Fiesta ST NASA TT5, Build-ish, Results, Track Videos

[slyez]

Another piece of info for people who search for it.... With stock fenders (maybe a little pulled out) and the stock front bumper mounting flanges, you can fit 245/40/15 tires on 15x8 35et Team Dynamics wheels with at least a 5mm spacer. To do this, you need coilovers to get inner clearance, also you need the top mounts leaned almost all the way in for max camber and as much negative camber as possible on the knuckle mount also. We run 3.5 dgrees negative on track, and there is no rub. We can run 5, 10, or 15mm spacers up front and still not rub. I think the tire would rub on the MeisterR strut with zero spacer though. 225/45 fit all configurations.
We do now have to consider brake clearance, but the TD wheels clear with a 10 or 15mm spacer, but as indicated above, the 15mm spacer is what we have to run.
Things get very close, and we have melted the adhesive off of all the wheel weights a few times now due to the proximity of the brakes, but it all fits.... for us.

 

[slyez]

Weight note:
We came accross scales at 2770 this past weekend. No front passenger seat, no rear seats but did have the bottom, and still all seatbelts. I weight around 220lb (unfortunately), and you can see the mod list above. We also had a roughly 10lb extinguisher mounted to the passenger floorboards. The target was 2750 for classing, and thats why we left the seat bottom and extinguisher in, to be safe.

We are still not making quite enough power to hit our 13.16:1 lb:hp rating for the class, but we are starting to get some tune help from Alex at Stratified to get us closer. Our last dyno was only 184hp on first pull, then down to 167 on the subsequent ones. This car doesnt like heat.....

 

[ronmcdon]

Another piece of info for people who search for it.... With stock fenders (maybe a little pulled out) and the stock front bumper mounting flanges, you can fit 245/40/15 tires on 15x8 35et Team Dynamics wheels with at least a 5mm spacer. To do this, you need coilovers to get inner clearance, also you need the top mounts leaned almost all the way in for max camber and as much negative camber as possible on the knuckle mount also. We run 3.5 dgrees negative on track, and there is no rub. We can run 5, 10, or 15mm spacers up front and still not rub. I think the tire would rub on the MeisterR strut with zero spacer though. 225/45 fit all configurations.
We do now have to consider brake clearance, but the TD wheels clear with a 10 or 15mm spacer, but as indicated above, the 15mm spacer is what we have to run.
Things get very close, and we have melted the adhesive off of all the wheel weights a few times now due to the proximity of the brakes, but it all fits.... for us.

very helpful info to know. my initial concern was running too much negative camber up front would rub the suspension, but good to hear thats not the case.

get the sense that wheel offset is what to look out for when avoiding rubbing inside suspension. maybe 15x9 +30 would be ideal, or so would be my impression. Curious what model 15x9 wheel are you looking at, whether in 4x100 or 4x108

 

[slyez]

There are no acceptable 15x9 in 4x108, at least as far as I can tell. I have a pair of Advanti 15x9 in 4x100 that I am planning on using once my drill template is received. I dont mind using hubcentric wheel spacers either, so I figure too shallow is easier to correct (with spacers) than machining a too deep rim.

Anyone know a good place to get a 4x100 drill template? I have ordered on from "Alexthemachinist" but there is no response from them as to when it will be ready. Ordered a month ago.

 

[slyez]

Some new updates on lower control arm rear bushings......

The Superpro bushings themselves have seemed to work well in holding alignment and keeping toe change to minimum.....even when they pop out of the control arms....

We were noticing some clicking when transitioning from acceleration to brakes at slow speeds. We looked around the bottom of the car and tie rod etc, and were able to make the noise with the control arms being hit with a mallet. We pried on the control arm a little and saw the the trailing part of the arm could move up and down freely. not in and out, but up and down. We removed the control arm and the bushing was completely loose and fell out onto the ground. We followed the instructions when installing them, and pressed the bushing flush to the top of the control arm boss. I am not sure why this happened. We removed the other side and it was also completely out.

We turned the bushings upsidedown and reinstalled them with the press, but this time we pressed them so there was around 5mm of the bushing metal ring above the control arm boss. The noise is gone, but we will see how this fix holds up.

Anyone have a good suggestion for the rear trailing arm bushings?

We may have to go with the DNA lower control arms that Whoosh sells, but that would give us some modification penalty in TT5 without any real performance gain, so we would like to stick with stock control arms. Suggestions welcome.

Referring to post #12

 

[slyez]

We have been getting ready for the upcoming NASA Time Trial season and have a few updates.
-NASA has updated the rulebook with new tire modifiers to HP/weight. We can now run almost 25 more HP from last year. Now we just need to figure out how, since we were under by almost 20hp last year, only able to make around 185 on the dyno in summer, when we could have been at 205. Now we can be at 230! So we had a local shop, AGP turbos in Tempe, put a billet compressor wheel on a core turbo we had, and are in the process, with all the help from Alex at Stratified, to get it tuned and see if it is a good fit. I am not currenty sure if it will hit the mark, but if it doesn't, I think either the Whoosh hybrid, or X47 classic is the next option.
-We are swapping the front wheels to be able to use 4x100 so we can run 15x9 wheels there. We had Justin at Aero Mach Precision in Mesa, machine some custom hube that have both 4x100 and 4x108 threaded holes in them so we can run 4x100 at track and just reposition the studs to put 4x108 wheels back on for the ride home, and so we dont waste all the wheels we currently own. We machined in m14x1.25 threads in the hubs, and got m14x1.25 to m12x1.5 reduction studs. We wanted to reuse the existing stud holes at 4x108 and have larger threads for strength, instead of using straight m12 studs. We got the studs from motorsporthardware.com, I think they are for a mini or something.
-Finally, we installed a gripper plate diff and a fidanza flywheel a few weeks ago, to try and help us put more power down out of slow corners. That seemed to be the cars weakest point, so ..... hopefully faster...
-A little more weight reduction was done, but based on the NASA rules we think we want to run the car at 2750lb. If we run 2749 or less we lose .3 modifier for running the tire size we run, and whatever power from the hp/weight formula that we end up at. Seems like the lightest we could even hope to be currently is around 2700 flat, so that would cost us 5hp for the 50lb..... Stay at 2750 makes more sense.

First event is Jan 15th and 16th and Wild Horse Pass East coarse with NASA AZ...

 

[M-Sport fan]

Which plate diff did you go with?

 

[ronmcdon]

what do you think is getting in the way of grip in the slower corners? also had this issue and not sure it if was lack of grip (going from 205/16 to 225/16 helped) or too much torque (going from cobb ots st 2 tune to stock tube and slighter lower boost helped)

 

[slyez]

I went with the Gripper brand from the UK. I was going to go with Kaaz, but saw people breaking the gears in fiestas, then considered Cusco, but the cost.....

Exiting slow corners was 2 things. The car never rotates great, its better, but still could rotate more, and spinning the inside tire on exit with the quaife diff. Also, it is hard to modulate the throttle effectively, too little and you lose boost, slightly too much and the inside tire roasts as boost builds back up. I think the plate diff should really help here.

 

[M-Sport fan]

I went with the Gripper brand from the UK. I was going to go with Kaaz, but saw people breaking the gears in fiestas, then considered Cusco, but the cost.....

Exiting slow corners was 2 things. The car never rotates great, its better, but still could rotate more, and spinning the inside tire on exit with the quaife diff. Also, it is hard to modulate the throttle effectively, too little and you lose boost, slightly too much and the inside tire roasts as boost builds back up. I think the plate diff should really help here.

Can you adjust the lockup rate via preload springs on the Gripper, like on many of the others?
(NOT that you would want to have to keep opening up the gearbox to change them anyway if your first choice was not suitable.)

I was considering the Drexler (made in Oz) until they emailed me the insane co$t of building one for our app (like close to $3K USD, just for the diff! ).

 

[slyez]

gripperlsd.com
they say you can make adjustments, and they definitely have several options to choose for the initial locking preload, and accel/deccel ramp angles.

 

[slyez]

The first TT of the season has gone really well. The car is much better, and puts power down really well with the plate diff. In fact, I would say it's one of the best things we have ever done to the car. The car seemed to work well, we had it run by 3 different drivers over the weekend and everyone went fast.
The event was at Wild Horse Pass East course. We pulled out 2 first place finishes, just beating a really well sorted 10th gen civic and a well driven first gen BRZ by around .1s each day, and there were 8 total cars as well. Our best time of the weekend was a 1:04.2, (down from a 1:07.8 the only other time we were here) which is only around .6s from lap record. Our second driver, 13yo kid, was able to lay down a proper 1:05.5 by the end of the weekend as well. We were also up around 4mph from the previous time at the track, mostly due to some more power from the Stratified tune.
We were able to fit the 15x9 35et Advanti Racing wheels up front with the new 4x100 bolt pattern. They barely clear the brake caliper and scrape the wheel a bit when anything bigger than dust gets between the rim and caliper, but it worked with no rub on fender or strut with the 15mm spacers and 245/40/15 tires. With the 15x8 and 205 rear the car was pretty balanced.
Up next is to try a bit higher front spring rate, as the car seemed to roll more than we thought was good for it, and to look for ways t get more power. The rules this year should let us run around 230 whp, so we need to find like 40..... Looks like hybrid time soon.
1:04.2
1:05.5

 

[M-Sport fan]

Does that Gripper diff require a special gear oil, or a bespoke friction modifier additive like some of the Nippon diffs mandate?

Also; You did not run a wing on these sessions?

 

[slyez]

Didn't run a wing, it hasn't seemed to help in any meaningful way. We have yet to be able to make the car loose enough to warrant the wing.... May have wasted a bit of money on that... There is a fast track around here that is where i was convinced we needed it, but have yet to go back. Slower corners the car doesn't need more rear grip, over like 80 it may want it then.

The gripper people say to run standard gear oil with friction modifier, red line says to run no friction modifier, but they also say we can run mtl and mt-lv at 50-50 to get a little higher viscosity. Redline did say we could run friction modifier but shouldn't exceed like 1%, so we are running 50-50 mtl-mtlv and 1% modifier. Redline was worried that the friction modifier would hurt shifting because it was a transaxle with brass synchros.

 

[M-Sport fan]

I am also guessing that our factory ST rear wing does very little as far as rear grip goes, at any speed, and that's why you have no ill effects from running just that smaller, base Fiesta wing, which is installed since it is the only way your aftermarket TT/TA type wing will fit on the car, correct? (Or do you have the M-Sport R5 wing, I forgot ).

 

[slyez]

I cannot feel any difference between the 2 wings. I am sure there is a small benefit with the ST wing, but if anything I want less rear downforce, and if there is a need for some I want lots... So for the typical less than 70mph corners rear lift or no rear downforce is fine, if not preferrable. For the 80+ corners I want lots of downforce because the repercussions are scary. So fast tracks Ill run base wing with 9-lives racing wing, and slow tracks Ill run just base wing. Plus it is slightly lighter...., and we just leave the brackets in it either way so its fast and easy....

 

[Dpro]

I am also guessing that our factory ST rear wing does very little as far as rear grip goes, at any speed, and that's why you have no ill effects from running just that smaller, base Fiesta wing, which is installed since it is the only way your aftermarket TT/TA type wing will fit on the car, correct? (Or do you have the M-Sport R5 wing, I forgot ).

We are actually running experiments right now sealing up the holes on the factory wing. So far it’s been pretty positive feel wise . Danny did a number of streamer tape tests to see how air was flowing both sealed and unsealed to see the effect if any it was having. I have noticed better gas mileage with them sealed up.

 

[ronmcdon]

gripperlsd.com
they say you can make adjustments, and they definitely have several options to choose for the initial locking preload, and accel/deccel ramp angles.

where did you purchase the gripper LSD? On their site I only see sales outside of the US.
Curious if you've already installed the gripper, how does it compare to the Quaife on low speed corners and if you see it being practical on something daily driven?
I don't daily drive my fiesta w/ wavetrack although I do drive it to the track sometimes a few hundred miles away and back w/out a trailer.
will also be interested to see how well it does on autoX

 

[slyez]

We purchased directly from Gripper, I am not sure if they changed their shipping policy since then...

Yes it is installed and is great. I imagine the Kaaz is similar, so if I couldn't get any other option I would get that. Pumaspeed sells the gripper also, and they ship to US. I doubt I would want to fully daily the car with a clutch diff, but we still use it for local errands, and street driving. Its a little noisy, and I will change gear oil with each oil change, or 2, but its fine.

The quaife would spin the inside wheel in 2nd gear corners, better than open diff, but not a ton better. The gripper puts a ton of torque to the outside wheel and the car pulls in the direction of where the wheel is pointed. I imagine its great for autocross. I have used the quaife at autocross and it was way better than open diff in HS, but I can imagine the plate diff being a second faster on a minute or so.

BTW, we also drive the car to every event. If I was going to trailer it, it would turn into an S2000 unfortunately.

We also tried taping up the ST spoiler holes at the fast course where the car was trying to kill me, and it did not make any difference on data for top speed, or cornering speed. At least nothing outside of noise. I am sure it makes a difference of + or - 10-20lb at over 80mph (at least I think that is within reasonable expectations) but I dont think I could feel 10-20 lb placed in the trunk either, so....

 

[M-Sport fan]

What kind of noises on the street does the Gripper make?

Is it a 'squawking' type noise or grinding?

The Eaton Posi in my old 4th gen Z28 was dead silent as long as I used the proper amount of the Motorcraft XL-3 friction modifier in it, but yeah, it probably had about a quarter or less of the lockup capability of your race diff.