Crown Victoria P71 Police Interceptor

That is due to the drive by wire throttle.

Check the axle tab, it may be a limited slip differential.

coaledsweat wrote: ↑

Thu. Sep. 09, 2021 10:39 am

Check the axle tab, it may be a limited slip differential.

It has an X5 code, 3.27:1 with LSD. Both tires spin, YAY!

Rob R. wrote: ↑

Thu. Sep. 09, 2021 9:57 am

That is due to the drive by wire throttle.

Ahh, that makes sense. Must be why the P71 Youtubers say the throttle by cable is better. What that really means is the stock tune limits the quick throttle response that would break the tires lose.

I guess if Ford computers were "tune friendly" we could do something about it.
At some point I will probably get an SCT tuner with a tune from Moe's Speed Shop. That should make it's tail wag a little better!

-Don

coaledsweat wrote: ↑

Thu. Sep. 09, 2021 10:39 am

Check the axle tab, it may be a limited slip differential.

The old cars with a throttle cable would burn both rear tires on demand. Drive by wire is setup to "roll into it" and spare the drivetrain from the stress of what would otherwise be a full throttle start.

Rob R. wrote: ↑

Thu. Sep. 09, 2021 3:29 pm

The old cars with a throttle cable would burn both rear tires on demand. Drive by wire is setup to "roll into it" and spare the drivetrain from the stress of what would otherwise be a full throttle start.

Well, I did it!

Yesterday I talked to Marty at Mo's Speed Shop, https://www.mosspeedshop.com/.

After doing a lot of internet research on how to make the P71 quicker I've found that the biggest bang for the buck is optimizing the tuning of the ECU. Some people put cold air intakes, bigger throttle body's, cut the mufflers off but that is all BS. You might get 6 more HP but it won't help the low end throttle response at all.

Marty has been tuning cars for a long time and has a lot of experience with the Crown Vic. I gave him some info about the car and the way it will be driven. He has a tune that will greatly increase throttle response, make more over all power and firm up the trans shift points. He also recommended that I switch the 3.27 gears to 3.73 gears.

I ordered an SCT X4 tuner with the tuning installed. It should be here next week sometime.
So much for good gas mileage.

-Don

I would not bother with the gear swap. It is a lot of work and $ for minimal improvement. Plus the transmission does not like WOT shifts into overdrive.

Considering what the roads in PA were like the last time I was down there I think you would benefit more from a good set of shocks.

Oh Boy! This whole deal oughta get real interesting,real fast!!(No pun intended)

That ride needs lights and a siren!
(You know, for those coal run emergencies)

Rob R. wrote: ↑

Sat. Sep. 11, 2021 10:14 am

Considering what the roads in PA were like the last time I was down there I think you would benefit more from a good set of shocks.

You got the right!
That's why we won't do anything stupid like "Lower It". Suspension travel is a wonderful thing around here!

The gear swap is more of a "wait and see" thing. Probably think about that next year if at all.

-Don

WE GOT THE SCT TUNER!!!

Last week we got the SCT tuner from Mo's Speed Shop. I loaded the 91 octane tune and have been driving it for the passed week. I call it a WIN!
It has much better throttle response, the trans is much firmer than it was and the engine winds out with noticeably more power. I am very sure that the usual bolt- ons that people on the internet put on these cars won't give you this kind of improvement.

The tuner is super easy to use and loading the tune took about 15 minutes using the instructions. Once you know how to do it it will only take a couple minutes.

Let's go for a ride!


-Don

Wow, it was last September the last time I updated this thread!?!?

TIME FOR AN UPDATE!

It's been 1 year since I bought this P71, 2009 Crown Victoria. Bottom Line, this is the best inexpensive car I have ever owned! With the 91 octane "Marty Tune" from Mo's Speed Shop, it runs great! We fixed a few minor things when I bought it, brakes, alt, thermostat. Over this year we put a wiper motor on it and did some work on the AC but that's it. It took a while to find it but I got the right one for me!



-Don

This is rather good news,Don!

StokerDon wrote: ↑

Fri. Aug. 12, 2022 9:00 pm

With the 91 octane "Marty Tune" from Mo's Speed Shop, it runs great!

I think most of the benefits from the tune are improved throttle response and different transmission programing. The gains from the 91 octane tune vs. 87 octane are probably minimal. With current fuel prices I probably would have started with the 87 tune.

Rob R. wrote: ↑

Sat. Aug. 13, 2022 9:33 am

With current fuel prices I probably would have started with the 87 tune.

Wow, I'm glad you remembered that. I thought I only had the 91 and 93 octane tunes!

I checked and, sure enough there is an 87 octane tune in there. I loaded it and drove it for a while. You do notice a little less power but we're gonna go with it. I'll be checking the fuel milage over the next few weeks to see if we can do better than 18.5 MPG.

-Don

Don, have you changed the rest of the drivetrain fluids in the car?