Correct speedo

Mike, I've been meaning to ask you this,why step down to the 15in wheels. Most people go larger 17-18inch to fill in the wheel well? Dave

Smaller wheel = more gear. Plus 255/60R-15 is fine for me. And I like the look of 'em =).

-Mike

Otay :-)

Pg. 129 of the 2004 FRPP catalog has a guide to get you the correct speedo gear.

** Smaller wheel = more gear. Plus 255/60R-15 is fine for me. And I like the ** look of 'em =).

Don't fall in love if you're planning on installing the Bullitt package or SFC's. Both are spec'd for 17x8's with OEM sized/rated tires. (Z-rating applying in this case to both rotational speed and lateral grip, both important if one wishes his car to handle like the original Bullitt GT.)

I know a couple of guys who went with the small-wheel thing, what I will term the 'poor-man's lowered ride' thing. While they do gain more engine RPM, they admit to poor fuel mileage and ride quality/traction problems. Interesting approach, but not a viable solution in terms of performance. If it were that easy, performance spring companies would go out of business.

I think Tungsten used little wheels on his GT as well, and he had a hellova time with body height and ride quality. A galfriend accidentally had smaller-than-stock tires mounted to her stock 15" wheels. (215/R70's instead of 215/R75's I think.) Anyway, the ride height was reduced by 1.00", which didn't seem to be that big a deal. Load ratings were within 200 lbs/wheel, which was acceptable. But the RIDE, oh man, was horrendous! She said it turned her otherwise comfortable-riding pickup into a freekin' buckboard wagon. I did travel with her occasionally, and it did ride pretty damn stiff, even for a pickup. Rode like a Caddie when she eventually put on the correct size. I can't EVEN imagine how bad it would have rode if she put 13-inchers on that thing!

-JD

________________________________________________________ | | | 1998 Laser Red GT RAMFM Member Since 1997 | | M-5400-A Suspension http:/207.13.104.8/users/jdadams || Subframe Connectors & Seat Bracing, Strut Tower Brace || 4-point K-frame Brace, Tremec T-45 & OEM 3.27:1 Gears ||________________________________________________________|

It's called the SpeedCal. The only way to accurately recalibrate for

3.73's in your car is electronically and this is the most reliable unit. The Brother's Performance unit is identical (literally) and may sell for a few dollars less. The FRPP is also the same piece (I think) but it will sell for a few dollars more.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Tom

1998 GT Coupe 5-spd. Bright Atlantic Blue K&N FIPK, Tri-Ax, 3.73's, FRPP Coated Shorties, SpeedCal, P&P 2K Heads, 2K Intake, Bassani X-Pipe and Cat-Back, Subframe Connectors, JMS Chip, Eagle Alloy Wheels

Now that I've ordered the M5400 package I noted here, as well as on your site, the reference to wheel size and the possible effect a change might have on handling. I am presently running 245/45/17's on 17x9 wheels. On the present stock suspension I can't discern any degradation in handling and in fact I believe the car handles better that it did with the 17x8 wheels. Is this possible?? I was also contemplating changing the tire size to 255/45/17 to better match the 9" wide wheels. Perhaps the key variable is not so much the wheel width but the wheel diameter.

My car could use improvement in the handling department, but it's not THAT bad at all. Ride quality is great. Traction isn't a huge issue. I'm not overly worried that the SFC's won't be ungodly optimal for my setup... I'm sure they'll get the job done & I'll let them do just that. So far on the

15" wheels I get 23-24mpg in city if I go easy on it. Haven't tried it on highway yet. I'm not trying to "lower" the car.. I actually don't like the "low rider" look. So far, I have no complaints whatsoever. If the GW subframes are going to cause problems though, I'll go with a diff. set of subframe connectors.

-Mike

Interesting

Ah that's right. That's what I was looking for. Can it take care of the 15" wheels too?

-Mike

It'll take care of everything. The wheel size isn't critical, the tire diameter is what's important. There's a calculator on DM's website to figure the settings for the SpeedCal.

The designer of the thing is a friend of mine from the Dallas area. I was having some freaky issues with my SpeedCal when I met him, I was working in Dallas at the time. He took it upon himself to invite me to his house to tech out the problem. We disassembled the gauge pod, traced leads, checked connections, etc. etc. until we determined that there was an intermittent short in the wiring harness which, thankfully, ended up getting replaced at no charge under an extended warranty. He absolutely refused to take any money for the work. That didn't stop me, however, from treating him to a steak dinner or two! We've been friends ever since.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Tom

1998 GT Coupe 5-spd. Bright Atlantic Blue K&N FIPK, Tri-Ax, 3.73's, FRPP Coated Shorties, SpeedCal, P&P 2K Heads, 2K Intake, Bassani X-Pipe and Cat-Back, Subframe Connectors, JMS Chip, Eagle Alloy Wheels

Awesome! I can't find the damn speedcal on the site though.. got a specific URL? Thanks, bud.

-Mike

** Now that I've ordered the M5400 package I noted here, as well as on your ** site, the reference to wheel size and the possible effect a change might ** have on handling. I am presently running 245/45/17's on 17x9 wheels. On the ** present stock suspension I can't discern any degradation in handling and in ** fact I believe the car handles better that it did with the 17x8 wheels. Is ** this possible?? I was also contemplating changing the tire size to 255/45/17 ** to better match the 9" wide wheels. Perhaps the key variable is not so much ** the wheel width but the wheel diameter.

It's possible. The 245's are pretty slim on 9" wheels; I would get a better tire size match, and as long as the tire diameter and aspect ratio are very close or identical to the OEM specs, I don't think it will make much of a difference. I'm sure that more sure-footed tire/wheel combos exist, and that Ford took a conservative approach when selecting OEM equipment. My biggest concern was matching the Bullitt setup part-for-part, so that everything would work well together, and my own car's suspension performance would match the original design.

-JD

________________________________________________________ | | | 1998 Laser Red GT RAMFM Member Since 1997 | | M-5400-A Suspension http:/207.13.104.8/users/jdadams || Subframe Connectors & Seat Bracing, Strut Tower Brace || 4-point K-frame Brace, Tremec T-45 & OEM 3.27:1 Gears ||________________________________________________________|

| Smaller wheel = more gear. Plus 255/60R-15 is fine for me. And I like the | look of 'em =). | | -Mikes

Ummm not necessarily :-) It depends upon outside diameter of the tire, not the outside diameter of the wheel.

Right... so get 15" wheels w/ little sidewall lol... I'm not THAT damn picky. I like the look of the 15" wheels more & it's a change. I want my car to be a sleeper. People think I have a V6 w/ GT emblems.

-Mike

Awesome, Gill. Thanks =).

-Mike

I hate it when THAT happens :-) I get that all the time in the 97 coupe, I have limited edition emblems on the fenders but the 302 sound kinda gives it away.

TIM -aka- MUSTTANGUY "at" AOL "dot" COM

Yeah no kiddin... LOL. Turbo mufflers give me away too. Some people are just that retarded though... V8 sound is pretty distinct.

-Mike