Chip

iTrader: (3)

Strange question this one, and im not sure anyone will be able to really help with an answer thats definitive, but im sure people on here must have moved engines forwards and backwards before, so I may get lucky with some info.

Basically ive been measuring up the location of where the V8 needs to sit in my engine bay on my calibra.

Engine is 70CM long, of which the back 60CM of it basically has any significant weight.

Where its going to need to sit, I would have 50CM of the engine in front of the centre line of the strut (and only 10cm behind)

IE the centre line of the struts would be roughly inline with the sparkplugs on the back two cylinders.

Normally this engine would be sat approx 20CM further back than that in other cars it goes in.



Now im aware in principle that this movement of the engine forwards is going to give it a tendancy towards understeer.

The engine weight is 190KG

So essentially, The 20cm thats being added onto the front, weighs about 70KG probably.


So effectively what I will have done is the equivalent of fitting a 70KG weight about 40CM in front of the strut top centreline (slightly less far foward relative to the centre line of the wheels of course as there is some caster on the vehicle)




How much is that going to ruin the handling, are we talking 1 second a lap and feeling slightly less willing to turn in, or are we talking totally fucked and being a complete nightmare to drive?


I guess easy way to find out is install a 70KG weight in front of the engine on my sierra and take it out for a drive, but just interested in opinions!

Jim S

Chip

It will be a bit like my Audi S2, 5 cylinders and four of them in front of the front axle line, it feels a bit nose heavy and you think it should be handling better until you look at the speedo and realise how fast you are really going.

Jim

xr-stu

was gonan say, audi engines such as in the S2 and S4 are waaay over the front end and although no elise they dont handle to badly. audi probably had slightly more time and money to pour into development than you though!

is there absolutly no way you can move it furhter back? boxing the bulkhead etc wouldnt be too much extra grief considering the ammount of work its going to take anyway..

R5FORD

iTrader: (1)

can you really comparw audi to chips project tho.. audi have the engines like tat and must develop the rest of the car knowing how the engine will be sat so they have the suspension etc sorted for it.

i think neway.

Paul Eggleton

Chip, I would have thought you just aim for as far back as you can........

I know in these situations you have to comprimise as going as far back as you can could end up with a car like the nova

Whats you limiting factor? Is it you don't want excessive fab work on the bulkhead and tunnel?

Just thinking about basic law of moments and the situation it will cause problems, e.g. braking and cornering, I would say, albeit obviously, as long as the majority of the weight was behind the strut centre line that would be best and any further back a bonus.

I don't suppose anyone here has the position of the centre of gravity for the V8????

foreigneRS

don't think you can have a definitive answer. you know that mass centralisation is best for a low polar moment of inertia (i.e. easier to rotate about the centre of the car for a corner), but how much difference it makes will not be able to be quantified.

it's like a posche 911 or beetle in reverse really. it probably makes the braking better at the expense of turn in. i'm sure it can be mostly overcome with suitable spring/damper/ARB rates

Lee_R21Turbo

iTrader: (1)

This ones easy......presumably its gonna be RWD....so dab the brake, kick the clutch & let the back end steer you round the corner!! LOL!

21Turbos as standard virtually have the whole of their 4 cylinder engine past the strut line and they do have a tendancy to understeer if you go into a corner too quick or if you apply too much gas too quickly - this obviously isnt helped by it being FWD either though!!

I was up against a similar problem when I mounted the Cossie engine in the 21 - I'd of loved to of gone further back but all the steering bits & pieces got in the way so I just had to get it as far back as possible - the cylinder head sits about 1" away from the steering stuff now.

panelbeater

all valid points but the car it came out of has the correct geometry for the engines location. unless you are going to redisign the suspension geometry on the calibra to compensate, i'd suggest fitting it as far back as poss

Luca

iTrader: (2)

Perhaps speak to Andy G as he has done this twice so will probably point out what to do

Chip

iTrader: (3)

Its my old 5 cylinder audi thats making me think it wouldnt be as bad as it first seems, so I kind of thought those might get a mention.

The difference in the amount of work involved between where it looks like it would fit (the positioning im describing here) and moving it 1" further back is a MASSIVE amount, as if I fit it where Ive described, I can keep the standard suspension / brakes / steering rack / upper bulkhead / ARB / Subframe and just modify them a little.
Where as if it were to go 1" further back (or 12" further back etc), it would mean cutting the entire front end off, building up a spaceframe front and fitting the front suspension / steering / brakes etc all off of a RWD car.



LeeR21Turbo, that does sound EXACTLY the same issue!



On the plus side, looking not at the car the engine came from, but at the recipient car, which the suspension has of course been designed for in the first place, there is actually MORE weight in front of the centreline of the struts on that (the entire engine AND gearbox) than there will be on the new setup, and TBH that doesnt handle too badly really as it is.



Hmm, decisions!
Once I pick a route, its going to be a ludicrous amount of work to go back and change to the other option.


And Im slightly letting how well it would do donuts sat this way influence me too, childish I know, but this is meant to a be fun car after all

Chip

iTrader: (3)

The suspension design of the calibra is designed for the engine and box to be sat forward of the stut, and in fact the gearbox too on the original car.

Here is my bay at the moment:


Essentially if you drew a line through the struts, if I do it the way im saying it would mean im going to put the engne in so the back edge of it sits a little further back than the current engine, and the front edge sits a little further forward, so i guess the centreline of the engine is going to be roughly where it is now, just overhanging both ways by more, and the gearbox will be moved back right behind the bulkhead.

Actually, the more I think about the current setup and weight distribution of the calibra, the more this is making sense!

Chip

iTrader: (3)

Right, using my "mad photoshop skillz yo" this is basically where the mass of the engine would sit in the bay (it would look further forward as its costs plastic covers over the front of the engine covering up the distributors etc, but this is where the mass would be, ie the block itself)

lead_foot

iTrader: (1)

Wow, its as if there really is a 1zufe in that bay. LOL

Chip

iTrader: (3)

Luke I know mate, people will wonder why im not driving it around yet after seeing it "finished on the internet"

lead_foot

iTrader: (1)

Slightly

It should be one of the main influences, along with burnout and handling (read as tail out action) capabilities.

rst in breaking

iTrader: (2)

if only the instalation would be that easy lol, love to see this if it goes ahead though mate

Turbosystems

iTrader: (5)

surely you can't make it understeer any more than vauxhall designers do

Lee_R21Turbo

iTrader: (1)

He does that everytime he sits in it & drives it!

RWD_cossie_wil

iTrader: (9)

Midmount and G50 / getrag 6speed transaxle

focusv8

Your not considering the whole "New package"

You are fitting engine, gearbox and propshaft, diff, and drive shafts (unless the Calibra was 4wd) Extra to the original.

The new car/set up will be heavier, but the balance will change from front heavy to more centred.

You may be adding 70kg forward of the Front axle centreline but you are adding weight behind the front centreline, gearbox diff etc. as well which will counterbalance some of that 70kg.

I don't know the exact layout of a Calibra but I'd be surprised if you can get the gearbox past the original Steering rack location.
The rack must be mounted very high or very low if you can.

.

Chip

iTrader: (3)

Already got one mid engine converted nova, I want the calibra to be front engined instead.

Chip

iTrader: (3)

It is a 4wd, the gearbox will fit under the very high standard steering crack position, and essentially everything you said is rubbish because of those two points, BUT, thanks for the input mate, as I know you were just trying to help

Between the weight of the old engine and gearbox and transfer box and front shafts etc, it comes to almost the same weight as the new engine and box, there really is only about 50kg at most in it between the two setups, so overall weight will vary by about 4-5% or so, ie nothing to worry about, and like you say, it will be more centre weighted now with the gearbox back so far, so Im pretty confident it IS going to work ok now ive looked into it more, especially as having taken my own measurements from the donor car now, it looks like I can get the front of it a little further back then I thought when I first posted this based on measurements from the net.

Chip

iTrader: (3)

LMAO

RWD_cossie_wil

iTrader: (9)

Still, why not run a transaxle then to get the weight distribution closer to 50/50? Drive an Alfa 75, having the box over the back wheels REALLY brings the car alive

Chip

iTrader: (3)

I'll see how it goes with the box I have first, rather than starting ripping the back end apart as well, enough hassle doing the front, something to think about for later on.

RWD_cossie_wil

iTrader: (9)

Actually, I wouldn't bother with a V8, stick in an old pinto, would destroy any 500BHP turbo engine with power adders which under "race conditions" would blow up in 3 mins flat

Chip

iTrader: (3)

Hmm, good point

(anyone not on anotherfordforum.com will think you have been smoking crack, lol)

RWD_cossie_wil

iTrader: (9)

http://anotherfordforum.com/forums/s...ead.php?t=3418

read it, some fantastically stupid comments by a few people, if you want to cut to the chase it gets good around page 6

lead_foot

iTrader: (1)

Mk1gaz, what a clueless cunt!! LOL

Charlie Chalk

iTrader: (1)

Is there no way you can tilt the engine to help with weight. I suppose the transmission stops that though?


Sorry for thread invasion Chip, Don't get me started on that brown nose CUNT!

Chip

iTrader: (3)

No cant tip it back.

Weight distribution is definately going to be improved anyway based on my own measurements, so im pretty sure im going to go this way now, espeically as when I crash it, it will be easier to reshell.