Twin / Rear engine nova

stevebarker · 23-10-2007, 23:00

Hi, after spending a year or so dreaming about building a rear engine / twin engine nova, I have decided to make a start. ( mainly due to the inspiration in the projects section thanks beardy & lee303 )

Beardy advised that the best place to begin was to make a jig. So I started construction of this at the weekend, its made from 100x60x5mm box, the steel cost me just over £200 and I have about 10hrs in it so far, next I am going to make some legs for it about 450mm high, and some way of clamping the nova to it.

Kev_cav · 24-10-2007, 11:49

any idea what engines u going for?

chip · 24-10-2007, 11:51

Use the backend of a car like a VX220 or MR2, and NOT the front end of a car like a calibra or corsa, thats my advice.

stevebarker · 24-10-2007, 15:02

its got to be two LET engines

Quote:

Originally Posted by chip

Use the backend of a car like a VX220 or MR2, and NOT the front end of a car like a calibra or corsa, thats my advice.

i would like to try and make a space frame. but will probs end up using a wishbone setup and the hubs from the front of the nova with the track rod ends in a fixed position. Will the back end from a vx220 be better ?

essexgte · 24-10-2007, 15:08

Quote:

Originally Posted by chip

Use the backend of a car like a VX220 or MR2, and NOT the front end of a car like a calibra or corsa, thats my advice.

Really?

I would have thought that steve is showing a definate steer towards some serious fabrication work by starting off welding up a jig.

I'd say the best way to resolve this design would be to fabricate a spaceframe to mount the rear suspension & engine to, not hack an old car apart for what minor amount of metal you'd actually retain.

I mean what would be the point in using the aluminium chassis from a vx when the car he'd be using it on is primarily steel... & why an MR2? is there any engine or drivetrain similarities, er no.

Steve, stick with your idea of spaceframe & using manufactured lower arms as mentioned.

Taking reference to lee303, why not add rose joints to the ends of the arms & tie rods etc for adjustment.

chip · 24-10-2007, 15:22

By "back end" I was NOT envisaging him angle grinding it off and using the whole clamshell etc, dont be so stupid!

I meant the suspension from the back end, not the rest of the car!

Have a go at it using the front end of a nova if you like, but the bump steer you get will soon change your mind!

If you are going to use any FWD front end suspension setup, then look at the mk4 astra, as the steering arms are located in a much better place for you to be able to eliminate bump steer, thats what Im moving to doing on my nova (as its already a mac strut rear end and hence too much hassle to swap to something very different)

BeArDy · 24-10-2007, 19:44

Nice work mate, will look forward to how you get on.
you need a centre line on there, an then you need to mount the Shell 100% level and straight.
I would also say buy a digital angle gauge which is twin axles as you can work out if things are 100% level, meaning if you garage floor is 2 degrees out you can work this into your suspension tops levels......

essexgte · 24-10-2007, 22:47

Quote:

Originally Posted by chip

By "back end" I was NOT envisaging him angle grinding it off and using the whole clamshell etc, dont be so stupid!

I meant the suspension from the back end, not the rest of the car!

Have a go at it using the front end of a nova if you like, but the bump steer you get will soon change your mind!

If you are going to use any FWD front end suspension setup, then look at the mk4 astra, as the steering arms are located in a much better place for you to be able to eliminate bump steer, thats what Im moving to doing on my nova (as its already a mac strut rear end and hence too much hassle to swap to something very different)

oooh check out your over reaction. . . nerves raw or something?

Why would you use just the suspension from the rear of a car?...

be more prescise next time unless you want people to think you are an idiot, i mean using an mr2 "rear end" as you phrased it... and you have the nerve to call me stupid, as far as I can see from looking at your "opinion" on things is that you don't know everything, so don't comment, unless you've ever actually built a rwd car from scratch other than just buying one done for you i'd listen to you, maybe....

Anyway, did I ever suggest you use a nova front end? No I said "spaceframe", that's bespoke triangulated fabrication fit for purpose adding some adjustablr tie rods / tca's, not "use the back end of a VX220". If an astra mk4 is so good, why not suggest that? Or is that like letting the cat out of the bag...

..besides, if you're talking about handling the last thing you'd do is make something as short as a nova rwd.

seriously chip, unless you have real value to add to posts don't bother just to get your number up.

That's just sad.

essexgte · 24-10-2007, 22:50

by the way, good luck stevebarker, I hope you'll be able to distiguish between the comments & the recommendations on here.

I look forward to seeing how you get on.

Rick Draper · 24-10-2007, 22:58

Quote:

Originally Posted by essexgte

I would have thought that steve is showing a definate steer towards some serious fabrication work by starting off welding up a jig.

seriously chip, unless you have real value to add to posts don't bother just to get your number up.

That's just sad.

Firstly if i was removing any major structure from my car (like in the case of fitting a rear engine) i would be wanting a jig to bolt the shell to to stop it twisting and flexing as the metal is removed.

Secondly i think chip brought a very valid point to this post. After all he has a RWD nova and knows the pitfalls of his current setup and where he feels it could be improved upon.

Clearly only you thought he meant use the whole rear end of said cars

.

stevebarker · 25-10-2007, 07:35

After thinking about it a little the MacPherson strut and the nova hub carrier’s setup probably isn’t the best way to go. ( thanks chip for making me think )

If I used the nova hub carrier I would have to fix the track rods in a set position. When the suspension travels upwards there will be slight movement in the wheel direction. I have read that the affects of this can be sorted out / reduced by the angle and position of the track rod.

This is going to be difficult. I might have to look into some kind of trailing arm setup. I know someone with a ZCars rear engine mini so I will try and get a look at that for some ideas.

Quote:

Originally Posted by BeArDy

Nice work mate, will look forward to how you get on.
you need a centre line on there, an then you need to mount the Shell 100% level and straight.
I would also say buy a digital angle gauge which is twin axles as you can work out if things are 100% level, meaning if you garage floor is 2 degrees out you can work this into your suspension tops levels......

i have a Digital Inclinometer, when you say twin axles do you mean you can have it set to display level, but you can also zero the level to a surface thats slightly out ?

BeArDy · 25-10-2007, 07:42

EssexGTE i think your the one over reacting; Chip was talking about using a suspension set up not just welding the front of a car in the back.
As even if he make a full space frame he is going to have to use a hub carrier off another car aswell as bottom arms.
Chip was giving him advice saying look out for bumpsteer and using a setup which has already come out of a mid engine car as the big companys will have already worked out the bump steer alinement.
If you go on Vauxsport there was a massive post about this.
If you use a FWD setup then its hard to get rid off the bumpsteer 100% you can work it out asmuch as you can by working out the movment of the wheels in line with where the bottom ball joint is aswell as the steering arm.
With my corsa i have worked it out to limit the bump steer as much as i can on the setup i wanted to use.

chip · 25-10-2007, 07:43

Quote:

Originally Posted by Rick Draper

Firstly if i was removing any major structure from my car (like in the case of fitting a rear engine) i would be wanting a jig to bolt the shell to to stop it twisting and flexing as the metal is removed.

Secondly i think chip brought a very valid point to this post. After all he has a RWD nova and knows the pitfalls of his current setup and where he feels it could be improved upon.

Clearly only you thought he meant use the whole rear end of said cars

.

Ah well Rick you know how it is mate, you make an idiot proof post and along comes a bigger idiot

The problem with using a spaceframe and the nova mac strut setup (essentially what mine is as although its calibra based thats fundamentally the same) is that no matter where you fix the track rod arms off to you WILL get bump steer introduced as the bottom ball joint moves in an arc with the bottom arm, but the steering arm moves in a a section of an elipse, so its just not possible to totally eliminate bump steer doing it this way, it will ALWAYS be there, so to go to all the effort of custom making a spaceframe just to end up down this route is a bad idea, hence my good advice.

Still if it offends essexgte so much that I happen to know some basics about suspension and he clearly doesnt, I wont bother posting in here again.

Steve Barker, if you would like any more advice from me based on lots of first hand experience of altering the angles on mine, and of driving it and generally knowing it inside out, then feel free to ask the question over on www.vauxsport.com where it wont upset any little children like essexgte who havent a clue what they are on about

alistairolsen · 25-10-2007, 07:43

either you need a mac strut setup wher the tie rod is level with the wishbone, with both the inboard and outboard pivots inline, or you need to be running double wishbone irs. Personally, Id be using the back end of a locost, just get the book and copy the geometry.

As far a essex gte goes, get back in your box if youve nothing useful to add mate, youre making a **** of yourself. As beardy has demonstrated, it is perfectly possible to make a very nice spaceframe then ruin it using cav front end suspension, all chip was trying to do was warn against the idea that you can just fix the steering on a front end and expect it to work. Hes one of only 2 or 3 im aware of on this forum who has ANY direct experience of tinkering and driving such a machine.

chip · 25-10-2007, 08:29

Actually, despite my initial thoughts to just "ignore the troll and he will probably go away" thats a pretty big swipe being taken at me there, so I will respond to it.

Quote:

Originally Posted by essexgte

oooh check out your over reaction. . . nerves raw or something?

I havent over reacted to anything, no one else in this thread thinks that anyone saying "back end" or "front end" thinks it refers to anything other than the suspension components, so I was just surprised anyone was silly enough to think it meant the lights or body panels or any of that too.

Quote:

Originally Posted by essexgte

Why would you use just the suspension from the rear of a car?

Because its been designed by talented chassis designers to have the correct characteristics in terms of the dynamic toe/camber to handle well in the back of a car, where as the front of a car hasnt

Quote:

Originally Posted by essexgte

...

be more prescise next time unless you want people to think you are an idiot, i mean using an mr2 "rear end" as you phrased it... and you have the nerve to call me stupid,

You are the only person stupid enough to think that is what I meant, so thats why you got called stupid, look at all the other replies, EVERYONE else understood I meant the suspension not the tail lights or bodypanels or whatever the hell you think I meant.

Quote:

Originally Posted by essexgte

as far as I can see from looking at your "opinion" on things is that you don't know everything,

You are correct, I dont know everything, in fact I dont even think the likes of colin chapman would ever claim that about suspension.

Quote:

Originally Posted by essexgte

so don't comment, unless you've ever actually built a rwd car from scratch

Well that rules out you and everyone else in the thread so far then as no one commenting has built one, and only beardy is building one.

Quote:

Originally Posted by essexgte

other than just buying one done for you i'd listen to you, maybe....

Ive had my car apart and back together numerous times and have learnt a great deal from the mistakes of the people who original built it, its not how I would do it as frankly I know a lot better than they did, but as I ended up with the car anyway, it makes sense to persevere with it rather than just scrap it and start again TBH, I really dont see how you think that somehow invalidates my opinion, lee303 for example has never as far as im aware built a FWD car from scratch rather than just modifying an existing shell, and yet I would very happily listen to his advice on FWD car handlings based on that.

Quote:

Originally Posted by essexgte

Anyway, did I ever suggest you use a nova front end? No I said "spaceframe", that's bespoke triangulated fabrication fit for purpose adding some adjustablr tie rods / tca's

It doesnt matter what its made from, if you are mounting nova struts onto it, you are still stuck with their fundamental design flaws for using in a mid engined layout, most notably the bump steer

Quote:

Originally Posted by essexgte

not "use the back end of a VX220". If an astra mk4 is so good, why not suggest that? Or is that like letting the cat out of the bag...

Its not "so good" its just got the potential to be a lot better than a nova or a calibra due to where the arms are mounted, its still inferior to the VX220 setup though, hence I suggested that instead, ive not got a problem with letting cats out of bags, quite the opposite, I only joined the thread to do exactly that and give him the benefit of my first hand experience.

Quote:

Originally Posted by essexgte

..besides, if you're talking about handling the last thing you'd do is make something as short as a nova rwd.

What a silly little response, he is going to want to make it as good as he can if he is bothering to do it at all.

Quote:

Originally Posted by essexgte

seriously chip, unless you have real value to add to posts don't bother just to get your number up.

That's just sad.

My only response to that Im afraid mate, is that it doesnt apply to me, but seems to apply very well to yourself

alistairolsen · 25-10-2007, 08:37

cars as short as a nova...

audi sport quattro, pug 205 t16, metro gr4, volvo 360 drift cars, renault clio v6, renault 5 gtt raider, and locost/se7en, most small mid engined kitcars, need I go on? Yes theyre all twitchy and require constant input, but I think we can all agree they handle "well"

chip · 25-10-2007, 08:41

Alistair, unless you designed the volvo 360 from scratch and hand built it using only a spoon, please dont comment on them even though you have driven one.

Essexgte will cry otherwise mate

alistairolsen · 25-10-2007, 08:43

sorry, Ive never built anything from scratch to my own deisgn, I prefer to take advantage of the multi millions others have spent in development as a basis for a project. Anyway, must get back to some work

chip · 25-10-2007, 08:46

Likewise, I find I can reach higher if I stand on the shoulders of others.

DaveB · 25-10-2007, 08:55

glad I subscribed to this thread after reading essexgtes drivel last night

Thanks for not disappointing chip

alistairolsen · 25-10-2007, 08:58

*off topic* is it the piund coin that reads "standing on the shoulders of giants" around the edge?

chip · 25-10-2007, 09:16

Quote:

Originally Posted by alistairolsen

*off topic* is it the piund coin that reads "standing on the shoulders of giants" around the edge?

EssexGTE doesnt use other peoples money, he draws his own out with crayons he makes from his own stools

**Orange Peel** · 25-10-2007, 09:29

Can we get back ontopic please guys

Started to look like a very interesting thread so lets keep it that way

Corsapaul79 · 25-10-2007, 09:31

Nice project Steve, will keep watching. Always fancied doing something as mad as this (Beardys should be mental!) but havnt got the bottle to try without some backup info!

chip · 25-10-2007, 09:55

Quote:

Originally Posted by Orange Peel

Can we get back ontopic please guys

Started to look like a very interesting thread so lets keep it that way

Indeed.

Im happy to carry on giving advice based on my experience of this sort of vehicle if people can just refrain from showing me in toys if I happen to get near their pram on the way to post it.

Stevebarker, if you can be arsed to come down to somerset then you are welcome to come out in mine and I will show you first hand just WHY bump steer on the back is SO bad, as I suspect that no one else in this thread except for me as ever experienced it and hence probably doesnt realise why im making such a big deal of it!

Its a LOT more of an issue than on the front of the car!