vr6 tuning

[aki 0]

hi guys

im in need of advice..ive polished and ported my own vr6 head,gave it a go figured id nothing to loose! im going to be fitting new cams of some sort probably in the region of 264 (regrinds hopefully) possibly 268s if dougherty can sort me out a pair at a reasonable cost ive also polished and ported the inlet manifold and exhaust manifold and having a go at the throttle body as well! :lol: firstly are the vr6 cams different in their duration to cope with the differing inlet and exhaust tracts? and will my standard motronic management cope with this sort of modification. ie will it run ok (i know to realise the full potential its gonna need a remap)

cheers!

andy

[Chris VR6nos 0]

Buy a charger!

Fit nitrous!

But apart from that, why not go for a higher duration cam and raise the compression?

The tracts in the head don't give a great deal of scope for removing metal, smooth it out and get rid of roughness and casting marks, mostly you should try and port-match the manifolds and head ports, this matching will mean more to flow than slight tract polishing but you need to make sure the gaskets aren't in the way of the ports either, if so you need to cut the offending area back.

Stop the hot water going to the trottle body and get a open slat front grille and use Optimax and once you've got the bits done, go to stealth for a remap.

 

 

Chris

[Kevin Bacon 5]

The two cams are symmetrical unfortunately, but the OBD2 management times the front 3 injectors differently to the rear 3 to compensate for fuel evap' down the longer of the 6 tracts. OBD1 just shoves the same rate of fuel down all 6 gullets!

 

The Schrick manifold was the only attempt to make the inlet tracts equal length. VW just didn't bother!

[andy 0]

The two cams are symmetrical unfortunately, but the OBD2 management times the front 3 injectors differently to the rear 3 to compensate for fuel evap' down the longer of the 6 tracts. OBD1 just shoves the same rate of fuel down all 6 gullets!

 

The Schrick manifold was the only attempt to make the inlet tracts equal length. VW just didn't bother!

 

Does that mean an OBD1 car with Schrick Manifold is better in that respect than an OBD2 car with Schrick Manifold?

[Chris VR6nos 0]

It really doesn't make a world of difference, sod the OBDII and get a DTA P8Pro and you can adjust everything and it even has fuzzy logig biases interpolation for injector timing as well as shovel leads of stuff and you can tweak it yourself as much as you like or no and let it learn it's self constantly.

There are always more ways to skin a cat

 

 

Chris

[VRTrickster 0]

Ive got a port matched upper and lower inlet manifold from Micha from Germany on my bedroom floor waiting to go on. This isn't matched to the head though! I have some 264s coming from Dougherty race cams for just over £200, bargain for brand new cams!

These are getting fitted along with a 2.9 re profiled TB and a CDA!

 

Stop the hot water going to the throttle body and get a open slat front grille and use Optimax and once you've got the bits done, go to stealth for a remap.

 

Was thinking of doing this myself will it make any difference? I suppose every little helps! :) That's why when people say I dont really need a inlet heat isolation gasket unless I'm force inducted! I'm going to fit it anyway and then its there for when I turbo charge it,but also lowering the intake temps till then!

 

As I'm on a budget and trying to prove you don't need to spend silly money to gain power I'm thinking of going to the Germans for a mapped chip!

[Chris VR6nos 0]

VRTrickster, forget buying a chip with a map on it, you may as well spread butter on the ECU, it's just not the right way to do it!

The TB heater pipes do help in the winter i'm sure but not needed in the summer and the supercharger warms it up on my car anyway as would a turbo you mentioned is in the planning.

The isoplates are a gimmic i'm sure and the difference is smaller than my penis!

It depends upon what you call silly money TBH, it's not expensive to tune the VR compared to many other cars as it has plenty of power to start with.

The cam choice is very mild if you are after power surely!

Why 264's?

you can get a far better profile and do a few things to get it working together so whom told you this was the best for power?

It all depends on what you want to do i guess but i want to see someone get some 310degree cams and run 12:1 C/R with throttle bodies and a few other things and get the thing to show it's teeth Grrrrrrrrrrrrrr................

 

 

 

Chris

[double-6s 0]

Yeah that sounds nice mr nos. A bit of a beast. :)

[Chris VR6nos 0]

Some cam profiles dictate using a C/R of 15-17:1 and that's going for it.

Now i don'r want anyone to pipe up slavering on about detonation blar-blar-blar because it won't.

Remember the Dynamic and Static C/R's? well there you have your answer.

If the valves are open for a long time then the compression has to be part of the equation and raised accordingly, i don't believe there are a great many people that could consumatelly construct a race engine with these perameters and get it to perform as predicted, but i had a good teacher, David (Wizard)Visard.

 

 

 

Chris

[VRTrickster 0]

Ok I get your point! The reason Im going for 264 is, doing a bit of research people found that you loose some of the idle quality. I still want to retain a smooth and powerful daily driver!

People have said that the ever popular 268s are good when accompanied by a Shrick or VSR! Im not fitting one of these and thats were I feel the silly money comes in to it a bit. Im looking to get some reasonable power gains with my budget and keep some smoothness and economy!

The 268s are said to come in right up the rev range were as the 264s give it a little bit lower in the mid, Im not a drag racer!

I fought I would be a bit different and try the 264 inlet and exhaust with port matched manifold combi and see what the outcome is?

 

Have you heard anything about these or are they just another gimmick,what would be the benifit?

 

http://www.bildon.com/catalog/DetailsLi ... .375&Nav=8

 

Do you really think I should bit the bullet and pay more money and get a propper remap with the likes or say Stealth? Who do you recomend?

[Chris VR6nos 0]

The spacer might do something slightly however, the idea is that your engine's protection is reduced, personally i'd leave the sensor alone, they aren't as responsive on the OBDI anyway so just a bit of a gimmik for the Corrado really.

Forget a lot of what you read about smoothness and what people say, people ware posting about my VR loosing torque and power and idling lumpy and stalling when i was fitting a 6lb flywheel but NONE of it's true at all!

You wouldn't know it has a rediculously light flywheel fitted apart that it revs so fast.

The VR has 6 cylinders to push it round one circle so go mad a bit, it'll all be just fine.

Mapping has to be part of the budget as it's as much or more important than the mods done!

A good custom map will get the engine producing the power it should and give you goose bumps and often yeild better mpg when driven normally, though a poor map ie. and off the shelf map can often have less than impressive results and in some cases i've experienced have caused engine failure, i site the Z-engineering maps engine failure which is well known.

Go to stealth but make sure that you have all the thought done right and the engine is in it's final state before the trip to see Vincent!

 

 

 

Chris

[aki 0]

hi, so will my existing motronic learn its new parameters after fitting some new cams to my diy polished and ported head and manifolds (prob 264 as im after torque not crazy horsepower at 7000 rpm) the existing cams peak at 5800 i think the factory rev limiter comes in at 6300 and thats fast enough for me! out of interest how fast will a vr6 spin before it throws a rod out the side of the block? vw obviously decided that 6300 was fast enough i dont mind increasing that rev limit a bit but im thinking 264's wont encourage me to thrash my car low down grunt is what its all about! thats what makes chargers so tempting! if i could afford one......where is peak power produced with 268s and where is the torque peak i could be tempted with 268s as long as the peaks arnt too high up in the rev band! obviously a remap will remove the vw rev limit at a later date,as long as the 268s give tha same or more torque as the 264s them why not! but id rather have for example 20nm more torque at 4500 rpm than a 5 bhp increase at 7000!

ive finished my head the ports are very shiney (exhaust shinier than inlet) and the inlet ports are matched to the manifold i took them out to the gasket holes it was surprising how much material i had to remove most noticably from the more oval ports than the round ones, took a while but easy enough with a dremmel anybody know why there are numbers stamped inside the inlet ports? i havent done any reshaping further down the port just removed enough metal to make it smooth! o and ive taken a bit off the guides so that they arnt as angular! i noticed that there is a seam in the valve bowl area right behind the valves that causes a proper lip sticking out into the flow so that was removed an shaped to make it smooth,also the short side radius was very angular and impossible to get to properly with my dremmel so i used strips of wet and dry through the port to remove any edges and they are now a smooth constant radius. should i cut the guides off flush or leave them sticking out as they arnt very long to start with and i havent seen a "properly done" vr6 head! sorry for banging on for ages :)

andy

[dazzyvr6 0]

on the subject of tuning the vr6 motor just found this on awesome gti's site

VR6 PowerGasket™ Plus

NewSouth Performance, LLC has extended PowerGasket Plus™ line to include the VR6 12V engine.

 

Using a composite material that is specifically designed for gasket applications, the PowerGasket Plus™ gives you up to 5% more power from your engine by reducing the temperature of the incoming air to your engine with an insulating gasket that radically reduces the heat transfer from the cylinder head to the intake manifold. This gives you cooler, denser air for more horsepower and performance from your engine.

 

Tested in an 800 HP, 40 PSI turbo VR6 engine, the PowerGasket Plus™ is rugged enough for most automotive applications and has shown a 20°F+ reduction in VR6 intake air temperatures in on-road testing.

 

is that a load of hot air?

[aki 0]

hi

must make a small difference most carbed engines have a small (usually about 10 to 15mm thick)plasticky sort of spacer between the manifold and the carb,so it must isolate the manifold or carb from the heat of the head i think it probably makes more difference on very highly tuned engines where gains of a few percent can actually be measured!! but i suppose every little helps,depends how much it costs for hp gain i guess!

[Chris VR6nos 0]

I can't comment on the power difference but it's oddly put, the carb situation is different as there are two reasons for the mica spacer, firstly for gaskets and secondly to reduce the heat transfer to the carb body as things like jet sizes may change and they use a fuel reservoir with a float in it and this will heat up and cause further fuek evapouration though prob minimal, the injection engines don't have jets but injectors which are externally controlled by an ECU.

Anything that cuts heat down is a bonus but by how much you will benefit, that's the question.

Onw point worth making is that these things claim things like 20% power increase, i think you should realise that this is misleading, doing a power run on a car that has warmed to 50-70C will give a figure of say 200bhp then umpteen runs later the car will only produce 160bhp, this could be termed as a 20% power increase if in the same situation the heat reducing item makes the engine maintain it's 200bhp figure, it's more of a loss reduction endevour rather than a power increase thing!

 

 

 

Chris

[VRTrickster 0]

Im going to be fitting one of those gaskets ,but with everything else fitted I wont be able to tell if the things made a difference!

I am also looking at a 6 lb fly in the near future. What do you think about lighter drive pulley like these ?

 

http://cgi.ebay.com/ebaymotors/ws/eBayI ... AMEWA%3AIT

 

Im I right in thinking you can still run 264 with a turbo as long as the CR is reduced accordingly?

My bottom block and pistons are brand new with existing crank and rods with new bearing less than 30k ago! Can I run a turbo kit on low boost with spacer gasket without blowing anything up? What sort of power can I push it to but remain safe? Would I be able to run the turbo with all existing mods mentioned?

 

Sorry for all the questions!

[Kevin Bacon 5]

It really doesn't make a world of difference, sod the OBDII and get a DTA P8Pro

 

How would you know? You've not used either!

 

What you keep forgetting to say when you're suggesting P8PRO's and CRs of 15:1 to etc is how much all this costs. And 15:1 on a VR is a ridiculous idea. No petrol production engine has a CR that high, why? Because it doesn't work. The E46 M3 is only 11.5:1 with variable everything. Any higher and it would grenade itself. The very best tuners can only extract 5hp from that engine, such is BMW's good work and even adding a charger makes hardly any difference on the track. So what do you know that M, VWMotorsport and Audi Quattro GMBH don't, and why aren't you employed by them earning a mint?!?

 

You're sipping the ale and spouting your internet readings again aren't you? :-)

[Chris VR6nos 0]

Kev, calm down mate, i was suggesting that someone should go for it instead of buying off the shelf minimal performance things and if they had the time and space to do a project car it would be great to follow the project, would it not?

I'm sorry you have this much myrth and feel you need to sputter it out at me like this but we are speaking about nothing of the same here, lets try and at least sing from the same hymn sheet Kev please?

 

The 15:1 thing is doable and no it wouldn't be great as a road car but the illustration waasn't purely for that, it was an extreme statement to push ideas forward.

 

Cost wise there doesn't have to be a fortune spent at all. As far as OBDII goes i have obviously driven Golf VR6's as a few mates have them in various guises.

I would like nothing better than to get into a DTA P8 and have a play and further my knowledge in this area as i'm sure you would be interested too!

The P8 has lots of great features and is way ahead of the old design that is the Golf ECU with OBDII and with an accurate UEGO sensor you can competently map the car yourself as long as you have the ability which isn't hard so most could do it if the aptitude was there.

 

I'm disappointed with your post mind Kev, thought more of your than to go on a slag off like that on open forum mate :sad:

 

 

Chris

[Kevin Bacon 5]

Don't take it personally!! ;-)

 

Slagging off on an open forum? I wasn't really slagging you off, but wasn't it you that threatened to stab a certain person on this 'open' forum last year? :-)

 

I'm serious though, you do seem to know your stuff and I'm surprised you're not employed somewhere putting it to good use.

 

Did we ever get a GB price on the P8s?

[Chris VR6nos 0]

i seem to remembe some convo but wasn't a huge amount, worth looking into again if there's interest

 

 

 

Chris

[VRTrickster 0]

Im going to be fitting one of those gaskets ,but with everything else fitted I wont be able to tell if the things made a difference!

I am also looking at a 6 lb fly in the near future. What do you think about lighter drive pulley like these ?

 

http://cgi.ebay.com/ebaymotors/ws/eBayI ... RK:MEWA:IT

 

Im I right in thinking you can still run 264 with a turbo as long as the CR is reduced accordingly?

My bottom block and pistons are brand new with existing crank and rods with new bearing less than 30k ago! Can I run a turbo kit on low boost with spacer gasket without blowing anything up? What sort of power can I push it to but remain safe? Would I be able to run the turbo with all existing mods mentioned?

 

Anyone ??

[junkie 0]

Just so you can explain then why would a 15:1 compresssion ratio not be good for a N/A road car?

 

As i understood it it will give more power as more compression but your engine wont last long like rally cars running high ratios albeit forced induction?

[Chris VR6nos 0]

The higher the C/R the faster the exhaust gasses expand and you need less fuel to make the same bang.

The higher it is though creates it's own problem when using petrol which isn't the best fuel to use for combustion, just the cheapest compromise.

Using methanol and oxyget would yeild double the Bhp but wouldn't be reliable as it's too unstable and thus dangerous.

The more you squash something the hotter it gets as the molecules rub against each other tighter and harder, this heat is good and bad.

If the piston or some part in the chamber gets hot enough then it will ignite the fuel, this is called preignition and causes engine failure, don't get it confused with pinking which is the act of ignition too far before TDC.

 

Compression is a relative thing, i could run the same engine on 8:1 C/R then change things and modify it to run at 15:1C/R and both would run reliable i promise.

The thing that makes all the difference is valve timing.

If an engine running 10:1C/R has it's valves closed at BDC then it compresses what's in the cylinder from the bottom to the top and the result is 10:1C/R

The same engine with a wild cam fitted that closes the valves half way ip can't start to compress anything until this half way point else the gasses just leak out because the valves aren't closed to make a sealed volume.

This engine would result in a C/R of only 5:1, The result is that you could run this setup with a 20:1C/R and it ould run on the same Dynamic C/R as the VR does as standard, 10:1C/R

It would be fabulously powerful as the small amount of gasses which were compressed would thus expand at an incredible rate and produce huge power though not a huge amount of torque as this needs the valves to be closed for a long time to push the crank as far round as possible.

The engine would still run correctly in the right stoichiometrical ratio and rev like a bike, this is the way many fully blown drag cars are setup to run 4.5sec quarter miles.

 

Pulleys

H8RRA and i are in the process of sorting out some CNC machined pulleys for the VR, let one of us know if this is of interest to you.

 

 

 

Chris

[Chris VR6nos 0]

When i was talking about dynamic C/R's and 15:1, well i thought i'd do a search for things to see what was out there and there is some pretty clued up folk out there for sure!

This is a screen dump of the results of H8RRA's engine with a couple of guesses so not totally accurate but does illustrate the difference between static and dynamic C/R that i keep waffling on about Kev!

This example turns out to show that the engine runs at 16.99:1C/R but dynamic compression ratio is 9.72 :1 which it is! and produces 331bhp and 311Lb/ft torque.

 

 

 

Chris

[Chris VR6nos 0]

Just found this page, though it was explained better than a lot of others, plus it proves i'm not talking waffle, never looked for DCR info on the net before but if you want to find out about the REAL C/R then there's plenty out there to read up on!

Dynamic Compression Ratios Explained

 

 

 

Chris