Falconiroc

Love this discussion, I think its great, thank you for posting everyone.

morrow

Technically yes you could. You can extend the lower arm like mine. Change the strut to a standard coil over mounted to the a arm.. then make a triangular upper arm with Heims for adjusting . There actually is a company who made this type of conversation kit for mustangs

morrow

http://www.agentfortyseven.com/racin...uspension.html. Here is the conversion

Falconiroc

This is very interesting, I assume you'd need to create a couple mounts for the upper A arm (aka short arm) in the wheel well? might have to support it from behind too.

Falconiroc

I'd consider toying around with this idea, I would however like to make sure that the process is reversible for now.

Falconiroc

They have a great video on that site showing the difference in how the outside wheel in a corner, especially under hard braking doesn't maintain a good contact patch when using MacPherson struts, in comparison to LSA style suspension. This could be interesting.

88Greg

I have pondered this Macstrut vs A arm thing too. Thing is, Many high end Porsches and BMW use (or did use) Macs to great effect. Thos are all the cars the Magazines rave about having "precise steering and road feel " etc.

Dreambird

I agree this would be very interesting setup. I have been in contact with SpeedTech they are going to start development of a front suspension for our cars later this year I sent them the link to consider during there development. It would seem possible considering the mustang and our cars have very similar front suspensions, they would just have to add the upper arm to the K-Member and relocate the strut which would also add more wheel tire space. It may even give them the opportunity to fix stuff like the Ackerman.

Falconiroc

I will contact them also, as the more interest they get, the more likely this will come to fruition.

Falconiroc

and honestly with this setup, it would be quite easy to extend 2", they could easily offer 2 sets of A arms with the setup, which would allow you to use 4th gen wheel offset on all 4 wheels, The main reason I'm interested in doing this is that there are many many times more wheels available, and more wheels that I like in 4th gen offeset.

morrow

As far as contact patch as they are talking about?? It's not accurate... there display is relative ... every car is different..?3 degrees?! If I ran 3 degrees I couldn't corner very well lol I down have that much movement lol... I run 1.5 degrees.. and it plants.. though the idea is good. I have this setup in my buddies 99 mustang American iron car

paul_huryk

Problem is that the car with the LSA suspension is a high downforce car that runs in the Unlimited class - the other one is not.

I have seen that video before - to me it shows how bad the OEM setup on a Mustang really is - not how good the SLA works. If this were the case, the 4th gen would demolish 3rd gens at road courses - but they are in reality about equal. But that could be the case of a great MacPherson strut system vs a half *** SLA.

Falconiroc

all three of my 4th gens handled well, but honestly most of my good third gens handled great too. my '88 IROC handled wonderfully, and my 1991 handles great too.

morrow

Exactly!! Thank you!!! lol I would bet that a third gen with stock geometry with a good alignment and good parts and tires could handle just as good as the unlimited car.. I have built both and there not far off.. I'm curious how my current set up would stack up against there setup

SlickTrackGod

Don't buy into hype.

Want a simple fact? it's quite obvious. Their so called agent47 race car in the video on the race track somehow is NOT in first place against the other strut cars that have their strut suspension set up with more caster/less camber.

This is ****ing hype people. Don't be naive. They are trying to sell parts

Note how Detroit speed got real quiet on here after I pointed out their massive brake wheel hop issues? yep

morrow

That's what I'm saying!! Haha

paul_huryk

We have about 20 CMC and American Iron teams running our wheels (not AI Unlimited) and most of those cars are in the 1.4 to 1.5g range on spec 275-40-17 tires and close to stock suspension (rules are very specific and restrictive).

Unlimited cars have the advantage of aero mods for downforce and also a lot more things you can do to the suspension. I guess some of those cars are in the 1.7 to 1.8g range with the downforce at speed. Due to the mods allowed and money teams spend to compete - there are no 3rd gen AI Unlimited cars that I am aware of. They are very competitive in CMC and AI.

Dreambird

I agree 3 degrees is a bunch for sure I run 1.6 and 5.5 castor and the tire temps are pretty even depending on the direction the autocross course runs in, I am also running 16" 245. Good conversation for sure, always good to get different peoples inputs so we can all continue to make these cars faster!

SlickTrackGod

Yes to both Morrow and Dreambird. The reason why 3rd gens do not run unlimited is they suffer from being able to run wide tires like the mustangs and 4th gens can without severe rule infringing modifications. When you can go dollar for dollar on modifications? the 3rd gen will win every time.

The key to making these cars faster is lowering unsprung weight (as would be the key for any car.) The strut assembly is very light weight. THis is why Porsche and others use it as well as pretty much all modern mid sized sedans.

I find itt hard to believe people are pulling sustained 1.4-1.5 gs on a 3rd gen race car with race rubber. That means if they switched to street rubber they'd be pulling about 1.1 or even better. I've never seen any CMC car with rules allowing it to be modified enough to match the lightness and exotic build I did with my old 3rd gen and I am the only person Ive seen documented to pull over 1g on street tires.

morrow

does this mean I have to put street tires back on?

paul_huryk

The rules certainly penalize the 3rd gens quite a bit - fox mustangs also.

I have telemetry from one of my sponsored CMC cars where the car is putting up those g figures in many of the turns on a course - consistently also. CMC cars only have to be 2800lbs or something like that - much lighter than a street car, but stiffer due to the cage and other safety items.

I think that a CMC car on street tires would definitely be in the 1.1g range - although probably hard to drive at the limit.

Thirdgen suspension build - .996g on a similar to CMC suspension and 245-50-16 tires:

https://thirdgenfbody.wordpress.com/...aft-july-1990/

SlickTrackGod

Having grown up with Dick Guldstrand and knowing his ability- he was my mentor in racing- Funny how he and Herb Adams could only get a 3rd gen to .95g's and Suspension Techniques does an independent magazine shoot selling parts and makes that claim. Not a chance= hype

I had a documented 1.07g's with witnesses on a car so tricked out and lightweight parts that put any cmc, AI, or Dicks shootout car to shame when it come to knowledge and exotic parts. You obviously have g-tech telemetry that is known to spike readings higher then a skid pad. hell, my Dodge Neon was showing sustained 1.3g's on one of them LMAO- that car never pulled more than .95 from my butt g-meter, and trust me my butt knows well.

SlickTrackGod

Ill tell you who has to be pulling some g's is nick Morrow's car. Nick puts some reputable rubber on that car like Michilen Pilot Cups and I am willing to bet that wide body v6 will be getting close to 1.1 g's

paul_huryk

I'm not doubting you for a second, but the article seems to have merit in general.

My race driver has a good on-board telemetry system (not a g-tech) and the data he gave me was meant to show the improvement of moving up to 275-40-17 tires from the previous 255-50-16 ones (same tire, new size). In the end, the car ended up putting about 7% more grip with the new wheels and tires - which was at the high end of my estimate (I said 4% to 7% originally). When I read the output and how much the car was puling in most corners, I was floored - a half *** race car with minimal suspension mods that could pull 1.4g or better without aero. I am digging for the data now.

The most important lesson of the data was the fact that the driver was more confident in the car with more grip and could brake a lot later and pull higher sustained g's in every corner. One novice CMC racer moving up to our wheels and 275 tires picked up 4 seconds per lap - all due to increased confidence in pushing his car harder.

morrow

Thanks dean... I'm actually running stickier tires than the cup 2 . My 295 r888 R compounds are at 100 wear rating.? You should drive it some time. It's very planted.. need to figure out how many gs it will hold

Beater79TA

Just to toss another data point into the mix. We run the Garmin Virb camera system on the car with its built in gforce meter and GPS to map the track and lap times. I'm not sure of the accuracy of the unit but have seen the numbers spike up to 1.8 g in the corners on the road course and routinely see it go to 1.4- 1.5 g on the autocross. But that is with suspension mods and a BFG Rival S tire. Some of the higher sustained readings have been after switching to a 315/30/18 tire size. As Paul stated the higher confidence in the car sticking in the corner has led to higher speeds into the corner and higher g readings. It would be interesting to see what a properly calibrated and mounted meter would read on some of the cars in this thread with current generation tires and suspension components on them.

SlickTrackGod

There is no properly calibrated g-meter. You want real numbers then you have to run it on a skid pad and time the car. I built my car using a skid pad for several years.

I will also not I accomplished that number on brand new Goodyear GS-D3 street tires with a 220TW size 245/50-16 and on factory 16x8 IROC wheels.
The car also did a 60-0 braking in 102 feet. The stock IROC did the same in 157 feet.

What killed me is the acceleration of the little 2.8V6 even with a lot of modifications was only a 15.9 sec 1/4 mile (145 rwhp).

I autox'ed that car that car earlier in the build against 11 others and it was not even a contest. The closest one to me was 3.9 seconds back on a aprox 65 second track length. If that happened two years later if would have been a lot more embarrassing for them. This is all documented in the So Cal forums. Ive also tracked this car on Calif Speedway running the same circuit as the CMC races on a CMC race weekend. On street tires and way under powered for a high bank oval track I still would not have been last. Id have to dig up the exact numbers in archives here but my little full creature comfort V6 beat aprox 3 or 4 cars qualifying times out of about 15 cars. Those cars could not touch me in cornering if I had the same rubber they were running. I never finished the 3.5liter motor (divorce ended that car's fate- it was the ex's daily driver grocery getter)

The only person Ive seen run better cornering grip then my car- and Ive driven many many peoples 3rd gens on race tracks) is Pablo's car with the stripped down tubbbed race car he built with 335 CCW's on all 4 corners sticking way out and scrubbing hard. He set the record @ Adams motorsports park beating any times of Pozzi and all the ultimate street car crowds 100k+ cars with a 44.5 sec lap. Note my 8ft bed Vetruck that could not hold a candle to my Camaro ran a 49.7 that same track on street tires. Put Pablos car on the street and it would not make it 1000 miles on any set of tires. My Camaro drove every day with the same setup I ran it on tracks and the tires would last 30000 miles. Take that to the bank. My tires did not wear because my car wheels tracked properly wether driving tame or aggressive and got that 1.07 reading on THAT ALIGNMENT

Now you might note Ive been out of the 3rd gen game with any personal car for a decade, but I continually help other with their cars and am in them quite often. There is not a V8 car alive that will hold a candle to my V6 cars agility. With that said, I am going over to Europe in 2 months helping my friend Berk in Istanbul Turkey to shake down his big block 91 Trans Am I helped him build over telephone conversations and internet. If all goes well we are railing his car up to Germany and running it on Nurburgring. I am probably the leading expert on 3rd gen chassis dynamics in the world. I help many many people on a continual bassis...and might I note all for free. My point of all this? I know what a 3rd gen car can and can not do. Anyone that does not know me may want to take a quick peek at my portfolio gallery and my experience level both driving and crew chief.

prossi

Would love to know what data acquisition systems are being used to get these numbers posted above




EDIT.. never mind I just read what it was...my bad

morrow

What's the best way to calculate g force ability

QwkTrip

iTrader: (22)

I've never looked in to this, but I would suspect the numbers can go higher during transitions than it can sustained. That is why SlickTrackGod uses a skid pad for testing.

Again, I've never looked in to this but these type of things are usually just a matter of getting down to the basics --> measure time to travel a distance in a circle.

SlickTrackGod

Nick, find a big flat parking, Center Post-preferably one with a weight attached to it, 100 feet of string and some chaulk, 12 cones, and a stop watch.

Make a 200ft diameter circle and jave fun.

morrow

I thinking of going to a rack and pinion setup and trying to change up the geometry to achieve a better Ackerman.. thoughts?

Beater79TA

The numbers will definitely spike in transitions. I don't for a second believe the car could hold those numbers on a flat surface for longer than a transition move without breaking loose and spinning. A banked track would yield different results. And we normally only spike to those numbers on autocross courses where we are close to drifting the back end around some of the corners. I would have to go back and see what the readings were on some of the road course laps to see what kind of values the meter is putting out during those laps. I suspect they are lower than the numbers from the autocross laps.

And SlickTrackGod, I don't for a minute doubt your qualifications. I'm just posting the numbers the datalogs are showing. I would be interested in the alignment specs you were running as a comparison to the specs being recommended on FRRAX. I'm not sure how long a set of our tires would last on the street as many of the autocross surfaces we run on are pretty rough and often have areas where the asphalt is coming apart. Those can be pretty rough on tires when the event allows unlimited runs instead of the 3 and done of most SCCA events.

paul_huryk

That is the "normal way" to test for lateral-g numbers, but what works best for a 200ft circle is not going to work the same on a dynamic race course (i.e. one with more than one turn).

Was just thinking of how many new car magazines are putting lap times and cornering g-loads of sports and exotic cars - many pull around 1g 0 maybe as high as 1.1g on the skidpad. Yet they are pulling 1.3, 1.4, or even 1.5g on many turns - some cars don't even have that much aero downforce for the assist.

I don't think for one second that 1.07g is the limit of a 3rd gen on the skidpad in street trim - just moving up to a 275 or even 295 tire (that is in the OEM wheel wells) can push a car well past 1.1g without having to be a stripped shell that can't be driven on the street. Not like 1.07g on 245 tires isn't impressive, but there is upside that should best that number by a decent amount.

I'm going to talk to my CMC customers and see if anyone has done skidpad testing.

morrow

Ok soooo Paul and dean . Based on deans numbers of 1.07 on if I recall very close to stock width track. Low unsprung weight. 245 tires with 220 Tread wear. And most of all the corrected geometry ... soooo mine being 6 inches wider than stock track width on 295 r compound tires 100 tread wear. Low unsprung weight. Low cg as well as the corrected geometry... the only thing I still need to work on is ackramen... plus all my aero which won't do anything unless your at speeds on a track.... plus it's frame stiffeners and roll bids welded to the suspension points creating a pretty stiff chassis. Custom made coilovers that work very well with this chassis and It's a v6 car like deans .... idk just curious on your thoughts

SlickTrackGod

Honest answer Nick- In comparison to my car? the only thing you have going for you is track width and tire width. There is so much difference still between yours and my old car. You do not come close to me in unsprung/sprung weight ratio. you have the lighter V6, but it goes way beyond that in chassis weights, bracing, balance, roll centers, spring rates, shock valving choice with spring rates, sway bar choice based on chassis bracing/twist, polar weight (you don;t come close here) roll induce understeer and overall balance of slip angles, rear locker, wheel base, bushings, and mainly alignment and setting of all those components to work in marriage.


We both have lowered seats, but I also lined the entire floorboard of my car with heavy dynamat for two reasons-1) to damper road noise which is what people mostly do it for, but also 2) I did this to increase negative roll weight to counteract the positive roll of the car- and also add sprung weight between the wheelbase.

As my car nears critical roll angle, the rear axle steered inward progressively and brought the attitude of the car back in a steady progressive angle which made the car EXTREMELY smooth at edge of traction. This has been verified in studying an old autox run I did with all the locals almost 15 years ago. you can literally see it happen. The car was so smooth it looks effortless.

Now to also add, you and I have talked about this in private, your car on a short course is a handicap because of the increase track width. It is stable in cornering and transition, but it is not as agile in transition. This is good for most high speed road courses, but if you run slalom the width you have to travel side to side from left-to right- to left through a cone slalom is about 1ft wider then what I needed to do. What that means is with the same length of car, once past a cone and turning left to attack the next, you have to now turn a steeped sharper angle of attack to clear the next cone then a trackwidth 3rd gen. My car was also 1 1/2" shorter wheelbase then yours so I turned quicker too.

QwkTrip

iTrader: (22)

Complete change of topic here, but what do you think of the Factory 5 '33 Roadster? I'm hankering for another project and always had my eye on a kit car like that because it is something I can "build" without special skills and equipment (just kind of bolts together). Just curious if you have seen any of those on at autocross or road course?

SlickTrackGod

To simplify my last statement about slalom transition, I will give everyone a simple example. If a cone is 1ft wide, and the car is 61" wide (5'1" wide) and lets say you miss the cone by 2" each side of car= the left side of the car right of the cone- transition to- right side of car left next cone in a straight cone path equals the car using a total of 11.5 feet wide of race track. You car being 6" wider needs to do the same in 12.5 feet of race track at a slower steeper steering angle of attack through each cone transition. Your slalom course speed will be much lower by laws of physics.

SlickTrackGod

Factory 5 knows their poop. Anything they make is nice

morrow

As far as sprung and unsprung weight I'm not positive but I'm guising we are closer than you would think. Though most of what I have learned has been learned from you. The front calving is perfect. I kinda feel like I need a little more dampening in the rear. Bunching said? I don't have any other that in the panhard bar . Everything is heims . Alignment is max caster equally. 1.5 camber with zero toe. One other thing I plan to do soon is make a massive spider web of chassis braces to connect strut towers to from frame rails to fire wall. Connected to dive frame back to rear portion of the cage. to stiffen up the chassis even more. You should really come out and go over it with me dean . I'm thinking of going to a rack and pinion and make mounts to try and get the ackramen in better form.

morrow

Yes I agree dean but I'll probably never need to slalom through COBE's... I strictly made it to carve around corners at higher speeds. Which so far it does well

morrow

Yes f5 stuff it bitchen

QwkTrip

iTrader: (22)

Short answers say a lot. Thanks!

SlickTrackGod

Yes, that is what we talked about. Reason I address this though is the topic of lateral g's and people talking about race cars on tracks. It is a prime example how wider is not necessarily better for autox type event racing . Fatter tires also mean a wider track width and less track to work with. I know this harsh fact because of Vetruck- that truck of mine is one big SOB.

SlickTrackGod

The rear ears of the control arms flex inward, The steering box has slack flex in the frame rails and needs bracing (Don;t know if you realize I had 4 lateral braces on the front half of my car (one being the wonderbar of course which everyone else pretty much has, the STB was custom altered store bought piece, the last two we're entirely custom. These took out critical steering wheel movement at high chassis load in cornering. Steering movement that will cause a car to loose mechanical grip on a skid pad if not controllable. You wheels and tires are much heavier. Your brakes are much heavier. You do not have a racing locker, your axles are heavier, your driveshaft is much heavier, even my rearend gears were shaved road race r&p and an alum diff cover. My entore build was focused on weight reduction.

My polar weight is much lower just by a quick glimpse of each car. You have added a lot of stuff (aero wise) in front of the front wheels and in back of the rear wheels. My exhaust was lighter on more lower and center compact. I also had an alum bumper support, plastic headlights, and a lighttened radiator support. THe weight in front of the front wheels and the weight behind the rear wheels was focused on and reduce. I ,as stated above, then purposely added weight low and center in the chassis between the wheelbase. My chassis polar weight was far better distrubuted. All these little things add up. My car turned like a jetfighter. No other 3rd gen Ive ever driven or ridden in turns like mine did.. I will post up vids showing a comparison.

morrow

By polar weight do you mean center of gravity?

SlickTrackGod

This is a comparison of the fastest guy close to me in that local challange 15 years ago. Not this is about 2003-2004 range. My car was not complete until about 2006. In other words it advance more then this old video shows. Unfortunately it is the only footage I have of that car.

Now the other car is GreyGoose. He has 18"x11" Sportlines in the rear of that car and I believe 17x9.5's up front (might even be 18x10's) He had brand new tires that day. Mine were 25K on them and replace the next day. My best clean run that day was 63 seconds, his (not so clean finish) was a 67 sec. He spun across the finish line taking out a few cones (Yes technicalities count so he should have been 4 second penalties and given a 71 if we really want to be precise). Not I am on 16x8 factory IROCs and my everyday alignment that the ex wife drove this car with (I did NOT alter it for the race day grudge match- this is how the car was every day of its life on surface streets).

Now in the two videos, take close note to two things. 1) just how quick the car takes that second to last corner just before George says "that was a sweet drift". Watch the front just change directions instantly without bobble. 2) note the rear start to step out and the rear axle you can lierally see the RR wheel steer inward as the car leans right. the car quickly resets itself and the wheel un-steers. This is roll induce understeer (or better known as rear axle steering. Then watch Mikes car which acts like the typical V8 car with normal chassis front and rear polar weight- when it steering into and through the same corner the chassis stays in motion and he has to bring the car out of that motion with steering corrections(this is typical of all other 3rd gens- my car was light and agile and it clearly shows, not just from being a V6, but all the weight and setup modifications.

Mikes (Note corner at 5 second video mark)

Mine (note same corner at 8 second video mark)

My car turned into a corner like a jetfighter. Just snapped into there and stayed put. The polar weight stops and the chassis settles quickly.

SlickTrackGod

Weight at the extremities of the car- meaning weight furthest from the pole (or center of gravity. It is like spinning a cirlce with your arms extened out and trying to stop your body from spinning, compared to tucking your arms close to your body and stopping your spin. Polar weight keeps a rotation in motion and harder to start rotation AND harder to stop rotation.

In a corner situation (even on a skid pad) if the chassis momentarily looses grip and re-catches grip, polar movemet/polar weight comes into play. Lower polar weight is maintain smooth motion and not cause loss of mechanical grip like the inertia of a higher polar weight vehicle.

Unlike lets say the CMC and AI cars, my car did NOT have a cage that increase upper chassis weight. this upper weight to protect the driver also hampers in roll and polar steadiness of the chassis when the car is on edge of grip. Less is more. Doesn't only matter how light a car is, it matters WHERE the weight is. We all cut our hoods the same to shave weight off the cars. I had light weight seats and brackets the same ($1100 Momo race recliners- yes momo use to make a racing recliner seat.)

morrow

Very notable differences

SlickTrackGod

Yes, and also note that Mikes car is built a lot like the typical performance V8 modified car with aftermarket springs, shocks, Global West Tq arm, tube LCA's and panhard..AND like I stated he was on very wide 11" wheels. Probably built a little better then the Guldstrand and Herb Adams cars in the shootout.

Im on 8" wheels and tires