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  • Probe hybrid race setup? (suspension)

    Hello Guru's. So got second in class and 12th overall in the roadrace last weekend!
    The LSD worked great but the inside wheel was lifting and spinning on about 50% of the corners but a lot less than the open diff. Consensus on the team is we need a rear bar and a lighter front bar. The car now has excellent balance though and i am thankful for that cause i went in too hot in turn one and was at about a ten degrees off axis angle through the corner at 90 mph. The car felt under control though but it took a half a lap to start breathing again. Hesitant to just remove the front bar. So i need to get another one that is lighter or find a way to depower this one (95 probe) Is there a lighter bar for the front like from a 4 cylinder model? Hydro

  • #2
    if you haven't changed the rear bar (it was 12mm stock) to at least a 16mm (found on the 00+ 626) there is no reason to bother with the front. There are some aftermarket rear bars (addco and someone else) in the 21-22mm range.
    '94 teal w/black int. some sort of sts, 65mm DE TB full KL31 ZE, CAI, Phenolyc spacers, mx3 flywheel, pacesetter headers, 2.5" exhaust, stainless brake lines, MS and LC-1. Charter member Club 15.2 - Mustang Dyno - 187/169 @the wheels
    '90 White GT "Pearl"....uh ohzzzz...I had turboz. Now with T3....now it's J-doggs
    '96 SE & '93 "Red-Eye" smashed and trashed. 97 GTS....crashed, not trashed yet

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    • #3
      Hello. No rear bar in the car now. Car is half austin 1800 and ford probe gt from firewall fwd. no rear sway bar will have to make one. looking around i see that the MX6 front bar is smaller but i can't find any info on how much smaller. Hydro

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      • #4
        I think you would do much better making a rear bar work somehow!
        Success is a measure of determination!
        Bonneville Dreamer-(AKA Purple Pimp Mobile)
        $500 Gas-Electric-Gas Reconversion/Restoration
        Mini-me & 500k "Old Gal" RIP
        Restoration of a legend

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        • #5
          Thanks for the reply back KLZE. I have a lot of respect for you and thank you for the info you have so freely given in the past. Yes a couple of the other members are engineers (one rocket and one mechanical) in a way thats good but in building the car one would have had the body in pressed aluminum with a titanium suspension!! you get the idea. But preliminary design is one out of a solid 3/4 4130 bar bent hot and heat treated at Seattle heat treat. Adjustable holes at 1.5 intervals. The front bar could be replaced with the mx6 but only if it is worthwhile But it is clear to me that the body roll is causing the inside wheel to lift. One of the mods i will be doing is lowering the car an inch cause the 300 lbs front springs i put in last year made the car 2" higher than last year. last year the problem was the same so it does not seem to be center of gravity that is causing the inside wheel to lift it seems to be the sway bar is pulling it up. Hydro

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          • #6
            When I used to race long ago -I always had problems with inside wheels lifting. The answer was sticker tires on the other three! It is not uncommon to have an inside tire lift. My theory is that if you have inside air -you are doing something right. I have a couple of photos of KL track cars with inside tires catching air. One is a professional team with big dollar sponsorship. I believe it is a Telstar and I can't remember if it was in Aus or NZ. But I believe it was one of the two.
            Last edited by KLZE Porsche; June 11, 2015, 09:21 PM.
            Success is a measure of determination!
            Bonneville Dreamer-(AKA Purple Pimp Mobile)
            $500 Gas-Electric-Gas Reconversion/Restoration
            Mini-me & 500k "Old Gal" RIP
            Restoration of a legend

            Comment


            • #7
              you're lifting the inside FRONT tire?

              i don't even know how you're managing that. inside rear tire, yeah, that's easy.

              regardless, you can get a smaller front bar off of the base 4 cyl.

              http://www.performanceprobe.com/index2.php


              only problem being, i think you've pretty much got to pull the whole front end off to swap that bar out.

              i'd try disconnecting one of the front sway bar links and seeing how the car drove on a test run before i went crazy trying to change the FSB.

              i'm assuming you've got a push? the cheapo rear bar option is the 626 bar.

              the rule of thumb is, more bar will make that end of the car slide more. because you're transferring more weight to the outside tire and over loading it faster.





              cause the 300 lbs front springs i put in last year made the car 2" higher than last year.

              you didn't size those springs properly.

              given that you're now going to go to the hassle and expense of lowering the car, just look into getting proper height springs and killing two birds with one stone.




              so it does not seem to be center of gravity that is causing the inside wheel to lift


              how in the hell can raising the ride height 2 fricking inches NOT be affecting Moment Center / CG?

              i never picked the LF front up on the *stock* GT springs. you should be getting LESS body roll out of springs that have a rate almost double OEM.

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              • #8
                Originally posted by bob k. mando View Post
                how in the hell can raising the ride height 2 fricking inches NOT be affecting Moment Center / CG?
                ^^^Agreed! 2" really makes a difference -even if you haven't perceived it. When I raced -yes I lifted wheels -but my CG was also very low. With the ride height the way it was -the camber was much better for grip in turns.

                Perhaps you might consider lowering and camber adjustable arms if they are possible on your car? Oh -and I experimented a lot with tire compounds until I found a tire that gripped well with my setup. But this all may be stuff you have tried. A rear sway bar can help keep the front inside tire from lifting.
                Last edited by KLZE Porsche; June 12, 2015, 04:20 AM.
                Success is a measure of determination!
                Bonneville Dreamer-(AKA Purple Pimp Mobile)
                $500 Gas-Electric-Gas Reconversion/Restoration
                Mini-me & 500k "Old Gal" RIP
                Restoration of a legend

                Comment


                • #9
                  just noticed that the frames programming screwed up my intended link

                  here's the proper link for 1989-97 suspension specs
                  http://www.performanceprobe.com/inde.../table_sus.htm



                  ^^^Agreed!



                  this actually reminds me of the guy who was asking why his car wouldn't handle ... and then we found out he was running one tire that was an inch shorter than the other three.

                  well, duh, that's going to screw your cross weight distribution all to hell. and give you opposite problems depending on which way you're turning.

                  the first thing you do with ANY car is to make sure that the suspension is straight and within spec. THEN you can start playing around with modifications AFTER you have established your baseline.



                  Car is half austin 1800 and ford probe gt from firewall fwd.

                  so you're saying this is an Austin 1800 with a Probe front clip?
                  https://en.wikipedia.org/wiki/BMC_ADO17

                  since the 300lb springs you've got are too tall, you do have another option:
                  IF you would like to try even stiffer springs yet THEN you could cut +2" of spring out of the coils.

                  i'd use a sawzall in an oil bath because you don't want to heat the spring up. heating the spring changes the temper and thus the spring rate. and it's very hard to get that consistent between the two springs you have to cut.

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                  • #10
                    sorry I am late

                    http://imgur.com/wKxyWYe

                    http://imgur.com/f1Ouxj0
                    I've Been Probed.

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                    • #11
                      300 lbs spring sounds pretty light.. what's the complete car and suspension set up?

                      For my autocross 323 (same basic suspension design as the probe) I run an 800lbs front spring 600ish rear spring..

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                      • #12
                        OMG. Get a rear bar on it yesterday, like MEOW!!

                        And more spring rate. Like the Canuk said, stiff, teh autox car is 12k/10k, stock front bar, addco rear bar...22 or 21mm, can't remember which.

                        Road race application could probably go stiffer.
                        Ryan
                        '94 Mazda MX6 V-6
                        SMF Prep:
                        MFactory LSD [] TEIN [] 15x11's and 275 Hoosiers [] Hawk HP+ [] Sparco [] AWR [] HotShot [] Headers [] Magnaflow [] Side Exit []

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                        • #13
                          Originally posted by dillinr View Post
                          OMG. Get a rear bar on it yesterday, like MEOW!!

                          And more spring rate. Like the Canuk said, stiff, teh autox car is 12k/10k, stock front bar, addco rear bar...22 or 21mm, can't remember which.

                          Road race application could probably go stiffer.
                          Rates would depends on weight balance. . I am curious what a probe/mx6/626 would come in at..

                          My 323 is 730ish front 300ish rear.. to get the exact numbers I'd have to talk to my codriver...

                          Dillinr have you have made it to any of the national tour events? It'd be fun to pit our cars against one another.

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                          • #14
                            Ask and he shall receive. This was from before Street Mod days, car is around 150lbs lighter now, but you get the idea:
                            http://www.mx6.com/forums/2g-mx6-gen...r-weights.html

                            LF 907 RF 863
                            LR 498 RR 467

                            IIRC according to the maths the Nf is a little soft in front still, somewhere around 1.9f 2.3r, but not sure the Teins will like much stiffer, and with only single adjustable suckage, not sure if jumping up to 14k will be so great for damping.

                            Next national event is in my backyard, Farmington Utah st Farmington Utah match tour, pie in the sky chance I'll make it to the big show this year though.
                            Ryan
                            '94 Mazda MX6 V-6
                            SMF Prep:
                            MFactory LSD [] TEIN [] 15x11's and 275 Hoosiers [] Hawk HP+ [] Sparco [] AWR [] HotShot [] Headers [] Magnaflow [] Side Exit []

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                            • #15
                              Hello guys. Sorry for the thread resurrection but i did not want to start over. Did not race the 1800 last year but its still the favorite car of the team. Just moving it in the the shop to start getting it ready for a race in April. So to remind everyone this is a hybrid car and the body is 1970 austin 1800 with a 1995 ford probe gt front clip welded to the car and 1800 fenders so it looks like a 1800 but runs like the probe GT. So far have done the external coil mod on the engine. Mazda 6 brakes. Also put a lsd in the transaxle. Doubled the front springs Still front wheel spin in the corners is a problem. Our engineer says we have to lower the swaybar rate in the front. So a shout out for anyone with a base probe (4cyl) front swaybar.
                              We also have a aggressive plan for the rear, currently running the stock Hydrolastic (google it). there is no shock and is a trailing arm type. What we are planning to do is add a adjustable shock. Increase the hydro pressure and lower the car by shortening the rod. Custom rear sway bar is also being made (solid 4130 rod)
                              I wanted to megasquirt the engine and install a set of colt race cams but i did not get the cams ordered in time.
                              http://s1346.photobucket.com/user/Hy...e%202nd%20year

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