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Sleeper stock motor in a coupe Pics.

205K views 831 replies 174 participants last post by  Sledger46  
#1 ·
Guys: Your information has helped me lots in the past with other projects. I just recently purchased a 1989 coupe 5.0 5 speed. It is in great condition and factory original down to the air box silencer, the factory intact exhaust system and the distributor boot etc...The ashtray door even works perfectly.

Let me start by saying that I am impressed with what these cars can do from the factory with knowledge and tuning alone. I want to take this coupe as far as can without putting parts on it.

I cannot use any visible modifications, I need to keep the 100% original appearance. I will add 3.73 gears (since I may add Nitrous later and 4.10's will be too much) and a short throw shifter, as well as remove the silencer to the airbox (Unnoticeable mods). I'll be running 10 hole rims possibly widened in the rear and narrowed in the front.

My tuneup consists of: The Downs Ford kit which includes motorcraft stock copper plugs, 9mm ford wires, brass cap and rotor, fuel filter PCV valve & motorcraft oil filter. My questions are:

Should I spend the $$ on a K&N panel filter or just run a paper one?
Stock spark plugs AR25's or different?
I'm going to cut back the electrodes on the plugs and index them. Yes?no?
What gap should I run?..I'll be running a hotter coil but it'll look factory.
What timing should I run? I know each motor is slightly different.
What fuel pressure should I run? I'll be swapping on a kirban regulator at some point.
I'll be running a short belt at the track
I'll be running drag radials on the stock 10 holes. What is the biggest/tallest tire I can fit with stock quad shocks and tailpipes? 265/60/15?
Should I run a bigger TB on the stock intake? Like a 65mm ford unit?
Should I run a bigger Mass Air meter? Is there a factory looking one?

I'm not looking to port the heads or intake yet, but will some smoothing on the TB/intake entrance help?

Will this thing ever run 13's like this? I wont power shift it until I have a backup transmission ready

Sorry for all the questions..I hope I provided enough information. I'll post pics soon.
 
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#4 ·
Should I spend the $$ on a K&N panel filter or just run a paper one? Put in a K&N and remove the fenderwell silencer.

Stock spark plugs AR25's or different? Stock
I'm going to cut back the electrodes on the plugs and index them. Yes?no? Cut back the electrode and then there's no reason to index.

What gap should I run?..I'll be running a hotter coil but it'll look factory. Stock - .054"

What timing should I run? I know each motor is slightly different. You might have to run 93 octane, but try bumping the initial up to 14 or so. Experiment watching your times changing only the initial timing. Or at the strip, remove the spout, and just lock in the total timing around 32-34 degrees btdc.

What fuel pressure should I run? I'll be swapping on a kirban regulator at some point. Stock pressure - if the regulator is working correctly (put a gauge on it first, 38-39 psig with vacuum hose disconnected and temporarily plugged at warm idle) don't waste your money on an adjustable.

I'll be running a short belt at the track
I'll be running drag radials on the stock 10 holes. What is the biggest/tallest tire I can fit with stock quad shocks and tailpipes? 265/60/15? You want the most traction you can get without compromising your gearing - taller tire makes your 3.73's seem longer, not the direction you necessarily want to go.

Should I run a bigger TB on the stock intake? Like a 65mm ford unit? The biggest bottleneck on the system is the stock lower intake. Have tmoss port the stock lower.

Should I run a bigger Mass Air meter? Is there a factory looking one? Pick up a 94/5 HO 70 mm unit.

I'm not looking to port the heads or intake yet, but will some smoothing on the TB/intake entrance help? No.

With traction, lots of gear, banzai launches and good driving, 13's should happen with no problems.
 
#5 ·
I did the same thing on my hatch,it was too pristine to full blown mod but was really boring.I had the heads ported with beehive springs,added a 2030 crane w/comp pushrods,had the stock upper/lower ported then added a FRPP 65mm spacer and t-body that look stock.You can use the MAF sensor from a 94/95 mustang and install it in the housing of a t-bird supercoupe so it bolts to the bracket like stock.The only items visible are ceramic mac shorties and pulleys painted black.Steeda shifter,offroad X-pipe,FM catback and 3.55's rounded it out.
The car is mondo fun now,sounds awesome and pulls hard with great drivability.Go for it.
Image
 
#26 ·
I did the same thing on my hatch,it was too pristine to full blown mod but was really boring.I had the heads ported with beehive springs,added a 2030 crane w/comp pushrods,had the stock upper/lower ported then added a FRPP 65mm spacer and t-body that look stock.You can use the MAF sensor from a 94/95 mustang and install it in the housing of a t-bird supercoupe so it bolts to the bracket like stock.The only items visible are ceramic mac shorties and pulleys painted black.Steeda shifter,offroad X-pipe,FM catback and 3.55's rounded it out.
The car is mondo fun now,sounds awesome and pulls hard with great drivability.Go for it.
Any videos or timeslips of that setup? That's almost exactly what I want to do with my GT. All the little details are the same, just debating whether I want to go with ported E7's & stock intake or Explorer GT40 stuff.
 
#6 · (Edited)
Now that sounds exactly like what I'm looking to do. I think i'll go with 3:73's so that I can run a bigger tire.

What timing do you run with 92 octane and do you have any timeslips with that setup?

Also post some specifics of your rear tire /rim/ suspension combo. Are you running stock 10 holes with quad shocks and tailpipes.

I'm thinking of routing the PCV elsewhere so that I don't get oil in the intake tract as well as running aluminum pulleys painted black with a 3" race crank pulley for the track only.
 
#7 ·
running aluminum pulleys painted black with a 3" race crank pulley for the track only.
WOW all the effort thats gonna take to swap that pulley. id be spending my extra time on the 60' times thats where you'll notice more....
 
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#8 ·
Crank Pulley swap will take me 20 minutes tops. But I hear what you are saying and will also focus on the 60ft setup. Sway bar will be off at the track and what do you guys think about 90/10's in a driver? Should I play it safe and go with 70/30's? what will be the 60ft difference between the two?
 
#9 ·
For a quick but stock appearing package, these are my suggestions:

Iron GT40 heads, mild port and polish, upgraded valve springs and 1.7 roller rockers
Send intake to TMoss for cut and port job, he'll putty it and make it look stock.
Stock HO cam, retarded 3-4 degrees.
Shorty unequal length 1 5/8" headers, high flow catalytic 2.5" h pipe, 2.5" cat back exhaust.
Underdrive pulleys, 130 amp alternator.
Electric fan and 180* thermostat.
A set of 70/30 Drag struts up front and 50/50 drag shocks out back, southsides out back, boxed upper control arms, drag springs up front, airbags in rear with 4 cyl springs, tubular front k member.
Widened 10 holes out back to 8" with 235-60-15 drag radials and narrowed 10 holes up front to 5" with 195-65-15 tires up front.
Rebuilt 31 spline traction lok rear diff with extra clutches and 3.73 gears and 31 spline axles.
Aluminum front and rear bumpers, relocate battery to trunk or install lightweight battery up front.
Hope I didn't miss anything, visually it won't seem different from any other stock Stang (with mufflers) out there. But it will have enough to run mid 12s on a drag radial, with a good 5 speed and a solid driver.
SS
 
#10 ·
If it just has to "look" stock there's LOADS of things you can do.
95% of people I've met thought my cobra intake was a stock peice since I never put the "cobra" sticker on it. If you have to stick with a stock intake and you're not tight on $ extrude hone is the way to go.
You'll want to do something with your headers since the stock ones SUCK hard core. The FMS stainless ones don't look like anything special.
Just depends on how much you want to do and still look "stock". Even a head swap isn't out of the question so long as you paint the new heads to match the OE's.
 
#11 ·
Here is a pic of my sleeper's engine bay :

Image


Except for the intake manifold that does say edelbrock, everything looks totally stock, right down to the distributor boot and dust everywhere :) You can kinda see the headers, but they are not shiny anymore, just a matte grayish color. I painted everything a cast coat iron or matte black finish. Can't see any wires for the shift light, autometer gauges/warning lights, etc.

You can always get whatever parts you want and paint them dark gray or black, or even a rusty color, to blend in. You wouldn't know it by looking under the hood, but I still put down ~300rwhp/350 rwtq with the build you see in my sig.

As far as parts go, def keep the stock cam so you don't have a lope, but get that stocker ported to hell by tom, and get some heads to match.

Paint is your friend!!

Eric
 
#12 ·
Okay..So I finally worked on the coupe. I did the following.

Oil/filter change 10-30 with motorcraft filter
Removed air silencer
Removed MAF mesh screen
New Air filter. Stock paper replacement
Spark Plugs. Autolite 25's @ .055 Could not round off the electrodes.
160* Mr gasket thermostat.
Flushed coolant and replaced. 70/30 water/coolant
New 9mm motorsport black plug wires
New Motorsport cap/rotor
Adjusted timing to 15* (It was set to 5*) OUCH!!
Cleaned IAC, TB, MAF
New Fuel Filter
Removed front sway bar
Removed Jack/Spare tire

Now..I got a free set of Convo Pro skinnies up front and I may have a set of slicks for the rear before I hit the track. First outing will be this Saturday at California Speedway in Fontana.
 
#13 ·
You might want to lower your timing a bit, because if you lug the motor (ie. 5th gear uphill) it will probably ping. Unfortunately we don't get 93 octane here in so cal, so you may have to dial it back a bit.

Otherwise, looks really good so far! We need some pics now!

Eric
 
#18 ·
Just as a data point, I think tmoss had Buddy Rawls do some modeling on his stock cammed, P-head, Explorer intake combo (280 rwhp/330 rwtorque) --- and the optimum primary tube diameter for that set up ended up being even smaller than 1.5" - close to 1 3/8". People oversize exhaust components all the time. A 1.5" primary long tube will support more HP than most folks make with streetable 302 combos -- and that will optimize low end torque if the rest of the combo is matched.
 
#19 ·
Mike - I actually modeled that in Larry Meaux's "Pipe Max" program. It models the exhaust system and intake system design parameters as well as making suggestions on a cam among other things.

Primary diameter suggested was 1.328" - round up to 1.5" and length was 19.8-22.9"
 
#24 · (Edited)
Extrude Hone a "dumb" process - it cannot remove material selectively to get the best shape and transitions in the runners. I had pictures of EH runners and hand ported runners that show the obvious differences on my site which is now down indefinately.

It is also VERY expensive and produces results no better or not as good as a good hand porter can provide at much lower cost in many cases.

It's a great process for polishing surfaces. Perfectly smooth surfaces do not promote the best velocity profiles in runners in my opinion. You want a surface roughly the same left by 80 grit sand paper in my personal opinion.
 
#31 ·
Tmoss, I wasn't trying to direct him away from you. I usually stick to recommending things I've seen with my own eyes. I had 2 different friends years ago with extrude honed cobra intakes on 351's that were floating around the 600 rwhp mark. I've read several of your posts and LOADS of posts from people with praising (or even worshiping) your work. I wish your website were still up, I'd love to see some of your stuff. You've probably posted this several times, if it's not top secret, but could you tell me how you port a stock intake so well? If you've already posted it several times just point me to a post I can read.
 
#25 · (Edited)
Heres a video of my 88 Sleeper Coupe.... http://www.youtube.com/watch?v=_PuFQj6G4XM
2nd run I missed 2nd lol.. :crying:

Also a picture of my engine compartment...
Image


My best time with this setup was a 13.42 at 101.9. This was also in very crappy weather, The Corrected Alttitude was over 3000... So the car definatly had more in it.

Heres a list of what I had done:
4.10's, Nitto Drags, TMoss Ported Stock Upper&Lower, 1.7 Rockers, Auto Specialties Racing Crank Pulley, K&N Panel Filter, FMS Shorties, Mac ProChambers, and DynoMax Ultra Flows... Timing was at 14 or 15 and I also had a 180 thermostat.. Everything else was stock. Plugs, wires, coil, TB ect....

I don't know much about the other stuff, I'm actually concerned about Fuel Pressure myself now that I recently added a pair of Ported Thumper E7 Heads to my setup above. I've left everything except the fuel pump stock and its been fine so far, so I don't know...

Good Luck with the car though, definatly post up some times when you get her out to the track.
 
#27 ·
I don't know much about the other stuff, I'm actually concerned about Fuel Pressure myself now that I recently added a pair of Ported Thumper E7 Heads to my setup above. I've left everything except the fuel pump stock and its been fine so far, so I don't know...
I'd sure like to know what your new results are once you get the Mike's ported E7 heads on the track.
 
#41 ·
It's the shear suprise of it all! :evilgrin:
 
#43 · (Edited)
GOT RESULTS!!!!!! And pictures...Finally. I hate the posts that have all kind of interesting scenarios and never make it to the end results.

First my prologue.
I am an idiot who is too familiar with Speed density and thus I made some mistakes that I realized after my track outing. I noticed that the car was bucking at low RPM's and would not hold a steady idle without dying so I scanned the entire system for vacuum leaks etc.. to find a reason. I noticed a MAP sensor on the firewall that had an open port on the bottom of it and figured it must not be getting a vacuum signal..man..of course the car was idling like crap. So Being the genius that I am I fabbed a vaccum source to the sensor from the vacuum tree. Problem solved? Well, the car still idled like crap...possibly worse than before and I could not figure out why.

I'n my prior posts that detailed my track preparation I had cleaned the MAF sensor and removed the air silencer. At the same time I had removed the metal screen that I saw as a minor restriction to airflow. It seems that there is a debate as to wether the screen plays a part in stabilizing the air going into the sensor thus improving driveability. I'll be putting the screen back in and unplugging my MAP(BAP) sensor in the near future.

Okay..now the good stuff. The car was prepped with the mods listed in the last post. I swapped the 160* stat for a 180* unit. I forgot to take out the spare tire and jack. I filled up on 93 octane..too much. After getting to the track I still had more than 3/4 tank full. I put on the set of convo pro skinnys with 160r15 front runner s and I got a set of 26x8.5 ET Drags. They fit perfectly with no issues.

Intake was iced through all passes, car was running very cool all day.

First pass:
15psi in slicks, 10* timing, weak burnout, left at 5000RPM, car spun, bogged badly, then I granny shifted my way to a 15.7 at 86 mph. 60ft time was a horrid 2.3secs. The car felt good while at WOT, no pinging or popping , motor sounded very smooth.

Second pass:
11psi in slicks, 14* timing, good long burnout, Left at 5000 RPM. Car hooked, bogged, Power shifted all gears en route to a 15.0 at 89 Mph. 60ft time was 2.1 and motor ran smooth as silk.

Then it started getting a little wet from an incoming storm and we called it a day. I think that with the BAP sensor and Mass air screen set up correctly the car will drive a little better.I loved the way the stock tranny powershifted, it was very easy. I think that if I can set up the suspension to get a 1.7 sec 60 ft time I'll have a low 14 sec pass with the rest of the mods below.

I still have these unnoticeable mods left:
Remove Jack & Spare tire
4:10 Gears,
H pipe & Dynomaxes with the stock exhaust shield welded on for stock appearance.
Bigger ford MAF (Stock appearance)
Bigger ford TB (Stock appearance)
Polyurethane bushings in the stock control arms. I might box them also.
More timing as track tuning allows.
Better launching practice
3" race crankPulley
1:7 roller rockers
Retard stock cam 4*
255lph fuel pump (Stocker is whining loudly)
Kirban FPR for tuning.

Here are the pics and video.

Image



Here is the video. It's a little past halfway to see the coupe.
http://www.youtube.com/watch?v=YGJRKzH-me8
 
#44 ·
GOT RESULTS!!!!!! And pictures...Finally. I hate the posts that have all kind of interesting scenarios and never make it to the end results.

First my prologue.
I am an idiot who is too familiar with Speed density and thus I made some mistakes that I realized after my track outing. I noticed that the car was bucking at low RPM's and would not hold a steady idle without dying so I scanned the entire system for vacuum leaks etc.. to find a reason. I noticed a MAP sensor on the firewall that had an open port on the bottom of it and figured it must not be getting a vacuum signal..man..of course the car was idling like crap. So Being the genius that I am I fabbed a vaccum source to the sensor from the vacuum tree. Problem solved? Well, the car still idled like crap...possibly worse than before and I could not figure out why.

I'n my prior posts that detailed my track preparation I had cleaned the MAF sensor and removed the air silencer. At the same time I had removed the metal screen that I saw as a minor restriction to airflow. It seems that there is a debate as to wether the screen plays a part in stabilizing the air going into the sensor thus improving driveability. I'll be putting the screen back in and unplugging my MAP(BAP) sensor in the near future.

Okay..now the good stuff. The car was prepped with the mods listed in the last post. I swapped the 160* stat for a 180* unit. I forgot to take out the spare tire and jack. I filled up on 93 octane..too much. After getting to the track I still had more than 3/4 tank full. I put on the set of convo pro skinnys with 160r15 front runner s and I got a set of 26x8.5 ET Drags. They fit perfectly with no issues.

Intake was iced through all passes, car was running very cool all day.

First pass:
15psi in slicks, 10* timing, weak burnout, left at 5000RPM, car spun, bogged badly, then I granny shifted my way to a 15.7 at 86 mph. 60ft time was a horrid 2.3secs. The car felt good while at WOT, no pinging or popping , motor sounded very smooth.

Second pass:
11psi in slicks, 14* timing, good long burnout, Left at 5000 RPM. Car hooked, bogged, Power shifted all gears en route to a 15.0 at 89 Mph. 60ft time was 2.1 and motor ran smooth as silk.

Then it started getting a little wet from an incoming storm and we called it a day. I think that with the BAP sensor and Mass air screen set up correctly the car will drive a little better.I loved the way the stock tranny powershifted, it was very easy. I think that if I can set up the suspension to get a 1.7 sec 60 ft time I'll have a low 14 sec pass with the rest of the mods below.

I still have these unnoticeable mods left:
Remove Jack & Spare tire
4:10 Gears,
H pipe & Dynomaxes with the stock exhaust shield welded on for stock appearance.
Bigger ford MAF (Stock appearance)
Bigger ford TB (Stock appearance)
Polyurethane bushings in the stock control arms. I might box them also.
More timing as track tuning allows.
Better launching practice
3" race crankPulley
1:7 roller rockers
Retard stock cam 4*
255lph fuel pump (Stocker is whining loudly)
Kirban FPR for tuning.

Here are the pics and video.



I think that you should have used the max possible air pressure in the slicks. 11psi seems way low for such a stock combo, also I hope you didn't shift more than 5-5.2k. You could had tried the regular street radials before the slicks IMO. I was able to get 2.0-2.1 60ft on my completely stock 04 GT on the hard factory goodyear tires. Keep going at it, there's a lot left in that car.
 
#47 ·
makes me wish i hadn't thrown away my 10 hole rims :D

looks really good, looking forward to the engine bay pics!

once i realized i could never make the car show quality, or anything close to it, things got a lot simpler once i decided to just sleeper the damn thing :D
 
#48 ·
I think that If I can get the car to Hook and 60ft better the times will be respectable. I'm thinking mid to low 14's with no new mods if I can get a 1.7 60ft time out of it. Here is what I'd like to do.

I'm looking to keep all my stock suspension components, UCA's LCA's and quad shocks. I'm trying to get the car to 60ft better. Bone stock motor with removed sway bar in front, skinnies, 26x8.5 ET Drags on stock wheels. Stock gears out back also. Best so far is a 2.1 60ft with 11psi in the slicks and launch at 5000RPM.

Should I box the lower control arms? Should I swap out the bushings for polyurethane ones, Iv'e heard that poly bushings will tear up the torque boxes. Where can I get the correct replacement bushings for the lowers and uppers? Any tips on the install? Finally, at this stock level should I get adjustable Uppers so that I can set the pinion angle ?

Thanks
David
 
#49 ·
Honestly, unless you're 5000 feet above sea level that is pathetic. I ran 13.95 in an almost stock '89 GT on street tires with a 2.0 60 foot. You should be running mid to low 13s with minimal bolt ons and slicks.
SS