• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

LS 240 Front Spring Rate

stevE85

stevE85

Formerly 1983_242
Joined
Mar 11, 2011
Location
Benicia, CA
I'm at the final stages of my 244 conversion. Combo is L33(Alum. block 5.3L), 7675 Turbo, T56. Car has PS only. So, my question is for those of you with similar combos/front weight is what spring rate makes for a good performance street feel? I have 300/lbx10" now, and it's pretty soft. Thinking a 350-400 might be better suited. Thoughts/suggestions? Car has revalved Bilstein short struts with 2.5" coil over springs.

I should also note I have about 1.5" of spring preload now.
 
Curious for knowledgable responses to this.

My very rough impressions, after pulling my 16VT/T5 drivetrain and sticking in an LH8 (alu Gen4 5.3)/CD009 is that so far, I think it's sitting a little higher in the front than it was. It's still missing some parts (radiator, mostly).

I wish I'd bothered to get a hoist scale when I was hauling the engine/trans in and out and about so I could put firm numbers on it.
 
Last edited:
I'm running short strut coilovers on mine with bilstien hds, I'm running a 400x9inch spring in the front and it feels pretty damn good. However, I'm lifting the car back up and getting rid of that setup here soon.
 
With my lm7 Im back to running 350lb x 10" almost compressed. Running Gaz front struts from Yoshifab, Ride is fairly good.
 
Thanks for the replies, just ordered some 375lb x 10's. I split the difference. I'll report back once I swap the springs in and recheck front ride height. I measured my current sag at 1.75-2" with the 300lb spring preloaded 1.5" as stated earlier. Hoping for only 1" sag with the 375's.
 
So, after driving the car a thousand miles or so now, I wish I'd have gone with a 350lb. Main reason being that the roads I drive regularly are absolute junk. With that said, The 375lb's are very fun on a nice smooth surface, and are definitely a good performance/street balance (for LS swapped cars).
 
stevE85 said:
So, after driving the car a thousand miles or so now, I wish I'd have gone with a 350lb. Main reason being that the roads I drive regularly are absolute junk. With that said, The 375lb's are very fun on a nice smooth surface, and are definitely a good performance/street balance (for LS swapped cars).
Click to expand...

I hate my 350lb. Im going down to a 200lb. The Lm7 is maybe 100lb heavier than the redblock.
 
Also very interested in this. I have JRZ Pro coilovers to install, I received the front ones, awaiting the rears. Ben recommended and included 300 lb springs on my fronts (engine is the same as OP, L33 5.3L). The roads around here are incredibly poor...
 
Texas240 said:
I hate my 350lb. Im going down to a 200lb. The Lm7 is maybe 100lb heavier than the redblock.
Click to expand...

Are they 350x10? I have an L33 in mine, I might have to try my 300lb's again before buying yet another set. I'll just have to preload the hell out of them to get my ride height up though. I assume you will be preloading your 200lb springs quite a distance. Are you going to a taller spring when you drop the spring rate that much?
 
stevE85 said:
Are they 350x10? I have an L33 in mine, I might have to try my 300lb's again before buying yet another set. I'll just have to preload the hell out of them to get my ride height up though. I assume you will be preloading your 200lb springs quite a distance. Are you going to a taller spring when you drop the spring rate that much?
Click to expand...

I was really vague. What I have now is 10" preloaded, ride height is pretty damn close to stock now. Im not like the "stance" but the roads are crap here in dallas and pot holes are like lakes here. I would go to a 12-13" next time. I remember my car back in cali 11 years ago with chopped stock springs and billys road rather nice and tight around corners but irvine had great roads.

Im also getting of my gaz and going back to a billy.
 
I have 250 lb. 8” coilover springs in the front with a little Eibach flat spring to keep them tensioned at full extension. I have an aluminum block 5.3 with a T56. I am happy with the ride and cornering. I use 28/25 Ipd sways and 250 lb 10” springs with BNE adjustable perches in the rear.
 
Last edited:
I have to give BNE credit for the coilover setup. He cut and rethreaded my front strut tubes. If anybody is thinking about front coilovers, this is the way to go. No warping of the tubes from welding. I used the RSI revalved Saab inserts and installed the roll center correctors. I have adjustable camber plates that I got from somebody on the board, I don't remember who.
I think the aluminum block saves a lot of weight up front but is offset by the T56-that thing is huge and heavy, so probably negates the weight savings on the front but moves it more rearward, so overall balance is better.
 
MikeSr. said:
I have 250 lb. 8? coilover springs in the front with a little Eibach flat spring to keep them tensioned at full extension. I have an aluminum block 5.3 with a T56. I am happy with the ride and cornering. I use 28/25 Ipd sways and 250 lb 10? springs with BNE adjustable perches in the rear.
Click to expand...

I am wondering how much of an effect your front sway bar is having with your combination. I have 25/25 bars, 375-F/250-R, L33/T56/7875/Intercooler, but with 300's in front my nose would sag really badly. I'm seriously considering swapping back to them and trying to get closer to 2.5-3" of spring preload. (Maybe I was just a wimp last time I preloaded them.)

If you have tender springs with 250lb springs, are you running no preload at all on the spring? Are you on the very soft ride side of the ride-spectrum?
 
I didn't pay attention to the amount of preload. I used the small helper springs and adjusted the ride height to where I wanted it. Ride is firm, but not harsh. I had it lower, but raised it a little and I am pleased with the feel. May have too much bar in the rear, but it's not objectionable. I have some 15"x7" BBS with 225/50s I want to try. I couldn't use them because my oil pan and downpipes were< 2" off the ground. I solved the oil pan problem with a Poor Man's Motorsport Holley knock off pan. I cracked my Hummer H3 pan coming off the dolly after the dyno session. The new pan is higher than the crossmember. Just need to take 2" out of the downpipes and with the 15's I think I can drop the front another inch or so. Gotta have roll center correction or the rack looks like it's flying,LOL.
 
I would always keep preload to a minimum if any at all.

Runny 400lbs front springs I can still take speed bumps at 40MPH and be fairly smooth and driving quick down rough farm tracks is no problem
 
With the stock bilstein HD's up front, I can only handle 200's and this is with the v8. Anything more feels like it's a jackhammer. Suppose the spring rate is totally dependent on the type of dampers one has.
 
Texas240 said:
I was really vague. What I have now is 10" preloaded, ride height is pretty damn close to stock now. Im not like the "stance" but the roads are crap here in dallas and pot holes are like lakes here. I would go to a 12-13" next time. I remember my car back in cali 11 years ago with chopped stock springs and billys road rather nice and tight around corners but irvine had great roads.

Im also getting of my gaz and going back to a billy.
Click to expand...
It's funny how that game goes round and round - I remember a previous build about 10 years ago, on revalved Bilsteins with 400# springs up front, riding pretty well and handling REALLY well... until a Memphis pothole took one out and I never bothered rebuilding it. Went for Koni Races and 400# springs on the next build (with an aluminum 5.3L), never really got 'em dialed in to where I was happy, been planning on picking up a set of GAZes just to see what they're like before I save up for JRZes or make another attempt at ordering revalved Bilsteins :p

As an aside, Bilsteins are great, but they're only really functional at the spring rate they were valved for. Sure, Spec Miata guys run 700# springs on B6s meant for 150#, but Spec Miatas ride like ****, are universally regarded as intentionally hobbled to make a cheap level playing field, and just dropped the idea of totally mis-valved street shocks in favor of what amounts to a giant Penske group buy.
 
Last edited:
You must log in or register to reply here.
Back
Top