ReplicaR's Time Trial Mustang build *Engine Rebuild*
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DKblue98GT
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Should be really fun to drive.
Hey guys, no exciting updates yet, but here is a nice list of stuff that's being taken care of right now. After I get the car back, it's off to the tuning shop, hopefully for the last time, which should nail down the drive-ability. Then corner balance the car, and autoX for a shakedown in November. Key things to stress will be the charging system (because alternators have been failing every 400 miles or so) and power steering pump reliability (because it would also fail during first session at last two events).
The car is complete with all the mechanical issues, and is on its way back to the tuner shop. I really hope that they will strap it to the dyno again, because I'm really curious to see the under-drive pulleys in action vs standard diameter pulleys.
Small update on some of the stuff I've been doing:
Mechanical issues and tuning: In the last visit to mechanic a lot of things were tackled, some minor, but others are niggling reliability issues that have been ruining the track days every time, two of the bigger ones being alternator and power steering pump issues. In order to deal with these, I have had my mechanic look through the wiring loom, check for any possible issues, add grounds, and add underdrive pulleys to help me slowdown the alternator and pump as well. For power steering pump, I've had the lines redone for everything that touches power steering, and changed the pump once again. The addition of underdrive pulleys will hopefully help as well, but one thing that might be the biggest impact is the location of hydroboost return fitting, which was about half way on the line returning from rack and pinion, but should have been pretty much at the reservoir. That's been addressed.
Before the car was taken back to the tuner shop, I made sure that there are no issues with the motor, by checking the vacuum leaks, and conducting compression and leakdown of the motor. The motor tested pretty well, registering 180 psi across all 8 cylinders (give or take couple of psi), and leakdown was around 9%, which is within spec for a fully forged bottom end, and build of this type. Full Throttle Kustomz tuned it really well, giving me a stable idle, great driveability, and excellent power. With conditions being different every time I dyno, there really wasn't a way to see if underdrive pulleys made a difference, this time the car dynoed 5 whp less than last time. Regardless of that fact, it drives great pulls really well, and at some point in the future, I will visit a dynojet to get the numbers from that for NASA.
Chassis Tuning: Power is nothing without control, and I am a huge believer or that. That's why I've started this build with suspension and chassis, but ever since the motor was built, I could never quite find the comfort in it after. It felt like the power was overwhelming the chassis, but I could never quite put my thumb on what. It took autoXing a different chassis to realize what I was missing, which was composure. Mustang would not have the same grip both directions, it would shift steering angle when off throttle, rear end grip needed to be optimized.
1. Corner balancing - I've decided to perform this, to check and see if the car has lost its balance since the last time I've had it on scales, about 8 years and considerable amount of parts ago. Turns out, the car was pretty badly out of balance, and the most affected corner was right rear, which would explain strong traction on the left direction turns, and poor traction on the right direction turn. After unbolting the sway bar end links to remove the preload, adjusting right rear and left front coil overs up and right front coil over down to transfer the weight, I able to achieve go from 46/54 cross weight to 50/50 cross weight, insuring that the car will grip similarly both ways. I reattached sway bar end links, adjusting them to make sure that I'm not introducing any preload to change the balance, and that was that. If you look at the image below with weights, you'll see that right rear is still pretty light, the reason for that is the battery location under the hood. A 40 lbs battery moving in the right rear would do nicely, not only keeping the cross weight the same, but also improving the left to right weight distribution, and front to rear weight distribution.
2. Alignment - This morning I took the car to a local race shop that does alignments. While on the rack, I had them address several issues, being thrust angle, and street and track alignment specs. I've decided that rolling around on the street wtih -4.5 degrees of camber is insanity, if you are remotely interested in preserving the tires, so we set the camber on spindle so that top camber caster adjustments could be within same range. As a result of this, I can now roll around on the street with least aggressive setting of -2.8 degrees of camber, and when I arrive at the track, I slam the plates all the way in, get my track setting of -4.5, and after I'm done, back to street setting. Thrust angle... it really is true that you can't rely on fender wells to set your location of rear axle using panhard rod. This whole time I've had an issue where the car would change steering angle as I would get on and off the throttle. Sure enough, thrust angle adjustment took care of that, no more issue.
There is a shakedown coming in two weeks, and hopefully at that event I will finally get a chance to run the car hard, and then drive it home afterwards.
Mechanical issues and tuning: In the last visit to mechanic a lot of things were tackled, some minor, but others are niggling reliability issues that have been ruining the track days every time, two of the bigger ones being alternator and power steering pump issues. In order to deal with these, I have had my mechanic look through the wiring loom, check for any possible issues, add grounds, and add underdrive pulleys to help me slowdown the alternator and pump as well. For power steering pump, I've had the lines redone for everything that touches power steering, and changed the pump once again. The addition of underdrive pulleys will hopefully help as well, but one thing that might be the biggest impact is the location of hydroboost return fitting, which was about half way on the line returning from rack and pinion, but should have been pretty much at the reservoir. That's been addressed.
Before the car was taken back to the tuner shop, I made sure that there are no issues with the motor, by checking the vacuum leaks, and conducting compression and leakdown of the motor. The motor tested pretty well, registering 180 psi across all 8 cylinders (give or take couple of psi), and leakdown was around 9%, which is within spec for a fully forged bottom end, and build of this type. Full Throttle Kustomz tuned it really well, giving me a stable idle, great driveability, and excellent power. With conditions being different every time I dyno, there really wasn't a way to see if underdrive pulleys made a difference, this time the car dynoed 5 whp less than last time. Regardless of that fact, it drives great pulls really well, and at some point in the future, I will visit a dynojet to get the numbers from that for NASA.
Chassis Tuning: Power is nothing without control, and I am a huge believer or that. That's why I've started this build with suspension and chassis, but ever since the motor was built, I could never quite find the comfort in it after. It felt like the power was overwhelming the chassis, but I could never quite put my thumb on what. It took autoXing a different chassis to realize what I was missing, which was composure. Mustang would not have the same grip both directions, it would shift steering angle when off throttle, rear end grip needed to be optimized.
1. Corner balancing - I've decided to perform this, to check and see if the car has lost its balance since the last time I've had it on scales, about 8 years and considerable amount of parts ago. Turns out, the car was pretty badly out of balance, and the most affected corner was right rear, which would explain strong traction on the left direction turns, and poor traction on the right direction turn. After unbolting the sway bar end links to remove the preload, adjusting right rear and left front coil overs up and right front coil over down to transfer the weight, I able to achieve go from 46/54 cross weight to 50/50 cross weight, insuring that the car will grip similarly both ways. I reattached sway bar end links, adjusting them to make sure that I'm not introducing any preload to change the balance, and that was that. If you look at the image below with weights, you'll see that right rear is still pretty light, the reason for that is the battery location under the hood. A 40 lbs battery moving in the right rear would do nicely, not only keeping the cross weight the same, but also improving the left to right weight distribution, and front to rear weight distribution.
2. Alignment - This morning I took the car to a local race shop that does alignments. While on the rack, I had them address several issues, being thrust angle, and street and track alignment specs. I've decided that rolling around on the street wtih -4.5 degrees of camber is insanity, if you are remotely interested in preserving the tires, so we set the camber on spindle so that top camber caster adjustments could be within same range. As a result of this, I can now roll around on the street with least aggressive setting of -2.8 degrees of camber, and when I arrive at the track, I slam the plates all the way in, get my track setting of -4.5, and after I'm done, back to street setting. Thrust angle... it really is true that you can't rely on fender wells to set your location of rear axle using panhard rod. This whole time I've had an issue where the car would change steering angle as I would get on and off the throttle. Sure enough, thrust angle adjustment took care of that, no more issue.
There is a shakedown coming in two weeks, and hopefully at that event I will finally get a chance to run the car hard, and then drive it home afterwards.
Believe it or not, you are educating me more and more with each new post.
I'm very happy to hear that. I am very eager to spread the knowledge I acquire, as I conduct various tests, and try to learn something myself. This hobby is all about community, and putting tested knowledge out there, for anyone interested to have for free, just makes us richer as a result.
Last weekend I took the car to the local autoX event, to test the reliability as well as the tune, and maybe dial in suspension a bit. After I ran the first session, I pulled into the pits to find that power steering pump is still working and the car is still charging, which allowed me to breathe a huge sigh of relief. All the prep work has finally paid off, and the car was reliable. From there I decided to start playing with suspension settings. The car exhibited a bit of oversteer, but not to the point where I felt that sway bar settings had to be changed, so I decided to stiffen up the front shocks (1.25 turns) and rear shocks (1.00 turns), which gave me a more stable car, and also balanced it better, giving me a more stable rear end. The corner balancing, and alignment setup have paid off as well, the car being very similar both directions, and I was able to actually lap faster than anyone else that day. I know this isn't an SCCA event with classing and all, but the competition was still pretty stiff, with a couple of new GT3s, older modified 911s, E36 M3, LS3 swapped 370Z. Definitely felt good to take it to the top of that pile.
Upcoming changes: I am currently still working on comfort with the car. One thing I did right before event is go to upholstery shop, and have them cut out a cushion out of some foam, which gave me a taller seating position (something I prefer anyway), and made it significantly more comfortable in the race bucket, which was very welcome on a 2 hour drive home in traffic. I will still have to figure out something with the pedals, as I can't find comfort in there, and add a few more gauges to monitor AFR and voltage. The car pinged pretty badly as well, as the temps rose in the afternoon, so a slight tune adjustment might be required too, since adding 98 octane to my 91 didn't really solve the issue.
Upcoming changes: I am currently still working on comfort with the car. One thing I did right before event is go to upholstery shop, and have them cut out a cushion out of some foam, which gave me a taller seating position (something I prefer anyway), and made it significantly more comfortable in the race bucket, which was very welcome on a 2 hour drive home in traffic. I will still have to figure out something with the pedals, as I can't find comfort in there, and add a few more gauges to monitor AFR and voltage. The car pinged pretty badly as well, as the temps rose in the afternoon, so a slight tune adjustment might be required too, since adding 98 octane to my 91 didn't really solve the issue.
Finally retired the 12 year old Pro5.0. The pivot ball overtime wore out, and there was about 2-3 mm tolerance, which surely enough didn't create for optimum driving experience, especially rattle at full throttle, which was so easy to confuse for detonation. Got in touch with Pro5.0 (after a very long wait to get back to me), and they said that the warranty is 90 days, past that there is nothing they can do, so I decided to buy a Steeda shifter this time around. Right out of teh box, I could see that Steeda had a bit more R&D put into it, because it was lighter as a unit, the handle was in a more comfortable position (not that it matters, since I'm using Roush handle), the opening inside is machined for more space for the handle to operate, and the access to the transmission bolts was significantly better than Pro5.0. So far the feeling great. The shifter is nice and crisp, exactly what I was looking for. The other shifter that was in contention was MGW, but that dropped off pretty quickly, since I can't reuse my Roush handle, and the centering spring is far too stiff, which annoyed me to no end when I drove a car with it. Steeda was the clear choice. And now, the media:
Videos are the links below:
Pro5.0 sloppy shifter
https://imgur.com/YKzDyw1
Steeda Shifting
https://imgur.com/HwRffXC
Videos are the links below:
Pro5.0 sloppy shifter
https://imgur.com/YKzDyw1
Steeda Shifting
https://imgur.com/HwRffXC
Last edited:
Patientzero
Member
^that is me^ haha
A full interior car with MM suspension, sound deadening added, etc. Considering that it was 3360 lbs when it was completely factory stock, this isn't that terrible, after you factor in all the stuff I've added. BTW, that's weight with me in it, at the time I was 170 lbs. So, without me, the car alone on full tank is 3270 lbs, which isn't bad.
Patientzero
Member
I'm wondering what we have different...hmm.
I thought the 94-98 cars were a little bit lighter to begin with. I'm at 3057lbs with a full tank of gas. Full MM torque arm and coilover suspension, 4 point roll bar.
I thought the 94-98 cars were a little bit lighter to begin with. I'm at 3057lbs with a full tank of gas. Full MM torque arm and coilover suspension, 4 point roll bar.
All aluminum engine vs my cast iron block and giant intake manifold, you've got a gutted dashboard, no radio, etc. There is an easy 200 lbs between all that. I don't tow my car, and still like to drive it on the street, so I actually ended up putting about 120 lbs of weight back into it. It was 3140 lbs fully gutted.
Patientzero
Member
Perhaps. If you don't care about A/C or heat my car is still street worthy. I drove it from Houston, TX to Kansas City, MO (~700 miles) when I moved and still drive it an hour to work on occasion.
I don't have AC in my car (removed it because young dumb and full of cum), but heater is still nice to keep, not to mention that it actually defrosts the windows. I just don't see the point of dropping more weight out of it in those extreme ways, when I'm not competing for anything. Maybe it's the old fart talking in me (36 going on 70 lol), but I like to be comfortable in cars, so as extreme as my car may be in other respect (full MM package, race valved shocks, built motor, rollbar and race seats) it still has decent street manners thanks to sound deadening, a few cushions on the seat in the right places, and quieter exhaust choice.
Patientzero
Member
What shocks/coilovers are you using? I'm about to pull the trigger on some MCS double adjustables before next season.
Patientzero
Member
I think we have 90% the same car, haha.
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