ReplicaR's Time Trial Mustang build *Engine Rebuild*

[mikey94gt]

Sick man! you wont be dissapointed.

looks like the MM K comes with a bit more adjustment and bolstering than my Griggs piece did, mostly in the back portion where the square tubing is welded to the small round stock. I cant adjust the control arm pickups either, I only have one hole for that.

I'm guessing you already had a bumpsteer kit?

I set my engine back 1" and noticed the rear end actually had grip! in stock location, I noticed the car tried to rotate mid corner, with the rear trying to take the lead, like it was a bit nose heavy. Seems like the new geometry is designed for the 1" setback. And, from personal experience, if you go to have your driveshaft shortened, find someone that is an EXPERT!

 

[ReplicaR]

I'm gonna leave it in stock location for now. Shop wants another 200 dollars to set the engine back in the process, not including the drive shaft and exhaust work. I'll do it myself when I have time, little by little getting all the parts ready. Also, don't forget that I have torque arm, so I've got all the rear grip I need, and then some.

 

[ba#97]

hey man.....i'll hit you up about how my car does in a few weeks at my next sacramento cup autox and next year i'm finally taking it out on infineon and thunderhill. right now i'm running maximum coilovers and 275/40-17 nitto nt-05's.....what do you recommend i do next? i'm hoping to run nasa time trials sooner or later. also habving my 3.55's and torsen diff put in this week!

 

[ReplicaR]

Weren't you the one who had a CMC2 car not too long ago?

 

[ba#97]

Weren't you the one who had a CMC2 car not too long ago?

yeah but i don't have the time or money to finish both cars so i was just going to go the nasa time trial route with the already running cobra i have. i am trying to sell the cmc car now so if you would be interested or know anyone that would be let me know.

 

[mikey94gt]

I forgot about the torque arm, lol. I didnt have to do any exhaust work to set the engine back, all I did was the driveshaft and power steering lines, and a little modification of the shifter opening on the trans tunnel. The P/S lines were an afterthought, as one got stretched and popped off when I was romping on it one night.

 

[MustangChris]

Dont take Mikey's advice on anything... you're better off not doing anything than what mikey tells you to do. ;-)


anyways, car is looking good! that hood came out stellar.

 

[ba#97]

Rear Coil Overs... I has them!

And this is BTW, how you run MM rear coil over kit on the street. You purchase a Hypercoil helper spring, and a spring spacer from Eibach.

As you can see at full droop shock length is longer than the spring that came with the kit. What the helper does, is keeping the spring in place, by putting a very slight tension on it. When the car is at normal ride height the helper is fully collapsed, and has no effect on how the car handles. Backing out of my very steep driveway, I've had no problems with spring coming loose at all

While I was there I also bumped the front spring rate as well, so the new rates are 350 front and 250 rear. One thing I can tell immediately, is how much smoother the car rides now, even though that the conventionally located MM track springs (415-515 progressive which turns to 188-233 coilover rate) is technically softer than the new 250 coil over spring. Hoping to see some improvements at the track this weekend.

i have this exact same setup on my car.....does the helper spring change the ride height at all? what exactly does it do? and i have 375lb springs up front and 250lb in the back on koni double adj......my car is stiff as hell....rough ride on these cali roads.....would the helper spring help that?

 

[ba#97]

seeing as i don't have the helper spring on my car.....do you think that say.....when i'm running at thunderhill at high speed.....when i go up and over some of those hills....would it be enough decompression to have the spring come loose before my car settles back down? i don't see it happening but i could be wrong and wouldn't want to find out the results of it if it did....haha.

 

[ReplicaR]

Those helper springs are super thin when they are fully compressed, and when they bottom out, then their spring rate becomes infinite (aka solid), so it no longer effects the handling. The whole helper setup does change the ride height slightly, but not enough not to adjust it out with the coil overs. Also, I don't think that the axle will droop fast enough in thunderhill for you to feel the springs getting loose, but there is only one way to find out. Go out, haul ass, see what happens.

 

[ba#97]

So do you think the helper spring would make much difference for me? I don't see much....hey im deploying soon and am selling that cmc car....let me know if you or anyone you know is interested in it. Seeing as your closer than most everyone else on the forum. Also...what did you make your hood vent out of??

 

[ReplicaR]

The helper springs are there mostly for clearing steep driveways, which I do every day. Other than that, they don't do anything else. Streetability is the name of the game. I don't know if anyone is looking for a race car right now, everyone is kinda broke. Can you PM me the details?

As for the hood vent, it's off 2010+ GT500. Ford part number AR3Z-16C630-AA

 

[ba#97]

ok cool. and yeah....i'll pm you some pics asap. it's a good deal though. it's a complete roller.....all it needs is a motor and trans (and now rear gears) cuz i stole those for my cobra....haha.....but other than that it is ready to go for cmc, ai, or just plain time trials.

 

[ReplicaR]

So, while nothing is going on, I decided to increase my bump travel on the rear shocks. The way the car sits right now, there is simply not enough bump travel (probably 1.5 inches), which causes the shock to bottom out if there is a lot weight transfer, like for example in a slow corner with a lot of grip, and causes the car to oversteer. There are several ways you can give yourself more travel. You can shorten the shock, you can move the shock mounting points, so that there is more travel, or you can play with bump stop and some careful measurements. I've done the bump stop trim, since it's free and effective. There were couple of steps prior to me cutting a bump stop that I had to take care of.

1. With the car's axle sitting on jack stands and wheels removed, take a sharpie marker, and mark where the shaft is in relation to body, and bump stop itself. After you finish that, you can disassemble the rear suspension and take the shock off.

2. With the shock off the car, gently compress the shock until it bottoms out on the foot valve. It is very important to do it slowly, so that you do not damage the foot valve. If the foot valve is damaged, your shock will lose it ability to dampen, and therefore will be scrapped. Mark the line on the shaft where it is fully bottomed out.

3. Trim the bump stop. It is really up to you how much to trim off. I would say that because most bump stops are made from soft material, they will compress a good deal, before they stop completely, so you don't want to give yourself 0 margin between where the bumpstop hits the shock, and where the foot valve hits the bottom of the shock inside of it. About an inch would probably be ok. Here is something worth mentioning. Some shocks, like my Koni SA do not bottom out at all. I had the shaft almost completely inside of the body, and it still did not hit the foot valve. This simply tells me that the bump stops on my shock are there purely to keep the wheels out of the wheel arches under full compression. I've spoken to Koni, and they have confirmed this is the case indeed, making it perfectly safe to trim the bump stop.

Following this process I was able to trim off 1.5 inches from the bump stop, which gave me just enough travel (over 3 inches now) under slow corners not to hit the rear bump stop, and be able to get onto power with out worrying that the car might unhook middle of the corner. Pretty soon I'll take the rear and front apart again, and take some pictures so you guys can see exactly what I'm talking about.

 

[ReplicaR]

Did some more suspension fiddling yesterday. I had to replace one of the coilover sleeves because the set screw on the adjustable lower perch got stripped, and I could not loosen it up and adjust it. Tried to drill it, but my bits were not doing anything, so I decided to just replace it. What I didn't know is that now MM no longer colorcodes their coil overs, and all the sleeves are black now, whether it's Koni or Bilstein. So now I have 3 blue coil overs, and one black. lol

Also, had a chance to level out the suspension since I can adjust all 4 corners now. Dropped front another half inch, and a full inch in the back. Still have plenty of travel front and back, because I was able to modify bump stops after traveling out the shocks and struts and verifying that it is safe indeed, and that shaft is not going to hit the footvalve. This way I can be low to the ground, and suspension will still have it's travel in check, and work as it is intended. I will post pictures of the car's ride height later.

Later next week I will also be converting to Bolt through style bumpsteer kit, and installing an 03 Cobra rack and pinion. The bumpsteer kit became necessary after I installed MM k-member, and ran out of the bumpsteer adjustment range with tapered stud kit. The cobra rack will hopefully give me a sportier feel in the steering as a lot of people claim, and help reduce the play that I have in my current rack.

 

[g36 monkey]

I always like listening to someone who really knows the art of suspension. awesome job.

 

[ReplicaR]

I just read a lot, and try to really understand what people are talking about, by figuring out how it works, rather than taking what people say for granted. Anyone can do this, and it gives you that much more understanding on the topic when you really put your mind to it.

 

[clark98gt]

reading through this thread really makes me wish there was a road course near me. I have always wanted to give it a try. Awesome car.

 

[g36 monkey]

I know some but I look like a complete baffoon when comparing to your knowledge ha

 

[ReplicaR]

Pictures as promised.

Here is the car before the ride height adjustment

And here it is after

lol, see if you can spot the difference.

Here is the hardware for the bolt through style bumpsteer kit. Those are probably the fattest beefiest bolts I have anywhere on the car. Seriously, the picture does not do the justice

And finally the 03 Cobra rack and pinion. It came to me disassembled, so I figured that it would be just easier to undo the inner tie rod ends on mine and swap the rack like that.

This is how you identify the racks on SN95 mustangs. They have dot matrix code on the side, which never lies. I've had people try to push a different rack on me, claiming that its a cobra rack, because "it was color coded by factory". Thank god I'm not stupid. SPR-ZM clearly marks it as the 2003-2004 Cobra rack