Boost questions

[tomaski]

Hi folks.

I'm looking to increase performance on the cheap, so I've decided to explore the option of fitting a dawes device style boost controller on my VR4.

I've had a look around the site and found out that 13psi is pretty much the max on the standard fuelpump / ecu setup so that'll be as far as I'll want to go.

And I've also realised that a boost gauge is a must as judging boost is pretty much impossible without it.

But I still have a couple of quick questions...

... Firstly, my car is bloody ancient and approaching 70k miles - will the engine really hold up to increased pressure? Is this an impossible question or is there a general rule of thumb on this one? For the record I don't have the 'tickticktick' or any other obvious nasty problems and I do my best to Amsoil her every 10 minutes but age is age, y'know?

Also... what does the standard setup boost at normally? I presume it can't be far off 8psi but when I thought about this I really couldn't put my finger on it.

Finally, to the folks who've been here and done this... any reccomendations on parts or proceedures? What about things to look out for, danger signs and the like? Is this really an easy process or is this one to leave with a mechanic? Again, for the record I've changed sparks and brakepads before... but nothing major.

Thanks in advance for the help amigos!

:2thumbsup

[Gowf]

Some people have used dawes devices with success. In my personal experience however, they can cause some horrendous boost spikes and i would much rather pay the extra and get a EBC as you have proper controlability of the boost curve rather than just bleeding some air away from the actuators.
Stock boost is around the 8psi mark yeah and the engine will take 13psi all day long (as long as it is 13psi and not 13psi with a 17psi spike). In all honesty, stock tubs do start to run out of puff above that, but if you keep to a safe 13psi your car will be more than happy.

1996 - old? bloody hell, god knows what you'd think of my NSU!

[Wodjno]

As above /yes...

To add a bit though..I used manual boost controller and didn't suffer from major boost spikes, mine was a simple screw and not ball and spring.. whether this made a difference i'm not sure. as i've not used ball and spring type either I can't comment on their behaviour.. I did get spikes, but I had mine set around 14psi and spikes of around 15.5 at most..

On the age and mileage of your car ?

At that mileage it's barely loosenig up !

Mines nearly double the mileage and can still pull sub 5 sEc 0-60's and top 160mph /yes
Well if it ever moves itself off the drive again that is :D

[bradc]

70k miles is hardly broken in, there are members well above 150k on their original engines

[amsoil]

I'll second that; engines with this low milage often still have the honing marks still in the bores!


70k miles is hardly broken in, there are members well above 150k on their original engines

[elnevio]

This is similar to what I want to do, i.e. keep it mostly standard. What sort of power increase can be obtained this way?

[Wodjno]

This is similar to what I want to do, i.e. keep it mostly standard. What sort of power increase can be obtained this way?

You notice mostly the acceleration difference..

0-60 times dropping to mid 5's..

[elnevio]

You notice mostly the acceleration difference..

0-60 times dropping to mid 5's..
Yep, that'd keep me sweet! :pimp2:

[Wodjno]

Yep, that'd keep me sweet! :pimp2:

And ... You'd be able to Kill almost any Bimmer at the lights, that isn't an M3 or M5....

or M6 :D

Wouldn't Mid 4's be even better ;)

[Beastlee]

I'm sure high 4s/low 5s would be obtainable for minimal extra cost...
I've spent approx £300 so far on mine and once the Profec is set up properly (supposed to have done some today but too lazy) I reckon it will be lower 5s. My next purchases will set be back about £500 but I reckon the gains will be very good. All items will be self installable but I'm guessing the eManage needs a rolling road to set up correctly.

[Wodjno]

but I'm guessing the eManage needs a rolling road to set up correctly.

You got the best rolling road you could ask for on the way home from work :D

[Beastlee]

Hehe, true but I'm sure I could easily destroy my engine if it's not right on the first fw runs.

[Wodjno]

Hehe, true but I'm sure I could easily destroy my engine if it's not right on the first fw runs.

Well only if your a complete fool :D

Because your starting at factory settings and you should only start with small adjustments, then i'm sure you will be ok.. If you want me to pass my eye over any map before you upload to the e-manage. I'd be more than happy to /yes

[tomaski]

Firstly, cheers for the re-assuance and helpful advice - most forums are full of scaremongers and it's always nice to see the nutters at VR4 encouraging boost play.

Right folks, boost gauge is now fitted after much swearing, straining and sore fingers.

Really not a complex process, but on the fiddly scale it's a clear 10.

Oh and major kudos out to the missus who had the patience to fish out the T piece not once, but twice from inside the engine after my stumpy sausage fingers dropped it.

But, it's working and boosting at 7psi, with good solid vacuum at idle. Next up, Dawes Device!

Will keep you lot posted so you can laugh when she blows up.

OH! Anybody know what bulbs to get for the front? My passenger side one has died and I figure replacing them both would be a good idea. Am I just going into Halfords and asking for H7 bulbs?

As always, cheers dudes.

[Beastlee]

Going to assume you are running a tiptronic based on that boost pressure. Glad to hear the guage is on, I was so happy to have that let alone the EBC facilities.

H7 is the main beam and H1 for full beam and/or fog lamps.

[tomaski]

Yeah, tiptronic/auto setup. How'd you know that just from boost pressure? I didn't realise gearing setup had anything to do with that.

And cheers for the info on the bulbs. I'll jump into Halfrauds later.

[Beastlee]

If you had a manual or facelift car (your profile info on the left shows 1996 so pre-facelift) the boost pressure would have been closer to 12 or 13 psi as that gives them the extra 20ps as standard.

[tomaski]

Ah. Well spotted mate. Hopefully I'll be ramping her up to about 12 psi soon enough so I'll be up with the facelift mob.

[Beastlee]

Mine is running between 10 and 12 now but I'm going through the setup again to get it just right.

[Wodjno]

Mine is running between 10 and 12 now but I'm going through the setup again to get it just right.

Is that with NO boost controller ??

[Beastlee]

No Glenn, that's with the Profec set as per my thread.

[Wodjno]

No Glenn, that's with the Profec set as per my thread.

Ah.. Ok.. Forgive my ignorance :D

What gesr did you set it up in originally ? And from what revs did you run it from and to ?

[Beastlee]

I always check with it from mid 3rd through to mid 5th, 6500rpm in 3rd and 4th before the change. Stays fairly well but low .8s bar for the boost.

[MarkSanne]

thats a nice-to-know little fact!

so my auto ECU must be pre-facelift then too, as mine runs at 0.5 bar... hmmm... need EBC too & fast...

[bradc]

yep, they ran the boost slightly lower on prefacelift auto's

[elnevio]

yep, they ran the boost slightly lower on prefacelift auto's
Apologies if this has been covered before (/pan) but is it the ECU that determines the boost on the pre-facelift autos? Hmm, that might even be a really daft question (/pan again), but I don't know!

If so, would upping the boost (whether EBC or Dawes-type device) to around 7-8psi get the extra 20 horses? And then to, say 12psi, to get another 20 or so?

Or am I just miles away with that? (/pan /pan)

[Beastlee]

Apologies if this has been covered before (/pan) but is it the ECU that determines the boost on the pre-facelift autos? Hmm, that might even be a really daft question (/pan again), but I don't know!

If so, would upping the boost (whether EBC or Dawes-type device) to around 7-8psi get the extra 20 horses? And then to, say 12psi, to get another 20 or so?

Or am I just miles away with that? (/pan /pan)

Correct in the first part but you already have 8psi so you are at standard boost. 12psi gives you back the 20ps (little more than bhp) that is missing on pre-facelift autos. The problem is that once you start to increase above 12psi you need to look at uprated fuel pumps and other aspects covered on here somewhere.

[bradc]

yep, thats about it! You can't increase the boost too much at the high end though because of the small turbos. You will however see a huge increase in the mid range from 3000 to 5000rpm

[Beastlee]

Yup, that extra kick is definitely noticable!

[Kenneth]

I have had a couple of MBCs and not had trouble with them.

in saying that, I always modified them... first one was home made out of pipe fittings, the second was a bleed valve which I converted to ball & spring.

My advice to anyone going down the MBC route (at least on a VR-4) is to ditch the spring and get a new one which is softer. a softer spring is good for avoiding spikes, however it does mean you may have to play a little until you get one that gets you to the boost you want. (springs are cheap though.)

In this way I didn't have any boost spikes of note.

[tomaski]

Nothing to do with turbos but I got my lights sorted. Bit fiddly again but after you see how it clips out it isn't too bad. Cheers for the advice on bulbs Beastlee.

[Beastlee]

No problems, glad you sorted it.

[tomaski]

Okok, I wasn't going to wire up the lights on my boost gauge because I've always felt they looked tacky as hell but curiosity has got the better of me so I've decided to see how it looks.

Thing is, the autogauge erm... gauge I bought has four damn wires coming out the back. And they're all only half a foot long.

So I presume one is ground, one is +12v ignition, one is a permanant +12v source (for constant supply - God knows what for?) and erm... I'm not sure what the other is for.

Came with no instructions whatsoever.

So yeah, any advice, suggestions or experience of fitting would be much appreciated. I'll take some pics of the bugger when I get up the road.

Cheers duders.

[Beastlee]

Perhaps for lighting? +12v permanent, +12v ignition, +12v lighting and a ground.
Some colours may help, I normally would go:

Red = +12V permanent
Yellow = +12V iginition
(The above may be inverted)
Orange = +12V lighting
Black = Ground

Perhaps a pic of it may help

[Subaru ETA]

mine had a + and -. plus 2 wires so you can change the colour when you turn the lights on

[tomaski]

^ Thats exactly what it was mate. Some of the settings look bloody daft but one is pretty much the exact same as the Galant dial colours so I guess it'll be staying.

Clock is now dead though, I pulled it and used it as the power supply. It hadn't been keeping time since I got it and I got sick of answering the same stupid question...

:thinking: 'Tommy, y'know this is an import yeah?'

:inquisiti 'Yeah.'

:thinking: 'So that clock yeah, it's erm... is that the time in Japan just now?'

:sad3: 'Uhm, yeah. Sure.'

[Beastlee]

LOL, I ripped mine out to fit the Greddy. I'm going to make a surround for the Greddy to tidy up the dash and I plan on modifying the clock unit to fit into the new surround.
Both cars had time warps but have been soldered to fix it.

[Subaru ETA]

yeah i just cut the wires off that make it change colour. the sd colour is the same as the dash gauges