SPRING RATES & DROPS: ALL IN ONE THREAD!!

[Gibbo205]

As long as the springs are clocked, they should be pretty close in the rear.

Ultralite definetely drop the rear about 0.25-0.5" more than the sport linear. I fitted ultralite linears and another UK owner fitted sport linears. The sport linears have pretty much perfect stance with equal arch gap front and rear.

Whereas on ultralite even though front is dropped more, the rear is dropped even further giving the appearance of reverse rake.

I love my ultralites but I did use an 8mm spring spacer to get the stance I wanted which was a little more arch gap in rear compared to front to give a good impression of rake.

 

[dsp4848]

I decided to put everything into a spreadsheet regarding springs rates and drops. The spreadsheet divides springs into linear and progressive and shows the spring rate change as a percentage of the stock GTPP springs. I only included springs for the GT Fastback - no convertibles, EB, or V6. There's a column for the source of information as well. When multiple sources had conflicting info for rates or drops, I went with the manufacturer's info by default.

If you guys find any other springs out there that are available for our Mustangs feel free to let me know and I can update the spreadsheet. There's also some values that I just couldn't find on websites, so if anyone has concrete info on these that would be cool.

 

[MtnBiker]

As am I. Has yours arrived yet?

Yes, got the Koni's last week. Also got the FRPP sways, FRPP sphericals for rear toe, extended ARP studs, spacers (15mm f, 13mm r), forged lug nuts, a bunch of new "one time" fasteners, a few other bits. Eager to try out the ultralight front/sport rear combo. Still debating camber bolts or plates. Need to schedule some shop time.

 

[TrackpackGT]

Curious to know the numbers on gt350r springs. Thanks for the sheet! Didn't realize the stock springs were linear, good to know. Probably read it and forgot.

 

[stresstest]

This thread is awesome. Not only should it be sticky'd but it's completely changed my mind on the springs I was planning.

Thanks for the work @ Gibbo205 & dsp4848

 

[MtnBiker]

Curious to know the numbers on gt350r springs.

That

 

[GTP]

I decided to put everything into a spreadsheet regarding springs rates and drops. The spreadsheet divides springs into linear and progressive and shows the spring rate change as a percentage of the stock GTPP springs. I only included springs for the GT Fastback - no convertibles, EB, or V6. There's a column for the source of information as well. When multiple sources had conflicting info for rates or drops, I went with the manufacturer's info by default.

If you guys find any other springs out there that are available for our Mustangs feel free to let me know and I can update the spreadsheet. There's also some values that I just couldn't find on websites, so if anyone has concrete info on these that would be cool.

[MENTION=11119]dsp4848[/MENTION] , Can you post the spreadsheet online somewhere? Not would it be available conveniently to forum members, but it would always be the latest version each time you update it.

 

[BMR Tech]

GT350:

194lb/in Front
914lb/in Rear

GT350R:

240lb/in Front
914lb/in Rear

 

[Todd15Fastback]

GT350:

194lb/in Front
914lb/in Rear

GT350R:

240lb/in Front
914lb/in Rear

:cheers:

 

[TrackpackGT]

Thanks!

 

[16s550]

Ok now I don't even know what springs to pick. I didn't want progressive and now I read lots of people like sport lines but those are progressive. I was leaning towards steeda but people say they have reverse rake ando bmr I like but doesn't seem to be much drop. In pictures looks like plenty drop. Sigh. Idk. What to do.. I just want car to handle great for daily and autoX. Yet I also don't want to leave pieces of my car scraped on floor from being to low.

 

[GTP]

I am with you. If you quadruple your budget then you can have it all with coilovers. Get the spring type and rate you want, crank down the ride height for track day, dial it back out for daily use. There is your "progressive"!

 

[Todd15Fastback]

Ok now I don't even know what springs to pick. I didn't want progressive and now I read lots of people like sport lines but those are progressive. I was leaning towards steeda but people say they have reverse rake ando bmr I like but doesn't seem to be much drop. In pictures looks like plenty drop. Sigh. Idk. What to do.. I just want car to handle great for daily and autoX. Yet I also don't want to leave pieces of my car scraped on floor from being to low.

Just got with the Steeda ultralite linears and pair them with the Koni struts/shocks and call it a day.

My car with 20's sets 1/8-1/4" higher in the rear. I just measured the height on my garage floor that is perfectly level. The rear is 27 5/8" and the front is 27.5"

Here are pictures of my car showing the level ride height. These springs with the koni's are the perfect match. So much adjustability with the Koni which make them perfect for long trips, aggressive mountain runs or track day/autoX events.

[MENTION=10893]David@Steeda[/MENTION] will take care of you for pricing on the ultralite linears and even the koni's, too

 

[Dragster]

Ok now I don't even know what springs to pick. I didn't want progressive and now I read lots of people like sport lines but those are progressive. I was leaning towards steeda but people say they have reverse rake ando bmr I like but doesn't seem to be much drop. In pictures looks like plenty drop. Sigh. Idk. What to do.. I just want car to handle great for daily and autoX. Yet I also don't want to leave pieces of my car scraped on floor from being to low.

I had Steeda Ultralites on my car, but didn't care for the drop (it still looked too high in the front), so I switched them out for Sportlines. I was a little hesitant about going with a progressive spring, but I'm 100% satisfied with them. Fitment was better than the Steeda springs, too. They are totally predictable for street and track use, and the car can easily pull over a g in corners. I don't autocross, but the car handles great at track days. I have never scraped on anything from being too low, either, but my car isn't a daily driver. Good luck with whatever you choose!

 

[16s550]

What is the fitment issue you are referring to? I think I have decided to not go progressive. So my decision is between steeda ultra lite, or sport , bmr performance or handeling.