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Discussion Starter · #1 ·
Hi guys,

I have a few problems with my EVO IV gearbox. Firstly, when changing from 2nd to 3rd gear, the gearbox seems to make a grinding/bumpy noise - I think this is referred to as crunching ?? Can this problem be fixed? And is this a serious problem?

Secondly, when the car is travelling at high revs (e.g 5000rpm) in 2nd gear, the gearbox seems to make a rattling noise. I am not sure what this is and it is very worrying. I have not yet changed the geabox oil (bought it second hand) but I will do that soon.

Has anyone else had the above problems? If so, what did you do about them? Thanks a lot guys, much appreciated!
 
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Discussion Starter · #2 ·
ng the dump valve round

At the rolling road day someone pointed out than turning the dump valve round increase response of the turbo through the gears.If this mod is done is it safe?
 
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Discussion Starter · #3 ·
Re:Turning the dump valve round

This was Kevin (T27) who showed us the mod on his car. I was thinking about this as well.

Kevin, I can't remember which way you need to rotate and amp; how many degrees. You also mentioned needing extended tubing if I recall (I had no brekky on Saturday morning, so my brain was not functioning properly at the time!)

Steve.
 
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Discussion Starter · #4 ·
You got it 2nd hand you say? Hehehehehehehe! I got my EVO4 second hand too! Had the same problem when I got it too now ain't that a coincidence then mate! http://www.ltregister.f9.co.uk/graphics/happy1.gif border|EQU| 0 align|EQU| absmiddle >

Could be a combination of worn clutch and the need for replacing the gear-oil. I replaced both. Get a thicker viscosity gear oil, maybe 85W/140 so it feels slicker. Improved the feel on mine a lot! [img]http://www.ltregister.f9.co.uk/graphics/happy1.gif border|EQU| 0 align|EQU| absmiddle > It would also be nice to replace the real LSD oil (if its an RS) also into something thicker, maybe 85W/140 but make sure it is LSD gear oil or it will make cruncing noises and could destroy your rear LSD. Anyways, there should be a small sticker at the back of the LSD casing that says LSD OIL ONLY

Noticed a difference in handling on mine, felt smoother under hard tight turns, easier to modulate the tail! [img]http://www.ltregister.f9.co.uk/graphics/happy1.gif border|EQU| 0 align|EQU| absmiddle >

As for your noisy tranny at 5,000 RPM, it could simply be something loose in the tranny, have them tighten the tranny casing screws / bolts. Worse case scenario, you have to adjust / replace the gear synchros as they might be loose or worn out.
 
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Discussion Starter · #5 ·
Re:Turning the dump valve round

You do need a longer piece of rubber hose,I have swapped it round and it did feel like it picked up quicker.I just hope it does not do anything to the engine or turbo.
 
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Discussion Starter · #6 ·
Re:Turning the dump valve round

I have done this on my car (1800GSR) and it definitely does help spool up quicker and there is also less boost leak at high revs. Speaking to a few folk they reckon it gives 90% of the improvement of a good aftermarket dump valve, without the obvious 'Oooh!' factor under the bonnet http://www.ltregister.f9.co.uk/graphics/happy1.gif border|EQU| 0 align|EQU| absmiddle >

The only downside is that lifting off abrubtly can give a more pronounced judder, I suppose this is the result of the valve pushing against the boost as opposed to closing with it (make any sense? [img]http://www.ltregister.f9.co.uk/graphics/happy1.gif border|EQU| 0 align|EQU| absmiddle > )

You will need a bit of tubing, I used 6bar fuel line from my local motor factor, about £3 and 15 minutes. I detailed the work on the GSR_Evo list a few weeks back, if anyone wants me to repost here just ask [img]http://www.ltregister.f9.co.uk/graphics/happy1.gif border|EQU| 0 align|EQU| absmiddle >
 
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Discussion Starter · #7 ·
Re:Turning the dump valve round

Chunky - I'm askin' http://www.ltregister.f9.co.uk/graphics/Wilk.gif border|EQU| 0 align|EQU| middle >

Steve.
 
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Discussion Starter · #8 ·
Hey there,

Thanks for ur reply. I've been asking a few ppl and have got mixed responses. Some say a gearbox oil change, worn synchro on 2nd and 3rd, or maybe a baulk ring is causing the problem. Anyway, tomorrow morning I'm gonna take it to RPM Performance and have it checked out over there. Hope it's nothing too serious. Just outta interest, does anyone know approx. how much would it cost to rebuild/replace the 2nd and 3rd synchro? Or change the baulk ring?

Thanks.
 
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Discussion Starter · #9 ·
Two baulk rings, a few shims and 5th gear synchro cost me 300 pound aprox inc VAT from Co-ordsport for an Evo1..
So add a few quid for a later model I imagine.

TonyC
 
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Discussion Starter · #10 ·
TonyC,

Was that just parts or the whole job incl. labour (seems too cheap for that)
My evo II does not like medium-fast changes from 1st to 2nd or 4th to 5th.
Will try changing gearbox oil as temporary fix but feel I may need to do something similar to you at some stage.

cheers
Jon
 
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Discussion Starter · #11 ·
Re:Turning the dump valve round

OK, this is the original post I made to the list. Bear in mind this pertains to the 1.8 4G93 engine, although the basics should apply equally to the 2.0 4G63:
The dump valve (BOV) mod is a piece of pi5s, takes 10 minutes. I'll take
it from the top, just so everybody is on the same footing. The layout
applies to a GSR.

Equipment required:
Flat blade screw driver
6mm rubber tubing approx 1m in length (I used reinforced fuel line from
my local motor factors, cost approx. £3)
Pliers
10mm spanner (not absolutely necessary but makes the job easier)

Standing in front of the car the valve is to the left of the engine,
it's black plastic and has an inlet and outlet of approx 1 3/4 diameter
entering/leaving at right angles (one at about 11 o'clock, the other
pointing directly down). There is also a 6mm tube running from the
inlet manifold area (behind the engine, the silver bit!). As standard
the 'bonnet' of the valve is on the top with the 6mm tube coming off at
about 1 o'clock.

Simply slacken off the jubilee clips on the inlet and outlet and wiggle
the valve clear. The tube coming from the inlet manifold can be removed
with the pliers easily at the valve end, the other end is easier if you
remove the injector loom bracket-thingy (10mm spanner ahoy!). The tube
can be a bit reluctant to slide off the nipple, the pliers do a good job
here too. There are 2 cable ties securing this tube, they can be reused
if you want. The rubber shroud protecting the tube can be reused
aswell, but in my case the new tube was reinforced and I felt it
unnecessary. If you want to refit it to the new hose, a bit of Fairy
Liquid will make the job a *lot* easier!

Refit the valve the 'wrong' way round i.e. with the bonnet pointing
towards the front of the car, and retighten the jubilee clips. Attach
the new 6mm hose at the manifold end and route it to the valve. Cut to
a sufficient length to reach the nipple on the valve (this is now
pointing to the offside headlamp) without kinking and attach it to the
valve. Refit the injector loom (if removed) and job done!

Check all the screws/nuts etc. are tight and go for a test drive. If
your valve is anything like mine you should immediately notice much
stronger low-end pickup. I checked boost levels at full chat in each
gear just to make sure I wasn't overboosting but everything was fine.
The operation can be reversed just as easily if you don't like it (?),
and the only negative thing I've noticed (but may be my imagination) is
a slightly increased judder from the car as I lift off. As I say I may
just be looking for faults now, it may always have been like that.
Hope this helps
 
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Discussion Starter · #12 ·
Re:Turning the dump valve round

Well reckon you covered it all there Chunky, it made a good difference on my car.Give it a try chaps.

Kevin A
 
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Discussion Starter · #13 ·
Re:Turning the dump valve round

I have also done this on my car, after my Blitz valve jammed half open. The only downside to it is that it does cause some compressor surge (can be heard) on my car when lifting off abruptly at high boost. If it will kill the turbo eventually remains to be seen. Besides the Blitz valve caused more surge if the spring was tightened enough to prevent it from opening under vacuum.
 
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Discussion Starter · #15 ·
Re:Turning the dump valve round

Thanks Chunky.

Had a quick recce in the engine bay last night and found the valve 'bonnet' pointing towards the front of the car, ie mine has already been done! Since it was like that when I got it I assumed it was normal. Also explains why I was confused when I saw Kevin's car last Saturday as I thought his looked exactly the same as mine. I can't say what the improvement is as I've never driven the car with the valve the 'right' way around, but I have had no noticeable problems in the 3,000 miles/5 months I've had it.

I suppose I have to confess to Uncle Darin that my car was not totally standard when it went on the rollers at Tuning Japanese....

Interestingly, when I was looking through some engine pics to check what was normal, the Ralliart test car S6 GSR had the valve reversed in the pictures from the original autocar review in March 1999.

Steve.
 
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Discussion Starter · #16 ·
Re:Turning the dump valve round

Steve,

I think you're car is still standard - as long as the pressurised pipe is feeding to the bottom of the valve rather than the side.

Guys,

I've been trying to work out how reversing the valve actually helps and all I can see is that the valve actually stops working.

The valve is designed so that boost pressure works against the inlet manifold pressure and a spring. During boost, the inlet manifold is at the same pressure as the other pipework after the turbo, so the spring basically keeps the valve shut. When you lift off, the inlet manifold pressure drops, so as soon as the boost pressure is greater than that of the spring (also helped by vacuum in inlet manifold), the valve opens.

When you reverse the valve, there is no boost pressure to open the valve up so (in theory anyway) it is shut all of the time.

Can you still hear the air whooshing through the valve on lift off with this mod or do you now get the sound of the turbo stalling (stuttering)?

I could be wrong but physics says the valve will not work.
 
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Discussion Starter · #17 ·
Re:Turning the dump valve round

Won't using a dump valve on an E4,5|PLS|6 stop the secondary air control system working ?

E4,5|PLS|6 have a form of antilag built in... If you keep full throttle for over 3 seconds at over 4000 rpm then you will get no lag between gear changes due to the SAC system. if you blow all the air away then this will not function.

I can't see the point in fitting a BOV to a 4,5|PLS|6 personally

Jonathan
 
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Discussion Starter · #18 ·
Re:Turning the dump valve round

I would of thought any pressure release device is there for precausionary reasons,I e BOV.
Realeases excess pressure in the system.a bit like blowing a hot water bottle up with a leak.It just won,t explode,unless excessive air is fed into it before the time it takes to realease the air.Then BANG !!!Don't try this at home only in the confines of a secure unit.Other wise why would you have it?
Perhaps the whole turbo engine should be stripped down put back together in a way that a racing engineer would do ,just to see what bits are thrown away and what bits are changed.
Ralliart do it .They just throw the whole engine away.
I am sure that if ever had the chance to speak to the designers of the mitsi turbo engine.The car would be capable of much more power based on standard equipment.
the perameter of 280 horses, with relaiability.

cheers

Paul s
 
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Discussion Starter · #19 ·
Re:Turning the dump valve round

I have looked into the BOV ,and its function.
Ummmm ,quite a few rally cars do not have a BOv at all ,but dispence the excess out elsewhere.This is very interesting,although I love the swooshes and whistles perhaps I might dispose of mine alltogether.Professionally of coarse.
My main concern being that rally cars have a little more sophistication as far as mapping than my E4,but then if it ain't actually there for a very prime reason then ,no harm can be done?I was told that similar effect as BOV can still be achieved,sound wise.
Any one stripped there BOv out completely with out having remapping done.and to what effect.?E4/5/6.
This may be a can of worms like the gromet.

cheers

Paul s

Obsessed with GROMET,cause I have the wrong trousers!!
 
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Discussion Starter · #20 ·
Re:Turning the dump valve round

Originally, my BOV vented into the secondary air valve. Most of the time the SAV wasnt opened so my BOV wasnt venting anywhere. (Ive run the car with the SAV feed onto the boost guage and it doesnt operate that much with my style of driving) The car was very quick through the gears, and certainly drove different to the other E6 I tested at the same time. I also prefer the noise I was getting when I lifted. Whether this is doing the car anygood I dont know, but it did 8000 miles like this and still goes. Currently I've put the BOV back to normal, but after further discussions Im going back to the original, but controlling the SAV directly with the vacuum as opposed to via the ECU controlled solenoid.

High power cosworths dont have BOV's and I dont think the Ford 1.6 escort turbos have them either. The value of a BOV is open to question, I've seen a nu
 
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