matth76 1 Posted January 8, 2006 Report Share Posted January 8, 2006 Ok... I'm going to be having my gearbox out fairly soon to have the timing chains done and wondered if I could take this opportunity to improve my gearbox in any way (ideally to get slightly shorter gearing)? I'm having a standard new OEM clutch which is apparently very good (better than an aftermarket item). The only one thing that I have found with my Golf VR6 (ODB2) (when it is running well) is that you really have to go down a gear each time to get the power going... which I assume is because it has fairly long gear ratios, unlike the Corrado which has better gearing and slightly shorter ratios (allowing better acceleration). Some people say that the old mark 2 Golf gti 16v had better gearing too. I have heard (but don't know much about) 3.68 differentials. What is this and are there different differentials available? What do the numbers mean - do they refer to the 'type/size' of differential? What does the Corrado VR6 have as I would want something similar to the gearing on the Corrado to improve my acceleration (I know it would reduce top end speed slightly but I want to concentrate on low down acceleration). What other parts are involved? And what would it cost for the parts?.. and approx time to fit while the gearbox is out?I've heard of Quaife but I assume their parts are very expensive? Also, are lightened flywheels supposed to improve acceleration? Whats the general cost for a lightened flywheel? I've been told by Stealth the standard flywheel is generally pretty good and shouldn't need replacing. However I'm interested in whether a lightened flywheel is a good thing or not? And while the gearbox is out are there any other easily accessible parts that could be replaced to be uprated with better parts to improve engine response?Thanks for any help.Matt Link to post Share on other sites
kilokilla 0 Posted January 8, 2006 Report Share Posted January 8, 2006 well im not positive but i was under impression that corrado passat and golf vr6 all used the same box the 16v box has different bell housing and can be modified to fit using vr6 bell housing and yep quiafe are expensive but most places will want a lump of money to start messing inside gboxs anyway not sure whether lightened flywheel is a good idea or not but technically should improve acceleration and reduce top end i always use sach clutches and find them to be outstanding ,and uprated engine mounts will help a little with getting initial power down. Link to post Share on other sites
kilokilla 0 Posted January 8, 2006 Report Share Posted January 8, 2006 sorry just realised you said mk2 golf 16v box was thinking ov rado 16v box mk2 box not very good and wont go anyway allthough you can probably get gears transferred . Link to post Share on other sites
matth76 1 Posted January 8, 2006 Author Report Share Posted January 8, 2006 Thanks for your reply. I've done a bit of research about this and it seems it is a "final drive" that I need to shorten the gear ratios - either 3.68 or 3.94 (which is even shorter) and quite likely a longer fifth gear to compensate. From what I understand the parts required to get a 3.68 or 3.94 final drive are: crown wheel (ring gear) and the matching pinion shaft. What's the cost of these parts? If I ask The Phirm about this will they have a supplier who will supply these parts new or is there a particular manufacturer that will supply these? Is it easy to set up a longer 5th gear or what extra parts / replacements are needed to implement this, and importantly how much? How much is a quaife/peloquin differential? With the gearbox out is this easy to fit? Is this similar to limited slip differential or different? Thanks for your help with this.ps. re the mark 2 16v gti I was commenting it had shorter gearing than the mark 3 vr6. I've heard a Corrado G60 had shorter gearing too. Link to post Share on other sites
VR6Will 0 Posted January 8, 2006 Report Share Posted January 8, 2006 if your changing the final drive, its probably best to do the diff at the same time, you can get peloquins for about £480, quaife is alot more expensive and you also have to buy a fitted kit for the quaife which the peloquin comes with.I have a 3.68 final drive in my vr, i have driven one with a 3.94 too but found it isnt the best if you do alot of motorway mileage. Link to post Share on other sites
matth76 1 Posted January 8, 2006 Author Report Share Posted January 8, 2006 Thanks. How much would the 3.68 final drive be (all necessary parts)? And is a longer 5th gear required for a 3.68? How much of a difference does a 3.68 make compared to the standard gearing (which I believe is 3.3)? Can a 3.68 final drive be used without the uprated diff?Also does a 3.68 final drive affect the speedometer in any way?Cheers Link to post Share on other sites
matth76 1 Posted January 10, 2006 Author Report Share Posted January 10, 2006 Update: I was told by a vr specialist that I couldn't just go for a final drive. I would need 'all' different gears too. And then you need a diff. They said I couldn't just have a shorter ratio final drive which was a pity. I'm having my gear box out soon so thought it would be an ideal time to have a shorter 3.68 final drive fitted at the same time (for an extra £200). But apparently it's not possible without all the other gears being changed too. They reckoned..with the diff and all different gears upwards of 2k !! So I gave the 3.68 final drive a miss Be nice to have it though. Link to post Share on other sites
Eat this 2 Posted January 10, 2006 Report Share Posted January 10, 2006 well theres a few ppl with lower final drives knockin about Link to post Share on other sites
matth76 1 Posted January 11, 2006 Author Report Share Posted January 11, 2006 Does anyone know if it's possible to 'just' have the shorter final drive fitted or do all the other gears in fact have to be replaced too with different ratios? I was hoping I would just need to pay an extra £200 and have a shorter final drive Is this true - do I need all the rest of the gearbox changed too if I want the shorter final drive?What does the shorter final drive actually mean and provide? Does it just mean 5th gear is more revvy but all the other gears are the same - or not? Link to post Share on other sites
matth76 1 Posted January 12, 2006 Author Report Share Posted January 12, 2006 Anyone? Link to post Share on other sites
FishWick 21 Posted January 12, 2006 Report Share Posted January 12, 2006 Here are some figures based on 3.39 (standard), 3.68, 3.94 and 4.24 crown wheels. Tyre circumference and rev limit are 17" Eagle F1s (1872mm) and 6500rpm respectively.Bear in mind if youre into 1/4 miles, you won't pull 60 in second with the 3.68 and lower diffs without raising the rev limiter to 7000rpm. 3.39 ----------------------------------------------------------------------------------------- Top Gear gives 24.509 MPH/1000 RPM 70MPH=2856RPM Top Speed in 1 gear = 35.402 MPH Top Speed in 2 gear = 63.123 MPH Top Speed in 3 gear = 91.658 MPH Top Speed in 4 gear = 129.923 MPH Top Speed in 5 gear = 159.310 MPH 3.68 ----------------------------------------------------------------------------------------- Top Gear gives 22.578 MPH/1000 RPM 70MPH=3100RPM Top Speed in 1 gear = 32.612 MPH Top Speed in 2 gear = 58.148 MPH Top Speed in 3 gear = 84.435 MPH Top Speed in 4 gear = 119.684 MPH Top Speed in 5 gear = 146.756 MPH 3.94 ----------------------------------------------------------------------------------------- Top Gear gives 21.088 MPH/1000 RPM 70MPH=3319RPM Top Speed in 1 gear = 30.460 MPH Top Speed in 2 gear = 54.311 MPH Top Speed in 3 gear = 78.863 MPH Top Speed in 4 gear = 111.786 MPH Top Speed in 5 gear = 137.071 MPH 4.24 ----------------------------------------------------------------------------------------- Top Gear gives 19.596 MPH/1000 RPM 70MPH=3572RPM Top Speed in 1 gear = 28.305 MPH Top Speed in 2 gear = 50.468 MPH Top Speed in 3 gear = 73.283 MPH Top Speed in 4 gear = 103.877 MPH Top Speed in 5 gear = 127.373 MPHI have the 3.68 in mine which is perfect for daily use. Yes you can fit just the "CWP" (Crown Wheel & pinion) without changing the other gears. It's the 'final' drive, so changing that changes the effect of ALL the gears.5th is noticably perkier at motorway speed, as is acceleration through the gears. No the speedo isn't affected.On the quaife v peloquin front, if you incorporate a gearbox rebuild (recommended) into the fitment of a quaife, the parts you get with the peloquin are included in the rebuild cost, so it works out the same. Link to post Share on other sites
Eat this 2 Posted January 12, 2006 Report Share Posted January 12, 2006 i reckon it is Link to post Share on other sites
Phat VR6 3 Posted July 7, 2007 Report Share Posted July 7, 2007 So what i want to do to my box so i never have to touch it again is3.68 final drive, peloquin diff, and a full gearbox rebuild!!! Is there anythink else you would recomend while the box is in bits, Can you heattreat the gears or make them stronger in anyway. Ive hurd turbos kill 3rd gear????Oh and has anyone on hear changed there final drive themselfs as in with out getting a gearbox rebuilter to do it for them.cheers people Link to post Share on other sites
FishWick 21 Posted July 9, 2007 Report Share Posted July 9, 2007 Unless you know how to setup diff preload, it's not something you want to be attempting yourself.If the conditions are right, turbo torque can destroy any gear, but 3rd usually bites it first.With sensible boost levels it shouldn't be a problem, just don't accelerate hard over bumps as it's the regaining of traction after a spin that usually busts your gear. Link to post Share on other sites
Phat VR6 3 Posted July 9, 2007 Report Share Posted July 9, 2007 Ah right, Yer that makes alot of sense. Donno if i will be able to control myself that much lol. I like my contry road driving which tends to be very bumpy and I seem to spent half my time in the air or going though big puddles. Prehapes a MK3 VR turbo isnt the car for rallying around!!! More of a track carSo out of intrest how many boxs have you been though, What boast do you run at and how much BHP are you pushing. One other thing is how controlable is the boost with a boost controler. Is it possible to go from 250BHP to say 600BHP taking that your engine is built to take it.Cheers for you help. You seem to know your shit Link to post Share on other sites
FishWick 21 Posted July 10, 2007 Report Share Posted July 10, 2007 VR turbos are fine cross country if you've got decent brakes and good suspension. A quaife LSD will help with traction, but on uneven country roads it can be a torque steering bar steward! It's good fun though.Still on my original gearbox mate! Boost is 11psi and that gives around 350-360hp. It's the torque that breaks gearboxes, not power, but that's well over 330lb/ft as well, so you do need a little mechanical sympathy!If the engine is built for 600hp and the turbo is big enough to provide enough CFM for 600hp, then yep, you can go up to 600hp very easily with a controller. The lower power limit will depend on the wastegate spring etc. An 8psi spring with a controller and a GT35R turbo will do from 320ish to 600hp. Link to post Share on other sites
Phat VR6 3 Posted July 10, 2007 Report Share Posted July 10, 2007 Thanks for that. Dare i ask about your MPG??? Link to post Share on other sites
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