Savage LRP ZR.28

[BenJammin]

Just fitted an LRP ZR.28 to my Savage X and am in the process of running it in.

I have one slight issue though - I can't adjust the throttle in such a way that the slide opens fully. It either opens too far on idle, or doesn't open far enough at full throttle.

Anybody have any suggestions or experience with this swap that can give me some input?

Many thanks.

 

[fstnd]

Are you only adjusting the trim of your servo? Did you try changing its end point adjustments EPA, or its dual (swing) rate?
Otherwise I only see the option of vhanging the servo horn

 

[BenJammin]

Are you only adjusting the trim of your servo? Did you try changing its end point adjustments EPA, or its dual (swing) rate?
Otherwise I only see the option of vhanging the servo horn

Annoyingly the radio set that I've throwm in it doesn't have throttle EPA or dual rate. I've adjusted the length of the throttle linkage as best I can and tried repositioning the servo horn with no luck.

I have a few different cars that have radios with throttle EPA, I guess they'll just have to sacrifice themselves to the Savage gods Need to get hold of a good radio that can store a few different recievers really.

 

[ohsnap]

Did you try changing its end point adjustments EPA, or its dual (swing) rate?
Otherwise I only see the option of vhanging the servo horn

Been there, experienced that, and feel your pain.
Changing the servo horn is difficult given the Savage's design and their push/pull throttle/brake servo horn arrangement.

The end-point adjustment (ATV if you have a Futaba controller) is the first place I'd start and even then there's no guarantee.

Don't completely torque down the Z282 step screw.
I've encountered instances where the servo had enough mobility to accomplish the task, but the collar spring in the 85051-servo horn was not up to the task. A slight loosening of the set screw can allow for further movement of the slide (& it may not).

I modify the linkage as shown in the pic.
Ignore where the servo is positioned in this pic - I use the same problem resolution for a "normally positioned" servo.
The spring forces the slide closed at idle, and the length of the linkage facilitates adjustability (when you change gearing etc).

You may also have to tinker with the carbs angle to get the right amount of leverage and movement...
You may also need to alter the angle of the uniball (where the linkage connects to the carb) for the same reason.

 

[BenJammin]

Been there, experienced that, and feel your pain.
Changing the servo horn is difficult given the Savage's design and their push/pull throttle/brake servo horn arrangement.

The end-point adjustment (ATV if you have a Futaba controller) is the first place I'd start and even then there's no guarantee.

Don't completely torque down the Z282 step screw.
I've encountered instances where the servo had enough mobility to accomplish the task, but the collar spring in the 85051-servo horn was not up to the task. A slight loosening of the set screw can allow for further movement of the slide (& it may not).

I modify the linkage as shown in the pic.
Ignore where the servo is positioned in this pic - I use the same problem resolution for a "normally positioned" servo.
The spring forces the slide closed at idle, and the length of the linkage facilitates adjustability (when you change gearing etc).

You may also have to tinker with the carbs angle to get the right amount of leverage and movement...
You may also need to alter the angle of the uniball (where the linkage connects to the carb) for the same reason.

View attachment 278272

Thanks for the info snap.

I'm currently having plenty of fun at 80% throttle, but I'll have a potch tomorrow and see what I can do. May need to order a few more bits to fashion what you've done yourself.

I have a pair of ET2070's in it, same as most of my other rigs - they seem to have quite a degree of 'extra' movement (from what I found while potching with my Inferno MPfrankenst9).

I'll try a radio with throttle EPA first, I guess that's the least faff. Spent so much time fixing crap on this since buying it that I just want to drive the dang thing! The .28 rips though, I'll give it that

Thanks guys

 

[easy rider]

I didn’t read the responses but, I’d use a solid servo horn, a linkage spring, Traxxas tmaxx linkage set, and build my own. It’s what I did on all three of my savages.

 

[ohsnap]

I didn’t read the responses but, I’d use a solid servo horn, a linkage spring, Traxxas tmaxx linkage set, and build my own. It’s what I did on all three of my savages.

Give us pictures and tips - don't just brag about it.

 

[easy rider]

Pretty straight forward. Everything you need is in the tmaxx throttle linkage. Use your factory brake linkage. Use a solid horn and throttle slides that come in the kit.


I haven’t attached the brake linkage yet in this pic. But, I’ll get pics of it tonight so, you can see the whole thing completed.

 

[BenJammin]

Pretty straight forward. Everything you need is in the tmaxx throttle linkage. Use your factory brake linkage. Use a solid horn and throttle slides that come in the kit.


I haven’t attached the brake linkage yet in this pic. But, I’ll get pics of it tonight so, you can see the whole thing completed.

View attachment 278871

If you could man that'd be sweet. I'll probably do this. I picked up a radio with EPA, but the servo horn is so worn out that the brake linkage keeps popping out. I'd rather upgrade it as it's kinda crappy anyway

 

[ohsnap]

Easy - I think I got how it works.
I'm guessing that you pass the stock brake linkage on the underside of the servo horn.
I never thought about the T-Maxx linkage.

I figured that there would be some amount of bending and routing involved - but the stock linkage didn't look like it wanted to work with how I mocked up that arrangement; and since I've always been able to make a stock servo horn work, I lost interest.

I'd rather upgrade it as it's kinda crappy anyway

Yeah.
To me, this set-up is a quick and sensible upgrade that's easy to sneak in during standard working hours.
Even though I get them to work, the weak servo saver spring and the stock throttle/brake servo horn itself are one of - if not my biggest Savage pet peeves.

Easy - What is the length of the servo horn?

But, I’ll get pics of it tonight so, you can see the whole thing completed.

That would be sweet.
I like that metal linkage throttle pivot (pole?).
I've not seen those before.
Bearings?

 

[easy rider]

You got it figured right. I forgot to add, the collars bolted on to the servo horn cam from Dubro. I think they come 4 to a pack for about $2.

The servo horn is just a cheap one that comes with amazon servos. It’s aluminum. The only requirement is it has multiple holes for mounting those collars in. Keeping the brake linkage straight as possible is important. It’ll bind if you don’t. You may have to widen the collars a bit with a drill bit. Depending on your linkage bending

 

[easy rider]

Servo horn.

https://www.amazon.com/YijiaLink-Al...6&sprefix=servo+hor,aps,177&sr=8-4&th=1&psc=1