I have purchased a set of digital scales and am adjusting the corner balance on my circut car and need some technical info to help me with the set-up . Can someone that has some experience in this help me with some info or point me in the right direction .
I have set the car on the scales and the total weight is 749 kg's . I have scaled it as it came off the track at Wakefield park , and than adjusted it to what I feel is good . I have all 4 corners independantly adjustable and can get an even amount of weight on each corner . The problem is that the car looks all twisted and bent . I have gone the other way now and set the ride height to where I want it and now the corner weights are now all unevan . I have 100 kg's of weight in the drivers seat and am now moving such things as the battery to different positions in the car to even up the weights .
I have ended up with 48% of the total weight on the left side and 52% on the right . I now also have 37% of the total weight on the front wheels and 63% on the rear . I am happy with what I have done for now but dont know if it is the corect way of doing it . I am back at Wakefield park on the 6th of December and if it handles like a bag of shit I know what I can adjust to transfer more weight to another part of the car . Some experienced help would be good , thanks ROD.
Warrenm ·
This is a lot of fun getting it right 🙂 Seriously it makes an enormous difference once you have it correct-You can even get to make minor adjustments for different circuits as you may already do with tyre pressures , sway bars and shocks.
Few articles here that may help.
Rod, I've been thinking about the corner-weight readings that you have been getting. The front anti-roll bar may be influencing the figures. I know that it cannot be dis-connected for corner-weight adjustments (normal race car practice), so David - my son - and I will try to work out a way to do adjustments with the roll bar in the normal situation. Will be in touch after Philip Island.
Cheers, Greg
matberry ·
Sway bars should be off for initial set up, then fitted and rechecked. The bars should not influence the corner weights for a base setup IMO.
Craig Torrens ·
Is the ground dead level ?
mactaylor ·
good stuff rod when i was ayoung fella working on sport sedans corner weighting was one of the best tuning tools we had, we made great gains. make sure your body double is basicly the same shape as you as this does make a diffrence also your not gunna get close to 50/50 without adding weight most 70's race porsche had about 40/60 front to rear, have you moved the gearbox forward any? do you remember what your tyre temps were from wakefield cause if the fronts are getting hot enough you may want to make very small adjustments as not to undo what is a good baseline to work from. ill ring ya this week some time and get some parts and have a chat!
1303Steve ·
Hi
Is the body double before or after lunch? As Greg said the front swaybar will be playing a part in all this, maybe adjust the front springs like a valve spring so that each is equal side to side, then do all the adjusting on the back end.
Ok just had a thought, maybe unworkable. On the front corner weight a solid fixed point each side of the car so that you get the car balanced side 2 side, then with those two fixed points corner weight the rear end, as I said this maybe unworkable.
Steve
Steve
nbturbo ·
Good day Rod-settled back to normal yet.Geez missing Dennys.Could you send me Michaels email and phone number when you get a chance.The Mustang and my parts left Able Cargo last Friday.
dangerous ·
I played with corner weights on my tube framed car and found that the anti roll bar was the biggest influence.
Although mine was only on the rear.
I disconnected the anti roll bar link at first.
I used the coil over shock 'spring base' to set the car level with me in the seat,
and then any drastic error was improved with slight preload of the anti roll bar.
Trying to make it perfect in a static situation was no good, with engine torque unloading the rear suspension,
but moving weight around made the bst improvements,(30kg ballast, 10kg battery and 20kg fue tank).
If the ground is not level that will make a huge difference.
All the books I have claim the corner weight should be set with anti roll bars disconnected
and adjust them at the track.
bigrudi ·
gday Rod dont forget to check that your rear torsion bars are set at the same height jack the front of the car up in the centre ,then measure the rear at the torsion mounts to the ground if these are different, must be set first otherwise big weight transfer problems,will upset all your readings, cheers Rudi
RodPenrose ·
Thanks for the reply's . I have done all what you have suggested with the exception of the front sway bar disconnection . This is a little tricky as it holds the front suspension in the correct place , so I will try to mount the front sway bar in the centre and see if this makes a difference . I also like the idea of the tripod theory if I can get a mount directly in the centre of the front . This is only a starting point for me and I need a base line in which to start from and improve it from there . I am also toying with the idea of removing the 26mm torsion bar from the right hand side only and replace it with a 27mm bar to compensate for the driver { before lunch } . I also have 275lb springs in the front and may go up to a 300 lb on the drivers side as well . I will scale it up again this weekend and see what it will do . I will also alter the thickness of the spacers on the wheels as this will alter the weights , but will also alter the track , ROD.
JVLRacing ·
Rod, go back to a zero adjustment....u need to take one wheel of at a time
adjust small amounts......
u will need to do this all for corners until right....
no adjustment on ur coilovers will be the same.....
swaybars disconnect!!
JVL
pm sent
mactaylor ·
rod why not make up 2 drag links that u can replace the sway bar with, then just tie up your sway bar in the approx place till you've finnished. make the links the same weight then subtract the percentage change from front to rear bias.
hellbugged ·
Did you make it to Wakefield on the 6th Rod?
RodPenrose ·
Daimo , I made it to the MX5 day and killed the engine on the first run . I had reset the suspension on the corner jacks and changed the oil to a heavier grade to boost the low oil pressure at the end of each run . I was concerned about the 10 psi of pressure at 115 degrees and decided to go for a heavier , thicker oil to prevent the oil breakdown .
On the first outing the oil temp was around 80 deg C as I left the pits , and after the 2nd lap I switched the fan on to operate the external cooler as the temp had got to 120 deg. . By lap 3 the oil was pushing 135 deg. and half way around the 4th lap it reached 150 deg. . I decided to back off and drove around at 3000 rpm's as this was the last lap . By the time I arrived back in the pits the engine developed a knocking sound . After letting the engine cool down , the crank pulley was wobbling all over the place and I thought that I had broken the crank .
I have stripped the engine and the # 2 conrod bearing is no longer there . The engine and cooler system holds almost 6 litres of oil and there was no issue with oil surging . I also have 1mm of sideways clearance across the lifter bores and 3mm of vertical clearance . I think that the engine was so hot that the magnesium has soften and gone all out of shape . The crank, rods , case and piston/barells are all stuffed . I have now built a 2276cc engine with all new components , the same fk46 cam and lifters , raised the comp. to 10.4 and changed to a set of superflo's and some 48mm IDA's . I will dyno this combo on Thurs/Fri this week and will run the car this weekend at Marulan with all of the other vw's , ROD.
PAZZAN ·
too much compression Rod I run 9.1 comp & a big oil pump + straight 40 grade oil..😵💫
HappyDaze ·
Heavy grade oil can cause over-heating, as I found out at Winton a couple of years ago Rod. As you will be at Marulan on Saturday, I'll explain why a lighter oil reduced the oil temp. Is your engine dry-sumped? If so, this can also cause high crankcase temps. See you on Saturday.
Cheers, Greg
vassy66T1 ·
Hope the new combo goes well for you Rod.
I had also heard the same thing about heavier grade oil not cooling as well.
Look forward to hearing of it all.
bigrudi ·
I ran my 1998 11/1 well past 140c 7500rpm for three seasons everythings still fine, floged out lifters and bores possible too hi valve seat pressures.what type of oil you using, a good 15w/40 turbo oil should be fine,have heard of cam follower bores flogging out before on mag cases,dont muck around use an alloy case, Also check condition of camshaft thrustbearings,have had a few of these look pretty ordinary as well may have lost drive on oil pump.How many are heading to Marulan on the weekend.
HappyDaze ·
I'll be there Rudi!
Cheers, Greg
bigrudi ·
Which car u running Greg
HappyDaze ·
Taking the '59 Beetle and the Turbo L bug! Can't have TOO MUCH fun, can you?
Cheers, Greg
Tim Andrews ·
What a bummer. What grade oil did you change to?
RodPenrose wrote:Daimo , I made it to the MX5 day and killed the engine on the first run . I had reset the suspension on the corner jacks and changed the oil to a heavier grade to boost the low oil pressure at the end of each run . I was concerned about the 10 psi of pressure at 115 degrees and decided to go for a heavier , thicker oil to prevent the oil breakdown .
On the first outing the oil temp was around 80 deg C as I left the pits , and after the 2nd lap I switched the fan on to operate the external cooler as the temp had got to 120 deg. . By lap 3 the oil was pushing 135 deg. and half way around the 4th lap it reached 150 deg. . I decided to back off and drove around at 3000 rpm's as this was the last lap . By the time I arrived back in the pits the engine developed a knocking sound . After letting the engine cool down , the crank pulley was wobbling all over the place and I thought that I had broken the crank .
I have stripped the engine and the # 2 conrod bearing is no longer there . The engine and cooler system holds almost 6 litres of oil and there was no issue with oil surging . I also have 1mm of sideways clearance across the lifter bores and 3mm of vertical clearance . I think that the engine was so hot that the magnesium has soften and gone all out of shape . The crank, rods , case and piston/barells are all stuffed . I have now built a 2276cc engine with all new components , the same fk46 cam and lifters , riased the comp. to 10.4 and changed to a set of superflo's and some 48mm IDA's . I will dyno this combo on Thurs/Fri this week and will run the car this weekend at Marulan with all of the other vw's , ROD.
Craig Torrens ·
RodPenrose wrote:Daimo , I made it to the MX5 day and killed the engine on the first run . I had reset the suspension on the corner jacks and changed the oil to a heavier grade to boost the low oil pressure at the end of each run . I was concerned about the 10 psi of pressure at 115 degrees and decided to go for a heavier , thicker oil to prevent the oil breakdown .
On the first outing the oil temp was around 80 deg C as I left the pits , and after the 2nd lap I switched the fan on to operate the external cooler as the temp had got to 120 deg. . By lap 3 the oil was pushing 135 deg. and half way around the 4th lap it reached 150 deg. . I decided to back off and drove around at 3000 rpm's as this was the last lap . By the time I arrived back in the pits the engine developed a knocking sound . After letting the engine cool down , the crank pulley was wobbling all over the place and I thought that I had broken the crank .
I have stripped the engine and the # 2 conrod bearing is no longer there . The engine and cooler system holds almost 6 litres of oil and there was no issue with oil surging . I also have 1mm of sideways clearance across the lifter bores and 3mm of vertical clearance . I think that the engine was so hot that the magnesium has soften and gone all out of shape . The crank, rods , case and piston/barells are all stuffed . I have now built a 2276cc engine with all new components , the same fk46 cam and lifters , riased the comp. to 10.4 and changed to a set of superflo's and some 48mm IDA's . I will dyno this combo on Thurs/Fri this week and will run the car this weekend at Marulan with all of the other vw's , ROD.
So how did the "new" 2276 go ?
71-BEETLE-SEDAN ·
You dont wanna know, Rod had to leave early which is very dissapointing.
cnfabo ·
faulty oil pump ???
71-BEETLE-SEDAN ·
i dunno what it was but was not good thats for sure.
Craig Torrens ·
so any updates on the 2276 failure ?
cnfabo ·
faulty oil pump, BOOM.....OH WELL, i think it made over 130 wheel horsepower and shit load more torque...
dangerous ·
Some interesting reading here related to Volksies.
Drag racing, but still relevent.(page 11)
Dave , thanks for the link . Some of the theories seem good and some sound like they are full of shit . It is always good to look at doing things in a different direction than what I would normally go in , ROD.
RodPenrose ·
Well , after killing another engine due to a lack of lubrication I have rebuilt it again . I disassembled the old 2276cc engine and found a really shitty conrod bearing and the other 3 were pretty well stuffed as well . The conrod was a throw away item and the crank needed to be ground on the mains and rods . I cannot find a major problem with the oiling system , but I did find a few things that I did not like in the pick-up area and the oil pump is now in the bin .
I have now rebuilt the engine with a new 84mm crank and new set of rods . The engine is now 2332cc and the compression has gone from 10.3 to 10.7 . I had a dyno session last Saturday and now the engine output has gone from 121.2 hp to 143.8 hp and the torque has also increased from 223.8 ft/lbs to 263.9 ft/lbs . These are readings are on a chassis dyno and are @ the wheels . Engine hp is now a stout 186 . I still have the 37mm venturies in it and did try the 42mm units and the power was up to 148 and the torque was 270.2. With the larger venturies the max power was @ 5354 rpm and held it to 5929 rpm . The max torque is now @ 5044 rpm . I will be using the smaller venturies as the torque curve is a lot better for what I want to do . I will now have a test day @ Wakefield park next Monday on the public holiday and try to kill this one , ROD.
whathaveidone ·
will be in goulburn will try to drop in
hellbugged ·
what size pump now Rod?..........not interested in the ole hellbug theory of less volume and quicker returning to the pick up?
RodPenrose ·
Damo , I was using one of the CB performance in/out oil pump and was supprised to see that it was 34mm wide . I have now gone for a melling steel 29mm pump and a convential full flow deal by returning the oil into the gallery . I now have 80psi of pressure when I first start it , and 140 psi at 7000 rpm . I am now using the ACE syn-x 4 oil . This is a 5-40 full synthetic deal with 6 litres of oil capacity , ROD.
bigrudi ·
GEEZE Rod thats a shit load of oil pressure better take some spare oil filters concrete and a broome , ur also not supposed to be using synthetic oil they cant clean it up, why so much pressure ? good luck with it cheers Rudi
Craig Torrens ·
will be interesting to read this thread on Monday night 😀
RodPenrose ·
Well , after a long day on Monday the engine is still together . I was too lazy to swap back to the smaller venturies , so I left the larger 42mm units in . The power and torque of the engine is increadible . I am using 4th gear all the way , and only use 3rd to help get into 3 of the corners . I am doing 142km/h on the 7000 limiter before the start line on the straight . I turned probably 40 + laps and would make a change to the car on every session . I must say a big thanks to Greg Mackie for his help and knowledge and am now looking forward to the nationals in 3 weeks time . I did not get any lap times , but I have actually passed a car for the first time . I actually passed a car on almost every lap and feel more confident in the car . It still amazes me on how hard you can drive a car around a corner and it will do what you want it to . The oil pressure seems to be good at around 10-12 psi per 1000 rpm's when hot and after a 12-13 lap stint the temps are all good . I will now give the car another wheel alignment and put it back on the corner scales and make any necessary adjustments . I have gone from tyre temps in the 75 degree range to 130 now , and the brakes are now opperating in the 340 degree range instead of the 200 degree last time , ROD .
hellbugged ·
nice
Taller 4th on the cards now?...i cant remember how far from the braking area the start line is?
PAZZAN ·
I was hitting the limiter 7500 in third just at the end of the straight at the first kink not sure what kph that was..???