Probe
Performance UpgradesProbe
Performance UpgradesBeing listed here does not imply suitability for your application. I may post parts of email messages I receive. If the author objects to this policy, I will re-edit or remove the text to satisfy you.
RPMTuners.com - 
A new tuner company devoted to the Probe and KL series
motors. A must for modified KL motors. 14Jul03
Ok, so you are ready to spend some money and time to improve the performance of your car. Where do you start?
First off, it's not safe to explore the performance limits of any car on the street, much less a performance car like a V6 or turbo Probe. Autocross and road race schools (see the Racing Page) are a much, much safer (and legal) way to test the limits of you and your car.
There are also lots of different ways to change your car depending on what your goal is.
So you've just installed your new exhaust/headers/tint, etc. and you want to test it out. So you back out of the driveway, slam it into 1st and floor it. Wow you say- that's really great!
What's wrong with this picture? Well, first, the car is probably cold. The 93-97 GT is much peppier cold than hot. Second, many mods increase the sound level of the engine. This is make it seem more powerful. Third, you are probably revving it a lot harder than you usually do, and most of the HP is between 4K and 6K RPM. Fourth, you really want to believe that the $500, 2 bleeding knuckles and 4 hours you spent made a difference!
Geez, you're thinking, what a wet blanket! But the performance parts industry is full of claims that don't translate to the dyno. I hear so much: 15HP for exhaust + 10 for intake + 15 for headers means I have 40 more hp. But it doesn't show up on the dyno. Check it out on the Dyno Page. Well, the real measure is if you think the car is more fun to drive.
Improving your driving skills will make the biggest improvement in the performance of your car. I thought I knew a lot of driving a car fast. I was wrong. If you haven't done any racing, neither do you. When I started racing autocross and road race, I realized that I had never even approached the real limits of a car on the street. You can't, really, not without crashing once a week.
Racing autocross will change the way you see corners, and will give you lots of practice with feeling the car at the limit of grip and speed. I highly recommend this book: Secrets of Solo Racing : Expert Techniques for Autocrossing and Time Trials by Henry A. Watts.
Ok, ok, let's get to the part where you get to spend some $$ on a 4 inch exhaust tip... :)
The 93-97 GT is a pretty well balanced car straight out of the box. Braking, acceleration, handling are refined and inspired. The 89-92 turbo GT is maybe just a little faster in a straight line than the later GT. The published horsepower figure of 145 for the turbo is generally considered NOT to be the peak horsepower, which may peak at about 190. The 89-92 Mazda turbo (GT) in particular is a great sleeper- fast enough to beat a VTEC Integra.
Check out the Parts Page for more info.
I make a distinction between appearance and performance. So I'm not going to talk about tint on this page. There are lots of ways to make your car look different, and everybody has a different idea about what looks good. I'm going to try to distill the effect of the many products available for (mostly) the 93-97 GT into those that affect the acceleration, cornering, ride, braking and feel of the car.
A while back I sent a message asking for a place to roll my fenders. I got responses ranging from "do it with a baseball bat" to "take it to Dinan". I picked the middle ground and had somebody do it cheaper than Dinan. Since then I have found the perfect solution. It's too late for me, but I think some of you will benefit from this.
I picked this up on the M3 mailing list. TireRack will loan you a very professional piece of equipment that would roll your fenders nicely. You have to pay for the shipment both ways, but it's well worth the price. The only catch is, they will charge your credit card $750 which they with credit back when you return the equipment. Some people on the M3 list in the same area have gotten together and shared the cost. Here are some pictures of it in action:
If you are considering aftermarket wheels, and especially larger diameter (17 or 18" wheels) you should consider the effect of the possible increased weight. Many of the cheaper brands weight considerable more than the stock wheels (which I think are about 24 lbs each, the chrome a smidgen more). Heavier wheels are far worse than just the adding the same weight to the car, the engine must accelerate each wheel rotationally. This will hinder acceleration considerably. The further the weight is from the center of the wheel, the worse the effect. If you have the $$, consider lightweight wheels, such as the Panasport C5R rims 16x8 ($230 at CBPerform@aol.com) ). The Mazda RX-7 3rd gen wheels are also lightweight and have the same bolt pattern.
Spoilers on street cars are ineffective mostly because street speeds (under 80mph) are too slow to create downforce or other aerodynamic effects. So almost all the spoilers you see are designed for looks, not air flow. But they do add a little weight and hinder rear vision slightly.
The main problem with body kits is that they add weight. They are also likely to increase the drag coefficient of the car. There have been reports of considerably diminished top speed with a large kit.
Here's what I found on the dyno. The data is uncorrected and smoothed (to avoid getting too many unbalancing peaks) to S=3 on dynojet's software. I made six passes on the dyno. Two with the Tornado unit installed followed by a 20 minute cooldown (with the engine idling) and two runs without the Tornado installed. Following yet another 20 minute cooldown with the engine idling I proceeded to make two more runs with the Tornado unit installed.
Run #1 w/Tornado: 145.1 HP, 147.3 lb-ft Run #2 w/Tornado: 145.3 HP, 146.7 lb-ft
Run #3 noTornado: 148.0 HP, 149.8 lb-ft Run #4 noTornado: 146.8 HP, 149.3 lb-ft
Run #5 w/Tornado: 145.6 HP, 148.8 lb-ft Run #6 w/Tornado: 146.3 HP, 148.4 lb-ft
As you can see from the above numbers, coming in "hot" from the street produced the lowest numbers. I did allow for about a 10-15 minute cooldown before hitting the dyno the first Time. So perhaps the second run wasn't surprising, with the car probably being a bit cooler. The third set of runs is what put the nail in the coffin when it comes to the Tornado. Although the third set was a bit improved over the first set, it was still visibly lower than the second of runs. (thanks to JTT)
Yet another snake oil automotive product.
Returns of around 2% hp increase (as measured on a dyno) across the band are reported for using synthetic oil in the engine and transmission. It is slipperier than dino oil and may keep the parts cooler. Redline MT90 (75w90, GL-4) in the gear box and Mobil 1 or equivalent in the engine are commonly mentioned.
Dyno results show about 4HP for transmission synth alone, not bad for $30. Read about it HERE.
K&N makes a direct replacement for the stock airfilter. It's supposed to flow more air, and also perform better as it gets dirty, unlike a paper filter that flows less. about $40.
The July issue of Car and Driver actually showed a performance drop with a drop-in K&N on a new Catera. 18jun98.
High performance plug wires work by providing a stronger and more consistent spark to the cylinder. There may be some small advantage to this, but no dyno results have been measured on a PGT to my knowledge.
The main benefit is to replace the failure-prone stock wires which can go bad every 35K or so.
Tires will have a huge effect on the safety and responsiveness of your car. Good quality tires will have better dry and wet traction. They will also communicate the road to you better and be more responsive when cornering. With the stock suspension you can go to a 245/45R16 size for a bigger contact patch. Some of the current favorites:
Lowered Probes look great. But unfortunately most lowered cars do not handle better or corner better than a stock setup. Stiffer strings can decrease the suspension's ability to respond to bumps in the road surface, causing the tire to bounce and lose contact or at least pressure on the road. The result is a loss of traction.
I've been told that the handling engineers at car companies are good at figuring out a really good suspension setup for a car, then they soften something up on it to make it understeer like crazy (safer for the majority of drivers). If we can put the suspension back to it's highly tuned state we can make full use of the excellent work by the Ford engineers.
CB Performance: The camber kit that I can get is made by Speciality Products. It runs $35.00. The set will be for both front tires and it will adjust the camber 1-3 degrees. email cbperform@aol.com for more info.
The 93-95 GTs have quite a stiff suspension as it is. I find road surface bumps can be alarming on a twisty mountain road as the car hops around, closer to the cliff edge, guard rail or oncoming truck. Top quality handling cars like the BMW M3 or Acura NSX have softer feeling rides than my 94GT.
Also available from J.C. Whitney (Mar99)
I called up Addco today to get a part for the bar on my other car and out of curiosity asked if they sold the Probe bar with _rubber_ bushings. Well they didn't, but they did tell me that they had changed the poly bushings. Apparently they got a lot of complaints about them wearing out too fast, so they switched to a different bushing manufacturer altogether and also made them thicker. I'm sure if anyone needed the new bushings, they'd have no problem getting them. I've called Addco twice, once for a missing part in the kit, and this time for a broken bolt, and both times they were very nice and sent the parts free. In case anyone needs bushings, the # is: 1-800-338-7015.
This often the first upgrade that people do. But the stock 93-97 GT exhaust is pretty good, and you won't gain much HP. A lot of people like the sound and/or look of a Borla or GReddy, but don't expect to feel much of a difference.
Borla, HKS, and GReddy are the most common cat-back exhausts for the 93+PGT. From the first Probe Summit I can tell you that hearing all those different exhausts at full throttle was pure music!
Greddy has a web page about California law and aftermarket exhausts: read it Here.
Greddy In Court: Exhaust violation ticket (noise) 11 days after I got my GReddy exhaust. Well, I plead not guilty and had my court date this morning. I contacted GReddy and they faxed me the noise testing sheet for the exhaust system. I also printed out their information on California vehicle codes from their web page. After reviewing the information, the judge dismissed my case. He actually thought the limit was 80db (yeah right!!) instead of 95db but wasn't sure, so he let me off. He did recommend that I carry the information with me at all times. Fixed up cars get hasseled a bit more in SoCal than in other parts of the country. They didn't even want to listen/see the exhaust. 21Oct98
To see Borla pics on this site click here.
The Borla has the advantage of being stainless steel and the cheapest of the three. It has dual tips rather than the big single tip like the GReddy. From inside, the Borla gives a little "burble" note to the sound, not at all loud.
Supposedly Brospeed is coming out with a matched exhaust and header set for the PGT.
*Coming soon*: WAV files and pics of the various exhausts. Anybody got a microphone and computer to capture the sounds?
Having just installed a Hotshot intake and K&N cone filter on my car, I can say that it sure is louder at WOT in 2nd and 3rd gears. There is maybe a little more power over 4K RPM. I actually noticed a touch of torque steer which may be from a little more power.
There is an excellent, impartial and intelligent writeup at http://www.slamsite.com/chrono/dyno.htm with dyno charts of with and without the hotshot intake.
Check out the Intake/Filter Page with an alternate intake system and air filter Jul99.
Reducing weight will increase acceleration, improve braking and cornering.
The 93-97 PGT weighs approximately 3000lbs, dividing by the horsepower of 165, we get about 18lbs/hp. So roughly every 18lbs removed from the car's weight will add an effective 1 HP.
Gas weighs about 8lbs/gal so 16 gallons in the tank weighs 128lbs. If you have only 1 gal in the tank, is it almost a 7 hp equivalent difference. A passenger can make even a bigger difference, not to mention the driver's weight.
You can remove things like the spare tire and jack, the floor mats, the rear seats, interior panels and anything else.
Here are some easily removable items:
Removing air conditioning is another extreme possibility.
You could replace the heavy power seat with a manual one or a lightweight racing seat. See the Performance Parts Page for lightweight seats. Replace the battery with a smaller one.
However, most of the things that came with the car have some important function; if you really want to rip out all the insides it's kind of a shame to do it such a nice car as a Probe. May I suggest a turbo'd Civic? =), ok, i'll stop now.... :)
There have been several discussions about chips lately. I am pretty skeptical myself since there is a noticable lack of meaningful dyno testing. In October 97, someone on the Performance List did a before and after dyno with a Superchips chip that showed a modest increase across the powerband (3% or so).
A dyno test recently reported on the performance list (may be the one mentioned above) for a Superchips ship provided more controversial results. 1Dec97
Here are the SuperChips plots on Mike's Probe Site.
Check the Underdrive Pulley Page for installation, performance reports, etc on underdrive pulleys.
Underdrive pulleys increase available horsepower by lowering the accessory drive speed (and thus their power requirements).
Some have reported that this makes the biggest non-turbo/supercharger difference in power. By reducing the weight that needs to be spun up, the engine will rev more quickly. No actual horsepower is created, but you can get it to the road faster.
A stock MX-6 1.8L V6 flywheel is 16lbs and presumably a bolt-on. It can be machined to 13lbs. A custom aluminum flywheel could be as light as 8lbs but very expensive. Reports on 13lb flywheel are no difference in driveability. 18jun98.
A PGT flywheel has been lightened to 13lbs and run hard for 2 years without failure. Requires a qualified shop. May99
Getting lighter wheels can make a dramatic improvement in acceleration especially at street speeds. Not only do they reduce the total weight of the car, but they have much lower rotational inertia. When you accelerate the car, each of the wheels must be accelerated rotationally, the smaller and lighter the wheels, the faster a given amount of power can spin them.
Bolt pattern and Offset: 5:4.5" or 5:114.3mm Take your pick...same deal either way. Almost ALL aftermarket wheel manufacturers out there will have an application for our bolt pattern.
The factory pgt wheel offset is +40mm. Aftermarket wheels with anywhere from a +30 to +45mm offset should be ok...as long as they're not some crazy wide rims.
See the new Headers Page.
Comparision of the Hotshot and Brospeed headers: 17Aug98
A brace that connects the two front strut towers. It reduces flex here and stiffens the chassis. Effect is more subtle than the rear bar.
See the FAST front strut tower bar Page on this site.
Connects across the top of the rear strut towers. Good for reducing rattles, increasing chassis stiffness, but cuts across the hatch area.
The RRE (Road Race Engineering) Rear Strut Bar is a popular one. c. $90. Search for the website. I think Mike is the contact there. Do it yourself installation but requires some cutting of the interior rear panels.
MotorSports Digest Forced Induction - Supercharger, turbo/NOS primer. Apr98
13May98: Unorthodox
Supercharger Kit.
*The kit will initially make 6PSI boost*
Unorthodox would like for all interested parties to call them @ (516) 253-4909. Unorthodox Racing needs $1000 deposit [Credit Card #] that will not be billed until it is shipped out.
Apr98: Unorthodox Supercharger Kit.
The supercharger will be located on the driver's side utilizing a shaft to drive the supercharger. The passenger side will utilize a new idler pulley and the pulley connected directly to the shaft. A longer belt will be employed.
The supercharging unit is still under debate, but a self contained unit is the most preferred. This includes the Paxton SN95 4.6L blower unit as well as the Powerdyne unit. The Paxton is good for 10psi maximum, with a HD unit availible. The HD will run up to 15psi. The regular SN95 can be upgraded to the HD unit when a stronger motor is assembled and you desire more hp. As the units are self contained, which means there are no oil lines to run to the oil pan, and no possible contamination of the oil from metal shavings often produced in a gear driven SC unit. Sean has expressed a strong desire to avoid running any oil lines. If one really wants a Vortech, maybe he can sell you everything else, and you could have a new mounting bracket made for the Vortech. The shaft will be allen keyed and locked right in to the front of the SC unit, eliminating another set of belts and pulleys.
Rounding out the kit will be all the plumbing necessary. I feel Sean's goal is to design a reliable system that will work well in everyday driving where reliability is a concern. Race upgrades will be possible, of course, and a set of guages, AFR meter, booster pump, and such can be easily added for a little more money. Whether or not Unorthodox will supply these, I don't know.
Sean estimates the HP range with 5-6psi to be anywhere from 250hp up to 280 hp.
If you're interested in the system, I'd contact unorthodox and let them know. Their phone number is (516)253-4909, and their web page is www.unorthodoxracing.com. The more interest, the more quickly things will get moving.
NOS kits are relatively inexpensive (c. $500) and provide substantial hp gains (50-75hp) for short WOT bursts. There is some fiddling with the NOS bottle required on a daily basis. You can blow up your motor with this if you make a mistake. Many people use NOS frequently without immediate engine problems.
A modded PGT with NOS has turned a 13.6 @103mph in the quarter mile. Not too shabby.
Known as putting your car "on the bottle".
See the NOS Page on this site.
MotorSports Digest Forced Induction - Supercharger, turbo/NOS primer. Apr98
Keeps inside tire from spinning under acceleration while turned. Called a "posi" rear end in old muscle cars.
Possible LSD source for PGT: Melissa Dunn Adelaide Jap Dismantlers www.adelaidejap.com.au adeljap@cobweb.com.au Ph) 61 + 8) 8369 1156 Fax) 61 + 8) 8369 1194 We have the diff centres in stock but what ratio do you need. The crown wheel is riveted to the diff centre and while it can be changed, it can be fiddly. We sell the centres for AUS$200. The exchange rate is AUS$0.61c=US$1
The stock Mazda LSD is a 20/80 mechanical clutch system. Only 20% of the power will go to the wheel with the most traction when the other wheel slips. If you've driven a FWD car with a LSD you will quickly realize why the split is so low. In the hand of even a reasonably skilled performance driver, sudden torque steer is a strong possibility which can lead to loss of control of the car. Litigation being what it is in America this is one reason why OEMs will not sell an LSD as an option in the US. The only exception to this rule was Nissan for a few years. The LSDs made by Cusco or KAAZ are a much better if you are considering power levels over 350hp at the wheels. The KAAZ unit has withstood the power from a 589hp twin turbo 2.0L V-6 in a friend's Xedo6. BTW the crown wheel is the differential ring gear and pinion set to you Yanks.
See the new KLZE Page.
The Bay Area Probe Owners Club does not endorse or avoid any specific automotive business or product. Use this information and these links at your own risk. I may post parts of email messages I receive. If the author objects to this policy, I will re-edit or remove the text to satisfy you.
August 1998
Bay Area Probe Owners Club Website