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KentF New Reader
11/28/17 9:01 p.m.

In reply to jstein77 :

Yes I have considered a manual swap. But it is a lot of work and for the way this car is used I am not sure it is as big an advantage is some might think.

On the plus side - The manual is lighter and with the engine directly connected to the wheels response is better and power transmission more efficient. All big deals!

On the other hand - The automatic has a torque converter. Another word for this is a torque multiplier. On a lower power car this does just what the name implies. Torque is multiplied by the difference in speed between the input and output shaft minus the losses in the device. Also a big deal!

Another item of note: On an autocross I typically launch in first gear (unless it is raining) and then manually shift to second. I typically stays in second the rest of the run. The 4R70W will not shift gears on its own if placed in second by the shifter. It does not redline until about 80 mph.

So - If at this moment my car is generating 80 ft-lbs of torque and the engine is spinning at twice the input to the transmission then the torque into the transmission is 160 ft-lbs minus say 8%. That comes to about 147 ft-lbs.Also the engine is spinning slightly faster so it is more in its power range.

I have made autocross runs with my car hooked up to a lap top via the SCT tuner. In an autocross run the locking clutch rarely engages and if it does, it is only for a second or two. It spends most of the run torque multiplying. It also spends most of the run wasting some power. Perhaps 8 to 12 HP at any given time based on some research I have done.

So my conclusion is that, given the power range of this car, the location of the extra weight of the automatic transmission (low and center), what I really need is a better, more efficient torque converter. 

It is on the spreadsheet as a future mod. I have been looking at suppliers for a custom unit set up specifically for this application but have not contacted one yet.

MazdaFace Reader
11/29/17 7:50 a.m.

Excellent write up, cool build, and impressive fabrication skills. Color me impressed 

PT_SHO New Reader
11/29/17 1:44 p.m.

Kent, just found the thread from a GRM mail suggested item.  I second/third all of the comments on your great posts. And your auto-x knowledge / journey is neat because a lot of it mirrors my experiences.

With all of the money/time you're putting into the motor, I am surprised you have not changed the rear end ratio.  My Taurus SHO had really long gearing, ~73MPH in 2nd, and all I could do was put on shorter tires.  In STX at the time I was only allowed, I forget, 245 or 265 width tires, but the fender clearance limited me to 235 or 245 depending on tire. If you move your redline down to, say 66 MPH you are getting an extra 21%-ish torque multiplication vs. 80MPH.  Way more useful IMO.  Even if your torque drops off past the peak, as long as it is more than the next gear would give with its longer ratio, you're ahead.

Just don't drop it too far.  My STI (I finally joined the dark side cheeky though I did get to frustrate a lot of WRX drivers who hadn't learned to drive yet smiley ) has a really short 2nd, only good for ~54, and it's a pain to have to shift on the faster courses. But again it digs out of corners like nobody's business once you build the boost due to the AWD and the shorter gear.

More torque is only useful up to the point you can put it down.  Locally (SanFran/Sacramento area) a very fast C Prepared was built out of a pumped up V6 Camaro.  In the speed / gear ranges of auto-x he had pretty much the ability to spin the tires at will, and had a weight advantage due to C/P rules, I think it was 150-200 lbs. 

While mentioning tires, as you said CAM-C is so wide open it's just amazing.  I would strongly suggest going to wider widths, particularly when you can adjust camber. If you get the same tire as your buddy with more HP, but have lighter weight (particularly on the front end v6 vs v8) you may well be able to match him on some courses.  FWIW the winning Camaro 2.0 turbo at Nationals in D Street this year was a half second faster than the F Street ponies! <edit: Scroggs' Camaro turbo also would have won in CAM-C! Of course he's in 'driving alien' category anyway....> Most of the weight comes off of the front end which helps balance as well.

As far as brakes, I just don't see ABS as a negative anywhere.  In fact when the STI finally wore out its rotors, I moved back from Hawk HP+ to Carbotech 1521, a very good street pad. It's consistent from first stop, while the HP+ needed at least a use or two to get full grip IMO, and you'll never get beyond what a good street pad can withstand temp wise on an auto-x course.  Because the 1521 does not grab quite as hard as the HP+(warm) it gives a little wider range of leg push between on and ABS which allows modulation. Though as you also said, many people don't brake hard enough!  The 1521's also dust negligibly compared to the Hawks, another advantage, as my car is also daily driven.

KentF New Reader
11/29/17 7:25 p.m.

In reply to PT_SHO :

You are very right – I should have changed the gearing long ago. The reason I didn’t was that I was traveling with damnation WRX cars in STX class with no gear changes allowed. I only switched to CAM two seasons ago and had other priorities at the time. Mistress has a 3.27 rear gear which is pretty low. Redline for 1st Gear is about 43 MPH and for 2nd is about 84 MPH (rev limiter is set to 4700 RPM).

This winter I plan on putting in 3.73 gears which will redline at about 74 MPH. This will yield a 15% increase in torque at the rear wheels. With the gears will come a differential girdle, new bearings, new axles, etc. I will write it up when I do it. I am sure I will be very pleased with the results.

I don’t want to go to 4.10 gears because this car sees too much highway travel.

Tires –You are right, probably, maybe, that fatter tires would be beneficial. My stock wheels are 16 x 7.5 and I am running 17 x 9s. The reason I did not go wider is the same as the gears – rules in STX. At the moment new wheels are not in the near term budget. But I am studying this. A recent article in either GRM or Sports Car detailed diminishing returns on larger/fatter tires. As I noted above, online postings from similar cars running on my RE71R tires appear to be logging the same G forces as me. If two inches more rubber width (9” to 11”) on each tire were that beneficial I would expect it to be more obvious. Or perhaps I am missing something as this data is somewhat anecdotal. Still studying…

I agree, for autocross there is really not much negative in ABS brakes. I love them. It is a tactile breaking gauge. Thanks for the input on pads!

KentF New Reader
11/29/17 9:30 p.m.

Sudden Catalytic Death? I am looking for some help as it appears my cats have failed during a dyno run tonight. Posted the question in the tech forum for a larger audience. 


Here is a link:


The_Red_Stig New Reader
12/1/17 5:37 p.m.

Was following your other thread, glad you found the culprit and hope you get it back on the dyno soon, I'm eager to see the results.

On another note, I was looking again at some of your previous posts on this build. What camshaft did you use? Is it a custom cam, and if so could you provide the specs? Also, where did you get those guide plates from, I haven't had any success finding ones that work with our engine, are those supersix motorsports plates?

KentF New Reader
12/1/17 9:34 p.m.

In reply to The_Red_Stig :

Hi Red Stig, Yeah that dyno test was disappointing. I basically paid to test a broken car. I am now on the hunt for some new metal core cats to replace the damaged ceramic cats. They are probably still good but in researching this incident I have found that metal core units should provide less resistance. Then back to the dyno.

The cam I put is is a special grind from Comp Cams recommended by Tom Yentzer at Super Six (photo below). Call him up, tell him what you are doing and he will recommend what you need. I believe consulting an expert is important for things like this. All the valve train parts in the kit he sold me are from Comp Cams including the guide plates.After some discussion he can recommend the push rods you need, springs, etc. With this cam you MUST replace the rods, springs and rockers. 

As noted in the earlier post I did this in two stages to spread the costs out over two seasons. I basically now have a Super Six Stage 3 Kit on Mistress with the exception that I had Tom leave the IMRC valves intact.

Current projects are battery relocation to rear seat, Rear seat delete. Replacing the Cats, Installing the new K Member kit and coil overs. Then new gears. Will be a long winter but should be a lively spring.

smeyers None
12/2/17 11:50 a.m.

Thanks for getting this information out here so we can be inspired and even supported by your adventures and efforts.

I'm developing a very similar 2001 Mustang V-6 here in the Phoenix AZ area. I wrote the letter to get the Mustang moved to H Street, which proved futile given the suspension shortcomings. Like you, I have moved on. I went through STP and now to Cam-C.

Here we face strict emissions regulations if we want to drive to events (which I do), so I've focused more on developing the suspension first. I guessing you don't have to pass an emissions test there (Camshaft, headers, etc.)?

So I've just changed from the Ford "C" springs (which were wonderfully balanced), to the M/M front Koni coil-over kit and the adjustable perch rear control arms (thus allowing the 2.5" Hypercoil springs). Will be trying them out next weekend. 

I had over time added the Koni Sport yellow shocks, BBK throttle body and shorty headers, 2.5" cat-back SINGLE exhaust, K&N intake, Steeda "89" Tune, Kenny Brown Caster/Camber plates, subframe connectors and adjustable front sway bar. Have the 9.0x17 wheels, with the Azenis RT615K+ 275/40/17 tires. Went to the 3.73 gears and a Trutrac, with a factory rear sway bar.

Afraid to do cams and heads due to emissions. Please do keep posting so we can share and learn.

Thanks again.

KentF New Reader
12/2/17 2:23 p.m.

In reply to smeyers :

Hi smeyers,

Thank you. I am having some fun writing this log. It helps to get ones thoughts together. Yes these cars do not really fit in any class, even H Street although that would probably be much better than G Street. I am glad to see there are others that share my madness. It is kind of fun. I think CAM is probably the best fit only because you can play with modifications more. On the Cam Nation FB pages there is always a discussion or two about a unicorn car showing up that meets the letter but not the intent of the limited rules. When it happens someday I don't think it will be a V6 SN95 machine. But anyway I am having fun and that is the point.

Is the Steeda "89" tune a chip or downloaded from a SCT device or similar? How do you like that Truetrac? That was a significant change for me. No more point and squirt. Is that thing a manual or automatic? How did you like th 373 gears? I am doing that later this winter. Do you have a build thread on GRM?

You are correct we do not have emissions testing here in the great white north. But we might someday. In spite of the changes I have made I have kept cats, O2 sensors, PCV, EGR on the car and everything works the way it is supposed to.  I think if it was tested and did not meet spec it would come fairly close. Look at it this way, it should meet them a lot better than any 16 year old car that had not been properly maintained. 

scott meyers
scott meyers New Reader
12/3/17 10:07 a.m.

Nope, no build thread. Did not know about a build thread option.

I have the SCT iTSX bluetooth tuner (works with Apple too!). I originally bought from Steeda, who provided two tunes, an "87" Octane and an "89" Octane. After I added some mods, and wanted to update my tunes, they admitted they could not do so for our V-6's (got a partial refund). So now I'm looking for who makes the best "out of the can" tunes for us (who also uses the SCT devices). Leaning towards American Muscle or Bama, but still researching. Will likely do a "91-93" Octane this time too, one that is adjusted for my few mods.

LOVE the Trutrac. Kept frying the one inside tire even when in Stock Class, so very helpful. Decided against the "geared" version because if you have one rear tire get light or even lift, it becomes an open diff. The 3.73 gears were among the best mods I have done. Biggest "butt-gain".wink Here is a link to a gear/speed calculator CLICK HERE. With my 3.73's and the 275/40/17 tires (5800rpm redline) I get 1st gear/35mph, 2nd gear/60mph, and 3rd gear/89mph. Nearly perfect for autocrossing. I have the T5 five-speed.

Even without the cams and heads, and long-tube headers, think I'm doing well here (azsolo.com). Paxing around 900-920 on a good day, and last event I finally beat a pesky 2003 Cobra Mustang with 315/35 tires! Made him very sad.yes Still about 1.0 to 1.5 seconds behind a fast 2016 V-8 Mustang, my next goal. We have a number of current and previous National Champs who run here, so sledding is kind of tough.crying



KentF New Reader
12/3/17 9:30 p.m.

In reply to scott meyers :

Hi Scott,

I have used VMP Tuning in Florida since 2012 or so.  They work with SCT tuners and are very familiar with V6 SN95 Mustangs. I think these cars were some of the first ones they worked with when when the company was created. They have created several custom tunes for me over the years.

One of the first ones they made for me locked the gear change for the automatic transmission so that "Drive" was only 3rd gear. No fourth gear, no automatic shifting (third would disengage under 45 mph).Then the car was basically a three speed manual shifter with no clutch. I would load this tune for autocrossing only. As it turned out I only needed it once in 2013 at Gratten Raceway in Michigan where they let speeds get up as high as you want at the end of the autocross on the straightaway. I got up around 90+ and needed third gear. A friend of mine in a NSX was up to 130 on that course. I no longer have that feature on my tune since it was not necessary.

Currently I have a custom VMP tune for 93 octane set for the specific cam, IMRC valves and so on as the engine is set up now. Last summer after the ported heads and intake were installed I did a 2nd gear "Pull" up an entrance ramp with a neighbor running the laptop taking data as specified by VMP. After reviewing the data and some discussion Joe Goodnough at VMP tweaked out the tune for me. It is custom for street and autocross just for Mistress as she is configured today.  I recommend you check them out next time you want to update. Use the contact form on the webpage for best response.

I also love the Trutrac. The tires work together no matter what. I can have one tire on pavement and one in snow and it pulls away with just the pavement tire and no slipping in the snow. It is one of those mods that makes the car much faster in an autocross but also make it much less forgiving. When the back tires break free they do it exactly together... always. Hence the concussion story in one of the first articles of this log.

With the automatic my car is geared differently than yours but the results will be similar. I made a spreadsheet that same as that handy online calculator (thanks) and it shows that with redline set to 5700 rpm I will hit 73 mph in 2nd. Ample for nearly any Midwest autocross. 

Yup it is grand when you beat a car that should, by all rights, be faster. That means you out drove them. I used to run with Saginaw Valley Region in Michigan. Small club also with some nationals ringers. Get them riding shotgun in your car and get in the car with them every chance you can. You can learn a lot from those people!

KentF New Reader
12/4/17 8:39 p.m.

Harness Bar

As I noted in the concussion story I got a four point harness from Team Tech right after that incident. People had been telling me to get a harness because it makes you faster. It does. It is very hard to drive at speed if you are using the steering wheel to stay in the seat. Lets face it, the SN95 seats do not offer much lateral support. At the time I was still invested in having Mistress look like an ordinary car when not at an autocross so I did not want to disassemble the rear seats and have big eye bolts sticking out all over. So I mounted the big eye bolts through the floor in the crack of the rear seat. When the harness was unclipped nothing showed.

However, this is a bad placement without also putting in a harness bar because if you were in a crash the belts would compress/crush your spine. Since I only used it at autocrosses I felt there was no issue. At least, until I started coming home from events with a very sore back. And until I started running at events at the Road America Moterplex where there is at least the possibility of getting into the rough (those are not SCCA events). Last spring I finally put in a proper harness bar. The harness still clips in the same location but it comes up over the bar at shoulder height.  Much more comfortable, no more sore back and much safer.

I looked at the Corbeau unit and the nearly identical Cipher unit. The Cipher was $100 less so being the cheapskate that I am that is what I went with (what me worry?).

Product Review: Two out of five stars.

Primary Issue – Crappy welds on the end clips that mount the bar to the shoulder bolts (The rest of the fabrication and finish was excellent).

Secondary Issue – (And I believe this is the case with both Corbeau and Cipher) - The clips rub on/bind on the shoulder belts and make them difficult to retract.

Tertiary Issue – (this is the case with both Corbeau and Cipher) – I am a tall guy and my seat leans back and hits the harness bar putting me in less than optimal position.

Quaternary Issue – The lower brackets at the seat belts pivot on their bolts allowing the entire assembly to move slightly. This would be less of a problem if you tighten everything down with no spacers but then the shoulder belts would not work at all.

Solution to all four problems – Re-weld the upper clips on an angle to reposition the bar towards the back a couple of inches. Add secondary supports at the lower clips to prevent rotation. I learned about the bad welds on the clips when I cut the tabs off to reposition them. Almost no weld penetration and looked like a child did it. Even I can weld better than that and I am a very poor welder (but I do have a grinder so that makes me better).

The photos below tell the story:

Finished Set Up - 

Revised Upper Clip on passenger side. Original parts used - Tab Cut off and re-welded on 45 degree angle. The corner ground off of bracket. Same done with driver side but mirrored.

Lower Clip added on passenger side (cut through carpet to base plate on car). Careful - There are cables under there on both sides.

Lower Bracket Fab Sketch. Both are the same.

Upper brackets receiving a professional paint job. This gives you a better look at them.


And one last issue I created myself: With the harness bar moved back a few inches it conflicts with folding down the rear seats. Solution - Fabricate Wing Bolts with the original hex bolts and a link of chain. It just takes a minute to unscrew them, swing the bar forward and move the seat. I don't have a photo in the car because it is all apart right now relocating the battery and deleting those seats. Here is a photo of the modified bolt on the removed bar. I fabricated this because I could not find a Grade 5 wing bolt anywhere (unicorn bolt).

KentF New Reader
12/6/17 8:09 p.m.

Harness Bar Camera Mount

I use Solo Storm in my Android phone as my data logger and I use the phone as the camera. Videos from outside the car are nice. But from inside the car where you can see the driver serves as a better learning tool to see what you were doing, where you were looking, etc.  So I wanted to mount the camera (my phone) to the new harness bar. This has worked out surprisingly well, better than I thought it would.

Again the photos tell most of the story. The roll bar clamp came from Speedway and cost about $15. The phone clip came from Best Buy or somewhere similar and cost about $20. 

The Parts:


Round off a Socket head Cap Screw so it just fits in the swivel joint on the clip and has some compliance to swivel.

SHCS inserted in clip - Note I have started cutting off the shaft already.

Layout of the overall Assembly

SHCS welded to head of stand bolt and then the weld/head ground to a radius. Note the tubing protecting threads.

Painted and mounted. 

KentF New Reader
12/6/17 8:44 p.m.

Follow up on the sudden Cat death. As was noted in the tech thread the problem was bad spark plug wires causing miss fire which pounded some of the coating off the ceramic cats (they are still intact however). Turns out the cross circuiting also damaged the coil. Wires clips replaced. New coil. Mistress runs fine & new cats on order from a local speed shop here in Green Bay.

After much consideration I went with Vibrant 7101 metal core cats. They should be effective and purportedly have lower resistance. I will test this!

From data logging with the lap top I know that Mistress moves about 23 to 24 lb/min of air at WOT. My electric leaf blower moves about 12 lb/min of air. How do I know that? I took the MAF off of the car but left it electrically connected and then hooked up the leaf blower to it (pulling through). I then used the lap top connected through the SCT tuner to get the readings.  I was testing the new cold air intake at the time.

What I learned is that the leaf blower moves only about 1/2 the air the car does and is marginal for testing the intake system. Think about that - The car moves at least twice the air as a mid priced leaf blower.

However, it also means the leaf blower is just about right for testing flow on the exhaust. I ran it through the old cats on the bench - lots of resistance.  I ran it through each side of the exhaust from behind the cats back. Very little resistance through the piping and the Spintechs.

When the new cats come in I will leaf blower bench test them against the old units with a manometer connected. Then we will see...

jfryjfry HalfDork
12/7/17 10:52 a.m.

If you haven't already got your rear-mount battery cables, look in the junkyard or eBay or etc for the cables out of a BMW e36 or Mercedes something.  Cheap, oem, quality. 

Thats what I used and very happy.  The e36 has a little distro block that was awesome for pulling power off of. 

GCrites80s Reader
12/7/17 8:40 p.m.

Pony car harness bar misery! You don't want to think about trying to do just a harness bar on a 3rd Gen Camaro since they have sail panel speaker holes and roof-mounted belt tensioners... 

KentF New Reader
12/8/17 12:52 p.m.

In reply to jfryjfry & GCrites80s -   Already purchased the battery relocation kit from Summit. But thanks for the tip on that it could be useful to others.

Yeah there is not much out there in harness bars for the SN95 Mustangs and what is there is flawed. The mount screws up the shoulder belt retraction - really? Great if it is a track only car but what about cars in dual use. Sounds like the Camaros are just as much of a problem. You might think Ford/GM might build some clips or hard points into the cars for these purposes given how they are expected to be used. I hope your seats are better. Good seats can go along way and help minimize the need for harnesses. The V6 seats do not have much side support (but it was not intended to be a performance car) and the GT seats are only a little better.

GCrites80s Reader
12/8/17 9:42 p.m.

Well, you know they weren't thinking of autocross when the 3rd and 4th gen pony cars were designed. Ford and Chevy were more focused on being cool on the streets. Autocross wasn't on their minds since back then it was the domain of British roadsters, Porsches, formula cars and later, hot hatches. That's why we suffer flat seats and marginal to non-existent provisions for harnesses. But nowadays they can't make that mistake... or else Miata.

My IROC's seats are almost as flat as they come, so what I do is tighten the harnesses (mounted to where the top of the rear seatbacks would be) as much as I can manually, then move the power seat forward to really clamp me down. Sorry passengers, it's Mr. Toad's Wild Ride for you! Nothing but regular belts on that side. I got motion sickness once while riding along with my co-driver on a large concrete course.

KentF New Reader
12/14/17 7:43 p.m.

Sudden Cat Death Part 3 -  Reposted in part here from the Tech Thread.

For what it is worth (which may not be much): Flow test of partly damaged (but physically intact) ceramic cats verses new, smaller metal cats:

From earlier tests hooking up my little electric leaf blower to the MAF (to do some testing on the new CAI ) I know that the blower puts about about 11 to 12 lb/min of air when the battery is fresh. The car moves about 23 to 24 lb/min at WOT using the same MAF to measure. So the leaf blower moves about as much air as one exhaust pipe (although this is cold air and that is hot exhaust gas - this is just a comparison).

Here is my cat flow test rig with a makeshift water manometer.


The original Magnaflow ceramics each had a back pressure of about 4.5 inches of H20.
The new Vibrant metal units each had a back pressure of 1.5 inches of H20.

This test is only valid as a comparison of the used, possibly damaged, units verses the new.  However, some of the coatings appear to have been knocked off the ceramic cats which might effectively open them up a little. Remember I had "sand" in the tail pipes and the dyno shop found it blown out on the floor from each exhaust. That is what keyed me into the potential cat damage from the misfire incident.

Also the metal core units are 1/2 the length of the ceramic units. However, even if I stacked the metal cats in series they would come out to roughly 3 inches of water. Still 1.5 inches less than the ceramics.

It is not a fair test.  But, assuming I don't have O2 alarms going off after install I am glad I replaced the old units. We will see...

Does anyone have any insight on what typical back pressure numbers might be expected from ceramic cats like this? 

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