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If I recall before I lowered my car, I had about 4 finger gap front and 3 finger gap rear. Which I think that was weird. I'm currently on RSR super down, specifically for my car directly from RSR (I did the work) and mine looks pretty even as far as gaps. It might be MFG issue. I've notice on RSR IG, they posted a is500 on RSR down and notice the rear was lower than the front.
If I recall before I lowered my car, I had about 4 finger gap front and 3 finger gap rear. Which I think that was weird. I'm currently on RSR super down, specifically for my car directly from RSR (I did the work) and mine looks pretty even as far as gaps. It might be MFG issue. I've notice on RSR IG, they posted a is500 on RSR down and notice the rear was lower than the front.
Has to be spring mfg quality control or packaging. I don’t know if they’re using different rated steel, or what. But the fact that is, I’ve had 2 sets of RSR down springs both with the same exact part numbers. One set was perfectly matched front to rear, and now this most recent set is 1.5” difference front to rear. Either RSR packaged the wrong springs with the right part#, or quality control with the MFG is an issue.
Would there be a significant difference between the 350 and the 500 application? I’m assuming they share much of the same geometry, perhaps a slightly different rate to compensate for weight differences?
Factory wheel gap is my only complaint on the 500 so far. My ISF has a tight two-finger in the front, vs. a full four on the 500. While I appreciate the ride quality, I do understand the desire for aesthetics.
Would there be a significant difference between the 350 and the 500 application? I’m assuming they share much of the same geometry, perhaps a slightly different rate to compensate for weight differences?
Factory wheel gap is my only complaint on the 500 so far. My ISF has a tight two-finger in the front, vs. a full four on the 500. While I appreciate the ride quality, I do understand the desire for aesthetics.
I agree on too much gap from the factory.
I’m not entirely sure on the 350/500.
My first set of RSR IS500 springs looked identical to the pics of 350 springs installed on 500’s.
Maybe my first set was 350 springs with 500 markings on the carton? I don’t know.
Either way, sucks because I love the quality of the ride, it’s not super harsh like most lowering springs. Retains the factory comfortable ride.
I had the same issue with my RSR springs on my 2023 IS500. I also had the RSR springs on my 2022 IS350 with no issue. I talked to RSR and they wanted me to do all of these measurements. I just decided to install my RSR 350 springs in the front of my IS500 and the car looks great. I can't tell a big difference in the ride. Thanks.
Not that this would ever happen but what's the worst case scenario of installing IS350 springs which are all but guaranteed to be rated lower, on a IS500? Could they theoretically snap during extreme weight transfer due to the extra power from the IS500?
I don’t think the front would snap. With the v8 power, it’s all in the rear that would matter imo. Is350 front down spring rate is 5.48kg and is500 front down spring rate is 6.53kg not a big difference. I would just think it’ll be slightly softer on the is350 front springs over the is500. In general, I would worry about the rear springs, since the is500 rear is 10.00 kg **** is stiffer than the is350. All the power would go towards the rear.
Update.
I did receive a call from a tech with RSR. I explained to him that I could not give him any measurements from my car due to the fact I am running my 350 springs in the front. If you are having this issue please contact RSR and provide them with the information they are asking for to correct this problem we are having.
If you are reading this thread and you are thinking about buying RSR springs for your IS500, I would wait until this issue is resolved. Thanks.
So in summary, their fronts springs don’t go low enough and their rear springs go too low. Lol they couldn’t have *****d that up any worse. Stevie Wonder could’ve made better springs. And to think Forsythe constantly shills for them…for shame for shame.
So in summary, their fronts springs don’t go low enough and their rear springs go too low. Lol they couldn’t have *****d that up any worse. Stevie Wonder could’ve made better springs. And to think Forsythe constantly shills for them…for shame for shame.
Yes, exactly. Front not low enough and rear is too low.
What sucks is I normally do all my own installs (and have for the past 25 years), but now my time is more important with 2 kids in multiple sports. So I paid $800.00 for the install. If I have to pay that again out of pocket because RSR didn't do their due diligence on the R&D side, I'm going to be pretty upset.
Shame... Was thinking of buying these because of how nice they looked and felt on my 300. They're still on the car after being installed over 3 years ago. I contacted their support and they mentioned: "We have not made any changes to the IS 500 springs (T594D)". Does anyone recommend any alternatives to these?
Shame... Was thinking of buying these because of how nice they looked and felt on my 300. They're still on the car after being installed over 3 years ago. I contacted their support and they mentioned: "We have not made any changes to the IS 500 springs (T594D)". Does anyone recommend any alternatives to these?
Look into Swift springs or wait until Eibach comes out with their version.
03-17-23, 01:42 PM
