Have just bought a series 1 rx7 racecar. Looking at getting a cordless impact driver to save me some valuable time on racing weekends.
Wondering what sort of torque numbers I should be looking at to tighten the wheel nuts too. Once I have established this value I need to find a suitable impact driver.
Cheers guys
skyline_guy_r34,
May 6, 12:11am
Bump. See most manufacturers recommend anywhere from 70-95 ft-lbs for their road cars. Mazda recommend 80-90 for most of their road cars.
Have read that on rx8s 90 for road and add 10 if using on track. So is it safe to assume if i run with 100ft-lbs torque on the wheel nuts of my 1980 rx7 itll be a good number. Remember that nuts and wheels will be off and on after every race anyway so not exactly leaving nuts on for months on end. Just worried if 100ft-lbs is too tight! or perhaps too loose!
rojakell,
May 6, 12:42am
Even after a run with the impact gun be sure to use a torque wrench to set it correctly.
zooki007,
May 6, 12:45am
On our rally car we torque the nuts to 85ft-lbs
skyline_guy_r34,
May 6, 12:59am
Sound like i should just buy a 14.4v or low torque 18v with around 100ft-lb max torque. Use that to get the nuts off and on. But use a torque wrench to get correct setting
sr2,
May 6, 2:04am
With tarmac rally cars I tend to run the wheel lugs at the lower end of their recommended torque settings and have the service crew check them at every service stop, this can often be after only two special stages. The rationale behind it is that unnecessarily pre stressing (stretching) a bolt will only increase the onset of fatigue and will add little to either its clamping force or resistance to coming loose. It??
unbeatabull,
May 6, 2:14am
You can get Torque sticks for Impact Guns, last one I brought was a Snap On one for $80 and torques to 135n/m as thats what the cars I work on mainly require, I use to check afterwards with Torque wrench but never found one that wasn't torqued to spec so gave up after a while, still check every now and again. The one I actually got acts as an extension and I can use any impact socket on the end which is handy, considering some torque sticks come as one unit so have to buy seperate ones for different sizes
You will have to make sure if going electric it is 100% Charged though.
carmedic,
May 6, 2:29am
Good advice! I??
zoltec45,
May 6, 2:47am
I set my ratchet to 'really really tight'
tool_shop173,
May 6, 2:53am
Overtightening is just about as bad.
tool_shop173,
May 6, 2:57am
also when you are doing wheel nuts up make sure you go to the wheel nut that is dirctly opposite to the one you have just done up because if you go in a clockwise or anticlockwise pattern you can get brake rotor distortion.
carmedic,
May 6, 4:09am
Believe me my Snap-On battery gun will reliably do-up a minimum of 50 wheel nuts on one charge! It comes with 2 batteries that more than last me all day. If you buy some cheap, Chinese 14v gun however, I??
johnf_456,
May 6, 2:56pm
A good tip that, doing opposite corners which is a lot of people forget.
pfemstn,
May 6, 3:31pm
12mm bolts! 65 ft lb would be plenty most manufacturers recomend 60-65 ft lbs. no need to have them any tighter for motorsport!
sr2,
May 6, 3:35pm
You're spot on with that advice, (see my earlier post).
skyline_guy_r34,
May 6, 10:55pm
Know about using the star technique for doing up nuts. I can get a cheapy 18v black and decker for $249 from mitre10mega with 130nm max torque (converts to 100ft-lbs). Or have looked on here and could get a makita 18v with around 120ft-lbs for around $300 mark.
The black and decker has a 4 year warranty. And with 100ft-lb max I would hope it could at least push out 80-90ft-lbs on all wheels 99% of the time (with charged batteries).
Sounds like anything from 65-85ft-lbs would be fine on my car from what you guys are saying, and id be re-torqueing after every race anyway so wont really risk losing a wheel if using the cheap black and decker.
What do you think carmedic! And also James. under the sill on my racecar is 105-110mm so will definately be buying the 2 ton low profile as that 3 ton was 140mm. Was thinking, wonder what sort of trade price they could do for that 3.5ton low profile he said he could do for $299 for me. If its cheap enough would you want to get it for me at trade and ill give you an extra $10 for your troubles!
skyline_guy_r34,
May 7, 1:35am
Bump for carmedic
carmedic,
May 7, 2:06am
Look at Makita Impact guns at Bunnings they had some on special the other day, I forget prices but thought they were fairly cheap. They??
skyline_guy_r34,
May 7, 2:11am
Yeah I went to mitre 10 mega but Bunnings never even crossed my mind. Ill get in there tomorrow arvo see what they've got. Yeah picked up he was a Cameron, and seemed to be giving a good price, but just wondering if you can get it cheaper. Id like the 3.5ton low pro, but might have to settle for the powerbuilt 2 ton low pro.
Cheers mate
pieman33h,
May 7, 3:16am
always used a cheap torque wrench to tighten the nuts on the stockcar wheels, never ever had a wheel nut come loose, even with major impacts - i:e the wheel turned inside out!
peril787b1,
May 7, 5:57am
One serious tip I must put forward is to get rid of the original wheel bolts that Mazda use and replace them with press in studs with nuts (like most cars have these days).The original bolts have a habit of tearing out of the hubs, and it's VERY common as most Rx7's have been abused over the years.
pfemstn,
May 7, 3:20pm
mellisa2000 a bloody truck mechanic i guess one of those that break off all the car wheel studs no less! we are talking about light cars here , get real
pfemstn,
May 7, 3:45pm
perhaps im being a bit tough there! been looking thru some manuals of 70,s 80.s cars and they are all around 60- 65 ft ilbs. however just done a google search and find current specs are now generally higher, mainly because of the use of mag wheels 80-85 now seems common! regardless i would stick with the manufacturers reomendation and not exceed it
saki,
May 7, 11:57pm
one thing the op hasnt mentioned is the hubs if they are the stock rx7 s1 the hub and disc are one piece so from memory cant press a decent stud in from the back, if hubs are machined up from say billet alloy they will take a high torque
Note that I have no idea what type of battery the black and decker is (nimh/liion/nicd) Bosch is li-ion. Has quick charge (full charge takes 1 hour). Both put out 130nm. Thinking should get the bosch being li-ion.
But how does 14.4v compare to 18v in relation to putting out max 130nm torque for amount of time! Would one out perform the other but being similar spec'd and main difference being voltage.
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