IFS Technology - No Limit Sniper IFS

[RobNoLimit]

We have had several questions about brakes, we have all of the designs/components for Bear and Wilwood, and now TBM. The TBM package makes the most sense to us as far a performance goes, but other factors, such as matching the rear, using existing components, style.... may come into play. Here is an assembly of the TBM components.



BTW, we are currently working on the rotor floater ring and caliper mounts to run the Z06 carbon brakes. Stay tuned

[RobNoLimit]

TBM Scalloped rotors save weight and aid in cooling. Also the TBM caliper design has proved to show less flex than others we have tested. 1. Don't forget to screw in the wheel studs first. We use and ARP screw in stud. The rotor adapter ring is machined to lock in place onto the hub. the fit is tight. Start all of the bolts and tighten in a star pattern to seat the ring. Torque to 40 ft.lbs., then remove the bolts, add locktite, and re-install. Torque to 45 lbs.

[RobNoLimit]

The TBM rotor has an 8 x 7" pattern, a bit smaller than the Baer and Wilwood 12 bolt patterns. Also, TBM rotors are not available in 14". We use standard grade 8 hardware to attach the rotor to the ring. Then following normal procedures, the hub and rotor is mounted onto the spindle, and the caliper is bolted on. The TBM calipers use the same "Supelight" pads as many Wilwood and Baer calipers. This is the common 'race' caliper design for many Oval and Road Racing classes, so there are a lot of pad choices available.

[TLWiltman]

I noticed the TBM setup is with a .81 wide rotor. How hard would it be to go with a 1.25 rotor?

[RobNoLimit]

I noticed the TBM setup is with a .81 wide rotor. How hard would it be to go with a 1.25 rotor?

Changing to a 1.25" thick rotor is simple. The rotor is a direct bolt-on replacement, all that's required is a caliper mount block that moves the caliper .218" inboard. Some would do this with a spacer, but we have a dedicated machined mount for the 1.25" rotor.

There is a small weight difference between a .812" and a 1.25" rotor, but remember, this is "un-sprung" and "rotating" weight. So, we try to cut this down as much as possible, as this is the worst weight you could have in the car. - This is why the car isn't getting 14" x 1.25" rotors, and, it won't need them to stop. Heat created by the type of intended driving is also a factor. The 1.25" will shed a bit more heat, about 12% faster after full heat soak. Now look at what we do. Aggressive street, Auto-X, drags, and track days. Even on a USCA event, the Road Coarse sections are limited to 12 to 15 minutes, so 10 to 12 laps. You may feel the brakes fully heat soaked by then, but the 200 TW tires are already gone, so it's not a huge concern. Properly venting the brakes is a better answer.

[Peter Mc Mahon]

What is the total weight difference between the 2 Rob?

[RobNoLimit]

I got the numbers from the source, TBM, and it's 1.1 lbs per rotor. Not a whole lot, doesn't seam like much. But, here's my thoughts. Lets say it's only worth .01 seconds on the brake 'in' in the corner, maybe .005 seconds rolling 'through' the corner, and again .01 seconds on the corner 'exit'. Remember, we're using the same brake on the rear, so a little weight savings there too which helps acceleration. It's not much, only .025 seconds faster in a corner. Now, from all my notes, the average Auto-x turns per run are like this, SCCA = 23 turns, GoodGuys = 14 turns, USCA = 16 turns (these are averages from the ones we've been to. yes, we keep notes on this stuff) But, if you do gain .025 sec per turn, that equates to SCCA = .575 seconds, GoodGuys = .350 seconds, USCA = .400 seconds. On a road coarse, due to increased acceleration times and the length of braking zones, they may be worth more, provided you don't overheat the brakes. Take a look at some of the top ten times at a recent event and see what .400 seconds would do for someones time/ranking.

[Peter Mc Mahon]

This is good stuff Rob, I cant' speak for anyone else but this is the stuff that ,by default, makes me consider it over another product. Good reasoning and facts to back it up. You are an asset to this forum, thanks.

[TLWiltman]

Good info! Thank you. I can see the heavier rotors being good for road course on slicks and the like. Thinner for street tire.

[RobNoLimit]

Thanks for the positive responses. To help with spring rate choices we have decided to include this chart with all Sniper IFS kits. Starting with a given Spring Rate (the pounds of force needed to compress the spring 1") we can calculate the true Wheel Rate (the pounds of force needed to move the tire up 1"). And from there, we can calculate the Suspension Frequency (think of this as the suspensions reaction time, where a higher number is a faster reaction. Like cycles/second, or miles/hour). Part of the calculation for Suspension Frequency includes the value of Sprung weight per corner. We have worked this out for two weights. A 3350 lb camaro will have appx 750 lbs of sprung weight per corner, where as a lighter 3200 lb car (check USCA rules here) will have appx 700 lbs of sprung weight per corner.

Where do you need to be on the chart? Well, that depends on what you want to do, and how sticky your tires are. With 200 TW street tires, the range is as follow (generally)
1.65 to 1.75 = smooth yet sporty street ride, good handling
1.75 to 1.85 = sporty ride, needs good shocks, great short coarse trainer.
1.85 to 1.95 = firm ride, needs dialed in shocks and sway-bars. Track day weapon.
2.00 and up = This is race car territory. Skill and slicks required. You can go there, but use caution, this may react quicker than you.

Note: If your going to tune and set-up using Suspension Frequency, the rear needs to match. Sort of. It needs to be balanced. If the car's weight balance is 52/48, the rear is 8% lighter than the front, I would start with 8% lower Spring Frequency in the rear than the front. Example, For Velocity, at 3400 lbs, if we use a 600 lb front spring to yield a 1.918 S.F. in front, we would start the rear with a 1.765 S.F. in the rear. This will have a slight push in corner entry, so we will then add to the total roll stiffness in the rear to balance the car. How do you calculate the S.F. in the rear? Sign up for one of Ron Sutton's Seminars, or just buy his new book.

[RobNoLimit]

As they say, "It's the little things.." yes, they sometimes make all the difference. We got in a batch of production sway bay bushings today (this is nice for us, because we don't have to cut them on the lathe our selves now). We couldn't find exactly what we wanted so we had these custom made. 1) We wanted a wide shoulder for the sway bar arm to ride against, this helps eliminate the tendency for the arm to 'tip' during hard cornering and eventually 'walk off' the end of the sway bar. 2) We wanted the the I.D. to have a slight taper on the cut from both sides. The bore of the new bushings has .01 degree lead in cut from each side, leaving a .280" band inside with a 1.260" I.D.

Why do this? Try as we do, the two mounts for the sway bar are not "Perfectly" aligned. Our build process is to weld in a full length of DOM across the subframe, and later cut the center out leaving the two separate mounts, one on each rail. I'm sure we are closer to "Perfect" than anyone else - without using a bearing (rattles). A standard style bushing with a wide and straight I.D. bore would cause a slight bind in the sway bar. Our new tapered I.D has plenty of load strength for the forces involved, and has very 'free' rotation of the bar. Remember that any 'drag' in the suspension motion can 'add' dampening and make suspension tuning a fight to figure out.

Will you notice the difference? maybe, maybe not. In comparison, a certain set of plug wires may give you 2 hp @ 6000+ rpm. That's a .33% gain (600 hp motor) and only above 6000. Do we run them, Hell yes. This bushing change will clean up the suspension movement at ALL speeds and driving conditions. So, is it worth it? I'll watch and see in the future if other suspension companies start using/advertising "Tapered seat" or "low resistance" bushings. - They'll have to to keep up.

[k7king]

what's the o.d. Rob. Just made a sway mount for my vette and wondered if they'd fit...1.500?

[RobNoLimit]

they are 1.505". I could sell the separate for $15 each. They fit a 1.250 bar

[frojoe]

What blend of Nylon is that? I'd also be interested in a pair as I'm about to embark on making my own swaybar and will be designing around a 1.25" bar..!

[RobNoLimit]

What blend of Nylon is that? I'd also be interested in a pair as I'm about to embark on making my own swaybar and will be designing around a 1.25" bar..!

Hmm, No. I will tell you this. In the materials category that would include Phenolic, Nylon, Teflon and Delrin, there is a sub group of UHMWPE materials. It is in this last group that we can find specialized materials suitable for space travel, and Hot Rodding.

[rchaskin]

.....suitable for space travel, and Hot Rodding......

LOL!! For the Win!!

[k7king]

Rob
I'll take 4. Is it best to call or email? my email is [email protected]

[RobNoLimit]

Rob
I'll take 4. Is it best to call or email? my email is [email protected]

Jessi will contact you today. Thanks Mike.

[RobNoLimit]

We'll be in Columbus this weekend for the GoodGuys PPG Nationals. Stop by the Auto-X pits and check the suspension out in person. Heck, you can even go for a ride!

[RobNoLimit]

Quick Performance update. Last weekend we were in Charlotte for the UCSA event. Had a great time, yes, it was HOT, but still fun. As usual, racing will find the weak links. Keith's starter (on Velocity) broke an ear off of the body by the outer mounting bolt - not all that un-common, so we push started it to get to DSE for the road rally. The kind folks at DSE let us use a lift, an old starter, some tools and their mechanic! Got it fixed. Pam (Keith's wife) was losing brakes after the Auto-cross in the morning. We got a new master from the Wilwood display trailer and swapped it during lunch and bled the brakes with a cut up water bottle and two little hoses, but they work better than ever. I had my own troubles with the HellBoy, that I thought were ignition woes, and I tried swapping plugs, wires and coils.... but no luck, so I sat out most of the road coarse runs (just limped through a few to get a time) It turned out to be a failing O2 sensor, better luck next time.
As for the Camaro's (and Keith's) performance, they both did great. We have been taking a break from tuning on the car to let Keith get used to it and gain seat time (in the same car every time) so its only air pressure and a few shock adjustments. The car was solid and predictable all weekend. Keith finished with a 7th over-all in the GTV class of 29 entries. With the first three spots being filled with Kyle Tucker, Brian Hobaugh and Mike Maier, I kind of look at this as a 4th place finish in a 'like' group of cars/competitors. Tire temps were even all around, and the car looked smooth. Mostly we're down to seat time and fine tuning. In reality, Keith has owned the car for 9 months now. The Sniper IFS has been in for four months, and this is the sixth driving event with the car. Keith ran his very first Auto-cross in March of 2014 in Pam's T-Bird. For anyone to be this competitive this fast is amazing. in a few weeks we will co-drive the car at a local SCCA event and do some actual tuning. We are all very impressed with the performance level, and the confidence that the suspension delivers.