so can't change that, anything else i can do?
Have a read of this thread mate, be sure to read it all as it may prove very useful to you
http://www.pngclub.com/forum/showthread.php?t=93429
stockcar racer
22-06-10, 02:49 AM
thanks read all 16 pages, given me a few ideas, someone told me to fit toyota starlet valve springs, do u think that will make any difference?
They will only make a difference if you are having valve bounce. a 1300 exhaust manifold will help. You can probably have a rebore to +40 so I'd do that. 3 angle seats will help on the head too, along with a new cam that hasnt been to the moon and back.
blue_peg_16v
22-06-10, 08:46 AM
1.6 maifols and downpipe may help too and still gm stamped so will look standard
or goto Kent/Piper and see if they can do a blueprinted cam... ie maximum everything from the manufacturing tollerences. They probably dont but hey cant do any harm in asking.
CatCams will. Will probably be better off with a AE cam. That said they may have to have a vauxhall cam.
are you permitted to kidney slot the cam pulley and adjust the timing to get the best results on the dyno?
stockcar racer
22-06-10, 11:37 PM
thanks for all your reply's guys, i have a 1300 manifold on already as per rules, May look into new cam as some of you have suggested, The timing can be adjusted but i have no access to a rolling road so its all guess and try, got it running at 26 advanced at the mo and seems to be going well. As for rebore, we are only allowed 1mm oversize, I've been thinking weather its worth doing or not.
every little helps, and the overbore will increase the compression ratio too :)
You will find that a trip to the rolling road will give you more gains that doing anything else. They will set your timing spot on which can be critcal. what revs are you doing for 26 degrees of timing?
stockcar racer
23-06-10, 01:36 PM
You will find that a trip to the rolling road will give you more gains that doing anything else. They will set your timing spot on which can be critcal. what revs are you doing for 26 degrees of timing?
no idea, we don't run rev counters, The gearing has been changed to give us as many revs as possible down the straights so at a guess i'd say just under red lining at the fastest part of the track, not sure what redline is, 5.5 - 6?
lol its carb, rev it to 8k...
lol its carb, rev it to 8k...they valve bounce at 7.5-7.7500 so no go
i'm sure there is some very clever way to get round that....... ie: making the hyd lifters more 'solid' by boosting the oil pressure or similar. or is it the actual valve springs, and couldn't you fit some stronger ones from another gm model, or just new ones?
MattBrown
23-06-10, 07:21 PM
Can solid lifters be used?
usually not in a series like this, which is why people are always looking for a way round it....
turbo-boy
23-06-10, 08:08 PM
skim you cam box mate but might not tick over the best
General Baxter
23-06-10, 08:10 PM
i'm sure there is some very clever way to get round that....... ie: making the hyd lifters more 'solid' by boosting the oil pressure or similar. or is it the actual valve springs, and couldn't you fit some stronger ones from another gm model, or just new ones?
std rockers snap around 8000rpm :thumb:
std old knackered, revved to hell by a leadfoot ones might..... i bet new ones last a bit longer
turbo-boy
23-06-10, 08:25 PM
derv rockers will work and if they break they dont do damage as they has a weak point in them so when they do break they dont cause damage
but diesels rev to about 4500rpm......
and I'd love to know how these loose bits in your engine avoid causing it damage, sounds like an engineering revolution to me
mk, one of our blokes jumped a canal bridge & changed down before landing in a 1.7d astra.... the bits were down the oil drain holes, but we accounted for them all with a telescopic magnet...
i took the rocker top off our merc sprinter & found three lumps of steel & half a torx bit that the factory lovingly left in there...... i took it off cos it got cracked when taking the injectors out. the engine was mechanically fine..with 575000kms on it
stockcar racer
23-06-10, 11:39 PM
std rockers snap around 8000rpm :thumb:
yep been there, missed the change from 1st to 2nd and shattered 4 of them, did a further 5 laps but engine was running rough so retired, took head off removed broken pieces, fitted new ones and now runs fine.
We can't run solid lifters.
Just want to thank you guys, i wasn't expecting many replies tbh, but you've proved me wrong. Thought i'd be in the bad books for taking nova's off the road :d
the ones you race probably aren't long for the road anyway
you should get a cam follower tool off ebay, then the head doesn't need to come off, also, i'd recommend stopping as soon as the noise starts
with a new set of decent lifters you should be able to make it to 8000rpm or just about. If they are old cruddy ones you may struggle.
You do know that you can make the hydros solid while keeping them looking 100% std.....
how does one do the whole shimming up thing though?
MattBrown
24-06-10, 01:27 PM
I was thinking before, if you skim the cambox, and alter the rake of the lifter arms, in theory, you can still make the valves close fully, and open further.
?
could you not gain more in shall and trachion mods ?
MattBrown
24-06-10, 01:46 PM
Whats shall and trachion?
I was thinking before, if you skim the cambox, and alter the rake of the lifter arms, in theory, you can still make the valves close fully, and open further.
?
because no one believes it will work..... Except unfortunately you and me lol
Shimming up is a piece of piss, just takes a bit of time.
because no one believes it will work..... Except unfortunately you and me lol
this it because you actually aren't moving the cam lobe laterally in relation to the valve & lifter thus there is no change in the rocker ratio, and also you aren't changing the lobe at all, you are only changing the cam timing by a small amount.
Shimming up is a piece of piss, just takes a bit of time. it would take loads of time & if the scrutineers asked for a strip down...... big bother
MattBrown
24-06-10, 03:48 PM
this it because you actually aren't moving the cam lobe laterally in relation to the valve & lifter thus there is no change in the rocker ratio, and also you aren't changing the lobe at all, you are only changing the cam timing by a small amount.
it would take loads of time & if the scrutineers asked for a strip down...... big bother
Lifetime ban FTLlol
MattBrown
24-06-10, 03:49 PM
because no one believes it will work..... Except unfortunately you and me lol
Shimming up is a piece of piss, just takes a bit of time.
Why wouldnt with work?
It physically has too.
stockcar racer
24-06-10, 11:05 PM
i agree, can't do anything thats gonna stand out to any other driver there or scrutineers, don't want a ban...lol
I'm liking the idea of the 1300 crankshaft and conrod's, what sort of HP gain are we looking at for that? I would imagine it would give more torque....... which is what i'm after. The only problem is getting hold of the parts, seem to be rare as rocking horse ****
hang on your scared of getting banned for a few shims yet your willing to change the crank :s
1300 cranks and rods arent that hard to get hold of. PM if you want some.
16xe_chris
25-06-10, 03:38 PM
hi guys, as you can tell from my name i race nova's in stockcar racing, Just wondering if any of you know any small mods that can gain some extra performance. Its a 1.2st engine, i've had the head skimmed to the minium allowed by the rules, new hydralic lifters, the cam has to be standard so can't change that, anything else i can do?
What gearbox ratio's are you using?
What final drive are you also using?
You can have the block decked:thumb:
RULES: Pistons may not protrude out of the block, anymore than 10thou (this means it can protrude 9thou:thumb: )
RULES: ALL ENGINE COMPONENTS MUST REMAIN STANDARD, the only component of an engine to be balanced is the crankshaft by drilling only. Air filters may be removed or replaced.
Get a very nice engineer to drill some random (safe) holes onto the crank then re-balance it back up. Saves a few grams and helps it rev up quicker:thumb:
RULES: Flywheels should be standard as manufactured and must not be lightened ( but you can have a fly wheel refaced which will lighten it by a few grams:thumb: )
I used to do alot of circuit racing and it was finding the bending of the rules the important bit, as you are probably aware a 2hp gain over another competitor makes one hell of a diference.
There are other tweaks you can do to a standard engine to make it go that little bit quicker, also little things you can do to your steering and suspension which will make it handle better.
When i was doing oval racing i had the inside tyres down to 12psi and the outer at 21psi as it was an oval i was already leaning into the bend lol.
If you need anymore advice or tips send me a PM :thumb:
What gearbox ratio's are you using?
What final drive are you also using?
You can have the block decked:thumb:
RULES: Pistons may not protrude out of the block, anymore than 10thou (this means it can protrude 9thou:thumb: )
errr if its no more than 10thou, that means 10thou is permitted but 10.1thou isnt ;)
http://www.spedeworth.co.uk/rulesdownloads/Spedeworth_Rookie_Rod%202010.pdf
rules about as standard as it gets. whack in some +40's and regrind your crank!
Why wouldnt with work?
It physically has too.
matt, didn't you read my previous post when you quoted it?
errr if its no more than 10thou, that means 10thou is permitted but 10.1thou isnt ;)
true.
they have kit to measure bore & stroke thru the sparkplug hole, so that is one area that is out for a start.
so its down to spending tons of money matching ports, measuring everything, finding a brand new cam that is exactly at the top tolerance etc..
then buying really expensive petrol that gains a bit...
basically thats why the rich kids win...
usually the most powerful car isn't the fastest, its the one that is better at not being slow, so its down to trying suspension tweaks, photographing & videoing the opposition to see what they are doing & what lines they are taking. trying new things & stopwatching them to see if they work.
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