I see guys talking about running the HPI center shock for 10th scale oval cars. Where can i find this shock?

Is this shock better then the Associated center shock?

the hpi is not better.. it requires less maintinance, and is easier to build... it wont make you faster running one or the other...

you can buy them anywhere.. tower hobbies, murdock ect...hpi sedan shock is all it is..

Thanks Burbs-
I thought the Associated center shock went together pretty easy,
I'm still not sure about the extra spacers they give you for pre-load.
I was just wondering about which shock works better.

The Part Number is HPI 72170

the hpi is not better.. it requires less maintinance, and is easier to build... it wont make you faster running one or the other...

you can buy them anywhere.. tower hobbies, murdock ect...hpi sedan shock is all it is..

I've built ALOT of shocks over the last 20 years, and I'll tell you first hand it's VERY, and I mean VERY hard to build an associated center shock properly. On the flip side, the HPI is almost fool proof :thumbsup:.

Later, Bret

i have my own qustion do they come stock with blaters??

i have my own qustion do they come stock with blaters??

The Hpi does come with bladders but they suck,they should be replaced with the General Silicones bladders they will be much smoother.Burbs and jet are right though, it's really just a matter of the HPI being much easier to build and maintain.

What is wrong with the stock bladders? I have been running the same internals in my HPI shocks for 2 years now and they are still glass smooth. Just curious what you have found with them.

replaced with the General Silicones bladders

Part # please ??
I bought some GS and they were too big for the HPI shock. I must have bought the wrong size.

vwal,

2 years with the same bladder? o-rings maybe,but the bladder would be shot after only a few rebuilds,I only change the GS bladder once a season,or as needed.

Yeah, maybe that is my problem...I don't rebuild it unless they feel bad and well to this day it is as smooth as the day I built it.... I was just curious about the bladders and what the differences were and what was wrong with the stock ones. And how do you determine the bladder is shot? I would believe as long as it holds the oil in that it would be fine, let me know.

Part # please ??
I bought some GS and they were too big for the HPI shock. I must have bought the wrong size.

Here is the website,they do have two diffrent sizes 1/10 & 1/8,they come in diffrent colors for some reason it's not like anybody can see them.LOL.They come in a rebuild kit with o-rings and bladders,the bladder isn't supposed to hold oil it is supposed to hold air so it will be a tight fit unlike the stock ones.If you pull your shock apart and the bladder is collapsed it's time for a new one.
http://www.gsracing.com/web/page.asp?pgs=products&catid=96

What weight shock oil should i start with 30wt,40wt?

And what would make you change to a different weight oil?(i.e rough track,a push, low rear traction etc..)

Thanks for everyone's info and advice!!

Curious to see what people say about center shock oils.

For 4 cell stock, I prefer to stick with a baseline setup, #2 piston, 50 wt oil - flat tracks and 55wt on banked tracks and then tune using center springs. For stock racing the Silva Copper is probably the spring that gets the most use in my box. At 7lb's its a good starting point for most tracks.

If car is loose then I will put a 3lb to 4lb spring on, if car is tight go to a harder spring 10lb or so.

Anytime you soften the center, with spring, t-plate etc, you are going to have more rear hookup, The downside to being to soft is the car may pick up a push or be so stuck that you lose efficiency in the turns. On the other hand, anytime you go to a stiffer center spring or stiffer T-plate, the car will turn harder, and should "free up" the car, but you run the risk of tire spin. So the key is to find the proper balance.

Once I get a baseline setup, I change center springs like its my job, to fine tune the car.

And take note, what works for some cars will not work with your car.
I have ran a few different chassis and the Hyperdrives seemed to like softer Center springs than the KSG and RIP cars on the same track.

Plus not everybody runs the same tires on a given track.
Some prefer soft tires and heavy springs, other may opt for Hard tires and Soft springs.

erock1331- when you say if the "car is tight" can you explain tight? i'm not sure what to look for.
Push and loose i've seen.
Thanks.

erock1331- when you say if the "car is tight" can you explain tight? i'm not sure what to look for.
Push and loose i've seen.
Thanks.

Tight =push
Free = loose

Erock,

Man! there are so many variables it ain't funny LOL.At the norcca nats this past weekend, turn one was a high banked very tight turn while turns two & three were of a flat sweeper type,talk about a fine line with the center shock.LOL next weekend it's the high banks of BMS,stiff stiff baby, 20lbs plus on the center shock there.

Pepe
I agree many variables to this hobby.

I want to hear what guys are doing with shock oils though. Mostly from talking to some, it controls weight transfer, heavy oil = slower transfer, soft oil = quick transfer.

I have heard some use light oil for bumpy tracks and i have heard some use heavy oil.
I want to know what is what, that is why I dont play with shock oil much and focus more on the springs end.

yep BMS is a tough one, bust out the IRS opaque center spring 20.5 lb'er for that track. Been there, never could quite get dialed in.

I can honestly say after all this time, and I have taken a few of the shocks apart and changed weight oil them, I have never seen a bladder be collapsed. I am not sure, but if it is holding air back it is also holding oil in. My shocks always rebound nicely and are smooth as glass. I do have 4 of them with different weights of oil them but I just run the 50wt one at most tracks so I donno. Thanks for letting me know what to look for.

I've been using the original HPI bladder for 2 1/2 seasons. Never had a problem with them.

I don't know guys,it's just what I've seen in all the HPI shocks I've owned.
erock,I normally run 60wt in the center shock with a #2 piston and a green tc3 spring,this gives my car (pro 2) a real aggresive feel,this past weekend I went to 40 wt and a sylva copper sring,I was trying to tighten the car up a little,it did help,it made the car feel Lazy to me.The thing that helped me the most though was the .020 shim that I put in the left rear,which took the snap loose out. I think I could have put some more pre load in to get some more of the aggresiveness back,but I was afraid it would bring back the snap loose again.I pretty much confirmed what Steve Salva's says about the center shock,the stiffer you run it the faster the car will be but you have to be able to hold on it.If I had drove the car like it should have been drove It would have been in the "A" but the driver let me down.

How do you like your Pro 3 Pepe? I,m still running Pro 2s but will get a Pro 3 soon ( I Hope ) Have your set-ups been similar to what you were running?
I keep looking at this thread for thoughts on center shock oil/springs. The two tracks I normaly run at are completely different concrete ovals. One is high banked has tight corners and is bumpy while the others almost flat with broad corners and very smooth, both have around a 320' runline. Funny thing is with the exception of center shock springs and oil I run virtually identical set-ups at both and run competively? I,ve been running a heavy spring and oil combo on the high banked track and a soft spring light oil on the flat track. Any thoughts?

Lee, Have Hyperdrive will Race :cool:

Thanks for asking lee.I typed pro 3 but meant pro 2,DUH i'm anxious to get my hands on a pro 3.Yea I really didn't change that much from what I normally run,but I think I could have gotten away with just shimming out the left rear and I would have been alright with the set up I had,I started out with my tires too hard but slowly went to a soft tire, stiff shock package set up which I like the feel of,the TQ car was on a hard tire, soft shock set up.I think what I'm going to do is put my 0700 on soft shock package setup and leave the pro 2 on the stiff set up,that way I can have the best of both worlds.

Curious to see what people say about center shock oils.

For 4 cell stock, I prefer to stick with a baseline setup, #2 piston, 50 wt oil - flat tracks and 55wt on banked tracks and then tune using center springs. For stock racing the Silva Copper is probably the spring that gets the most use in my box. At 7lb's its a good starting point for most tracks.

If car is loose then I will put a 3lb to 4lb spring on, if car is tight go to a harder spring 10lb or so.

Anytime you soften the center, with spring, t-plate etc, you are going to have more rear hookup, The downside to being to soft is the car may pick up a push or be so stuck that you lose efficiency in the turns. On the other hand, anytime you go to a stiffer center spring or stiffer T-plate, the car will turn harder, and should "free up" the car, but you run the risk of tire spin. So the key is to find the proper balance.

Once I get a baseline setup, I change center springs like its my job, to fine tune the car.

And take note, what works for some cars will not work with your car.
I have ran a few different chassis and the Hyperdrives seemed to like softer Center springs than the KSG and RIP cars on the same track.

Plus not everybody runs the same tires on a given track.
Some prefer soft tires and heavy springs, other may opt for Hard tires and Soft springs.

I am confused as hell. I thought it was just the opposite. I thought the more rear force being placed by a spring to the rear pod, the more traction you would have. If I could get my car to handle I would be dangerous.......... :dude:

LOL, Dang Pepe I was excited for ya! Thought maybe you managed to get hold of one of them elusive Pro 3s. Congrats on the great run!

Lee, Have Hyperdrive will Race :cool:

Any picture of PRO3 from last weekend's NORRCA Nats? ...I heard there are several PRO3 .......Barry...Humpty....etc..anyone care to share the pic here? Thanx

LOL, Dang Pepe I was excited for ya! Thought maybe you managed to get hold of one of them elusive Pro 3s. Congrats on the great run!

Lee, Have Hyperdrive will Race :cool:

Flash,

Mike Burbey was the TQ car he was on a Maverick,my run well it wasn't all that great,actually it sucked pretty bad,but it didn't have anything to do with the car it was my over aggresive driving that did me in more than anything,it was a learning experience that you have to stay calm when your in a clutch situation,which I didn't,it was my first real national event and I learned a lot.
Ginsu,

You kinda have to think like the real cars,you soften up to gain traction and stiffen up to free up or loose traction.If you watch nascar they let air out of the tire to get more bite or to gain tracton and put more air in to loosen up the car or have less tracton,of course there's a lot more that goes with it but that's the general concept.

pepe I prefer stiff center. But it didn't geter dun.But you probably noticed how hard my tires were.in main.i said i would probably go high or spin. but didn't do either.shoulda had more spring in center. The only problem is after 1.5 years I finally needed new o-rings in my H.P.I center. Not much of a problem. I wish they made some slightly smaller same design for side shocks. cause there soooo smoooth.

To add another question to the topic:

When you put on a softer spring to gain traction or a harder spring to reduce traction, should you change shock oil wt. or keep it the same?

Tight =push
***Free = loose *** wrong


Tight = pushing = understeer
Free = neutral = balanced = fast :thumbsup:
Loose = oversteer = spin around :freak:

Nozz1. It would depend on the track.smooth track versus a bumpy one.

So is there a baseline you should start at i.e. 20wt,30wt,50wt?
and then tune with the center spring?

Slider,

I prefer the stiffer center as well,I think you had the general Idea for getting through turn 1 by burping the throttle just as you enter the turn,but you had better stay on power the rest of the way through the turn or were going roundy round.

Yes free is the good type loose,where as just loose is the bad type loose,LOL

So is there a baseline you should start at i.e. 20wt,30wt,50wt?
and then tune with the center spring?

This is where it gets tricky,your own personal driving style comes into play,in which you have to decide how you like to have your car feel,get it where you like it and then make small changes to get it faster.Some folks will say 30 some will say 50 or 60 in the center I started with 60 and ended up with 40.There is a thing called pack or something that has to do with how the shock works but I'm not very versed on it so I won't try to explain something I don't understand myself.

What do you all use to mount the center shock HPI to the shock mount? In my case its an L4 with stock mount. What I have used is small fuel tube. I would think a "solid" sleeve would work better.

Fuel tubing is probably most common.

I've used the tubing also. I finally found some HPI balls to put in there that work well also. Just have to drill out the end a little. I've not noticed a huge difference though.

What do you all use to mount the center shock HPI to the shock mount? In my case its an L4 with stock mount. What I have used is small fuel tube. I would think a "solid" sleeve would work better.

When you buy an hpi center shock there is 3 size caps to choose from.. there is one that you put a ball cup on, its flat with a hole in it.. this is nice for adjustments.. can adjust shock lenghth with the cap..

or i use the medium size one.. i take the ball from the associated shock,. the one that fits in the cap.. I put a scrww through it and put it in my dremel.. I slowly sand it down until it fits perfect in the hpi cap.. i like this better then guel tubing just ebcause i think it feel more free.. the tubing doesnt really bind. but the shock doesnt seem as free side to side,.

Doesn't having a "solid" (without flex) vs fuel tubing (with flex) make a huge difference?

M.P.

Why would a person want fuel tubing anyhow? I want my shock to do all the work instead of having a false amount of travel do to rubber tubing I have had mine like burbs.since built the car and won't change. SOOO much more free.