Getting Back into an Astra Woohoo!!

patricks

Regular Member
#1
Gday all z22sers. corsaZ22se vocky evocarlos Been a while since my old car was written off and ive posted here but the bug to get another Astri Sri is biting.... hard. I will apologise in advance for the long winded nature of this post.

I have my eye on this

https://www.carsales.com.au/dealer/details/Holden-Astra-2001/OAG-AD-16213396/?Cr=0

Took it for a spin today and the good news is no death rattle in site (or earshot rather) AND as far as i can tell it still has its original paint no accident damage whatsoever- rusty in places and underneath the carpet in the boot, front subframe and slam panel - which is odd because of the galvanised body so i suspect water damage sometime during the cars life.. Also noticed the engine was considerably quieter than my old Astra - not sure what to attribute that to - at first i thought it was the metal rocker cover instead of the plastic one my old car had but then i remembered that pre 2002 models have a precat whereas newer cars dont??? Perhaps someone here can enlighten me on that one

The bad news is 2nd gear is awful which myt not be so ( bad see below)

Planned mods are

1. Ported exhaust ports
2. Balance shaft delete
3. 6 Speed conversion
4. ported throttle body
5 de restricted intake
6. Sound deading over the rear wheel arches
7 Astra mk 5 torsion beam rear
8. skimmed head for higher comp ratio
9. remap

The car is to be a daily driver and the objective is to make the car smoother, quieter, faster and use less fuel than than new - im aiming for 170bhp and 6.0l100km fuel consumption on motorway with the engine sitting at about 2500 revs at 66 -70mph. Specifically my questions below are directed to those who have done the above mods

1. whats the m32 box like behind a z22se? I like a shorter shift rather than a longer throw and a smooth quick action, will the m32 do the trick - id have to say the only thing i dont like about mk 4 astras is the first to second shift gear change which is a lot slower than it should be and a bit notchy too
2. Does balance shaft delete and skimmed head improve fuel consumption noticeably?

Any input/comment into any of the above areas would be greatly appreciated.

Cheers
Patrick
 
#2
If you are only looking for a daily driver and not bothered with speed then the Astra G z20let f23 gear set or that from a Corsa Combo 1.7 CDTI van will improve cruise speeds, i'm at 2500 for 70mph and on smaller tyres than you. 215/35/17.
also look at removing precat if it has one and fitting a 200cpi main cat with full exhaust system.
you might struggle for 170bhp without cams though?
 

patricks

Regular Member
#3
Thanks - throttle response and speed is important - and one of the main reasons i miss a z22se - i dont want crazy power but i do get frustrated with slow toyota drivers and like to plug traffic gaps - im constantly darting between traffic and that was something my old car did brilliantly that my current alfa giulietta 1.4Turbo doesnt do well at all. Not sure if my old car had a pre cat - it was only fitted was basic intake mods and ported throttle body and that was fine for me. Ive always felt that the in the standard f23 first gear was too short and fifth was also geared too short as well - id be sitting at 3100rpm doing 115km/hr. Also the shift from first to second is slow and a bit notchy - in my view the only real shortcoming of an astra g sri is its gearbox so if a m32 is smoother with a quicker throw to me that would make a perfect car. PS what fuel consumption do u get with that setup - thats a charged car isnt it?
 
#4
no idea really, i measure it in smiles per mile :D:D:D
think the n/a one is getting around 35mpg but she's very heavy with the audio gear in her over 1500kgs now
the supercharged one is 20-25mpg but really only gets driven hard and on boost so the chargers whining all the time
 

patricks

Regular Member
#5
Ha ha chargers whining i can imagine and hear them coming on song from here lol ...for 1500kg 35mpg is very good i was getting 6.7-6.9 in my old astra (about 1220kg) which equates to about 40mpg roughly. The alfa gets 47mpg (1300kg) about the only good thing about it - oh and it looks good!
 

Berto

Regular Member
#6
Welcome back Patricks!


... rusty in places and underneath the carpet in the boot, front subframe and slam panel - which is odd because of the galvanised body so i suspect water damage sometime during the cars life ...
I'd stay away from any car with such rust issues. Better look for another example in better condition.


... the shift from first to second is slow and a bit notchy ...
First thing to do is to drain out the OEM red watery p**s (these cars came from the factory with ATF inside the manual gearbox :hungover: ), and refill with some real 75W80 or 75W90 transmission stuff. Shifting and gearbox longevity will improve inmediately.
 

patricks

Regular Member
#7
Thanks Berto im glad the forum is still here - z22se is now an 18 year old engine!!! ive got my eye on a few examples out there but this one appealed to me in particular because it has its original paint - the rust is just surface stuff more orange powder than real cancer - it had a sagging hood lining and damaged antenna so i figured water seeped thru the roof into the boot and floors. Drove real nice aside from the gearbox - in my old car i used POA gearbox oil along with a teflon additive - i found that the thicker POA oil smooths out the shift but slows it down somewhat - the best compromise between shift smoothness and speed was to use the thinner factory oil combined with the teflon additive - even then, quick 1 - 2 gear changes are not possible with this box. If i had the expertise of some of the guys around here i would put in a 6 speed m32 box in a heart beat.

Just curious hows ur oil consumption going did u end up resolving that??
 
#8
I found the M32 in the Corsa D and Astra H very notchy and rough like stirring a bowl of porridge when compared to the F23. that's on low mileage cars as well, 13,000 miles. Have you tried a F23 with a short shift linkage on the box?
it's not advised to use heavy gear oil in these boxes as it kills the syncro rings fast and makes for heavy gear shifting. stick with factory spec transmission fluid but not atf which personally i have never found in any F23 yet? the amount of cars/trucks etc that i have seen with dead boxes from the use of gear oils rather than transmission fluid "just to quieten them down" or "make shifting smoother" is shocking. stick to what manufacture recommends as im sure the money they put in to research is more than worth it.
 

patricks

Regular Member
#9
Yeah id have to agree with that - the f23 definately shifted slower with thicker oil even tho it was smoother with it. I have experienced the m32 in another car called a Holden cruze which is powered by a 1.4t ecotec engine - not related to the z22SE family - and found it GREAT - nice short throw with a smooth quick shift. Also found the M32 nice behind an alfa 2.2 jts engine which in my book is one rip snorting engine sounds amazing. I want to try the m32 behind an astra H but have limited opportunity i feel bad to waste someones time test driving their car when i have no interest in buying it. All reviews i have read about astra H seem positive enough tho.

Can u tell me more about the short shift because that seems like a far easier option than swapping out to a 6 speed - i was under the impression it made the shift action more notchy?? What does a short shift feel like??
 
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Berto

Regular Member
#10
... i found that the thicker POA oil smooths out the shift but slows it down somewhat ...
Yes, specially when the gearbox oil is not yet warmed up.

... the best compromise between shift smoothness and speed was to use the thinner factory oil combined with the teflon additive ...
IMHO running a manual gearbox on thin ATF is recipe for disaster in the long term, the synchros will bite the dust sooner or later. Teflon might help somewhat, but what we really need inside the F23 is a real quality thicker manual transmission oil.


...
Just curious hows ur oil consumption going did u end up resolving that??
Just managed to mitigate it to more bearable levels, about 1 litre of oil consumption every ~2500 km (1 quart every ~1500 miles) on Mobil 1 5W50. Current mileage is ~230K km / ~143K miles. Car still pulls like a train.
 
#11
had the short shifter on the Vectra B from 80,000 miles ish. shortend the throw between 1-2, 3-4 only real problem was play in the linkage around the gear stick's ball and socket.
I have the Mtec kit on mine, the newer kit is much better than the first kits they made.
160,000+ miles on GM trans fluid and still all good inside when i fitted the ATB diff. where as the other F23 which was on 30,000 miles and been run on gear oil had major faults, worn bualk rings and syncro cones. and a shattered selector ring on 1st/2nd. thick oil does not allow for speed matching on the syncro's as it causes to much drag until it is very hot by which time damage is done.photo is from the box that had been run on gear oil.
20171019_122206.jpg
 

patricks

Regular Member
#12
Yes, specially when the gearbox oil is not yet warmed up.

IMHO running a manual gearbox on thin ATF is recipe for disaster in the long term, the synchros will bite the dust sooner or later. Teflon might help somewhat, but what we really need inside the F23 is a real quality thicker manual transmission oil.

Just managed to mitigate it to more bearable levels, about 1 litre of oil consumption every ~2500 km (1 quart every ~1500 miles) on Mobil 1 5W50. Current mileage is ~230K km / ~143K miles. Car still pulls like a train.
Good to hear its under control I managed to get it down to 200ml per 1000km just before it was written off with 563K on it. Prior to that it had been burning/leaking 600m//1000km for the last 200K of its life. Your thread about oil consumption was actually the inducement i needed to start reducing it - i just had assumed that it was a consequence of high mileage even tho engine performance contradicted it. I certainly don't doubt that your car still pulls like a train - you can bet on that for at least another 400K as long as u look after it.. As for the F23 - i have tried every possible combination and permution of gear oil + additives and unfortunately no oil is going to fix the slow notchy 1-2 shift - just such a shame the astra g was spoiled by it and the overly short 5th gear - cruising at 3100 revs on the motorway is ridiculous especially when the engine has bags of torque to cope with cruising at say 2600 revs. I personally wouldnt worry about the longevity of the f23 box on ATF fluid tho - mine did 300k on the factory oil before i experimented with other oils and that included many 0-100km/hr sprints dumping the clutch at 2500 revs. If the f23 box wears out its more likely that the owner doesnt know how to use the box properly and crunches the gears - the example i drove recently had 200k on it and it was shot - mine shifted like new in fact better than new because of the teflon additive and it had 560k + on it.
 
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patricks

Regular Member
#13
had the short shifter on the Vectra B from 80,000 miles ish. shortend the throw between 1-2, 3-4 only real problem was play in the linkage around the gear stick's ball and socket.
I have the Mtec kit on mine, the newer kit is much better than the first kits they made.
160,000+ miles on GM trans fluid and still all good inside when i fitted the ATB diff. where as the other F23 which was on 30,000 miles and been run on gear oil had major faults, worn bualk rings and syncro cones. and a shattered selector ring on 1st/2nd. thick oil does not allow for speed matching on the syncro's as it causes to much drag until it is very hot by which time damage is done.photo is from the box that had been run on gear oil. View attachment 68572
Yeah that box got the treatment - some people just dont know how to change gears without crunching them ha ha
So the million dollar question does the short shifter give a quick, smooth and light throw??? I hesitate because i know of ppl that have had the short shifter only to remove it later because the shift action is heavier and notchier even tho its a shorter throw???
 
#14
been good for me. if you adjust the cables correctly after fitting one.
the poor feel is more often due to to much play in the ball and socket of the stick which was made in factory like this.
very smooth shifting in mine now with Mtec short shifter's.
removing, cleaning and re lubing the selector shaft from the box is good to on higher mileage/aged cars.
 

patricks

Regular Member
#15
Thanks u just saved me the hassle of going six speed + i dont want the extra weight of the M32 + f23 is a stonger box too.. I still have to find a higher 5th gear tho - in urban driving i used to go from 3rd straight to 5th, hell the engine had the torque to do it so i would potter around town @ 60km/hr in fifth. So ideally now id just need slightly taller 4th and fifth gear ratios - if its possible to mix and match them from an M32 box as a donor then thats what im going to do!!! Makes me wonder how useless an astra g sri would be on German autobahns sitting at 4500 revs doing 180km/hr - what were the opel engineers thinking??
 
#16
M32 is a lighter box. built to a budget. not as strong as the F23 internally.
nothing looks like it could be swapped?
you could try swapping gears from other F23 boxes to get a taller top gear? May be a z20let gear set/final drive? 3.64:1 where as the z22se has 3.94:1 in the astra g
 

patricks

Regular Member
#17
Yer, would be nice and easy to just swap boxes from z20let but then i loose the 3.94 final drive i want. I really, really, really loved 3rd gear in my astra with its 3.94 final drive.........gave the car instant throttle response and strong acceleration anywhere from 45km to 120km/hr. Very flexible to drive.....

After a bit of research it looks like i can get 5th gear of 0.689 and 4th gear of 0.848 from a F23 wide ratio box that were fitted to mk4 and mk5 deisels like u said earlier. So that looks like the way to go - keep my 3.94 final drive and get 4th and 5th gears from diesel F23 astra.

Great resource below by the way about every gm box..............

https://www.opel-infos.de/technik/getriebe/f23.html
 
#19
you get the same bush with the MTec kit. they do wear over time.
if you are going to change gears in the box you will need a very heavy duty press as some gears are sweated on to the shafts. my 30 ton press wouldn't shift them.
if you did swap all the gear sets you will not notice the difference in how it pulls, just in first gear it's a bit slower on take off N/A. with the charger it means i can plant the throttle sooner without both wheels spinning out. also means it will do over 70mph in second :) (on the race track or private road obviously :whistle::whistle:;);))
 
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