Another suspension question
Another suspension question
I have question regarding using the d-50 springs,
I read the DQ article and everything else I could find and from what I gather a 160 lb front spring set up should match-up nicely.
My question is regarding cutting the coils ( I'm asking because I haven't dropped the rear crossmember yet ). When (if) you cut the coils do you have to cut them in one coil increments? Or can you cut a half coil? Or with the d-50 spring. If you install them "as is". How much drop can you expect to get?
The reason I'm asking is that I'm looking for a lowered stance but I don't want a pavement scraper. I also don't plan on autocrossing or racing . Just looking to firm up the suspension a bit. I'm also thinking about a 1" front swaybar
I have a set of shortened front 510 struts that I'm planning on using along with the MR2 struts.
Any thoughts would be appreciated
BP
I read the DQ article and everything else I could find and from what I gather a 160 lb front spring set up should match-up nicely.
My question is regarding cutting the coils ( I'm asking because I haven't dropped the rear crossmember yet ). When (if) you cut the coils do you have to cut them in one coil increments? Or can you cut a half coil? Or with the d-50 spring. If you install them "as is". How much drop can you expect to get?
The reason I'm asking is that I'm looking for a lowered stance but I don't want a pavement scraper. I also don't plan on autocrossing or racing . Just looking to firm up the suspension a bit. I'm also thinking about a 1" front swaybar
I have a set of shortened front 510 struts that I'm planning on using along with the MR2 struts.
Any thoughts would be appreciated
BP
1971 Datsun 510 2 door
08 VW R32
69 BSA 650 Firebird Scrambler
Too Many Bicycles
08 VW R32
69 BSA 650 Firebird Scrambler
Too Many Bicycles
Re: Another suspension question
Based on my plans for the car I think I'm going in the right direction on the suspension. I just want to make sure I'm not overlooking something really basic.
I forgot to mention that I have a set of Bryon's brackets that I will install to correct the rear alignment . And that for the time being I will be running the 13" wheel / tire combo I've shown on my thread
BP
I forgot to mention that I have a set of Bryon's brackets that I will install to correct the rear alignment . And that for the time being I will be running the 13" wheel / tire combo I've shown on my thread
BP
1971 Datsun 510 2 door
08 VW R32
69 BSA 650 Firebird Scrambler
Too Many Bicycles
08 VW R32
69 BSA 650 Firebird Scrambler
Too Many Bicycles
Re: Another suspension question
BP, I'm running the uncut, full length D50 rpings in the rear of my brown car, they are a touch too tall, I think that you can cut smaller, partial bits from the open end of the spring as you try to get the right height and stiffness as you go along. I'm going to confirm that over the next couple of weekends as I'm finally starting to work on the car again ... Got a bit of late start this year!
Jason
Re: Another suspension question
BP, you can certainly cut less than a coil off a spring. It's easier to do the math to calculate the resulting spring rate when you have integer coil numbers, but that's not really important. For the rate I quoted in the article, you'd need that particular spring and cut that one full coil. That's the only reason one coil is specified.
What you're going to want to deal with is not "how much does it lower the car" since each car is different and different mods do different things to the resulting ride height (new vs. old spring rubbers, for one example). One measurement I use to compare between cars is from the ground to the bottom of the rocker (not the vertical pinch weld) just behind the front wheel and just in front of the rear wheel. If you've seen other cars in person or on The Realm that have the ride height you're looking to emulate, you can ask what their measurements are and have something to shoot for.
You can also install the springs, then trim and reinstall the springs until you get down to what you want. Sometimes it just ends up being the way to do things, but it's a PITA for sure.
I'll look at the article to see what I said in it regarding ride height. I since modified my D50 springs to adjust the height, but I don't recall if I did that before or after I wrote the article.
What you're going to want to deal with is not "how much does it lower the car" since each car is different and different mods do different things to the resulting ride height (new vs. old spring rubbers, for one example). One measurement I use to compare between cars is from the ground to the bottom of the rocker (not the vertical pinch weld) just behind the front wheel and just in front of the rear wheel. If you've seen other cars in person or on The Realm that have the ride height you're looking to emulate, you can ask what their measurements are and have something to shoot for.
You can also install the springs, then trim and reinstall the springs until you get down to what you want. Sometimes it just ends up being the way to do things, but it's a PITA for sure.
I'll look at the article to see what I said in it regarding ride height. I since modified my D50 springs to adjust the height, but I don't recall if I did that before or after I wrote the article.
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson
Re: Another suspension question
Regarding stock ride height, what is the measurement to the bottom of the rocker at the rear for a stocker?
Jason
Re: Another suspension question
I...have no idea
The FSM suggests 190mm/7.5", but the graphic is pretty general so no idea where they're actually measuring. That sounds low to me, given how much I lowered Whitebird and it only sits 6.75" off the ground.
Alright, who still has a stock car?
The FSM suggests 190mm/7.5", but the graphic is pretty general so no idea where they're actually measuring. That sounds low to me, given how much I lowered Whitebird and it only sits 6.75" off the ground.
Alright, who still has a stock car?
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson
Re: Another suspension question
Julian,
From what I've read, it is better to have the front spring rate equal to or greater than the "effective" spring rate for the rear.
From the info in DQ. It looks like with the 160 lb springs up front I would be safe to cut up to one full coil which per the article gave you 6.75 inches clearance in the rear. PMK's car's ride height (7.5") looks about right to me. But then again I don't know his tire dia. Nor your's when you measured it.
I think my goal is to try to minimize the angle of the half shafts or to find a happy compromise. As I stated before. A good compromise between "stance" and "driveability"
Thanks for the feedback
BP
From what I've read, it is better to have the front spring rate equal to or greater than the "effective" spring rate for the rear.
From the info in DQ. It looks like with the 160 lb springs up front I would be safe to cut up to one full coil which per the article gave you 6.75 inches clearance in the rear. PMK's car's ride height (7.5") looks about right to me. But then again I don't know his tire dia. Nor your's when you measured it.
I think my goal is to try to minimize the angle of the half shafts or to find a happy compromise. As I stated before. A good compromise between "stance" and "driveability"
Thanks for the feedback
BP
1971 Datsun 510 2 door
08 VW R32
69 BSA 650 Firebird Scrambler
Too Many Bicycles
08 VW R32
69 BSA 650 Firebird Scrambler
Too Many Bicycles
Re: Another suspension question
My tires were/are 185/60/14s. Falken no longer lists that size in the 912, which I have, so I can't give you their diameter/roll-out specs.
My experience is that the rear rates want to be equal or higher than the fronts. Not too high, but 10-20in/lb stiffer seems to help remove some of the bob caused by the shorter wheelbase. For me, this was most evident on sectioned concrete (some local streets and much of the freeways are made with this). With softer rear springs the sectioning would set up a fore/aft bobbing. Stiffer rear springs (only change) made this go away.
I looked through my build pictures. I have pretty beat rubber rear spring seats, so I supplemented them with some ~1/2" spacers to get my ride height where I wanted it (level front to rear). YMMV on the fine tuning of ride height. It is possible duplicating my springs will give a lower ride height. Nothing that can't be adjusted, but I was aiming for the correct rate first, then dealing with ride height second.
My experience is that the rear rates want to be equal or higher than the fronts. Not too high, but 10-20in/lb stiffer seems to help remove some of the bob caused by the shorter wheelbase. For me, this was most evident on sectioned concrete (some local streets and much of the freeways are made with this). With softer rear springs the sectioning would set up a fore/aft bobbing. Stiffer rear springs (only change) made this go away.
I looked through my build pictures. I have pretty beat rubber rear spring seats, so I supplemented them with some ~1/2" spacers to get my ride height where I wanted it (level front to rear). YMMV on the fine tuning of ride height. It is possible duplicating my springs will give a lower ride height. Nothing that can't be adjusted, but I was aiming for the correct rate first, then dealing with ride height second.
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson
- StrutlessWonder
- Supporter
- Posts: 334
- Joined: 03 Mar 2012 12:59
- Location: Menlo Park, CA
Re: Another suspension question
Because of the 3.8:1 ratio of the rear control arms, a little cut in spring length can have a huge impact of rear ride height.
If spring rates were in the ballpark, I'd only cut little bits off at a time and reinstall and re-check.
But remember, you are trying to achieve parity in wheel rates, so Julian's "get the right rate 1st, adjust the height 2nd" is the correct approach. But without coilovers, adjusting the rear ride height with shims is a PITA. Also remember that any change in ride height will change your corner weights, F:R weights and cross weights, etc.
If you really want to go nuts, find your car's magic number by using some version of a weight transfer worksheet to get some real data:
http://www.racing-car-technology.com.au ... ksheet.htm
http://www.smithees-racetech.com.au/wtt ... sheet.html
http://www.locost7.info/files/suspensio ... dsheet.xls
Good data is good, more good data is better
If spring rates were in the ballpark, I'd only cut little bits off at a time and reinstall and re-check.
But remember, you are trying to achieve parity in wheel rates, so Julian's "get the right rate 1st, adjust the height 2nd" is the correct approach. But without coilovers, adjusting the rear ride height with shims is a PITA. Also remember that any change in ride height will change your corner weights, F:R weights and cross weights, etc.
If you really want to go nuts, find your car's magic number by using some version of a weight transfer worksheet to get some real data:
http://www.racing-car-technology.com.au ... ksheet.htm
http://www.smithees-racetech.com.au/wtt ... sheet.html
http://www.locost7.info/files/suspensio ... dsheet.xls
Good data is good, more good data is better
Kurt Hafer
'70 2dr VG30et "Strutless Wonder"
'70 2dr VG30et "Strutless Wonder"
- PoorMtnKid
- Supporter
- Posts: 1219
- Joined: 28 Aug 2010 14:43
- Location: Las Vegas NV
Re: Another suspension question
Im running 205-50-15 Nitto NT01Bike papa wrote: PMK's car's ride height (7.5") looks about right to me. But then again I don't know his tire dia.
looking for pass. side arm rest
Re: Another suspension question
I have 8.5" on both sides at the rear. About 8.25" at the front. Running 175/70r/13 Falkens. All stock AFAIK.
Finished is better than perfect......
Re: Another suspension question
Thanks James, my stocker is sitting at 8" front and rear on 175/70/13's. I'm guessing the springs and shocks are a bit tired, guess I'll be replacing the rears first as I have new stuff for that ....
Jason
Re: Another suspension question
On a '70 tudor I 165/80/13s they are 23 1/2" in diameter. I have 9 1/4" to the rocker on all 4 corners.
ice D
ice D