View Full Version : SDBC and N75j
Leon'02 Cupra
Over the last 12 months I've played with a Dawes Device and am currently running the Upsolute remap with a N75 J.
This gives sustained boost over the standard valve which holds boost longer....................fact.
I have in my garage a Dawes device which is sitting on a shelf and mocking me.
The Dawes when fitted and bypassing the N75j was absolutely unbelievable with take off and mid range kick that defied my expectations.
example.......standard boost with Dawes produced a 0 -60 in 6.5secs estimated with co pilot and stopwatch but significantly quicker than the standard car by some measure.
Question.
If I run the N75j and attach the Dawes between the wastegate and the J valve(Dawes set at least 15psi)I will get the benefits of the Dawes faster spool up/bigger under the curve boost,but as soon as the Dawes hits the Upsolute/n75 j pre programmed upper boost limit(still below Dawes 15psi setting) will the J valve comandeer the control of the wastegate and boost and drop the boost level to the upsolute pre set.
I understand that the J valve monitors the boost throughout the rev range but will the Dawes over ride this?
Does the Upsolute remap have built in over boost to cater for the standard wastegates spiking.
I don't know if this a sensible question or a pile of old cobblers.Some people on 20vturco/vw vortex are running this configuration with positive results.
I expect Bill will send another murderous reply to this old question
I've just bought a N75J valve but I'm wary of fitting it in case of overboosting/spikes and limp mode. I found a similar device to yours here:
http://www.boostvalve.com/index2.html
Should I fit the J and see how it goes or fit the overboost protection along with the J? The overboost valve only costs £35.
This is my dilema................
I fitted the j valve after lots of reading on vwvortex and 20vturbo.It would seem that on a 'chipped 'engine the other valve(h as I remember)would push the boost just far enough for the ecu to react and enter limp mode.
With my remap and j valve I have experienced no proplems whatsoever including main dealer service.
What I want is the kick off the Dawes controlling the boost with all the standards engine electronic safegaurds still in place.
Just remember if you fit the J then it installs 180' to the standard
ibizacupra
19-11-2003, 08:33
Originally posted by fickel
Leon'02 Cupra
I expect Bill will send another murderous reply to this old question
Ewww, Murderous eh? :p
Nah.. :) ;)
I would guess that the Dawes setting can be dialed in to the acceptable level ofr the N75 you will use.
On my Dawes... yep I have one... (not fitted) the setting of the pressure was quite 'iffy, with pressure creap on the spring setting and seal seat pressure. I never fitted it to the car as I could'nt get a reliable operation when bench testing the pressure settings.
How do you find yours in operation? Trial and error adjustment I guess. Overboost for info is a programmed table, and will vary from tuner to tuner.
Valves don't monitor anything, no matter what revision. They are just frequency valves (solenoids) with the MAP sensor giving feedback to the ecu on target vs actual boost, hence trying to control via the N75 control loop (duty cycle). The differences in the N75's would seem to be orifice size and their ability to bleed the control pressure. (electronic bleed valve as such)
regards
bill
Snoopstah
20-11-2003, 20:18
Someone want to explain to me what these are and what they do? Why does Bill not like them?
ibizacupra
20-11-2003, 20:52
Originally posted by Snoopstah
Someone want to explain to me what these are and what they do? Why does Bill not like them?
Did I say I did'nt like them? :confused:
Snoopstah
20-11-2003, 21:13
No, I just got that impression from the OP saying you were going to send 'some murderous reply' and you not having it fitted.
You're not the sort of guy to have something that improves performance sat on a shelf in the garage, if you know what I mean. ;)
Anyway, apologies if I was wrong. :flame:
Well it stopped raining at lunchtime so I decided to take the car out for a spin.I connected up my boost gauge at the manifold and did some in gear runs on the moor tops.
With The n75 j my leon recorded boost peaks of 17psi falling back nicely as the revs built up.All in all a very nice result as the car felt strong and smooth...............but no I have a Dawes device.
10 minutes later I am on the moors again with the dawes inline from the waste gate and n75.
After several runs I got it dialed in to allow 17psi as before.
Starship Enterprise
The turbine spins up very very quickly,and has in comparison heaps more pulling power.
I was hesitant for the snappy turbo (on off feeling)that I had experienced before I had the car remapped and 75 j'd but there was nothing untoward.It just felt smooth like before but a good deal faster.
I really don't know other than what I have read what I am doing but this seems to have worked.
Suppose I should really start saving for the IHI kit before I go too far and send my turbo vanes down the exhaust
ibizacupra
21-11-2003, 07:15
Originally posted by fickel
Well it stopped raining at lunchtime so I decided to take the car out for a spin.I connected up my boost gauge at the manifold and did some in gear runs on the moor tops.
With The n75 j my leon recorded boost peaks of 17psi falling back nicely as the revs built up.All in all a very nice result as the car felt strong and smooth...............but no I have a Dawes device.
10 minutes later I am on the moors again with the dawes inline from the waste gate and n75.
After several runs I got it dialed in to allow 17psi as before.
Starship Enterprise
The turbine spins up very very quickly,and has in comparison heaps more pulling power.
I was hesitant for the snappy turbo (on off feeling)that I had experienced before I had the car remapped and 75 j'd but there was nothing untoward.It just felt smooth like before but a good deal faster.
I really don't know other than what I have read what I am doing but this seems to have worked.
Suppose I should really start saving for the IHI kit before I go too far and send my turbo vanes down the exhaust
So are you saying it jumped to 17psi and stayed there?
No........................
what happens is that 1st and 2nd I struggle to get over 12 psi but that be down to traction etc etc but in 3/4/5/6th gears the turbo spools up real quick and hits 17psi..........It holds the pressure with no obvious variation until I hit around 5k and then as it did pre Dawes the boost falls smoothly away to around 10-12psi(may be wrong on this part as I was more concerned as to how it fell away and not what to).
I like my cars smooth and quiet and am deffo not one of roaring exhaust types.It really has made a major improvement.
One thing I did notice when I took delivery of my DD was that I had to be very careful when re-assembling it(I always take stuff to bits)as the spring is easy to mis aligne off to the side of the nipple(oppo end to tiny ball).This made my DD mis behave