G40 Charger rebuild

Mine is bored out to 1308cc!!!

Pitstop do theirs to 1341cc.

We both use forged pistons and a 9:1 compression ratio (I think pitstop's is).

Mine is fully lightened and balanced, crank is a machined flat plane and flywheel lightened and balanced, and revs out to 8000rpm cos ive solid lifters.

I use a supersprint 4-2-1 exhaust manifold (the charger/engine mount bracket has to be ground away slightly to fit it.)

Exhaust's, most prefer custom built system (200 for mild steel, lighter, quieter, last about 2years. 350 for S/S system, lifetime, abit noisier, heavier, shinier). You could go for a Jetex one which isn't to loud, scorpion ones are I think, or remus which is quiet. ALot of people prefer a quiet exhaust so they and everyone else can hear the humm of the famous G40 G lader!!!!


Oil cooler should drop temps down by 20-25degC. Non thermo one is cheaper but if your in town traffic alot get a thermo one too kepe a constant coolness instead of relying on incoming airflow.

The cars problem is likely to be thermostat as Alan said or the fan temp switch isn't working probably.
Thermostat is about 5, could be worth also changing the black water coolant temp sensor (it is the sensor that shows the temp in the dash) which is 25, and a rad 2 stage temp switch is about 15. Change the blue coolant sensor while your at it, for 12 you may aswell.

G40 intercooler is pretty good really, the G60 ones are pooe! Alot of people want to change the IC but it can cope with upto 160 odd bhp quite well. Youve an option of changing it if you want to a 2wd cosworth IC (PSD), VW sharan tdi IC (not great but better) or a proper twin core (twin core is the best!) Pace or Allard one which relly must be built to a spec/size you give them. ALot if people rave about the Aquamist Water injection 1s system, injected in just behind the IC exit, cools the charge air alot giving more ignition advance safely (knock sensor adjusts automatically) and hence power and torque. Can be mixed with methanol too.

G40's destroy other cars of similar power due to their awesome supercharged power delivery in the mid range, and more powerful heavier cars due to their great power to weight ratios!!! With decent suspension on, their lightness makes them very nimble and agile. Brakes just have to be upgraded as they are the weak point.

 

G40's are quick as standard, it'll be quicker than your old jetta anyway, but they start to come into their own in terms of outright performance when chipped and pullied and the charger has been upgraded. And the performance comes from little !

A chipped and 65mm pullied, S4 charger'd G40 can keep a Scooby at bay quite easily!
No imagine a G40 with just 65mm toothed pullies, a full blend twin induction charger, and a good SNS chip!!!

 

What sort of cost would i be looking at for a Full blend charger, I see that alot of people say they are better than jabba also i had the Twin inlet charger explained the other nite so i think i will be doing that as a DIY mod . The toothed belts i have been told by a Vag mechainc are going to be putting alot of stress on the charger because the belts slip for a reason , but i see that alot of people are talking about doing it or have done it, Also where would i get the SNS chip fitted and programmed,

What size belt is on the G40 as standard, and if u use a shorter belt dosent it make the charger rev more so decreases it's life, or is that a trade off for more performance,
As for a mildly tuned G40 keepin a imprezza at bay sounds like fun

 

Thats a load of rubbish, toothed pulleys will allow you to have less tension on the belts than vee belts that need more tension to stop them slipping.

 

Hurm i understand that you dont need as much tension on a toothed belt but the normal v-belts on slip when there is a lot of back pressure in the charger dont they so what happens then, Have u got the toothed belts on your neil

 

Your getting a llttel bit confused. Stop listening to anything VAG Mechanics try and tell you about G's, they are sh*t, they do not know anything about VW's unless it a current model. And even then they are usually wrong. They are bullsh*t baffles their tiny little brains types of people who feed poepl cr*p and then book them in for alot of unnessary expensive work!

As you can see, I dont like VAG Stealer's or their so called technicians.

Vee belts slip at top end inherrently, that's why your boost guage will show a constant boost pressure up high rpm of say 0.8bar (if pullied), due to really loss of grip in a friction system, sort of. No matter how much tension you put on them.

If you add toothed belts, you dont get slippage at all as the charger is getting constant drive and is producing more boost as its not losing it anymore from slippage. They say it wears the bearings out quicker, too be Honest, No one has found this to be a problem and alot of charger's with toothed belts are now reaching service time again.
A problem we are finding is the belt snapping. Its not a serious problem, you just lose you boost capability and alternator drive. Most of use carry spare belts. The sapping belt problems is just a case of R&D'ing to find whick belts are lasting.
Some people are snapping them 3 times in 8000miles, some never, some justy once in 10K.

The full blend charger is the PSD charger, about 450 I think. you have to specify to them weather you want twin inlets or not so they can port open the other inlet. Then add induction kit, hosing, and collars cost on top.
I DIY'd both my G40 charger's, the previous one was a twin inlet, done partly by myself and by beavis (in the very very early days of PSD) and my current one has been DIY'd and fully polished up so it flows a hell of alot better and is built to a single inlet blanking plate charger. As I fancy testing to see if a 2nd inlet does get the extra gee gee or if its from just losing the boost return. Shall see but I expct to be converting over to twins again I expect.

A PSD charger isn't polished up, generally due to time/labour. It took me a whole day to polish my airways up to a seriously smooth surface, so you can imagine the cost if you paid someone to do it.

Bearing Lifetime; you ahve to expect that if you want extra power from the charger by under pullying it that the bearing/seal lifetime reduces also. So genrally a rebuild/service happens on an uprated charger about 40Kmiles or so. And standard micing about charger's last longer. You have to expect this in the performacne world, the same as the brake pads have to be renewed and engine oil renewed.

 

Hey thanks for the info i think i am gonna book the car in to PSD but i live a feckin long way from em so i guess it is gonna be a case of leavin the car with em, I am gonna ring em up and have a chat see what they got to say,Cheers Polog4tracer

 

Yeah, have a chat with Beavis and he'll dispell any fears or queries about G ownership. Phone him up rather than email, as they get very very busy sometimes. Yeah it is far to get to.

you could just remove the charger from it yourself (its easy and its on the PSD website how to do it) then get them to do the full blend for you, send it you back (turn round is about 3-5days), refit it (its easy). Then you can go down to theirs another time and just for the day while they fit the toothed pullies or whatever you want doing.

Where do you live? As G owners always help others out if necessary or give you all the advice needed to do anything.

I take it you are 'Jono_G40' on the PSD forum then, im 'hardchargin40'.

 

Sorry, 'Beavis' being Steve Pitt.

 

Yeah i am Jono_G40 on the PSD forum, I am in west wales i have read the details on how to remove a charge dont seem like to much hassle plus are the haynes manuals any good cos they sometimes have there uses. Cheers agaom for offerin to help if i get stuck i shall be dropin posts no doubt

 

Yeah, its easy... a quick 10mins job. But I'll give you 30mins cos you aint done one before. lol.

Get the mk3 polo haynes (and a mk2 one - gives greater details to some things), but it wont tell you how to remove a l G-lader, or generally anything about it. Actually I think there is one reference to the vee belts and their tensioning torques, from memory.

I would help but im currently in the Gulf, serving under her majesty and dont return to the UK until April. But I can help in terms of info giving, since I know the G40 inside out now.

 

I have picked the car up and poo me what a diffrence to the GTI it is, i think the handling of the car seems good it seems very squat and very rigid to the extent where i am gonna rattle me fillings and my brain loose, But i guess that is just a - for a stiff car. Who needs a performance exhaust the charger whine is enough and deffinetley turns peoples heads, Does anybody now or have any idea how much a Bottom end Rebuild would be

 

Are you sure it hasn't also got the G40 Cup Car Sachs Suspension on if it rattling your fillings out?

Mine has, but it is purely a trackday car so I can live with immensely stiff suspension. About 300-350lb front and 450ish lbs on rear im led to believe. I dont know what mine has. Im going to get some more springs and play about with spring rates.

Handling isn't a best trate of the G40 - Its certainly no mk1 GTi! It understeers alot due to skinny 175 tyres and needs a good suspension to get the bets from it.

Yeah, isn't charger noise great! Wait until you hear a twin inlet charger with toothed pullies then!!
Its why im trying to decide between a loud single rear silencer racing exhaust for the trackday car or a normal 2 silencer jobbies so I can hear the charger.


My 8000rpm engine (just bottom end and headwork) cost about 2500 (but I got 500 knocked off as I got it from a mate of mine from TRC mag so should have been 3K.)from Race Power Motorsport.

A bottom end rebuild, depends what you want done. But bottom end full lightening and balancing, crank flat planed, arp bolts, total seal competition piston rings, flywheel lightened, plus labour@500, would have cost 1100 on mine. Then plus whatever needs replacing.

The 1272 G40 blocks are known for being really really strong and you shouldn't need a rebuild unless its a high powered track car or something equally as mad. If anything just do the piston rings if your stripping it down, but balancing rods, etc is really cheap.

 

Sachs suspension was commonly painted 'red'. But mine was painted over the red in blue paint when I bought the susp.

It'll have silver/gunmetal grey spring that are 6" long and 2 1/4" or 2 1/2" dia (cant remember which, been a long while since ive seen them).

If your on the G40 Yahoo group (accessed through www.clubg40.co.uk or should be) then click into the files section and have a look in 'Paul C's track car build pics' for pics of the suspension if you think you've got cup car susp.

 

Not sure if the car has Cup car suspension but i know for deffs the car is a cup car if that makes sense, The thing rattles me fukin fillings out but hey i tell ya it pulls like fuk , I daint realise what the thing was gonna be like i took it down the back lanes by my house the other nite and i totally smoked the brakes aswell gotta get me soem decent brakes on it i got Audi 16v calipers and servo but they just aint enough really they feel w*** in comparison to my GTI 16v discs on my 8v GTI