What springs upgrades are most used for street?

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zxr250cc
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What springs upgrades are most used for street?

Post by zxr250cc »

Hi all,

I watch the videos of Andy Rouse in UK racing and note that the car is flat in corners, not heeled over as mine would do. I don't want a log truck ride but a more stable update would be desirable. I am almost loaded up with enough parts to take the front and rear apart and while changing struts and shocks might choose to do springs as well. Why do the work more than once, right?

Cheers
Last edited by zxr250cc on Mon Aug 13, 2018 8:52 am, edited 1 time in total.
1986 XR4Ti Mineral Blue Metallic
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andyofcolumbusmerkur
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Re: What springs upgrades are most used for street?

Post by andyofcolumbusmerkur »

If I ever take mine apart I will ditch the slightly stiffer lowering springs and get something from MC Squared Racing.
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Re: What springs upgrades are most used for street?

Post by Marc »

Race cars like that would be terrible to drive on the street. For front springs I think 350 lbf/in and 171 lbf/in rears (coilover location) is still OK for street use. But of course opinions differ on what is acceptable for street use. Thicker antiroll bars will also help to prevent body roll but not give a such a hard ride.
zxr250cc
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Re: What springs upgrades are most used for street?

Post by zxr250cc »

Hi all,

Thanks for the replies. I am looking forward to how the car will feel without the worn struts and tired rear diff mount.

As the car is now legally out and about again it will be fun to use it for a vacation and travel/work session combined in the next few weeks. I have paid for six months insurance on it and plan to have fun driving it around in the two lane twisty back roads as I find four lane slab to be very boring. As a long time biker and business road warrior I have learned to loath four lane straight roads. I miss the Blue Ridge Parkway from my time in North Carolina. Oh, I used to see a white '87 or '88 XR4Ti sitting in Holly Springs from 2003 to 2008 or so but never stopped to talk to the owner. Anyone in here own that one?

Cheers
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Re: What springs upgrades are most used for street?

Post by cmouta »

from the mc2racing web site:
http://www.mc2racing.com/products/xr4ti ... index.html

Stock-height daily driver
Don't convert to coilovers. Use the 200lb/in drop-in stock ride height springs we have, and use 600lb/in rear springs with flattened isolators.

Lowered daily driver
Convert to coilovers up front. Use 225lb/in front springs, and use 600lb/in rear springs with spring isolators removed.

High performance street/track car
Convert to coilovers up front. Use 350lb/in front springs, and use 650lb/in rear springs.

Dedicated track car
Convert to coilovers up front. Use 500lb/in front springs, and use 700lb/in rear springs.


The "How to prepare the sierra for motorsport" book has some race car build specs in the back of it.I think there's a scan of it floating on the web
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Re: What springs upgrades are most used for street?

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Re: What springs upgrades are most used for street?

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zxr250cc
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Re: What springs upgrades are most used for street?

Post by zxr250cc »

Thanks for the XR4i links. I have had that download for some time and have read a lot of it. I don't think race springs are what I am seeking. I would like to have a more firm but not log truck jouncing ride. Who in here is using a daily driving with up rated springs? Parts chosen and vendor please.

Thanks again.

Oh, I am only interested in stock ride height, not lowered springs or coil overs. These cars are low enough stock for a daily driver.
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Spaldino
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Re: What springs upgrades are most used for street?

Post by Spaldino »

I'm running 350/lb springs up front and 650/lb rear. I don't find it that harsh at all. Every upgrade to my suspension was supplied by MC2 Racing.
88 Mono-white XR: Side exhaust, Walbro, MC2 Front Adjustable Coilovers, Rear Bilsteins, Full Poly bushings, MC2 Diff Mount, Rapido intercooler, Some sort of mild cam(?), Rear Disc conversion, 225s on 17x8 wheels.
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Re: What springs upgrades are most used for street?

Post by my8950 »

zxr250cc wrote: Thu Aug 16, 2018 2:12 pm Thanks for the XR4i links. I have had that download for some time and have read a lot of it. I don't think race springs are what I am seeking. I would like to have a more firm but not log truck jouncing ride. Who in here is using a daily driving with up rated springs? Parts chosen and vendor please.

Thanks again.

Oh, I am only interested in stock ride height, not lowered springs or coil overs. These cars are low enough stock for a daily driver.
You're best bet is to call the vendor/s. I have called MC2 and spoke to Grayson before, he is very helpful and will give options based on your desires. There are other vendors as well that can help, Rapido, BAT...I guess when most think of XR suspension they think of MC2.
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Re: What springs upgrades are most used for street?

Post by cmouta »

zxr250cc wrote: Thu Aug 16, 2018 2:12 pm Thanks for the XR4i links. I have had that download for some time and have read a lot of it. I don't think race springs are what I am seeking. I would like to have a more firm but not log truck jouncing ride. Who in here is using a daily driving with up rated springs? Parts chosen and vendor please.

Thanks again.

Oh, I am only interested in stock ride height, not lowered springs or coil overs. These cars are low enough stock for a daily driver.
MC2Racing seems to be the best option for stock height springs with varying rates.
http://www.mc2racing.com/products/xr4ti ... index.html

BAT offers 25mm lowering springs
http://www.batinc.net/merkur.htm

Rapido seems to offer a "lowering kit" without much more detail
https://rapidogroup.com/products.htm
Chris
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Re: What springs upgrades are most used for street?

Post by LITTELHAWK »

I believe the stock height springs from MC2racing is what you're looking for. I just did the fronts in mine and the difference is amazing and I think perfect for a daily driver. They're stiff enough to eliminate the body roll but still a comfortable ride. I ordered the rears at the same time but I'm waiting to get the money to order the diff mounts and rear bushings they offer as well.

Front Pair:
http://mc2racing.com/products/xr4ti/sus ... index.html

Rear Pair:
http://mc2racing.com/products/xr4ti/sus ... index.html

Diff Mount:
http://mc2racing.com/products/xr4ti/sus ... index.html
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Re: What springs upgrades are most used for street?

Post by reddy2300 »

MC2 is gone. They're not really accessible and getting the info on the springs that they USED to sell is difficult, at best. Does anyone know what we would be looking for when it comes to the rear springs on an XR?

I bought 5" x 9.5" free height springs for the front and am now looking for the rears.
1987 XR4ti--Mustang Cobra 5.0/T5 transmission, AFR heads, fake BBS wheels, Koni Yellows, Rapido sway bars, poly/aluminum bushes, Eurolights, Sierra rear/Focus front discs,
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