Updated: 1st Run In 86 Gt, Low Mph (in My Opinion) Any Ideas?

v8stang289 · Sep 20, 2015

Hey guys, I ran my 86 GT for the first time a few weeks ago. First run was terrible, second was a little better. But I feel my mph was low for the cars mods

This is my setup:

86 GT 5.0/5-speed
stock 89 shortblock (re-ring and new bearings)
96 explorer GT40 heads -F3ZE casting- with mild port and polish (cleaned up bowls, smoothed transition etc.) with Trick Flow springs
stock rockers
9333pt felpro head gaskets
TFS-1 Camshaft installed dot to dot
Edelbrock Performer EFI intake with Edelbrock 7220 gaskets
65mm explorer TB
67mm FMS egr spacer
Stock 55mm MAF
19 lb 4hole injectors
155lph walbro pump
Motorcraft copper plugs
Ford Racing 9mm plug wires
Accel cap and rotor with brass terminals
Cold air intake with K&N conical filter in inner fender
Flowtech shorty headers, 1 5/8" primaries, 2.5" ball flange
off-road 2.5" H-pipe
Flowmaster 2.5 cat back
A9L computer
12* initial timing with spout removed
Taurus 3.8 electric fan ( with 3G upgrade)
Stock T-5 (3.35 first gear)
8.8" with 3.73 gears and carbon fiber clutches
225/55/16 falken street tires on pony wheels.

Car should be close to stock weight, has A/C, no smog, stock sway bars are on and hooked up, stock suspension with replacement shocks/struts.
Runs and idles good, no smoke, doesn't use oil.
Car was at operating temp ~180* at the time of runs with 1/2 tank of fuel and 215 lb driver

The first run was bad, I spun like crazy in 1st and 2nd, missed 3rd, and ended up with a 15.6 at 94.17
second run was a little better, not as much wheel spin, ran a 14.3 at 93.96

Based on what I've seen my friends cars do, and what I've read, I was expecting closer to 100 mph trap speed. Is that unreasonable?

My buddy has a 91 lx hatch, with nearly the same setup other than a b-cam, and he traps 102. (all praise the B-cam! )

I did have to replace the battery before I went to the track, the car sat for a few hours with no power to the ECM, so it probably lost any data/memory it had from the current setup. Could this have affected my trap speed?

Any ideas on this? or am I asking too much from this setup?

I'm probably going to get a set of drag radials in the near future, and work on my reaction times and driving skills, but the trap speed thing is worrying me now.

here are the slips from the 2 runs.

revhead347 · Sep 20, 2015

It is only as powerful as the weakest part. a stock maf is not going to cut it.

Kurt

mikestang63 · Sep 20, 2015

Something is wrong. A stock 5.0 is a mid 14 second car if you can drive it right. your 60 time is terrible. What are you launching at and what is your air pressure

I agree. Stock MAF is a choke point, Get a 70MM MAF off a 94-95 GT . bump the timing to 14-16 at the track. bump up the front tires to 40 and lower the rears to 25-28. reduce all un nneed weight like spare tire, jack, etc. Ice down the intake.

Put some real rear tires on it like Nitto and you'll drop.5

from your ET and MPH if the car weighs around 3400 LB then you are around 220 rwhp. With that trap speed you shoud be around 14.5-14.1

v8stang289 · Sep 20, 2015

I know the stock maf is a choke point, but I think it should still be capable of higher trap speeds than 94 as i've seen it done. I can work on the ET with better tires and more seat time (these were my first passes in several years) I'm just concerned about the trap speed at this point.
Wasn't really launching per se, going from idle to about 1/2 throttle at the light and slipping the clutch a little trying to control wheel spin.
Thanks for the input guys! Keep it coming.

mikestang63 · Sep 20, 2015

v8stang289 said:
I know the stock maf is a choke point, but I think it should still be capable of higher trap speeds than 94 as i've seen it done. I can work on the ET with better tires and more seat time (these were my first passes in several years) I'm just concerned about the trap speed at this point.
Thanks for the input guys! Keep it coming.

Your setup is making around 220rwhp. If you get the larger MAF that will increase air flow which will increase HP. That and you need to tune the car better and learn how to drive. What is your launch and shift points. Are you keeping a log of everything, including launch, shift rpm, tire pressure, ambient temperature,. etc.

v8stang289 · Sep 20, 2015

Haven't been keeping any logs, It's just a street cruiser I plan to run from time to time. I may start making notes on the back of the et slips. Temp was in the mid 80's, high humidity, tire pressure was 35 psi all around. I added above how I was launching, and I was shifting at 5600-5800 (on the stock tach).

I've been thinking about getting a quarterhorse and a wideband to dial everything in better. I've got a 70mm mustang MAF housing, but I don't have the sensor for it. I need to get on that.

I just wonder if putting some miles on it will allow the computer to adjust better, and pick up power. Because I live so close to the track, I literally had less than 15 minutes run time since the computer reset when I ran it at the track.

mikestang63 · Sep 20, 2015

MAF sensors and housings go together. You can't put a sensor in from a different MAF. I doubt the computer had anything to do with it as you removed the spout connector which locks the timing.

v8stang289 · Sep 20, 2015

mikestang63 said:
MAF sensors and housings go together. You can't put a sensor in from a different MAF. I doubt the computer had anything to do with it as you removed the spout connector which locks the timing.

I know about the MAF which is why haven't installed the 70mm, since I don't have the sensor. I only had the spout out to set the timing, It was in when I ran the car. The A9L is an adaptive ECM that can change fuel trims and other variables that it "learns" based on sensor inputs. That's what I'm referring to and wondering if it being freshly reset had an effect on power or WOT performance. I guess the only real thing to do is put some miles on it and run it again to see what it does.

mikestang63 · Sep 20, 2015

v8stang289 said:
I know about the MAF which is why haven't installed the 70mm, since I don't have the sensor. I only had the spout out to set the timing, It was in when I ran the car. The A9L is an adaptive ECM that can change fuel trims and other variables that it "learns" based on sensor inputs. That's what I'm referring to and wondering if it being freshly reset had an effect on power or WOT performance. I guess the only real thing to do is put some miles on it and run it again to see what it does.

sounds like you have it covered.

Good luck to you

jchav02 · Sep 20, 2015

Whats your altitude and DA? My car when na was similar to yours t moss ported cobra, gt40 heads, tfs stage 1 cam, 70 mm throttle body, 90mm LMAF, full exhaust, tko 600, 3.73s, tuned via quarterhorse. Ran consistently around 14.7@ 94 but my altitude is 5500ft with DA's hovering btw 7000 to 9000ft.

stykthyn · Sep 20, 2015

The ecu being cleared shouldn't have anything to do with this.

v8stang289 · Sep 20, 2015

jchav02 said:
Whats your altitude and DA? My car when na was similar to yours t moss ported cobra, gt40 heads, tfs stage 1 cam, 70 mm throttle body, 90mm LMAF, full exhaust, tko 600, 3.73s, tuned via quarterhorse. Ran consistently around 14.7@ 94 but my altitude is 5500ft with DA's hovering btw 7000 to 9000ft.

Elevation is about 50 feet above sea level, so I should be good in that respect.

stykthyn said:
The ecu being cleared shouldn't have anything to do with this.

Thanks, I wasn't sure if it would or not. I know WOT doesn't depend on as much sensor input or tables as part throttle driving does, but I didn't know if it would affect it at all or not.

Guess i'll check compression and go over a few other basic things to see whats happening.

stykthyn · Sep 20, 2015

v8stang289 said:
Elevation is about 50 feet above see level, so I should be good in that respect.

Thanks, I wasn't sure if it would or not. I know WOT doesn't depend on as much sensor input or tables as part throttle driving does, but I didn't know if it would affect it at all or not.

Guess i'll check compression and go over a few other basic things to see whats happening.

Those aren't exactly Johnny racer parts. They are marginally better than stock. I run practically the same combo and it makes a great street car, but if you aren't going to put a drag suspension and sticky tires on what's still a full weight car I wouldn't expect more than high 13s on a good pass.

stykthyn · Sep 20, 2015

Also just noticed 180* engine temp. Why so low? Car will run rich at this temp. The 195* tstat really is what the ecu likes to see.

v8stang289 · Sep 20, 2015

Mid 13's is all I'm after, and should be doable. I'm just trying to figure out why a relatively well proven combo is trapping 5-7 mph slower than I usually see. Even with the 94 mph I'm seeing now, I should be able to get to a high 13's with a decent 60' time.

I'm running the 180* because it's warm enough to get the ecm into closed loop, and the injector pulse width increase is very small going from a 195* to 180* t-stat

revhead347 · Sep 20, 2015

When did people start putting 94-95 Mars in cars; I've thrown like 3 of those out. Not worth the effort in my opinion, just get something better.

Kurt

A5literMan · Sep 20, 2015

Definitely some improvements can be made with seat time,better tires,etc etc. I do agree that your mph is a little low(I'd expect 2-5mph more). One other thing you can try is changing your shift points(stock tachs are notoriously off). I'd try a lower shift point first(say 5200) see what the car does. Then go up to 6k(you already know what it does at 56-5800). The tach could be off by 500 rpms. Also don't disregard what Mike already told you(I agree with his advise).

cleanLX · Sep 21, 2015

At sea level I would expect a lot more out of that combo.
For reference, when my car had nothing but off road H, stock MAM bored to 60mm and 3.73's it would consistently run 99-100 mph at sea level. I added drag radials and went 13.2 @ 100.1.
I don't know what could be holding you up?
I'd start by junking the Accel cap and rotor for FoMoCo.
Larger MAM.
Are you running 0.54 gap on the plugs?
If you have an aftermarket coil, ditch it and put a stock one back in it.
How old are your O2 sensors?
Is the TB fully opening?
I guess what I'm asking is, how good is the tune?

v8stang289 · Sep 21, 2015

cleanLX said:
At sea level I would expect a lot more out of that combo.
For reference, when my car had nothing but off road H, stock MAM bored to 60mm and 3.73's it would consistently run 99-100 mph at sea level. I added drag radials and went 13.2 @ 100.1.
I don't know what could be holding you up?
I'd start by junking the Accel cap and rotor for FoMoCo.
Larger MAM.
Are you running 0.54 gap on the plugs?
If you have an aftermarket coil, ditch it and put a stock one back in it.
How old are your O2 sensors?
Is the TB fully opening?
I guess what I'm asking is, how good is the tune?

Still running the factory coil, O2's have less than 1000 miles on them, (cap, rotor, and wires do too) plugs are gapped at .054. I was thinking about the TB this morning, I need to verify it is opening completely.

v8stang289 · Sep 21, 2015

A5literMan said:
Definitely some improvements can be made with seat time,better tires,etc etc. I do agree that your mph is a little low(I'd expect 2-5mph more). One other thing you can try is changing your shift points(stock tachs are notoriously off). I'd try a lower shift point first(say 5200) see what the car does. Then go up to 6k(you already know what it does at 56-5800). The tach could be off by 500 rpms. Also don't disregard what Mike already told you(I agree with his advise).

I'm going to bump the timing up and try different shift points next time out to see if it makes a difference. The tach actually seems pretty close when compared to the readings on the digital timing light. It might be off too though.

Thanks for the ideas guys, keep em coming.

Updated: 1st Run In 86 Gt, Low Mph (in My Opinion) Any Ideas?

v8stang289

revhead347

Apparently my ex-husband made that mistake.

mikestang63

v8stang289

mikestang63

v8stang289

mikestang63

v8stang289

mikestang63

jchav02

Active Member

stykthyn

I want to measure mine. It doesn't look that tall.

v8stang289

stykthyn

I want to measure mine. It doesn't look that tall.

stykthyn

I want to measure mine. It doesn't look that tall.

v8stang289

revhead347

Apparently my ex-husband made that mistake.

A5literMan

At least it is lumpy...

cleanLX

v8stang289

v8stang289

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Updated: 1st Run In 86 Gt, Low Mph (in My Opinion) Any Ideas?

Apparently my ex-husband made that mistake.

Active Member

I want to measure mine. It doesn't look that tall.

I want to measure mine. It doesn't look that tall.

I want to measure mine. It doesn't look that tall.

Apparently my ex-husband made that mistake.

At least it is lumpy...

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