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my slow auto Mach 1

11K views 94 replies 19 participants last post by  blownstang 
#1 ·
Took the Mach to the track yesterday just to see where it sits before I drop it off at the shop in 2 weeks. I know the autos are a lot slower than the sticks and from what I've read they run 13.8-13.9 @ ~102mph stock. It was slick and drag radial night so the track prep was top notch. I think I made the mistake of putting a dr on a stock auto Mach because it did not help me at all and my times didn't even come close to what it "should" run. Car is very stock with the only mods being welded in Flowmasters and Steeda sport lowering springs. The car sat on 17x9 front Mach black wheels with 255/45/17 rubber and 15x8 Weld Prostars with 275/50/15 BFG drag radials with 19psi.

Out of 3 runs fastest 60' and 1/4 pass was:

60': 2.150
330': 6.154
1/8: 9.323
MPH: 78.81
1000': 12.011
1/4: 14.296
MPH: 98.73

It just couldn't get off the line quick enough and didn't have top end pull. The 2.15 60ft came from brake torquing to 1100 rpm and then hammering it. The car did not spin or bog on any of the passes. I was expecting a 13.6-13.8 out of it because of the drag radials, but it was a dog off the line. Basically running in stock GT territory.

So comparing this to my blown GT, at ~3,475lbs it is already 40lbs heavier than my GT with longtubes, intercooled centri blower setup, Cobra front brakes, full length frame connectors, and driveshaft safety loop. If I could've somehow got it to do a 1.90 60' it might have ran a 13.80.

This was the first time for me going down the track in an auto. Boy is it boring! lol Didn't know what to do with myself for the next 12 seconds after the car got moving.

I'm hoping that in a month it will be a completely different animal. Circle D 4c 3800 stall torque converter, BCA modified valve body, VRS o/r x pipe, and intercooled Vortech V1 S at ~11psi should wake this thing up.
 
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#2 ·
Don't feel too bad about your ET's, that 98.73 MPH is saying the car will run right at 13.6 if you can get it to leave harder.

Was 1100 the highest you could hold it against the brake?

When the traction is good you want to stall has hard as you can against the brake to cut the best 60' but if its only stalling at 1100 that's why your 60 is slow.

As you already figured out, if the Mach autos run a 13.6 you would need a 60' in the range of 1.9 to hit that time.

The Circle D will make a big difference, mine has a 3400 stall speed and I can foot brake the car to around 2500 to 2600 RPM, you'll be able to go probably 400 RPM higher than that.
 
#3 ·
Im not too worried about the times. First pass it went 99.56mph. I didnt test how much it can actually hold against the brake. Just wanted to get it up higher than the 600rpm it idles at. Im hoping that with the converter i can just flash it instead of dealing with holding it against the brake.
 
#4 ·
If the track is good and your tires are hooking well you will always run quicker 60's and ET's by stalling against the brake as high as you can.

Flashing it from idle is a last resort if the car isn't hooking up.
 
#7 ·
Unfortunately without a transbrake a 2 step won't help you.

Your stall speed against your footbrake won't increase with a 2 step, since its the brakes that are holding the car.

If they will only hold 2500 RPM then it doesn't make any difference if your hit that 2500 RPM with or without a 2 step on, 2500 RPM is as high as you'll be able to go.

No doubt you can run a quick ET flashing from idle but if the car's hooking hard it will run a quicker 60 and quicker ET stalling against the brakes.
 
#10 ·
Hans at Deans Performance. Have been using him since 2008. Does great work and you will not find a comparable shop that is less expensive than him. Im going to give Mike a try for the tune.
 
#16 ·
Don't feel bad. Hell my first outing with my 5 speed Mach 1 I managed a 15.05 spinning like hell with street tire BFG KDW's. I really need radials and more practice for sure. I cant remember my MPH. Id like to get a set of 4.10's and upgrade the axles as well before I try again. I might throw the stock rear springs back in as well. Im sure the Eibach springs aren't helping either.
 
#17 ·
Finally got the car back from the shop. It was there all winter which worked out well as I wouldn't have been driving it anyway. On a base/start up tune now until Friday. The Circle D 4c converter is nice an tight for normal street driving. Can't even tell there is a converter in it. The BCA modified valve body is as smooth as stock. Can't wait to see what it does at WOT after the car gets tuned. Told Darrin to build it for smooth and comfortable street driving and balls to the wall at WOT. Some pics below during install.

Big TruCool 40,000 gvw trans cooler painted black.



Tranny cooler and Procharger 3 core mounted.





Engine shot.



On the GT this blower setup made 12psi at 6150rpm. Guessing it will make 11psi on the Mach. Will try to limit the rwhp to 450.
 
#22 ·
Dropped the car off at 11pm last night. Will be on the dyno today and then street/driveability tuning on Saturday or Monday depending on the weather.

Anyone have any guesses? Its a Dynocom so it reads close to a Dynojet. From doing some research it seems like 1-2% lower so very close.

Vortech S trim with 3.12 pulley and powerpipe. Procharger 3 core intercooler. Vrs o/r x pipe. Im estimating around 11psi. Will be dynoed with the converter unlocked and locked to see the difference. Will be left unlocked though for street and track as that is what Circle D recommended.
 
#23 ·
Sub'd. Hopefully it puts down something that you are satisfied with op gl.
 
#28 ·
Not really. Was on the dyno today but had an issue with going lean above 5k which is getting worked out.
 
#29 ·
Have a little update. At 5900rpm, 10.3psi, 12 degrees of timing, unlocked converter, and 11.2 afr it made 420/445. Tuner texted me if im good with that or do i want more. Just got off the phone with him and we're going to add 1 more degree of timing and pull it to 6200rpm. Right now every degree of timing has been gaining 10rwhp. Another 300rpm should get the boost up just a tad. We're guessing it will be sitting in the low 440's. I will know tomorrow.
 
#31 ·
For sure. I hope I can get it in the mid 11s. Two friends have ran high 11.90s with 370rwhp, high 1.6's 60fts, and 3200 stalls. One was a KB 01 GT and the other a 99 SS both full weight on MT ET street radials.
 
#33 ·
I didn't make the 11's until I got up to 460rwhp, but I'm a manual trans and don't speed shift. I'm always wondering how guys with blowers are getting their torque higher than the horsepower. My car has always had the torque lag about 15% below the hp. Post up when you're shooting to go to the track and I'll see if I can make that day too.
 
#34 ·
I might have misheard him. Think torque came in at 387 from his text just now. He will email me the graph. Still needs to street tune it. So 423/387 should be the final numbers. At 6200rpm, 11psi, 11.5 degrees of timing. At 5900 rpm it made 419rwhp, 10.3psi, 12.2 degrees. With the timing and 11.2 afr its tuned very safely. Should be equivalant to around 470-480 through a stick.
 
#38 ·
With a stock converter the variance is close to 5%. Unlocked stall you loose atleast double that depending on how much the converter is slipping. You can seen as much as 15% variance with an unlocked converter. The dyno was estimating my locked number to be 450 something. Through a stick that would be 470-480 range. The dyno numbers with an unlocked converter are very deceiving.
 
#39 ·
Graph attached. Last two runs are presented. 423/387 and 425/384. Data is presented kind of crappy. I'll throw it on a dynojet at some point to get a nicer looking graph with rpm reading. Not a fan of how the data looks from this Dynocom. It does have a wide torque power band. With the max torque coming on at 5200rpm I hope the Circle D 4c converter flash stalls over 4k with the blower and power the car is making. Not sure if the car might have a 3.90 gear in it because the mph doesnt correspond with the 6000rpm max hp reading. With 3.55s im thinking it should be around 125mph at 6k not 115mph. I'll have to get under the car and check within the next few weeks. Last night the temp was mid 40's coming home and with crappy Nitto 555's it spun at a 60mph hit on the highway.
 

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#41 ·
Got the Toyo drag radials on last week. Took the car out for the first time on them last night. Initial thoughts are these tires are great. Mid 50 degree weather with 30psi in them they were hooking up from a 25mph roll on the street. Didnt test any lower than that.

Heading to the track tonight. Im guessing with the unlocked converter Im going to run out of gear with the 25.8" tires. 6200rpm should be about 117-118mph. Im going to bump the rev limiter to 6400rpm and hope i makes it through. I have brand new 275/50/15 Hoosier drag radials that I bought for the track, but if I cant make it through on the Toyos I'll have to sell the Hoosiers and step up to a 27" tire for the track.

My goal was 11.60's with this car, but it will be weighing around 3800lbs with me in it so it might be hard to get there. Also a little concerned about the stock axles since it is hooking so well on the street.
 
#43 ·
Not good at all. They made street tires and drag radials run right lane. Slick only cars ran left lane. I thought slicks and drag radials would run on the same lane. Tune needs to be looked at. I took data logs for my tuner to review but would anyone else be willing to review? Someone who knows what they are looking at. Car spun everytime. Couldnt get the launch right. In an auto when you spin it also throws off the shift points so i have some runs shifting very low and others closer to 6k.
 
#45 ·
I somehow missed the dyno updates to this thread.

What converter are you running? Why was it not locked up during tuning? And with your concerns about having enough gear, why is it not locked up in the top of 3rd gear at a minimum to get down the track?

Also, depending on what converter is in it, it shouldn't be anywhere near 15% less horsepower on the dyno, at least not once you're well above the stall speed. A locked converter 4R70W is usually around 5% less than a manual. Depending on the converter, most of the well-built aftermarket ones will see efficiency above 95%, with many of them at 97-98%. So worst case scenario, an unlocked auto would see numbers 2-5% lower than a locked auto, and 7-10% lower than a manual. Obviously, those numbers don't hold up at all under the stall speed, or even just a little over it, as it takes some amount of time for the input shaft to come all the way up to speed. But the fact that an unlocked auto can [potentially] keep it in the powerband better means that it could actually trap better than a manual. Just one more bullet point to throw under the "dyno numbers don't really mean ****" list.

That sucks about the track being crap. Have any slips to post? Curious as to how it trapped and what the back halves look like.

You talk about the shift points fluctuating when you spin. That's probably because you are backing off the throttle when it spins (as you should), and then it upshifts when you do that. In the tune, transmission shifting is a function of two variables: throttle position and vehicle speed. Generally speaking, as the throttle position goes down, the vehicle speed at which the upshift occurs also goes down. So when you backed off the throttle, you crossed that point, and it upshifted.

The good news is that that's fixable. You can set it so that your normal WOT upshift speed occurs at any throttle position above xx % (I use 10%). This means that as long as you don't go below 10% throttle when pedaling it, it won't upshift. Obviously, this would make normal street driving difficult, but it works great for the track. Also, the downshift shift points need to be adjusted also if you do this.

The bad news is that the vast majority of tuners out there either don't know how to do little tricks like this, or aren't willing to spend the time on it. So hopefully you've got a good one that is willing to help you out on this stuff. I didn't, and is the reason I started doing my own tuning.
 
#47 ·
Single disk Circle D 4c. Thats what they recommended. Asked if there would be a benefit to the multi disk and they said not really at my power level. Would maybe pick up 1-2 mph on the top end. They dont recommend locking the single disk and I also have the stock trans. I dont believe i was lifting as it would spin but not to the point where it would cause it to bounce off the limiter. I dont have the slips on me right now, but from what I remember 60fts were in the 1.9-2.10 range. 1/8 mph was 87-90mph. 1/4 mph was 112-114mph. Best run was 12.73.

I tried stalling it against the brake up to 2krpm, flashing it, and rolling and then flashing it. My shift points were coming in at 5300-5400rpm. I bumped them by 5mph on the last two runs. Car shifted early from spinning on the 1-2, at 4800rpm, and then the 2-3 came on at 5900rpm.

Its also pulling way too much timing i think. Ending runs with 6 degrees at 140F iat.

Can I also email you the logs?
 
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