spydur
07-19-2008, 05:47 PM
I have recently purchased a set of Tokico D Spec's, a set of Progress Progressive Sport Springs and a Progress Alignment Kit for my stock 04 Si (I had also purchased an Energy Suspension Master Bushing Set, but I decided to return it since my car only has 21K on the clock and I learned of the equipment necessary and challenges one can encounter when removing the original bushings). I thought I had worked out a deal to participate in a Saturday installation of the struts, springs and alignment kit at my mechanic's facility, but it looks like liability exposure concerns have stopped that. My mechanic would be happy to install these components during normal working hours at their normal rate (approximately $400 + alignment costs). Being a "Do It Yourselfer", I thought of the DIY threads posted on EPhatch, ClubEP3, K20a.org and HondaTech, I found two strut and spring installation how to's. I then posted a thread last week on EPhatch in which I was basicly asking if it was feasible for me to install these suspension parts in my own garage (thanks to those of you who took the time to share your personal expertise and experiences in your responses).
My car is a DD and occasional autocrosser so I want to install suspension components that will improve the stock handling (improving the appearance by lowering the car is a secondary benefit). I chose Progress Springs do to their fine reputation and historical experience of working with HONDA on suspension components for new HONDA models. I also liked the fact that their springs are progressive and the drop is what I considered to be "reasonable".
While doing my research through Ephatch and other various information sources, I came across some information that concerns me. I read about the challenges that one is confronted with when modifying a McPhersion Strut suspension on a front wheel drive car. More specifically, I read several informative threads on EP3 suspension tuning by MUSTCLIME[/FONT
Direct quotes from one of his treads is:
"The suspension design is greatly effected by ride height....as you lower the suspension the LCA (lower control arm) goes flat and then past one inch of drop it starts to angle up. This is very bad for the suspension when you you look at the side loads (cornering forces). If the LCA is angled up and the weight of the car pushing sideways while the tire is trying to stick to the road, this force will "tend" to push the LCA up more and cause the suspension to blow through its travel. If the LCA is flat or angled down, the cornering loads are directed down the LCA in to the sub frame."
"If you have the HFP suspension, that is a great set up. Because of our suspension design, dropping the EP more than an inch kills handling. Once the front LCA's get past flat (one inch drop), cornering loads push the suspension through its travel and you end up ridding on your bump stops through the turns... Iam sure there will be a couple people telling you that they have a 1.5" to 2.0" drop and their car rails the turns... trust me, take them to an auto-x and watch their cars through the turns. The front suspension will just tuck under and they will have a bunch of understeer."
"If you are just DD your car, here is my advise.... keep your HFP suspension, add some crash bolts in the front and add as much negative camber as you can in te front with about 1/32" toe out in the front.... use 0 toe in the rear. If you really want the car to rail the turns change out the suspension bushings with a energy suspension bushing kit. The stock bushing are very soft , the front LCA bushings are designed to effect toe when cornering.... this sucks unless you are a grandma..... bushing changes are hugh pia and no one can see it,.... but it is one of the biggest changes you can do to your suspension."
BASICALLY HE IS SAYING - IF YOU INSTALL SPRINGS THAT LOWERS AN EP3 MORE THAN ONE INCH IN THE FRONT YOU ARE DECREASING RATHER THAN INCREASING THE HANDLING OF YOUR CAR AS THE LOWER YOU GO, THE MORE YOU INCREASE UNDERSTEER AND HARM HANDLING. IF THIS IS TRUE, THEN THE PROGRESS SPRINGS WHICH LOWER THE EP3 1.8" IN THE FRONT AND 1.5" IN THE BACK WILL [FONT="Arial Black"]DECREASE RATHER THAN INCREASE THE HANDLING OF OUR CARS. IF MUSTCLIME'S THESIS IS CORRECT THEN, I DO NOT WANT TO INSTALL ANY SPRINGS ON MY CAR THAT LOWERS IT MORE THAN ONE INCH! (THEREBY ELIMINATING NOT ONLY THE PROGRESS SPRINGS BUT APPROXIMATELY 85% OF THE SPRING SETS AVAILABLE FOR OUR CAR. THE SUSPENSION STICKY LISTS DROP MEASUREMENTS FOR 14 DIFFERENT SPRING SETS, ONLY 2 ARE LESS THAN 1.0", 3 ARE BETWEEN 1.0" & 1.5" AND 9 ARE 1.5"+, THIS DOES NOT INCLUDE HFP OR MUGEN SPRING/STRUT COMBINATIONS). I DON'T QUESTION MUSTCLIMES THESIS BUT I FIND IT INTERESTING THAT PROGRESS AND SEVERAL OTHER SPRING MANUFACTURES WHOULD PRODUCE A PRODUCT THAT DETRAMENTALLY IMPACTS THE HANDLING OF OUR CAR, BUT THEN SHOW (LOWERING) MAY BE MORE IMPORTANT THAN GO (HANDLING) AND IN BUSINESS THE MARKETING DEPARTMENT HAS MORE SAY THAN THE ENGINEERING DEPARTMENT $$$$$$$$$$$$$$$ !
SO;
(1) HAVE ANY OF YOU WHO HAVE INSTALLED PROGRESS SPRINGS ON YOUR EP3 EXPERIENCED INCREASED UNDERSTEER AND BUMPSTEER (PLEASE MAKE SURE YOUR NOT CONFUSING BETTER FEEL WITH BETTER HANDLING)?
(2) IF YOU HAD IT TO DO OVER AGAIN, WOULD YOU BUY PROGRESS SPRINGS AGAIN FOR PRIMARILY PERFORMANCE REASONS?
My car is a DD and occasional autocrosser so I want to install suspension components that will improve the stock handling (improving the appearance by lowering the car is a secondary benefit). I chose Progress Springs do to their fine reputation and historical experience of working with HONDA on suspension components for new HONDA models. I also liked the fact that their springs are progressive and the drop is what I considered to be "reasonable".
While doing my research through Ephatch and other various information sources, I came across some information that concerns me. I read about the challenges that one is confronted with when modifying a McPhersion Strut suspension on a front wheel drive car. More specifically, I read several informative threads on EP3 suspension tuning by MUSTCLIME[/FONT
Direct quotes from one of his treads is:
"The suspension design is greatly effected by ride height....as you lower the suspension the LCA (lower control arm) goes flat and then past one inch of drop it starts to angle up. This is very bad for the suspension when you you look at the side loads (cornering forces). If the LCA is angled up and the weight of the car pushing sideways while the tire is trying to stick to the road, this force will "tend" to push the LCA up more and cause the suspension to blow through its travel. If the LCA is flat or angled down, the cornering loads are directed down the LCA in to the sub frame."
"If you have the HFP suspension, that is a great set up. Because of our suspension design, dropping the EP more than an inch kills handling. Once the front LCA's get past flat (one inch drop), cornering loads push the suspension through its travel and you end up ridding on your bump stops through the turns... Iam sure there will be a couple people telling you that they have a 1.5" to 2.0" drop and their car rails the turns... trust me, take them to an auto-x and watch their cars through the turns. The front suspension will just tuck under and they will have a bunch of understeer."
"If you are just DD your car, here is my advise.... keep your HFP suspension, add some crash bolts in the front and add as much negative camber as you can in te front with about 1/32" toe out in the front.... use 0 toe in the rear. If you really want the car to rail the turns change out the suspension bushings with a energy suspension bushing kit. The stock bushing are very soft , the front LCA bushings are designed to effect toe when cornering.... this sucks unless you are a grandma..... bushing changes are hugh pia and no one can see it,.... but it is one of the biggest changes you can do to your suspension."
BASICALLY HE IS SAYING - IF YOU INSTALL SPRINGS THAT LOWERS AN EP3 MORE THAN ONE INCH IN THE FRONT YOU ARE DECREASING RATHER THAN INCREASING THE HANDLING OF YOUR CAR AS THE LOWER YOU GO, THE MORE YOU INCREASE UNDERSTEER AND HARM HANDLING. IF THIS IS TRUE, THEN THE PROGRESS SPRINGS WHICH LOWER THE EP3 1.8" IN THE FRONT AND 1.5" IN THE BACK WILL [FONT="Arial Black"]DECREASE RATHER THAN INCREASE THE HANDLING OF OUR CARS. IF MUSTCLIME'S THESIS IS CORRECT THEN, I DO NOT WANT TO INSTALL ANY SPRINGS ON MY CAR THAT LOWERS IT MORE THAN ONE INCH! (THEREBY ELIMINATING NOT ONLY THE PROGRESS SPRINGS BUT APPROXIMATELY 85% OF THE SPRING SETS AVAILABLE FOR OUR CAR. THE SUSPENSION STICKY LISTS DROP MEASUREMENTS FOR 14 DIFFERENT SPRING SETS, ONLY 2 ARE LESS THAN 1.0", 3 ARE BETWEEN 1.0" & 1.5" AND 9 ARE 1.5"+, THIS DOES NOT INCLUDE HFP OR MUGEN SPRING/STRUT COMBINATIONS). I DON'T QUESTION MUSTCLIMES THESIS BUT I FIND IT INTERESTING THAT PROGRESS AND SEVERAL OTHER SPRING MANUFACTURES WHOULD PRODUCE A PRODUCT THAT DETRAMENTALLY IMPACTS THE HANDLING OF OUR CAR, BUT THEN SHOW (LOWERING) MAY BE MORE IMPORTANT THAN GO (HANDLING) AND IN BUSINESS THE MARKETING DEPARTMENT HAS MORE SAY THAN THE ENGINEERING DEPARTMENT $$$$$$$$$$$$$$$ !
SO;
(1) HAVE ANY OF YOU WHO HAVE INSTALLED PROGRESS SPRINGS ON YOUR EP3 EXPERIENCED INCREASED UNDERSTEER AND BUMPSTEER (PLEASE MAKE SURE YOUR NOT CONFUSING BETTER FEEL WITH BETTER HANDLING)?
(2) IF YOU HAD IT TO DO OVER AGAIN, WOULD YOU BUY PROGRESS SPRINGS AGAIN FOR PRIMARILY PERFORMANCE REASONS?