Raising the compression?

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turblio

New Member
My R decided to start boiling up water and trying to split hoses under boost when we stripped it, apart from a slightly suspect rebuild the JE's were melted so was the liners exhaust side, and the exhaust sides of the chambers in the head, as for the cometic totally buggered in fact it did not fit very well to the size of the bores, my engine was not blown up by a dodgy oil pump but probably ignition timing and/or weak mixture (running too much boost as well)
however I know the pain as my rebuild was barely 6 months old! and the company that done it are long out of business so I bit the bullet and spent out again this time supplying almost everything myself to Hiteq and so far its still alive after 15,000 miles...
 
kenan

kenan

South West Regional Rep
What a feck3r :(

Would be interested to see how this turns out and if they will stand by their word and fix it ?!?
 
F

fulingbusen

Guest
hmm, seems like noone has had this problem before or you all just think I´m a twit for asking suuch a stupid question :)
 
S

soin

New Member
it was the sides of the pistons , the top edges down to the bottom of the ring gaps ,
I m pretty sure the clunk and bottom end knockin i heard was something coming away into the engine which then got chewed up into smaller bits which finally made there way to the oil pump gears .. the gears have not worn out theyve been mashed badly with all the case hardening coming off ..

the bottom end had only done 4000 since rebuild but as id overheated car briefly i asked them to pull the pistons and check them and the bores and bearings .. all were given a clean bill of health , just the head needed a re-skim and a re work , so something has happened since the engine was re assembled , which in my eyes is their responsibility whatever way you look at it ..

im fightin this all the way , if needs be ... its not just the cost of the rebuild its the work i previously had done that im out of pocket for as well , block bore , pistons , new set of bearings etc this happenend whilst in their hands ... and apparently no oil light came on

bob , i wish i could just bite the bullet and get it done somewhere like hi teq , but im all out of dollar , £6000. 00 spent in this latest little flurry ..


im awaiting the phone call tommorro ... i ll update the thread then
 
Braveheart

Braveheart

New Member
I have no idea what to advise you.... :oops: :roll:
There are a few threads surrounding the operation of transfer box, diff, gearbox etc but it's a bit ambiguous.
This one askes.... "where is front diff located?" and has 41 replies.... :lol: :lol: :lol:
It's a very interesting read if you have time.

Here's a little on the gearbox / drives that I found... hope it helps:

Section 7 – Gearbox


V10) The standard gearbox is reliable enough in an unmodified car (227bhp & 200 lb/ft @ 0.65 bar). Other options now (August 2001) include Quaife, Becker and Nismo – the latter comes sealed on an exchange basis for your old gearbox, with a guarantee to be able to take big power: but it’s not cheap. Obviously, if you’re running over the standard power figures, the lifetime of your gearbox will shrink accordingly. There have been many cases of stripped 2nd gear in these circumstances. Other options include gears from Xtrac etc.
​

Section 8 – Driveline


Q The GTI-R uses a system called ATTESA! (bless you) - what's that, then?
=========================================================================
Here are a few mails received on the subject ...

Thanks to Dean Browne for the following;-

ATTESA - Advanced Total Traction Engineering System for All-terrain

Yep, that’s what ATTESA stands for and that’s what it does, except it is not so advanced. One thing to note about the ATTESA system in the GTI-R is that it is not electronically controlled. The R33 and R34 Nissan Skyline GTR have the electronically controlled version of this but that system has the actual name of ATTESA-ETS. The R32 and ["luxury"] GTI-R Nissans have a mechanical system based on so called clutches

GTI-R Rear Diff and front diff: It may not be called an LSD by most people but in fact it's design and function are very similar. The basic function of the limited slip diff is to distribute power to the wheel with the most traction. The GTI-R ATTESA set up is built to do this. The rear and front diffs have clutches in them (well almost), these look like a CDROM disc with the last 1-2cm of the CDROM bent out on an angle. These clutches work in a surprisingly easy way. When the person driving the car puts the foot to the floor so to speak there are a several events that happen.

1, The power to driveshaft increases.
2, The spider gears push the side gears away from the diff towards the wheels.
3, This increased load(push) causes the clutches to straighten and lock.
4, The lock increases the power to that wheel (remember this happens to both sides of the car).

What happens when a wheel loses traction? The clutch on that side of the diff will lose its lock and therefore power will be forced onto the other wheel. Simple??

The centre diff on the GTI-R:
There are 2 type systems used on GTI-R’s, If you own a rally version you should be able to see the centre diff underneath your car. If you own a road version the centre diff is actually incorporated inside the gearbox housing. The reasons for this are obvious as the rally cars may have needed to have the centre diff changed during a rally and the easiest way to do this is to have the centre diff on the outside of the gearbox. These 2 systems function in the exact same way though.

I have heard stories about the centre diffs in the GTI-R about whether they are a fluid/gel based unit or just another locking unit with clutches. I don't know which one it is yet but they both do the same thing it will sense (not really, it's mechanical) the loss of traction and distribute power in the other direction.

That is as simple as I can make it and about as much as I know at the moment. When I get more information I will pass it on. There is nothing really advanced about this system and most other 4wd vehicles have a very similar system. As for the 50:50 torque split, it is well known that this split is best used on gravel or wet roads.

Hope this enlightens some and helps others. Any feedback or other ideas about this system will be appreciated. Dean

Anthony Dix adds ...

The rally cars (Group A/WRC car not the homologation version) have an active centre diff (hydraulic clutch), just like a R32 GT-R. I assume they also had electronic control using g-sensors and wheel speed inputs. ATTESA is totally rear wheel drive until wheel spin is detected, then the centre clutch is engaged to feed torque to the front. ATTESA E-TS is the same but can also electronically control torque split between the rear wheels.

Joe Peterson says (and I believe him!) ...

The ATTESA 4WD system is not a true all time 4WD. The rear diff has a viscous coupling permitting both wheels to drive under power, if one looses drive it is then transferred to the opposite wheel locking the rear drive shafts as one, the front is a conventional spider gear diff with no viscous coupling inside thus power is lost when one front wheel loses traction, the front viscous coupling sits between the transfer case and drive shaft to the rear diff, which would allow a certain amount of slip to the rear diff. Drive from the gearbox is always available to the rear wheels through the transfer case. If 4WD was to be maintained all the time i.e., 4 wheels truly under power you would not suffer from oversteer as GTI-R 's do because the car would be pushed and pulled through a corner not just pushed. If you look at the homologated GTI-R its a totally different ball game, as it is a true all time 4WD dependant on what diff and transfer case combination you choose. It had additional electronic torque split and controlled slip diff with an automatic rear torque releasing system. In race or rally cars all time 4WD is feasible as with wheel spin or lifting off one or more wheels during hard cornering you don’t suffer from diff bind as you would in a road car. Hope this helps without getting to technical, (all this is out of the w/shop manual & the original FIA GTI-R Homologation Grp A Forms)

Finally (for now) from Anthony Dix ...

I have been in contact with Protech Developments in Melbourne re the GTI-R 4WD system.

The Nissan WRC car based on the GTI-R had an active centre diff under computer control. This car is far from the 'Rally' version available to the public. (i.e. your car.)

The two versions available to the public (luxury and rally) had the same* 4WD system:

- viscous limited slip diff at rear
- viscous coupling at the centre (passive)
- open front diff


v10) *addendum The Rally (GTi-R B) spec came with a viscous front LSD in the Close Ratio G/Box
 
P

pulsarboby

Guest
yep thats a lot of money there! dont blame you for fighting it all the way it is the right thing to do, but it wont be easy, if there that way inclined they will have one getout after another!
lets just hope they do the honourable thing and decide to sort the motor for you.
 
Braveheart

Braveheart

New Member
What a downer soin to say the least.
Sounds like you tried and alerted your tuner of everything to avoid any serious mishaps.
Overheating was not ideal but you informed them, clunk and drop in oil pressure was another issue that conserned you that was dismissed by tuner.
Stand your ground, try to keep you cool and hopefully you will get something back for all your time and money.
Best of luck!!!
 
MORF114

MORF114

Active Member
What caused it to start operating like this?
How do your know clutch is ok ?
What make of clutch do you have?
Maybe glazing flywheel?
Where does the mechanical noise come from when it happens?
When were your diff oils changed?
What oils do you have in gearbox/transfer/rear diff?
Do they all have the right amount of oil in them?

Would a crank seal on box side (if there is one i dont know) failing let oil in to cause a occasional slip once its burnt away its fine oil pressure rising on acceleration forcing it through?

If it is 1 of your diffs it could be cheaper to take them out and check them before they do go bang and break something else or cause you to crash.

I would have thought a diff failing/failure would mostly grind and clunk and you would definately notice it if it was your drivetrain do you get any vibrations through your gearstick?

Just clutching at straws mate few ideas i suppose.

Its not really a common thing for diffs in a R to fail, is it?


Its not a New techni clutch is it!

Hope you find out whats wrong with it.
 
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F

fulingbusen

Guest
Thank you for your help/input

This occured while driving normally. The clutch is recently changed and the fact that it occurs as a mechanical on/off situation rules out the clutch. The problem can occur when starting in snow where the engine just revs and the wheels barely spins, If I then stop revving and reshifts to 1 st gear again, the car can all of a sudden act nornal and I have no problems until the next time it decides to act up. It is as if the gears aren't gripping somewhere but it still transports some tourque to the wheel (10 %)

It is tricky to see where the noise comes from since I need some kind of resistance on the wheels therefore I cannot just take the car to a lift and then listen to where the noise comes from as it would not occur when the wheels are spining freely in the air.

Don't know the diff oils. I have come to the conclusion that all I have to work with is that there is some kind of mechanical failure and what mechanical failure can cause the car to not grip some gears and still transport some tourque the ground?

For example/Guess; the transfer case sometimes looses its grip on the gears causing it to spin freely while the center diff is struggling to distribute the poweer to the front diff instead of transfer case.
 
P

pulsarboby

Guest
i maybe wrong here as im far from being an expert on gearing and transfer boxes
but! although these cars are awd actually i believe they are front wheel drive untill one of the rear wheels slips which engages the diff / slipper clutch, hence you then have awd.

if so your problem (although youve changed it) could still lie with your clutch assembly because if im correct you would still have fwd if the diff wasnt working as it should do but your awd would not work correctly!
as morf said above it could be a dodgy plate, flywheel glazed or oil contamination on drive plate which would notice more when clutch is warm and oil gets drawn to surface

i would check out my theory with either gtirx2 or kieron on this site as they both know far more than i do regarding the drivetrain and gearing etc, but i believe im right hence the post lol
 
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fulingbusen

Guest
Thank you, I will send PM to gtirx2 and kieron.

I am still not willing to accept the clutch as the villain since there is a definite on/off problem. When it works, there's no slipping whatsoever even when accelerating in 5th gear.
Your theory is interesting, I just can't figure out what would make the rear wheels rotate while the front wheels are not connected to the transmission.

How is the chain of components lined up? Is it Gearbox -> centrediff -> frontdiff and transfer case (transfer case is then connected to reardiff).

Maybe the centerdiff is not working and those 10% it propels forward with is simply the gears trying to grip together but instead keeps slipping off causing the noise...
 
O

Odin

Guest
pulsarboby said:
i maybe wrong here as im far from being an expert on gearing and transfer boxes
but! although these cars are awd actually i believe they are front wheel drive untill one of the rear wheels slips which engages the diff / slipper clutch, hence you then have awd.
Click to expand...

Bob they are permanent 4wd matey, Both axles drive all the time, It may only be 3 wheel drive at times because of the open front diff but it's never just front wheel drive, Unless you have a f*cked transfer box.





Rob
 
P

pulsarboby

Guest
yep i appreciate that there is drive to all wheels, but i thought the diff locked drive to the rears when it detects slip.
if you jack car up on the front with it in gear you can still turn front wheels with out turning the rears (although be it hard) which tells me that the diff only locks when slip is detected on one wheel! ie if you removed the transfer box and could hold the oil in the gearbox alone then it would work as a fwd car, which is what im trying to get across with regard to it slipping and losing all but 10% of his drive, surely if the diff or transfer box was playing up he would just lose drive to rear wheels not all 4 as hes suggesting!
but as i said im far from being an expert on this stuff and i could well be wrong here thats why i suggested either kieron or gtirx2 answer the question as they both seem to know these eystems inside out.
 
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F

fulingbusen

Guest
My thoughts: the viscous diff works through friction in the oil, this friction is increased as the temperature increases when there is a difference in rpm between the 2 sides.
I'm not sure how the viscous diff acts in a situation where one side spins freely but the 10% I keep talking about could come from the viscous diff trying to grip the side that does not spin freely.
If this is the case then the viscous centre diff is working, but that really doesn´t narrow it down much...

I guess I will have to locate the mechanical moise that can be heard when it is not working and take it from there.

edit: I could not find a keiron on this forum, only keira
 
gtirx2

gtirx2

Active Member
Tbh i am not to sure either, i know a bit about the gearboxes but when it come to the diffs i would not be sure?
What i was wondering is if it is a problem with your front diff,say for instance the planet wheels in the diff where fooked or the shaft from the passenger side drive shaft that connects to the front diff had lost its splines or something simular.
Where it is an open diff like a fwd car the torque would just slip away though the side with least resistance.For example if you was to remove a front drive shaft on a fwd car with an open diff the car would not move as the power would take the path of least resistance.
I think the same would happen on a gtir? and then i think the viscous center diff would slip when you try and drive it,[ as you would be loseing more power though the front then the rear] , and the only drive you would get would be from the drag of the plates and fluid in the viscous center diff trying to send some torque to the rear wheels?
tbh i have not got a clue:lol: its a bit of a quess really as if thats how the 4wd system works?
Also i think even if there was no viscous fluid in the center diff and it acted as an open diff it would still drive okish and you would only really notice if you lost traction then all the power would either be spun away at the front or the back,proberly front?
Heres how a viscous diff works...
http://auto.howstuffworks.com/differential5.htm
 
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