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TeeLew

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^ That's the trick. It's not an issue of physically up or down shifting. It's figuring out the best place(s) to do it.
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BlueHPP

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Here is a video of me autocrossing the M3 with three upshifts and downshifts on one lap. Listen for the shifts. Shift points on the M3 are similar to the Ecoboost Mustang around 50-55 mph. Shifting the Mustang is easier with a much better shift linkage. Next autocross in 12 weeks.
 

TeeLew

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I did a test/tune day last weekend. I've changed around the engine quite a bit since the last time out, but I'm still on stock boost, so not a ton more power. It runs on the top end much, much better. Ford has that screwed up on all the Eco's, HPP or otherwise.

My last time out, I was fighting rear grip, so I went from a 24mm RARB to a 20mm one off a base V6. Also on the chassis side, I've been playing with my DSC damper controller, which is allowing me quite a few options during the day. The course was all second gear, so I didn't give the new MGW shifter much of a workout, but, damn, it's nice.

This event was not a competition, but just a chance to go run in a parking lot with cones and a timing loop. The surface was low grip and had a lot of tiny stones that acted like ball-bearings under your tires. It was super windy, so as fast as the cars would clean the track, it would get dirty again.

My first 3 runs were to learn the track and get a decent feel for the car baseline.
Baseline times : 37.4 (2 laps within 0.030 sec)

First change was to stiffen the front with a spring rubber. If you're not sure what that is, I've included a picture. My Vogtland springs are 220#/in and they have about 3 total coils. This stiffens one of the coils considerably. I haven't tested it, but I would suspect it comes out to maybe 275 #/in?
Spring_Rubber.jpg


The stiffer front spring was _much_ better. It gave a ton of stability, which allowed me to be more aggressive, but it also seemed to increase front grip (counter intuitive). On my first lap, I overcharged the entry to a corner and lost time, but on the next run, I ran a 36.3, which means a 1.1 second gain. Clearly, that was a gain in driving and car, but the driving gain was easy to do because the car was more manageable.

Over lunch, I tried to stiffen the FARB (BMR 35mm, started in middle/middle setting) to the stiff/stiff setting, but that doesn't work on a Magneride car, so I ended up putting it back and working on the dampers. Re-running the previous setting post lunch netted a 36.6 lap (dead cold tires to start, so a good run). The first damper setting I tried was a softer/pushier combo. I was hoping this would add grip, but really it just added a big U/S and sloppy transitions. On my first run, I lost the front and went off-course. On the second run I didn't do anything particularly stupid, but only ran a 37.2 and had a big U/S pretty much everywhere.

In my final session, I hooked up the laptop and shuffled the damper mapping. Now I had the 'baseline' map in 'Sport' mode and a map in 'Track' mode which would make O/S. This was pretty good in long duration steady-state corners, but it was too loose in transition and on exits. My first run was a 37.1 (hardly better than the 'pushy' setting) and on the following run I spun entering a slalom. I can't blame the car as much as ham-fisted driving, but it was definitely more difficult to control. For the final run, I went back to my previous best settings and cleaned up my driving. This lap was my best at a 35.3, which was a full 2 seconds faster than my AM baseline. I always feel good about a day where you run my best time at the end.

If I were to guess, I'd say 3/4 of my time improvement was in driving, but with the stiffer front end, I wasn't just happier with the balance, I was happier with the stability of the car. These changes made for a much easier car to drive. It was also cool to be able to make noticeable damper changes with the mode switch. I didn't feel like the Ford maps were really all that much different. These definitely are.

I'm running a 950# rear spring, which conventional wisdom tells us is a reasonable match to my front. I don't think it really is. I feel like the rear is entirely too stiff on this spring. I've previously noted I like a car to understeer as long as it does it in a predictable manner. This will do both. I get U/S or O/S based off my feet, but the rear never really feels as if it rolls or squats much. The front moves, but the rear feels entirely too rigid. When the rear does slide, it's an abrupt breakaway and has poor recovery. The commonly used term is 'flat slide' and it's an indication the car is too stiff for the conditions. This spring might be appropriate for a good track, but I tend to run on low grip surfaces, so I'm going to drop the rear spring significantly and see where we end up.
 

SteveW

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I did a test/tune day last weekend. I've changed around the engine quite a bit since the last time out, but I'm still on stock boost, so not a ton more power. It runs on the top end much, much better. Ford has that screwed up on all the Eco's, HPP or otherwise.

snip

I'm running a 950# rear spring, which conventional wisdom tells us is a reasonable match to my front. I don't think it really is. I feel like the rear is entirely too stiff on this spring. I've previously noted I like a car to understeer as long as it does it in a predictable manner. This will do both. I get U/S or O/S based off my feet, but the rear never really feels as if it rolls or squats much. The front moves, but the rear feels entirely too rigid. When the rear does slide, it's an abrupt breakaway and has poor recovery. The commonly used term is 'flat slide' and it's an indication the car is too stiff for the conditions. This spring might be appropriate for a good track, but I tend to run on low grip surfaces, so I'm going to drop the rear spring significantly and see where we end up.
How much did rake change with the spring rubber up front? I would imagine less rake, so don't rule out the possibility of that change contributing to better performance. I do agree though that much stiffer front springs work on these cars even though you aren't close to the area I'm thinking of in terms of being 'stiff'.

When you are tuning your shocks are you able to differentiate between compression and rebound control? Loose on exit like you mentioned can be too much rear compression force and/or not enough rear rebound. Shocks shouldn't be much of a factor in steady state cornering other than being responsive to minute driver inputs to maintain balance.

Did you measure any tire temps? Curious if you are getting heat in the rear tires.
 

TeeLew

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How much did rake change with the spring rubber up front? I would imagine less rake, so don't rule out the possibility of that change contributing to better performance. I do agree though that much stiffer front springs work on these cars even though you aren't close to the area I'm thinking of in terms of being 'stiff'.

When you are tuning your shocks are you able to differentiate between compression and rebound control? Loose on exit like you mentioned can be too much rear compression force and/or not enough rear rebound. Shocks shouldn't be much of a factor in steady state cornering other than being responsive to minute driver inputs to maintain balance.

Did you measure any tire temps? Curious if you are getting heat in the rear tires.
The spring rubber has a 38 mm section width and the coils are spaced about 43mm apart. Because of this, the coil has to compress a bit before it has an influence. It didn't change static ride height much, but it will have raised it some. That picture I posted is on the ground, so you can see it's not overly squeezed. The next time I get someplace flat I'll check it out the actual difference. My front springs have a relatively large drop (35mm), probably enough to get the geometry a bit ugly, so raising this change might be a gain a couple different ways.

Yes, I'm able to differentiate between rebound and compression, but that wasn't what I was doing. I was just shifting both force curves globally to try and determine what overall level was appropriate, then I'll start working C/R biasing. Unless I'm wrong, I really feel like the rear of the car is too stiff on springing, not damping. As far as the damping end of things, I disagree with your prescription, but like anything, it's all the spices in the soup that make it work.

I was getting as much heat into the tires as I could, but it was a short lap, 65* ambient, 30 mph winds and very little grip. No one was spraying tires, I can promise you that. Pressure rises were on the order of a 1/2 psi. In general for me, I don't struggle getting tires warm. My issue is an over-abundance of aggression, not the lack of it. I was one of the quicker cars (although this was not a competition) among a bunch of Mustangs/Camaros, but none of the really fast guys in the area were around, so who knows how I would have been in the competitive crowd. The only car I know was quicker than me was a 80's Honda Civic Prepared car that was definitely fastest car.
 

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I'm running a 950# rear spring, which conventional wisdom tells us is a reasonable match to my front. I don't think it really is. I feel like the rear is entirely too stiff on this spring.

I've previously noted I like a car to understeer as long as it does it in a predictable manner. This will do both. I get U/S or O/S based off my feet, but the rear never really feels as if it rolls or squats much. The front moves, but the rear feels entirely too rigid. When the rear does slide, it's an abrupt breakaway and has poor recovery.
Might only be too much spring for your tires under that day's temperature and dust conditions. It might be worth the effort to try the same settings (and springs) when conditions are more favorable. If nothing else, you might get an idea of how sensitive it all is to the conditions of the day.


I have a feeling that a turbocharged car might be harder to drive under those conditions, as things like boost lag and progressivity aren't under direct pedal control (basically you end up doing a bit of guessing that you wouldn't with a NA engine). I don't know how the EB is set up (especially in HPP trim), but I can tell you that some turbo cars are pretty decent in those respects while others are terrible. I've owned a good one and a not-so-good one . . .


Norm
 

TeeLew

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Norm, you're 100% right about tuning to the track/conditions...Horses for courses and all that. It just so happens that where I generally run (parking lots around the racetrack in Fontana, CA), the asphalt is in really bad shape and it's always very dusty due to high winds and sand (it's on the edge of the desert). One of the other guys described it as driving in the wet without the water. It's entirely possible that my feedback is an outlier for this simple reason. Regardless, this is where all the local SCCA stuff is run and I have to make my car work on this type of surface, so off I go.

This is my second time out with this rear spring. After the first outing, I decided maybe it was just too much RARB, so that's why I found the smallest made. No doubt it helped traction somewhat, but the gain wasn't massive. Rear springs are a relatively inexpensive and easy change, so why not take a stab at it? That's kind of why I bought this car in the first place.

I'm starting to play around with engine tuning a bit. The guy I'm working with to tune is Ryan Martin, who is well respected in the world of Eco's. In my email to him yesterday morning, I asked if we could work with the throttle pedal/blade mapping to make it more linear. Right now it feels as if it's too aggressive initially. I think this is probably a trick that Ford is using to reduce the sensation of turbo lag. To be honest, the lag is minimal. The turbo is so small that it comes online almost instantly, especially at anything over 3.5k revs. It makes boost about as fast as the driver can apply the throttle. It's just that initial tip-in that I'd like to soften.
 

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TeeLew are you running in Sport or Track modes? At least on the GT the Ford throttle response maps are too twitchy for smooth driving IMHO in anything beyond the default mode. The EcoBoosts also have a lot of torque down low which might also be making it worse. Anyway yeah, I think its a smart idea to make that throttle mapping more linear for more control. I would guess that a tuner would assume you want a fast throttle map, but no, not for our purposes.
 

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TeeLew are you running in Sport or Track modes? At least on the GT the Ford throttle response maps are too twitchy for smooth driving IMHO in anything beyond the default mode. The EcoBoosts also have a lot of torque down low which might also be making it worse. Anyway yeah, I think its a smart idea to make that throttle mapping more linear for more control. I would guess that a tuner would assume you want a fast throttle map, but no, not for our purposes.
He actually - having DSC controller - can run a Normal mode throttle map and upload whatever he wants as Magnaride calibration for that mode (and turn off all the Advancetrac crap). It effectively solves the problem of non-GT350 cars having preset modes without ability to select suspension mode independently.
 

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TeeLew

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I was leaving my 'daily driver' damper map in Normal mode and running in both Sport and Track mode depending on which damper map I was interested in running. There's definitely a throttle mapping difference from Normal to Sport, but the difference between Sport and Track seem minor.

I really think this Eco engine is pretty damned good for autocross. I wish it could make an extra 100 HP and turn an extra 1000 rpm, but that's not in the cards. The ability to produce good low-end torque and reasonable power while knocking down high 20's mpg on the freeway is hell of a nice combo.
 

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Just got my tires for next season. Falken RT660's in 305/30ZR19. I saw all the chatter about this being a suitable replacement for the RE71R and went for it. Still have lots to do before my first event on March 6th.
 

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Just dismounted the tires from my almost new Apex 18x11's. Should make shipping a little more reasonable if anyone is looking for lightweight wheels.

These are the last of my GT parts sitting around.
 

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CAMC aero question - "Front splitter, air dam, and/or spoiler may be added below the bumper and may extend a maximun of 6.0” forward from the integral bumper as viewed from above or the original body excluding non-integral bumpers."

For our S550 cars, does that mean 6" forward from the front edge of the factory splitter or 6" from the painted portion of the body?

Anybody seen this rule tested yet?
 

TeeLew

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CAMC aero question - "Front splitter, air dam, and/or spoiler may be added below the bumper and may extend a maximun of 6.0” forward from the integral bumper as viewed from above or the original body excluding non-integral bumpers."

For our S550 cars, does that mean 6" forward from the front edge of the factory splitter or 6" from the painted portion of the body?

Anybody seen this rule tested yet?
In other sanctioning bodies this is determined by the plan (top) view of the bumper, not the stock splitter.

If you were to take a plumb-bob & hang it over the bumper, that would define your datum. The splitter is allowed to protrude 6" beyond that (imaginary) line.

The GCR would have the proper SCCA definition, but I'm away from home presently & don't have one available to check.
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