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    Results 1 to 5 of 5
    1. #1
      Join Date
      Aug 2015
      Location
      NJ
      Posts
      282
      Country Flag: United States

      Martz Chassis subframe, 4-link and components praise

      I just wanted to take a minute and say that these forums are a great place for knowledge, but you guys scared the crap out of me with some of the bad posts I read about Martz Chassis on here. I originally priced out complete PT kits from Art Morrison, Chris Alston, Detroit Speed and ridetech for my '68 Camaro and made my decision to go with Martz only because he spent the time with me on the phone to answer all of my questions. Gary(the owner) also told me where to spend $ for better parts and where to save $ which went a long way in my book especially being that I was a newbie and could have sold me the world. He is a great guy and I could tell he is in the business for the love of cars and hot rodding. I went with his front subframe, tubular a-arms, power R&P, frame connectors, 4-link set-up with a 9" rear, mini tubs and rear frame rail notching kit. We added Wilwood brakes front and rear and QA1 coil overs. Fast forward to the present, My car is now on the street, handles absolutely incredible and I couldn't be any happier! For all the money I have into it it should, but not kidding at all when I say this rides better than my 2018 Silverado(I know car vs truck, but just making a point that I never expected a 50 year old car to outride a brand new vehicle of any type). I was also very surprised at the ride with the low profile Proxy's on there and speaking of stick to the road like glue! Also super happy with the handling - the back roads around here are ever-windy and fun if you have the right vehicle/motorcycle. Will I be taking it to the autox track? - probably not so this is not a review for the hardcore track guys since I have no knowledge of that. It will however hit the drag strip occasionally to see what it can do. Just my review for what it's worth.
      '68 Chevy Camaro Pro-tour ~ project DMENTD
      '57 Chevy 3100 Pro-tour pickup ~ under construction

    2. #2
      Join Date
      Apr 2001
      Location
      Central CA USA
      Posts
      6,108
      Country Flag: United States
      Can you post some photos of the front sub and rear suspension?
      I'd like to see if they've improved it from the earlier version we didn't like. We tried to tell them what was wrong with it years ago, but didn't make much progress. steve chryssos had to re-engineer his front sub to make the car corner very well.
      67 Camaro RS that will be faster than anything Mary owns.

    3. #3
      Join Date
      Aug 2015
      Location
      NJ
      Posts
      282
      Country Flag: United States
      Quote Originally Posted by David Pozzi View Post
      Can you post some photos of the front sub and rear suspension?
      I'd like to see if they've improved it from the earlier version we didn't like. We tried to tell them what was wrong with it years ago, but didn't make much progress. steve chryssos had to re-engineer his front sub to make the car corner very well.
      Here you go.
      Attached Images Attached Images          
      '68 Chevy Camaro Pro-tour ~ project DMENTD
      '57 Chevy 3100 Pro-tour pickup ~ under construction

    4. #4
      Join Date
      Apr 2001
      Location
      Central CA USA
      Posts
      6,108
      Country Flag: United States
      Thanks for the photos. They haven't changed as far as I can see.
      I'd like to see them box in the center crossmember. That would add a lot of torsional strength to the sub. It looks like they have fairly thick steel in that crossmember but if it's not boxed it can still twist & flex. The down tubes help, but they would help twice as much if you added an "A" shaped brace over the upper A arm, adding some triangulation. The attachment of the down tube ends are not great. The front attachment has a flexible flat plate to the bolt hole which is going to reduce rigidity. It would be better to weld or bolt the tubes directly to the frame rails.

      If the front frame rails are 3" height, then they are skimpy. If they are 4" height they are OK. It's hard to tell from the photos. I can't tell if the suspension geometry is good or not but the outer tie rod ends are inboard more than they should be for proper Ackerman. The front tires will be pushing against each other in a tight turn ( too much toe in during turns). This sub looks like more of a drag race type sub than a handling sub. It is probably nice cruising on the street, just not as good for handling as it could be. Do not run the car with inner wheelwells removed. You will lose a huge amount of torsional rigidity. The fenders & sheetmetal support the front suspension & torsionally contribute as much strength as the subframe.

      The rear is a drag race oriented design, OK for going straight and mild cornering. The rear side view shows the trailing links converging towards the front. This is good for drag launching (antisquat) but tends to bind up in cornering at the limit. It hurts rear traction out of corners when the car is in roll and rear squat under power making the inside tire lift. The panhard bar again is a drag race design. If cornered hard, there is a lot of tension/compression happening on that link and I'd watch it carefully for wear of the rod ends & brackets. A car set up for cornering will have the panhard bar attached directly to the rear axle and adjustable for height to tune the handling. Yours is very low so it's not adding much rear roll stiffness.

      Customers seem to be happy with this sub and it's ok for what you are doing with it, but for Pro-Touring quality handling, it needs improvement.
      It's good to hear its working well for you. Not everyone is after that last couple of seconds on the track.
      Last edited by David Pozzi; 08-31-2018 at 03:05 PM.
      67 Camaro RS that will be faster than anything Mary owns.

    5. #5
      Join Date
      Aug 2015
      Location
      NJ
      Posts
      282
      Country Flag: United States
      Quote Originally Posted by David Pozzi View Post
      Thanks for the photos. They haven't changed as far as I can see.
      I'd like to see them box in the center crossmember. That would add a lot of torsional strength to the sub. It looks like they have fairly thick steel in that crossmember but if it's not boxed it can still twist & flex. The down tubes help, but they would help twice as much if you added an "A" shaped brace over the upper A arm, adding some triangulation. The attachment of the down tube ends are not great. The front attachment has a flexible flat plate to the bolt hole which is going to reduce rigidity. It would be better to weld or bolt the tubes directly to the frame rails.

      If the front frame rails are 3" height, then they are skimpy. If they are 4" height they are OK. It's hard to tell from the photos. I can't tell if the suspension geometry is good or not but the outer tie rod ends are inboard more than they should be for proper Ackerman. The front tires will be pushing against each other in a tight turn ( too much toe in during turns). This sub looks like more of a drag race type sub than a handling sub. It is probably nice cruising on the street, just not as good for handling as it could be. Do not run the car with inner wheelwells removed. You will lose a huge amount of torsional rigidity. The fenders & sheetmetal support the front suspension & torsionally contribute as much strength as the subframe.

      The rear is a drag race oriented design, OK for going straight and mild cornering. The rear side view shows the trailing links converging towards the front. This is good for drag launching (antisquat) but tends to bind up in cornering at the limit. It hurts rear traction out of corners when the car is in roll and rear squat under power making the inside tire lift. The panhard bar again is a drag race design. If cornered hard, there is a lot of tension/compression happening on that link and I'd watch it carefully for wear of the rod ends & brackets. A car set up for cornering will have the panhard bar attached directly to the rear axle and adjustable for height to tune the handling. Yours is very low so it's not adding much rear roll stiffness.

      Customers seem to be happy with this sub and it's ok for what you are doing with it, but for Pro-Touring quality handling, it needs improvement.
      It's good to hear its working well for you. Not everyone is after that last couple of seconds on the track.

      The sub-frame crossmember is totally boxed in now. I guess they changed that.



      I am aware welding the downtubes will make it much stiffer, but again, this is not or will ever be a track car and I personally am happy with the fact that they can be removed if I ever needed to easily.

      Front frame rails are still 3" thick. When I originally spoke with Gary, I told him I wanted the car to handle great on the roads as a driver and still wanted to be able to take it to the track to run the 1/4 every now and then.

      Mild cornering? you mean like a street handling? I am fine with that.

      I will be sure to keep an eye on the panhard bar ends and brackets - thanks for the heads up!
      '68 Chevy Camaro Pro-tour ~ project DMENTD
      '57 Chevy 3100 Pro-tour pickup ~ under construction






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