first meeting for LS 914, Racing at the MG Classic meeting, Manfeild Park |
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first meeting for LS 914, Racing at the MG Classic meeting, Manfeild Park |
returf |
Nov 16 2016, 11:58 AM
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#1
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Member Group: Members Posts: 67 Joined: 15-August 12 From: New Zealand Member No.: 14,806 Region Association: Australia and New Zealand |
While most of you guys are nearer the end of your racing season, we are just beginning down here in New Zealand. I finally managed to get my car to it's first meeting last weekend. A classic meeting that is in it's 31st year of running and right at my local track. Practice went well but i noticed that I still had the wheel shake up front under brakes. Race 1 was going well with a demon start but unfortunately a lower arm on the left front broke and that put me out for the rest of the day. Day two, and another good start and went from grid 18 to 9th before the first corner, gee it's got great acceleration!!! Race three and off to a flyer again but three corners from the chequered flag and an axle broke. But all'n'all a great start to the 914's racing. Here's a video of race three. check out the shaking. Once i get that sorted i'm sure i'll be able to brake a lot later.
https://www.youtube.com/watch?v=C4OPnfSt_Lw |
stownsen914 |
Nov 16 2016, 01:11 PM
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#2
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Senior Member Group: Members Posts: 911 Joined: 3-October 06 From: Ossining, NY Member No.: 6,985 Region Association: None |
You've got some serious straight-line speed there! What kind of hp is it making?
I did notice the shaking. I'm guessing you feel it pretty clearly in the driver's seat. Do you know what's causing it? Sounds like it was a successful outing overall. Scott |
Toast |
Nov 16 2016, 02:13 PM
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#3
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Not bad for carrying sway bars. Group: Members Posts: 3,377 Joined: 20-January 04 From: Las Vegas Member No.: 1,580 Region Association: Southwest Region |
Great video. Thanks for sharing!
Good luck and enjoy your race season! Which LS do you have? Or should I say what are your engine specs. (I dont get to the Paddock very often) |
Andyrew |
Nov 16 2016, 02:16 PM
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#4
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Spooling.... Please wait Group: Members Posts: 13,376 Joined: 20-January 03 From: Riverbank, Ca Member No.: 172 Region Association: Northern California |
Are you still running really low boost?
Car looks like its running great!! |
Andyrew |
Nov 16 2016, 02:17 PM
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#5
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Spooling.... Please wait Group: Members Posts: 13,376 Joined: 20-January 03 From: Riverbank, Ca Member No.: 172 Region Association: Northern California |
Whats the red nob for, boost?
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returf |
Nov 16 2016, 05:04 PM
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#6
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Member Group: Members Posts: 67 Joined: 15-August 12 From: New Zealand Member No.: 14,806 Region Association: Australia and New Zealand |
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returf |
Nov 16 2016, 05:07 PM
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#7
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Member Group: Members Posts: 67 Joined: 15-August 12 From: New Zealand Member No.: 14,806 Region Association: Australia and New Zealand |
[quote name='Andyrew' date='Nov 17 2016, 09:16 AM' post='2423786']
Are you still running really low boost? Car looks like its running great!! Yes only 8lb boost Andyrew. engine wise all i have to do now is fit a rear sump, Sump to it as looking at the data from the ECU it was dropping off oil pressure on hard acceleration ( thank goodness I had fitted an accusump) |
returf |
Nov 16 2016, 05:14 PM
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#8
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Member Group: Members Posts: 67 Joined: 15-August 12 From: New Zealand Member No.: 14,806 Region Association: Australia and New Zealand |
You've got some serious straight-line speed there! What kind of hp is it making? I did notice the shaking. I'm guessing you feel it pretty clearly in the driver's seat. Do you know what's causing it? Sounds like it was a successful outing overall. Scott Its a standard LS1 un-opened, with bigger injectors borgwarner SX 475 turbo and Link engine management. Dynoed at 527ft/lb torque and 525hp ATW. It's a great feeling after all the years building it to finally race with other cars. Can't wait for the next event |
wndsrfr |
Nov 16 2016, 07:24 PM
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#9
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Senior Member Group: Members Posts: 1,428 Joined: 30-April 09 From: Rescue, Virginia Member No.: 10,318 Region Association: MidAtlantic Region |
Crazy fast, thanks for sharing--especially like the left hand shifting arrangement, cool.
I'm betting on a warped rotor or at least uneven bedding of the pads/rotors. Put a dial indicator against the front rotors & rotate them to check warp/runout. Bedding a new set of pads/rotors takes a series of hard stops & then a cooldown time of about 5-10 minutes & never sit still with foot on the brake if they're at all hot. Keep us posted! |
Cracker |
Nov 16 2016, 08:49 PM
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#10
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Advanced Member Group: Members Posts: 2,148 Joined: 2-February 10 From: Atlanta (area) Member No.: 11,316 Region Association: South East States |
Another potential issue is a wheel out of balance. Did you mount the outside weights on the inside of the drum or lip of the wheel? If inside, it gets too hot there - you will need to mount them on the lip (and tape them too). I bet you will find this is most likely the issue. The date says 2013 - wrong? What gear box are you running?
PS: I just watched the video...you might BOTH rotors and wheels out of balance. That is crazy amounts of shaking. Keep us posted... Tony |
flat4guy |
Nov 16 2016, 09:00 PM
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#11
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Member Group: Members Posts: 442 Joined: 10-October 16 From: nor cal Member No.: 20,484 Region Association: Northern California |
Wow that sounds great, wish we saw more 914's out this way.......
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returf |
Nov 16 2016, 10:58 PM
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#12
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Member Group: Members Posts: 67 Joined: 15-August 12 From: New Zealand Member No.: 14,806 Region Association: Australia and New Zealand |
I'll check it out in the next few days Tony. the rotors are new J Hook AP's and I bedded the brake pads in at Friday practice. I suspect that some of the problem may lay in the attachment of the caster arms ( too light given the torque applied when braking) but I'll let you guys know what I find re runout ect. |
returf |
Nov 17 2016, 03:24 AM
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#13
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Member Group: Members Posts: 67 Joined: 15-August 12 From: New Zealand Member No.: 14,806 Region Association: Australia and New Zealand |
I've been out to the workshop and with the steering wheel locked solid you can get sideways movement of the wheels. I'm picking this will be from the steering joint under the fuel tank. is there any aftermarket fix for this and do you think this may be the cause of my violent wobble that happens only under brakes?
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Cracker |
Nov 17 2016, 07:28 AM
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#14
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Advanced Member Group: Members Posts: 2,148 Joined: 2-February 10 From: Atlanta (area) Member No.: 11,316 Region Association: South East States |
Ok. A couple other possibilities: 1) There are four bolts that hold the steering column to the chassis mount - make sure they are tight. These are located underneath the column in the two slots; 2) The outside bearing on the same rack (in line with the turn singal stalk) can wear/enlarge its retaining bore. Due to the notch for the signal cancel its far from a perfect design. I once used a band clamp around this bearing and it helped a great deal before fixing it appropriately.
Tony |
returf |
Nov 17 2016, 11:11 AM
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#15
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Member Group: Members Posts: 67 Joined: 15-August 12 From: New Zealand Member No.: 14,806 Region Association: Australia and New Zealand |
Sorry Cracker, I didn't answer your previous question re gearbox. Its a 6 speed from a Subaru STI V7.
My steering column down to where it goes through the body is all different from stock. it's electric power steering and all the uj's are late model and secure. I'll check rotor run out today. what's an acceptable figure? |
wndsrfr |
Nov 19 2016, 10:28 AM
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#16
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Senior Member Group: Members Posts: 1,428 Joined: 30-April 09 From: Rescue, Virginia Member No.: 10,318 Region Association: MidAtlantic Region |
Sorry Cracker, I didn't answer your previous question re gearbox. Its a 6 speed from a Subaru STI V7. My steering column down to where it goes through the body is all different from stock. it's electric power steering and all the uj's are late model and secure. I'll check rotor run out today. what's an acceptable figure? There's a good guide that you can download from Centric Stoptech on rotor installation. Shoot for less than.002"....closer to .001" or less is desired. If they're off, try taking them off the hub & advance them one or two lug positions & measure again....keep us posted. |
returf |
Nov 20 2016, 03:51 AM
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#17
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Member Group: Members Posts: 67 Joined: 15-August 12 From: New Zealand Member No.: 14,806 Region Association: Australia and New Zealand |
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Cracker |
Nov 20 2016, 06:44 AM
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#18
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Advanced Member Group: Members Posts: 2,148 Joined: 2-February 10 From: Atlanta (area) Member No.: 11,316 Region Association: South East States |
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stownsen914 |
Nov 20 2016, 09:50 AM
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#19
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Senior Member Group: Members Posts: 911 Joined: 3-October 06 From: Ossining, NY Member No.: 6,985 Region Association: None |
I would think that if the steering coupler were the cause of that violent shaking, that the car would be darting all over the road, and you'd feel strong shaking in the steering wheel. Even if it's not the cause of the shaking, you may still need a new coupler if you're seeing movement ...
If the shaking happens primarily under braking, I'd look at your rotors. |
Cracker |
Nov 20 2016, 10:26 AM
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#20
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Advanced Member Group: Members Posts: 2,148 Joined: 2-February 10 From: Atlanta (area) Member No.: 11,316 Region Association: South East States |
Trust me on this...I had thought I had a mechanical failure earlier this year due to the violence of the vibration on my car. We looked at everything and missed the most basic culprit. I had thrown wheel weights and was out 8 ounces. Mount the outboard weights on the lip and tape. You might be very surprised..I believe I've mentioned this before.
Tony If the shaking happens primarily under braking, I'd look at your rotors. |
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