Ask Ben Cosgrove 2004

[Ben Cosgrove]

Hi all

I am happy to offer my advice and support for all of you guys in X-Ray land. If you have a question please post and I will get back to you asap.

If you have any chat then please pm me as it will get the moderators angry. Also check out the FAQ thread if you have a similar question (saves time).

Ben Cosgrove
Team X-Ray/Hudy/Peak/LRP

[Adi Wright]

OK Ben, I'll provide your first question :-

What is the preferred battery position in the Xray T1: down one side or saddle pack on either side of the chassis? Do you interchange the position of the cells depending on the track you're racing on?

Cheers

Adi

[STEPHEN E]

Hi ben

Im still having problems building xray shocks i can never seem to get them all the same so any tips ?
Also when screwing on the top cap of the shock do u do it up all the way or till it just bites on the membranes.
And i Just seen the Foam inserts for XRAY shocks any good and what will they do?

thanks
steve.

[jimmy-maddison]

when building shocks you are best off putting a caster spacer at the bottom of the shocks when building so you can get each shock the same for the rebound you really need the shaock cap as tight as possible so no oil will leek out of the top, as far as foam inserts at the top of the shock i run them and the new soft bladders it does make the shock better but you have to rebuild more often to keep the same rebound,, not sure if ben runs these or not im sure he will let you know

thanks jimmy
sorry if i answered ben just thought i could help on this one 8)

[Ben Cosgrove]

Hi

Adi - I have experimented with all the layouts of battery positions. I prefer to have the cells in the saddle pack at the rear layout, best all round compromise. I run 40 grammes of weight under the front belt in the centre at the front to help the balance.

Stephen - Jimmys method will work fine!! I personally build them the following ways

Fill the shock body to top with oil, pump the piston to remove air, place diaphram and cap on to the shock body, tighten cap all the way. There should be a little leakage as the excess oil escapes. This is to have medium rebound

For no rebound use the same method and once complete loosen the top cap 2 full turns and push the piston all the way up, then tighten the cap. This will give less rebound.

The foam 'bits' for the shocks are to increase rebound, the shocks should be built as the medium rebound suggests but they should be inserted in between the diaphrams and cap.

Rebound I hear you say??

Refers to the rate at which the damper will extend after compression.

Doesn't the spring control this??

Well yes and no. the harder the spring then the more force you will have on the tire thus working it harder. Also a harder spring will make the car worse on bumps.

What are you actually saying??

Well on tarmac the dampers have to respond very quickly to bumps and ruts in the surface. Running a harder spring may actually give you more grip but it makes it harder to drive. You can get the same effect from rebound as a spring. The rebound will force the damper to react quickly to bumps allowing softer springs to be run and an easier car to drive with high grip levels.

So we want rebound then??

Well indoors on carpet you dont necessarily need to have the damper working so hard. A harder spring is usually beeter as grip will increase along with reactiveness (to an extent). Rebound on carpet can cancel out the spring effect and give you less grip. On tarmac i think you would want it.

Its something to play around with and depends greatly on driving preferences and track conditions. Give it a try and let me know your thoughts.

**X-Ray now have a super smooth shock seal/o-ring set which really improves the shock action without leakages** should be out very soon if not allready out i think.

Hope this helps

Ben

[Ben Cosgrove]

Hi guys

If anyone is interested here is my setup from Don Valley finals. Factory Team kit.

https://www.mytsn.com/setups/setup.asp?sid=2342

Ben

[STEPHEN E]

cheers for the very informative reply.
All the time i was thinking rebound was a bad thing . :-[
Will be getting the foam & shock seal/o-ring set and have a play.

[Matt Brewerton]

FAQ updated with Ben's shock building and rebound tips.

Matt

[redlinezak]

hi ben thanks for taking the time to help us lot. Just a couple of questions. Any i dea when the new parts from the factory spec will be released separately as i already have a lot of them so dont really want to buy a whole new car? Also i have both an evo 2 foc with ally c hubs and a racer again with ally c hub kit (all round) i have the short wishbones all round on the evo and both cars use the same springs all round White front and light blue rear yet the raycer carries more corner speed (the evo seems to bog down) i race indoors on carpet any ideas.

Thanks

Nathan Pearce

[cobra81li200]

Just to say : it's nice to have you back on the board Ben.

[Ben Cosgrove]

Hi

Nathan - As far as I am aware the new shape bulkheads will not be released as separate items. Most of the other bits are around allready i think. There are major benefits in the lightweight axles/diffs and driveshafts not to mention the lightened layshaft. I know it is expense but the factory kit really is a completely new fresh car!

The T1R car is designed to be more forgiving to drive especially on carpet. The Evo 2 s designed to be more precise and react to setup better. Depending on setup will depend on which car is best. The Evo 2 has always been faster in testing as it will ultimately carry more corner speed with the correct setup, it is harder to find though.

Nice to be back.

Ben

[cbcbcb]

Hi Ben,

I set the droop screws at the rear so that the springs are held in place when the shocks are fully extended. I see other drivers allow the springs to move about, but when I had my car set up like that it made the rear very loose and it was undrivable.

I understand the effect of the droop settings in theory, but I don't really know how much droop should be used in practise. Should the springs be allowed to move freely or not?

[redlinezak]

are the lightweight parts new items released only with the factory kit then as i have not seen or heard of them before as it is these that i mainly want to get hold of

[Ben Cosgrove]

Hi

Charlie - the amount of droop needed depends on the track surface. For smooth tracks i run less droop than on bumpy tracks. I always use this method to setup droop

Set the ride heght with cells/motor in the car, usually to 5mm on a flat track. Then lift the chassis up slowly until the wheels lift off the ground. When they leave the ground you need to measure the ride height at the point they leave the surface. I start with 5mm (10mm overall) droop on the back and 3mm (8mm overall) when running 5mm ride height. The 8mm and 10mm are the point at when the wheels leave the ground.

If i raise the ride height to 7mm then I add more droop to 10mm at the front and 12mm at the back. Keeping the same aspect ratio front to back. These are std starting points I use and different drivers prefer different amounts.

On carpet I will use 1mm on the front and 2mm on the back above the ride height set.

Nathan - I am not sure but i think the lightweight parts will be released. The bulkheads have different roll centre positions which all the team use though. You will have to double check with centrepoint on the release of those parts.

Ben

[kev kirk]

Ben
Another question on shockers
I have a new evo 2 (1 month old) and the shockers leak all the time. is this standard? Could I use some sealant on the top cap thread? And finally, what weight oil would you recommend for a technical indoor carpet track?
Cheers
Kevin

[Ben Cosgrove]

Hi

Kevin - the shocks should never leak!! Check that you have correctly tightened the black plastic cap where the o-rings sit at the bottom of the shock. They should push on and then be twisted till they dont move. I guarantee this will be your problem. Just double check the instructions.

Oil indoors probably xray 30 with 2 or 3 holes open on the piston. 3 for more reaction, 2 for less chassis roll (smoother).

Ben

[steven bough]

When ive been building my shocks,after i have put oil in and got the top cap on,ive stood the shocks up-side down-so the shaft is to the top & un screw the plastic cap bit that the o-ring is in & left it to vent for 10mins-as i thought this was what the instructions ment by letting the shocks vent-/stops any re-bound?
I guess from reading your posts ive been doing it wrong?? :-[

Stevie

[Ben Cosgrove]

Hi

Steven - I have never even tried that method :o I just build them as I said in my earlier post. Works for me :)

Ben

[steven bough]

I have the T1R,And at carpet wars i noticed many T1R drivers had replaced there plastic top decks with carbon top decks?
Im thinking of copying-Which carbon top deck should i buy?

Regards

Steve

[Ben Cosgrove]

Hi

The top deck is a mod to try and get less chassis flex and therefore more response from the chassis. The correct top deck is the full carbon one. It makes the chassis a little stiffer which may not suit everyones style, worth a try.

Ben

[Petermarkphillips]

Any good setups for carpet, on T27's or schumi dragons that I can see? Generally what springs/oil/pistons do you run on different surfaces, ie carpet, tarmac? For short wishbones. Do you ever use the longer ones now? Oh and sorry for so many questions at once, :P

Cheers
Pete

[Ben Cosgrove]

Hi

I will post some starting setups for the Factory kit car for carpet and tarmac very soon.

Ben

[John Stones]

Hi Ben,

I have just rebuilt the diffs and im just not sure how tight or loose they sould be. What are the signs on the track if the diff is slipping and how tight should i set them now i have rebuilt them?

thanks

[Ben Cosgrove]

Hi

John - the signs of a slipping diff will be loss of acceleration and if it is the rear diff then you might lose rear grip during the run. I always make sure that my diffs do not 'slip' when I hold the spur gear and one wheel, whilst trying to turn the other. They should always feel smooth.

As promised here is a very good starting setup for tarmac tracks with the factory kit car

https://www.mytsn.com/setups/setup.asp?sid=2353

Ben

[Petermarkphillips]

Hopefully you can clear something up for me, i've heard that xray shock oil of say 30wt is of different viscosity to say 30wt associated, by about 10 or 15 wt. Ive been using associated oil in my car, due to availability of xray oils. Can you tell me if there is a difference and if so by how much.

[Ben Cosgrove]

Hi

Peter - yes the xray oil seems to be completely different to most other brands. There is also a huge difference between the line like 20 is thin and 40 is mega thick. I do not know how different they are but they are different.

Associated 30 oil is thinner than xray 30 i think. Other brands 40 is similar to xray 30.

Ben

[Petermarkphillips]

Think id better order some oils with gav then, cheers ben.

see ya in bedworth for the first national, if I dont pester you on here before then.

[John Stones]

HiI always make sure that my diffs do not 'slip' when I hold the spur gear and one wheel, whilst trying to turn the other.


Thanks alot, Im just a little unsure about what people mean when they say 'slip' though ??? when you turn the left wheel while holding the right and spur, IS the turning of the left wheel the diff slipping?

thanks again

[Ben Cosgrove]

hi

yep john, your spot on. try to make it so it doesn't slip.

ben

[Chris Thompson]

would the above set-up work for a T1R at bedworth?

[Ben Cosgrove]

Hi

Chris - the setup may not work that well with the T1R car at bedworth because the factory car runs different roll centres to the T1R.

Run high rear roll centre and plastic 3 deg castor blocks. Should be ok then.

Ben

[redlinezak]

ben will the short wishbones all round work ok as a direct replacement without any of the roll center modifications as i have been having major handling probs since fitting them (i ran the front upper link in the outermost hole and the rear link standard in the bulkhead. I have since reverted back to the standard wishbones to see if this cures the problem as the car was basically undrivablebut i wont know the result until friday evening( i was having no rear end grip entering a corner (so under braking or lifting off) and no grip whatsoever front or rear when exiting (car just pushed wide) also could you tell me if the droop settings i see on my tsn setups can be directly copied using the hudy gauge?

Thanks

Nathan Pearce

[steven bough]

Hello Ben,
How do you higher the roll centre on the T1R?

Also what does using the the higher holes in the rear bulk head do/where you alter the anti squat-& in what situations would you use the two higher holes?

Kind Regards

Stevie

[Ben Cosgrove]

Hi

The upper holes you talk about are the holes for a higher roll centre. I would use them all the time as the car will stay flatter through direction changes and generally feel like you have more steering.

Ben

[Ben Cosgrove]

Hi

nathan - the short wishbones do work as a direct replacement (no changes to set up) the droop depends on which roll centre position you run and that is a potential area the setups could be flawed on. Make sure when changing from the long to short that the droop you had remains the same. the problems you experienced sound weird, let me know how you get on tomorrow night.

ben

[redlinezak]

yes they are weird noone seems to have an answer and i have set up a few other xrays with no probs but will let ya know saturday as its getting to the stage where if i cannot sort it i see no alternative but to change cars but am very fond of the xray so want to stay with it if possible

[John Stones]

hi

yep john, your spot on. try to make it so it doesn't slip.

ben


Hi again,

Im still confused with diffs, if i try to make it so it doesnt slip, does them mean i cant rotate it at all with my left hand, without the right opposite wheel turning? (while holding the spur of course)

[Robfo]

In my opinion on the Xray you don't need to set the diffs so they don't slip, i only say this because of the way we set them up ie on the car rather than outside the car.
I ran a mission before the Xray and set the diffs outside the car on there own. I ran them so they didn't slip as i tryed to turn the diff pulley, but on the Xray we put alot more pressure on the diffs by setting them up by turning the wheel rather than the pulley.
All i'm trying to say is, by turning the wheel we put more pressure on the diff because the wheel is bigger so its easier to make the diff slip.
Hope you understand what i'm trying to say (i do tend to babble on a bit sometimes), Oh and sorry for posting an answer/opinion in your question section Ben ::)

[John Stones]

Front belt skips when i try turning the front diff in the way the instructions say, i think it might be a little too tight ::)

[redlinezak]

ok ben have a couple of developments on my car probs. Having changed the wishbones back to the long type the car was very slightly better i then decided to refit the standard top deck instead of the xtreme racing solid i had fitted when i bought one of their chassis kits (my chassis was ground away doing some oval racing) and upon fitting the top deck i noticed that the belt became much slacker (not too slack i only race 19 turn so slipping isnt a problem) so i have to guess that the xtreme racing top deck i had was slightly longer although on inspection it appeared the same length which must have been affecting the car as it was much more drivable with the origional top deck back on (i am going to try the genuine solid top deck next friday to see if the problem reoccurrs but at the moment this seems the most likely explanation for the probs (the difference in belt tension before and after was huge).

[cobra81li200]

About diff tightening, I agree with Rob. Your wheel will spin before your diff slips even if you can turn the wheels while locking the spur gear. This is for a setting when you need to apply a considerable force onto the wheel, not if you can make the wheel turn with one hand).

Besides, I take into acount the fact that the diff reaches a higher temperature when the car is on the track, thus tightening the diffs (as the balls and plates grows with temperature by a small amount). For this reason, sometimes my diff slips if I apply throttle suddenly on the first couple of accelerations, and then stops (so what I do is be easy on throttle in the warm up laps) as the temperature raises. Actually, I usually try not to have this, but it's a really sensitive setting on some cars, and sometimes you just get it slightly under tightened. Anyway if you're not sure of what you're doing, it's ALWAYS better to have a diff slightly over tightened than massively slipping, this way you're sure not to destroy it.

[steven bough]

At ashby track this week end i gear'd my car higher than normal(carpet) i put a 30t pinoin on,& the only way it would fit is with a 90t spur.but something that i noticed was that were the brushes go in the motor was pointing down out of the bit of the chassis that is cut away for air under the motor,Which i did not like because of dirt getting in the brush hood,plus the 1st race i must had bottom out & it had cut the wire on the brush..is there any way around it..i increased the ride which stopped the brushes coming off,but it still nerves me that the brush hood is pointing out of the air gap?

Steve

well done Ben(who was uncatchable in the mod final)!!

[xraydad]

Hi

nathan - the short wishbones do work as a direct replacement (no changes to set up) the droop depends on which roll centre position you run and that is a potential area the setups could be flawed on. Make sure when changing from the long to short that the droop you had remains the same. the problems you experienced sound weird, let me know how you get on tomorrow night.

ben

Hi Ben
sorry to keep banging on with this short arm stuff, but you say no changes to setup. Does this mean that I have to move the front camber link location on the shock tower to the outer hole, or can I leave it in the centre standard position for a T1R?. I noticed that the standard long arm setup seems to position the top pivot almost directly over the bottom in standard form.
Any help is much appreciated
Cheers Phil

[jimmy-maddison]

hi phil im sure ben wont mind if i answer this one/

u are best off shorten the front link to the outer hole this will give same feel as long arms in middle hole but the shorter arms are just far better

thanks jimmy

[cobra81li200]

At ashby track this week end i gear'd my car higher than normal(carpet) i put a 30t pinoin on,& the only way it would fit is with a 90t spur.but something that i noticed was that were the brushes go in the motor was pointing down out of the bit of the chassis that is cut away for air under the motor,Which i did not like because of dirt getting in the brush hood,plus the 1st race i must had bottom out & it had cut the wire on the brush..is there any way around it..i increased the ride which stopped the brushes coming off,but it still nerves me that the brush hood is pointing out of the air gap?

Steve

well done Ben(who was uncatchable in the mod final)!!


Sorry, Ben, I think I can answer that one ;D

Hmmm, why not move to a slightly smaller spur (let say 87t or even less) and smaller pinion ? This way you can have the same overall ratio but with the motor a little higher, so the motor won't touch the ground.

[redlinezak]

hi ben sorry to keep pestering you with this. The car is now "OK" but is basically suffering from a general lack of grip ie not much steering and a very loose rear end upon entry and low grip on exit under power (it seems better in more sweeping bends under full power) but indoors there arnt to many of these. would it help if i pmmed you my set up to see if you can spot anything glaringly obvious. Thanks and apologies again.

Nathan

[cobra81li200]

hi ben sorry to keep pestering you with this. The car is now "OK" but is basically suffering from a general lack of grip ie not much steering and a very loose rear end upon entry and low grip on exit under power (it seems better in more sweeping bends under full power) but indoors there arnt to many of these. would it help if i pmmed you my set up to see if you can spot anything glaringly obvious. Thanks and apologies again.

Nathan


:o

I don't call that "OK".

Usually when I think my setup is allright but on the track my car is shit, I check that I don't have my hinge pins bent, or anything loose in the suspension (like suspension mount screws, what do you think of that Rob ?), and since now, it's always been the case...

Just my 2 pennies

[steven bough]

Is the Factory Xray Been released yet?

Nathn
Try going back to kit set up-as im not to far off kit set up and i have to dial steering out-as i have plenty of steering...all i have changed is to use 0%kick up & 0%anti squat.

stevie

[Robfo]

Nathan, if your car is as bad as you say i would take cobras advice and check the hinge pins and the screws that hold the plastic parts which hold the hinge pins in place.
I had a problem a few months ago which sounds similar to yours ie my car was c**p! I thought it must be my setup so i changed it many times. After that didn't work i swore at the car and that didn't work either (which was a suprise because this method always worked with my mission).
Then i rebuilt the car and in the process i found that the screws that held the hinge pins in were slightly loose. After that the car is going really well and i'm back to swearing at myself 8).
Have a good check around the car for bent/broken or loose parts as no setup will help you if the screws have worked themselves loose!

[cobra81li200]

And how many times did I ask you "are your hinge pins ok ?" ? ;D

[Robfo]

I bow down to your superior knowledge O god of rc!
I still beat you on sunday though ;D

[SMTCA Focal Point]

This may be a long shot but I had similar problems with a set of tyres where an insert had split after it was glued on. The car was unpredictable. Went away after I changed tyres. It took me three weeks to find that one.

[cobra81li200]

I bow down to your superior knowledge O god of rc!
I still beat you on sunday though ;D


I drove shit though, it happens. By the way, Alban had its first run today. Seems to be the same feeling as mine, which is a good point.

[Matt Brewerton]

Please keep chat to PM's
Thanks

[Ben Cosgrove]

Hi all

I have been experiencing computer problems and wont be able to answer questions till next wednesday. sorry.

ben

[redlinezak]

ok tyres not the problem as im running foams indoors hinge pins not bent arms are totally free all round and screws not loose as i have only just rebuilt the car (yet again) when i reverted to the long wishbones as far as settings go im probably not that far off althought i am using alloy hubs and steering blocks all round front settings are: 5mm ride height 1 deg camber 3 deg castor white springs 40 wt oil (schumacher) 2 holes open upper shock pos middle lowers shock pos outside, upper camber link in middle lower hole, 3 deg anti dive ackerman pos inside on servo saver rearmost on steering arms 40 shore tyres diff zero slip but still turns freely. Rear : 5.5mm ride height 1.5 deg camber white springs 40 wt oil (schumacher) 4 holes open upper shock pos 9 (middle row 2nd nearest the outside) lower pos middle, 0 deg anti squat upper holes used 35 shore tyres diff same as front maybe tiny bit lloser but still zero slip. Stiff upper deck batteries mounted saddle pack rear of car. Low ratio pulleys fitted. No doubt i have forgotten something but hope this helps.
I knew i would forget summat: the wheelbase is 256mm (4mm in front of the arm)

[steven bough]

I don't know much about using foam tyres-but when i first had my T1R i had white springs at the rear & blue at front-& i had oversteer & the rear was loose,i tried alsorts to calm it down,but did not work,then some one said try going harder at the rear as he said it was to soft-i did & it was lots better.

stevie

[STEPHEN E]

I think you should try harder spring as well.
I run red on the front and purple on the rear works for me.
foams should give great grip so i think a harder setup will work better.
Wont hurt to try can you loan some from another xray driver to give it a go.

[redlinezak]

i have the full set of springs but am just worried that i could get too lost in the set up and never find the real cause of the problem there are 2 other xrays totally standard running at my club and dont seem to have the same probs so its somewhere in the car

[university_dave]

there are 2 other xrays totally standard running at my club and dont seem to have the same probs so its somewhere in the car


Or in the car's response to you're driving style, two people can drive the same car and one will find it perfect and the other will hate it.

Looking at your setup I would highlight the springs, wheelbase and rear roll-centre as being front-grip biased.

Go harder on the springs, either purple/violet or red/purple (front/rear).
Set the wheelbase to max.
Use the lower holes in the rear bulkheads.

Each of the above should calm the rear of the car down.

The diffs could also be a problem, are you checking the tightness as directed in the setup book?

[redlinezak]

firstly thanks for all the response it is much appreciated. On the rear roll center i am using the standard location in the bulkheads i will try the wheelbase set to maximum on friday dave and may also try a different spring setup as you suggest. i have driven the other xrays and have found them much easier to drive than mine although my car is quick (well as quick as it could ever be with my thumbs driving) it is very hard work whereas other cars are more forgiving (and yes they are evos and not racers as i know racers are slightly more forgiving from what i have been told)
Have also just noticed whilst checking my setup that in trying to use the standard shock posistions (upper pos 3 ((lower row middle hole) and lower middle position) on the rear that i cannot get less than 7 mm ride height? is this usual

[Robfo]

!!! the ride height is likely to be the problem !!!

Check the shocks are built right! Did you build them or someone else? Are ball joints on the bottom of the shocks wound up too much?

Also are you sure the shocks are xray ones as earlier cars came with serpent shocks.

[redlinezak]

yes the shocks are the correct ones and i built them myself the length of the rear shocks fully extended (including where the notch is for adjustment it 70.5mm

[Robfo]

I'll check the length of my rear shocks when i get home, i'm sure the ride height is your problem.

[redlinezak]

ok thanks altrhough i say i cannot get the ride height below 7mm mounted in the positions i mentioned i normally use the second row of upper holes which allows me to run a ride height of 5.5mm its is only when using the lower holes as the standard kit setting suggests that i have a problem

[redlinezak]

ok my last 2 posts are incorrect i am using a different rear shock tower (extreme racing) and have just noticed that the holes are in slightly different posistions than the standard tower they are all slightly lower which will obviously affect ride height however i would still be interested to know the length of your shocks robfo thanks

[Robfo]

The length of my rear shocks are 70mm, if you can't get less than 7mm ride height have you thought about getting your foams trued down to a size that you can set a reasonable ride height? Are your foams huge?

[John Stones]

looks to me like this rear shock tower is all wrong.

[Petermarkphillips]

Hi ben,

Any suggestions on what bodyshells to use outdoors this year?

Have you tried the losi skoda, the protoform mg and what did you think of them on your car?

Cheers

Peter.

[cobra81li200]

Hi all, just a notice, ben told me on sunday he'll be back on the net tuesday (today) or wednesday. He finished 22nd at the LRP race, his car was ballistic, but he had glitching all week end. Besides, even his final was of a very high level, with drivers like Joel Myrberg, Sakke Ahoniemi, Martin Hudy etc...

I already told you : well done Ben ;D

[Luke Hobson]

yeah well done ben good drive

luke

[John Stones]

I just hope that in time i can get anywhere near that speed, well done Ben

[Ben Cosgrove]

Hi all

Thanks for all your support guys

I have some (sad?) news, I will have to close my thread for a while as I cant devote enough time to it and I do not feel that I am doing you justice at the minute.

You can always pm me with any specific questions which i will try to help you with.

I hope you all understand.

Ben