Board logo

MNR Inboard Front End??
Krismc - 23/4/11 at 04:33 PM

Went out for a BLAT today with a few cars including a MNR RT, MK indy and a Robin Hood, and they all managed on all the roads we went on, but my car skipped around the road and hit every bump in road and bottomed out a fair few times, My car is around 2" lower than all the other cars. But i cant get the ride height any higher.

Ive wound my suspension up as much as possible, if i wind it up anymore then the alluminium suspension tops(the bit the push rod attaches too) Hit and bang the chassis rails, the bottom wishbones are as flat as i can get them and the push rods are wound out quite far 15mm thread exposed on both ends.

Here are some pics of what i ended up with - although with all the suspension settings the same each side the car is 5mm higher on the right, which is a bit strange but can be adjusted around and the car body is only 80mm off the floor at Sides at front, and the nose cone is 55mm from the floor.

Which is probably why i hit every thing


(measurements taken on flat drive, not on that spungy floor)




Can any other MNR owner with a Inboard front end RT plus, can you let me know how high you can get your car off the deck at the front end? and how close your alluminium suspension tops are too the chassis rails??

[Edited on 23/4/11 by Krismc]


coozer - 23/4/11 at 04:57 PM

Cracking day out. you missed the best bit Kris, the road from Tan Hill over the Stang had me in stitches... totally clear air under Terry's car at a couple of places

Mine stuck like glue and never bottomed out anywhere, totally knackered and sun burnt now

[Edited on 23/4/11 by coozer]


lotusmadandy - 23/4/11 at 05:02 PM

It was indeed a good day out,though i need to look at my sump guard.
It's wrapped around the bottom of my sump and doesnt sound very good.

Still,the oil pressure held and i had a good run home.

We have to do that run a good few times over the summer,it's a cracking set of roads.

Andy


daniel mason - 23/4/11 at 05:05 PM

the bottom bones are not flat and the pushrods need winding out a bit more. 15mm is not a lot


Craigman9 - 23/4/11 at 05:06 PM

I am super jealous reading this thread


Krismc - 23/4/11 at 05:27 PM

quote:
Originally posted by coozer
Cracking day out. you missed the best bit Kris, the road from Tan Hill over the Stang had me in stitches... totally clear air under Terry's car at a couple of places

Mine stuck like glue and never bottomed out anywhere, totally knackered and sun burnt now

[Edited on 23/4/11 by coozer]


Aye, Mud guard snapped off 3 times, fuel guage failed at last minute(just a wire broke) and car bottomed out loads, apart from that it was a great great day out.


Krismc - 23/4/11 at 05:29 PM

quote:
Originally posted by lotusmadandy
It was indeed a good day out,though i need to look at my sump guard.
It's wrapped around the bottom of my sump and doesnt sound very good.

Still,the oil pressure held and i had a good run home.

We have to do that run a good few times over the summer,it's a cracking set of roads.

Andy


My sump is now totally silver again, all the paint is worn off!

quote:
I am super jealous reading this thread



you should be, it was indeed a good day out - especially as we all filled up when we left - At first petrol stations Coozer, and (sorry i didnt get ya name in the BEC) didnt require a fill up Andy used £7, the Robin hood(sorry i didnt get ya name) used £23 and i used £24. Hmmm

Although my car was missing and running on 3 occasionally at certain revs, but on getting home, i found that the plugs too the injectors aint over clever and one doesnt click into place very well.

quote:
Originally posted by daniel mason
the bottom bones are not flat and the pushrods need winding out a bit more. 15mm is not a lot


Thats 15mm plus what ever is behind the nut say 8-9mm !! i think thats a lot, how long are the rosejoints??


[Edited on 23/4/11 by Krismc]

[Edited on 23/4/11 by Krismc]


INDY BIRD - 23/4/11 at 05:46 PM

ws going to say winde the push rods out to raise height. also what spring !lb are you running you could also turn the dampers firmer by clicking them clockwise to increase damping this may help,??

nice day for a drive


Krismc - 23/4/11 at 05:51 PM

Ive got the standard MNR spring, (175 i think), how many clicks is a normal setup? Id like to be able too take the car out and keep adjusting until its better, but i need to remove bonnet and nose cone to get at them behind rad

[Edited on 23/4/11 by Krismc]


Davey D - 23/4/11 at 06:20 PM

what you will probably find is that most MNR are bike engined, thus lighter at the front end. I bet youve got the same rated springs, and dampers, and because youve got a boat anchor... erm i mean car engine it will be heavier thus needing higher rated springs


Krismc - 23/4/11 at 06:58 PM

quote:
Originally posted by Davey D
what you will probably find is that most MNR are bike engined, thus lighter at the front end. I bet youve got the same rated springs, and dampers, and because youve got a boat anchor... erm i mean car engine it will be heavier thus needing higher rated springs


No I've got the right springs for sure!


whitestu - 23/4/11 at 07:32 PM

I know nothing about MNRs but it looks too low to me.

As for skipping about over bumps, I improved my Indy a lot by adjusting the rack height to get rid of as much bump steer as possible. I ended up with the rack being nearly 10mm higher than it was before and it stopped the car feeling like it was going to throw me into a ditch every time one wheel hit a big bump.

Stu


daniel mason - 23/4/11 at 08:35 PM

im on 350lb front srings by the way! are you sure your spring rate is correct? take a rosejoint out and see how long it is. i think you will have a bit to play with. they need winding out.
i know from reading your posts that funds were very tight but i would consider taking the car to prcomp for a full geo set up! after reading posts from some of the racers on here.procomp seem to set them up as well as anyone. obviously when funds allow.


MikeR - 23/4/11 at 08:52 PM

Daft question - was your car designed for the road or track? The sort of hight your running has me thinking its designed for the track. Have you spoken to MNR? Surely they should be able to say what ride height it should be running at and what you need to do to get it there.


coozer - 23/4/11 at 08:53 PM

As said Kris, another vote for Procomp


Agriv8 - 23/4/11 at 10:14 PM

for road going cars bottom arms parallel with the ground.

can you wind the spring platforms up but looks like you have tried that. so three options left wrong push rods ( too short ) bottom arms on upside down ( depends on vintage )

ps cant remember the springs proping up my v8

regards agriv8

[Edited on 23/4/11 by Agriv8]


paublo999 - 24/4/11 at 12:00 AM

car definately too low, longer push rods would be my suggestion and it looks like you could be getting loads of bump steer as stated in previous posts.

Standard protech shocks are valved too heavy IMO, but I know Marc has different thoughts on optimal setups. If the shocks are damping too much the car will be skipping around like on hot coals.

Cheers
Paul.


Johneturbo - 24/4/11 at 07:56 AM

One of the things i'm going to do at stoneleigh is speak with protech (if they are there) about different valving

Stu, is there a formula on how to check for rack alighment/bumpsteer, mine is like it's on hot coals...even more so with our lovely british well maintained roads!
but that could be over valving on the shocks.


Krismc - 24/4/11 at 08:18 AM

Well all is on the right way, as its been to MNR a year, im sure they would have spotted a mistake. Longer push rods would be nice but id have to get them from MNR i suppose


daniel mason - 24/4/11 at 08:26 AM

i would take out a rosejoint first to see the length of it. jack the car up and wind the pushrods out until the bottom bones are past parallel than lower it down again.bottom arms should sit almost parralel.


Krismc - 24/4/11 at 08:36 AM

Can someone first confirm how much thread i can leave exposed, i wouldnt want to snap them!!

33mm of thread from shoulder to end of rosejoint.

[Edited on 24/4/11 by Krismc]


whitestu - 24/4/11 at 10:22 AM

quote:

Stu, is there a formula on how to check for rack alighment/bumpsteer, mine is like it's on hot coals...even more so with our lovely british well maintained roads!



What I did was:

Park the car so one wheel was parellel with the garage wall with the wheels straight ahead

Measure the ride height then take the shock off and get the chassis to the same height as measured

Attach a laser pointer [one of the cheap ones that are mounted on an angle guage] so that it is at 90 degrees to the brake disk

Draw a vertial line on the garage wall in line with where laser pointer points

I then lifted the hub up and down and watched how the laser pointer tracked the line on the wall. If no bump steer it should go straight up in line with the vertical line I had drawn.


Mine was well out so I spaced the rack up a bit at a time by puttting big washers under each mounting point until I got it so the laser pointer was as close as I could get it to the vertical line across the normal range of movement of the hub.

I then did the same on the other side.

It made a big difference.

Stu

[Edited on 24/4/11 by whitestu]


Johneturbo - 24/4/11 at 05:59 PM

Kris, i'd check how much thread is on the insert in the pushrod that would be the minimum i'd have threaded in, if that makes sense?

Stu, that makes perfect sense.. (unlike my answer) i will give that a go easy enough just to get a rough idea if it's out by much


Krismc - 24/4/11 at 06:42 PM

The push rod looks to have nuts welded on each end - one lefty loosy and one righty loosy - so id say 8-9mm is the average nut width.


Ive managed to get the front of the car up by 20mm by lenghtening the push rod and then winding the springs up at the same time so that the Top Ally rocker above spring doesnt hit chassis - car sits a lot higher now and back is 25 mm higher than front.

Just the camber and toe to set up now and im done.

From rose joint shoulder to where it enters push rod is 34mm can anyone else confirm how much they have sticking out?? this is only under very little tension and lots off compression so the rosejoints cant snap like this can they?? ( Taking pic now)

[Edited on 24/4/11 by Krismc]


lotusmadandy - 24/4/11 at 06:53 PM

Kris,if you only needed to add say the thickness of a nut
to lengthen the pushrod why not buy a pair of nuts and screw them
onto the rod ends leaving say 20mm thread on the end of the rod end.
Screw the rod end back into the push rod and weld the new nut onto the end
of the pushrod.

That would give you at least another 10mm adjustment for a small outlay.

Andy


Krismc - 24/4/11 at 07:01 PM

quote:
Originally posted by lotusmadandy
Kris,if you only needed to add say the thickness of a nut
to lengthen the pushrod why not buy a pair of nuts and screw them
onto the rod ends leaving say 20mm thread on the end of the rod end.
Screw the rod end back into the push rod and weld the new nut onto the end
of the pushrod.

That would give you at least another 10mm adjustment for a small outlay.

Andy


Ahh of course!!

Except i need 2 Left hand 1/2 unf nuts, and 2 right hand ones


Krismc - 24/4/11 at 07:05 PM

Right here goes,

Wishbones are totally level, ive got 105mm clearance at front (measured just after wishbone from body to floor), and 140mm at rear just in front of the rear arch (dont know why but this has increased) so i need to lower the springs at back. MNR quote 25mm differance in height.

The Rosejoints look like this, Dirty mark is where they used to sit..........




and the car looks like this........







[Edited on 24/4/11 by Krismc]


lotusmadandy - 24/4/11 at 07:12 PM

Mcgill motorsport sell the nuts for a couple of quid mate.

Andy


Krismc - 24/4/11 at 07:16 PM

quote:
Originally posted by lotusmadandy
Mcgill motorsport sell the nuts for a couple of quid mate.

Andy


Brilliant cheers,


RickRick - 24/4/11 at 08:27 PM

my cars number 80 somthing, and it was about the time they were having a difference of opinion on the wishbone fittmeant, mine have the pushrod mounting upper most, could be you have the short pushrods for mounting on top, i'd be tempted to flip lower wishbones, i know i've got 100ish mm with nothing like that amount of thread showing


Krismc - 24/4/11 at 08:38 PM

Mines chassis no 40, wouldn't like too flip wishbones with out speaking to marc first, what lenght are your pushrod threads.


daniel mason - 24/4/11 at 10:06 PM

you cant flip the wishbones. there was a post a wile back on here regarding this


Krismc - 25/4/11 at 08:51 PM

Had my suspension setup by a fellow 7er today, but before setup we checked over and push rods could do with being longer but are safe enough i recon as they are, but no harm in making them longer- they seem too be missing some of them small top hat spacers (not sure who removed them) so they are not fully fixed properly at present i need to ask MNR if i should fit a bigger bolt to take up slop (unf one as a metric one is fitted and the rosejoints are unf) along with the missing spacer top hats.

As for the rest of the car.... Well..... where do i start.

The front car width is 68 1/4inch, the rear car width is 65 1/2 inch ..... thats a job for another day, i need wind the back right out and back left in a little to stop the crabbing and take spacers out the front wheels and realign arches

Tyre pressure front 40PSi rear 30Psi

on the Front raceleda hubs the rear bearings on both sides had a wrongly located spacer so they where tight but i could move brake disc a fair few mm in every direction, front wheels had 2 degrees off toe out, 1/4 degree of neg camber and 4 degrees of caster, but with the wobbley hub that could move toe and camber out even further - probably why the car wobbled along the road!



Now the bearings sorted and tight, the pushrods still need top hats but dont affect settings, camber 1 1/4 neg on each wheel all round, Even toe in all round, think we finally agreed on some where between 2 and 3 degrees , tyres down too 20Psi all round. ( dont quote me on these settings, i think thats what we did its been a long day)

Car is unbelivably better now, much more control at high speed, less bump steer and doesnt follow every bump on road. the front is over 100mm off the floor and the rear is 130mm so might reduce the ride height a little when i set up rear and then setup too suit.

[Edited on 25/4/11 by Krismc]


blakep82 - 25/4/11 at 09:05 PM

just a thought, there isn't a chance that your lower wishbones might be able to go on the the other way up is there? putting the push rod mounting on top, and 'raising' it my about 30mm or so?

remember i don't do 7's so i don't know how possible it might be

oops, just saw daniels post

[Edited on 26/4/11 by blakep82]


Frosty - 26/4/11 at 08:40 PM

I think I can see the problem. I presume you have some form of height-adjustable coilovers?

If so, my guess is that you have it set to the lowest setting? If you add an inch of preload into the springs (that is, raise the spring platforms by an inch), you'll raise the ride height, which you can then fine-tune with the push rods.

Does the front end of the car look like this?

http://bp3.blogger.com/_lxVDE01wMCw/R-Lwny7kxTI/AAAAAAAAAQI/YxZ_cfvdd3k/s1600-h/c.JPG

Winding an inch of compression on to the springs will do the job nicely in this case.


procomp - 27/4/11 at 08:34 AM

Hi

Somebody pointed me in this direction as there was reference to the Protechs for the MNR's inboard setup.

Just to let you know that we at procomp have already done this for both the MNR and the MK setup. Prices can be found HERE The kits consist of bespoke valved dampers and springs to suit the applications.

Cheers Matt


40inches - 27/4/11 at 09:32 AM

quote:
Originally posted by Krismc


Tyre pressure front 40PSi rear 30Psi


[Edited on 25/4/11 by Krismc]


Really They are hellish high pressures, normal tyre pressures for a 7 are between 16 - 20psi, I would take extra care if it rains


daniel mason - 27/4/11 at 09:44 AM

they were high. which is probably part of the reason he was skipping around the bends. but as hes changed them to 20 psi it should improve things
also. have you been driving around with the top of the pushrod not fixed in the mounting bracket? or have the spacers been replaced with washers


Krismc - 27/4/11 at 10:09 AM

Yea I think where the top spacers should be where i have washers in them so there's play in push rods, I've emailed mnr to get some spacers if i need them and asked if metric bolt in rocker/pushrod is right, as the push rods are unf. (are they open this week ive had no reply)

And yes I now have 23psi.

[Edited on 27/4/11 by Krismc]


Frosty - 27/4/11 at 02:51 PM

quote:
Originally posted by Krismc
Yea I think where the top spacers should be where i have washers in them so there's play in push rods, I've emailed mnr to get some spacers if i need them and asked if metric bolt in rocker/pushrod is right, as the push rods are unf. (are they open this week ive had no reply)

And yes I now have 23psi.

[Edited on 27/4/11 by Krismc]

Did you check your coilovers to see if they are height adjustable?