1.8 and 2.0 16v tuning mods - good site

[davidwort 0]

just found this site from the Club GTI Forum, loads of info and dyno plots of various mods and their results, mainly mk2 16v's but lots relevant to KR and 9A engines.

Plots on 'J485 GVK - Tune up' link are quite interesting showing different cams and their results on hp and torque.

 

http://www.gvk.altrezia.com/menu.html

 

David.

[dubbprince 0]

dave, was the Kr block he got tuned at stealth just a normal std 139bhp one? cos thats what it sounded liek when i read it, then stealth did something to the warm up regulator, tweaked the fuel timing etc and he got an extra 21bhp...for £88 he says.

Am i reading that right? or has he got the cams in to do that. :|

 

Sorry to offload the topic..but hows the engine transplant getting on? :lol:

[Bobby 0]

from what i've heard the best bet for more power from the kr lump is a set of decent cams and a 4 branch manifold along witha good tuning session. my engines is in for a rebuild at the moement would some porting to the head make any difference by itself? thanks B :mrgreen:

[Bally 0]

Good link mate, I was thinking the same as sanj. :?:

 

hows things David, good to catchup the other day :wink:

[aposegil 0]

or do what ive done 190 bhp 150+mph and alot of fun :)

[Bally 0]

Alex, you'll have to take me out in yours once its back on the road.. :wink:

[davidwort 0]

dave, was the Kr block he got tuned at stealth just a normal std 139bhp one? cos thats what it sounded liek when i read it, then stealth did something to the warm up regulator, tweaked the fuel timing etc and he got an extra 21bhp...for £88 he says.

Am i reading that right? or has he got the cams in to do that. :|

 

Sorry to offload the topic..but hows the engine transplant getting on? :lol:

 

I did that myself ages ago, basically you remove the warm up reg, drill the top of the brass dome on the back of it off carefully and there is s screw adjustment inside for the fuel control pressure, it's set a t the factory. By reducing the control pressure here you boost the fuel pressure to the injectors at all revs.

It's a crude way of richening the mixture, but works well with modified engines as K-jets tend to run lean at the top end anyway.

all you need is a 5 or 6mm drill bit and a bit of time to try out different settings, only turn it about 1/8 of a turn at a time though as small amounts increase the fuelling quite a bit, check the plugs after a hundred miles or so and if they're not too sooty then you've probably got it about right, a rolling road will just help you get the setting right quicker.

I've got the 6A Audhi block sorted now, just need a few bits at the weekend and it should start to come together, my old TSR 2.0 block is junk :roll:

 

Here's the notes I did on this mod before:

 

Remove the regulator by unscrewing the two 5mm allen bolts that hold it to the head.

 

On the back of the regulator is a tamper-proof cap! - drill the top off this carefully and you can adjust the fuel control pressure by turning the 4mm allen screw.

 

Anti-clockwise reduces control pressure and therefore increases fuel pressure to the injectors, be careful to mark the factory set position and turn about 1/8th of a turn and see how it runs.

 

Be careful to check the fuel unions when re-connecting, the aluminium washers should really be replaced, and check for leaks when you re-start the car.

 

The K-Star unit basically by-passes this unit in a controlled way with a valve (actually a fuel injector) to lower the control pressure, but adds the ability to map the pressure control to speed and load conditions. The manual adjustment is fixed across the rev range and is therefore a bit less fuel efficient and not finely tuned to the engines needs.

 

It works really well tough, giving a boost where it needs it to high rev. mixture richness.

 

If you want to check the richness, drive the car for a few hundred miles and remove one or more of the sparkplugs, they should be running cooler and have some brownish deposits, possibly a bit of black carbon fouling but not on the electrodes themselves, just the base at the end of the thread that sits inside the combustion chamber. This shows a fairly rich mixture, but not too rich. It's surprising how accurately plug condition can determine if fuelling is right, especially on a K-jet engine. Most Haynes manuals have colour pictures of plugs in various conditions, useful as a guide.

 

All at your own risk of course :wink:

 

 

cheers,

David.

[davidwort 0]

from what i've heard the best bet for more power from the kr lump is a set of decent cams and a 4 branch manifold along witha good tuning session. my engines is in for a rebuild at the moement would some porting to the head make any difference by itself? thanks B :mrgreen:

 

I've always understood the standard manifold is OK, perhaps with a little internal polishing. most 4 branch manifolds have no flexibility and can crack especially if your engine mounts get worn and you drive hard.

Personally cams are only really suited to a ported and gas flowed head, but you can get 155bhp plus from a 1.8 with this work done properly.

If you have to rebuild your 16v head, then I'd def say get it ported and gas flowed while it's off, 1.8 or 2.0.

 

David.

[davidwort 0]

dave, was the Kr block he got tuned at stealth just a normal std 139bhp one? cos thats what it sounded liek when i read it, then stealth did something to the warm up regulator, tweaked the fuel timing etc and he got an extra 21bhp...for £88 he says.

Am i reading that right? or has he got the cams in to do that. :|

 

Sorry to offload the topic..but hows the engine transplant getting on? :lol:

 

Forgot to say, It's a 2.0 9a engine with KR cams that gets the extra hp,

however, most engine tuners I've spoken to say the 9A/6A 2.0 bottom end is only good for about another 7bhp on top of the 1800 unit, a well set up 1.8 16v with standard KR cams could well give more than the factory bhp output if in very good run in condition.

[dexteruk 0]

well u will have seen my power curves on those graphs

 

 

although the 1.8 kr with std cams one is not my most recent

 

std kr head, bottom end, cams with stealth warm up reg, k&n filter, modded airbox, 8v downpipe, 8v stainless jetex gave 155bhp and 124lb/ft on stealth's rolllers

 

(the exhaust mods alone made 5bhp through most of the rev range)

 

 

GVK's car is a 9a engine with kr cams, std manifold and aftermarket exhaust, also stealth warm up reg mod - he made 175bhp and 150lb/ft on the rollers on his most recent run

 

as you can see i now have a Blydenstein stage 1 head and schrick 260 cams - that boosted output to 173bhp and 134 lb/ft

[Golden 0]

I did that myself ages ago, basically you remove the warm up reg, drill the top of the brass dome on the back of it off carefully and there is s screw adjustment inside for the fuel control pressure, it's set a t the factory. By reducing the control pressure here you boost the fuel pressure to the injectors at all revs.

 

cheers,

David.

 

Just to be anal it doesn't increase fuel pressure at the injectors but reduces the resistance above the metering head plunger, it is this that casues the mixture to richen.

[exturbo2003 0]

I did that myself ages ago, basically you remove the warm up reg, drill the top of the brass dome on the back of it off carefully and there is s screw adjustment inside for the fuel control pressure, it's set a t the factory. By reducing the control pressure here you boost the fuel pressure to the injectors at all revs.

 

cheers,

David.

 

Just to be anal it doesn't increase fuel pressure at the injectors but reduces the resistance above the metering head plunger, it is this that casues the mixture to richen.

to be anal the injectors open with pressure and nothing else, so to get more fuel in you need more pressure

you can also do this with the system pressure but it is not as accurate. control pressure lowering allows the air flap to open further for a given throttle setting. the flap lifting lifts the plunger and so more fuel, but there is an increase of pressure at the injectors

[exturbo2003 0]

well u will have seen my power curves on those graphs

 

 

although the 1.8 kr with std cams one is not my most recent

 

std kr head, bottom end, cams with stealth warm up reg, k&n filter, modded airbox, 8v downpipe, 8v stainless jetex gave 155bhp and 124lb/ft on stealth's rolllers

 

(the exhaust mods alone made 5bhp through most of the rev range)

 

 

GVK's car is a 9a engine with kr cams, std manifold and aftermarket exhaust, also stealth warm up reg mod - he made 175bhp and 150lb/ft on the rollers on his most recent run

 

as you can see i now have a Blydenstein stage 1 head and schrick 260 cams - that boosted output to 173bhp and 134 lb/ft

 

nice to see you doing well Dex

how come your joining a corrado site, tho its good to get new blood.

welcome mate and also you too Golden, tho i dont know if we have met.

[Golden 0]

I did that myself ages ago, basically you remove the warm up reg, drill the top of the brass dome on the back of it off carefully and there is s screw adjustment inside for the fuel control pressure, it's set a t the factory. By reducing the control pressure here you boost the fuel pressure to the injectors at all revs.

 

cheers,

David.

 

Just to be anal it doesn't increase fuel pressure at the injectors but reduces the resistance above the metering head plunger, it is this that casues the mixture to richen.

to be anal the injectors open with pressure and nothing else, so to get more fuel in you need more pressure

you can also do this with the system pressure but it is not as accurate. control pressure lowering allows the air flap to open further for a given throttle setting. the flap lifting lifts the plunger and so more fuel, but there is an increase of pressure at the injectors

 

 

First thanks for the welcome Stuart but the above is incorect, the pressure at the injectors is the same regardless of control pressure (i.e. WUR mod) it is only the lowering of the fuel pressure resistance above the metering unit plunger that richens the mixture. Although the pressure controlled by the WUR is called the control pressure it has nothing directly to do with the injector line pressure.

[davidwort 0]

First thanks for the welcome Stuart but the above is incorect, the pressure at the injectors is the same regardless of control pressure

 

 

OK, so how do you get more fuel if the pressure at the injectors stays the same?

I'm still missing something here I think :scratch:

 

The control pressure influences the fuel distribution. If the control pressure is low, the air drawn in by the engine can deflect the sensor plate further. This results in the control plunger opening the metering slits further and the engine being allocated more fuel.

taken from: http://www.volvoclub.org.uk/tech/fuel_injection/k_jetronic3.htm

 

 

David.

[Golden 0]

Well David, the way the metering head works is a plunger is connected to a large flap, the engine "sucks" on the flap, pulling it up. The more the flap raises the higher the plunger goes, the plunger has cutouts in it allowing fuel to move from a pump fed chamber to a chamber feeding the injectors.

 

The ease with which the engine can suck the plate is controlled by feeding a certain amount of fuel pressure to a chamber above the plunger. This is purely used to control plate resistance, this feed of fuel pressure goes nowhere near the injectors.

 

So by dropping the fuel pressure above the plunger the engine can more easily "suck" it up and so for a given load (suck) you get more fuel to match. This is what is actually being done with the WUR mod, people are simply reducing the resistance above the metering head plunger.

 

It is a bastardisation of the cold running system used on K Jet.

 

To sum up, all it does it make the engine richer throughout the rev range.