Dawes Devices, Superchips, Fuel Cut etc
26 January 2002, 06:49 PM
#1
Scooby Regular
Thread Starter
Join Date: Apr 2001
Posts: 258
Likes: 0
Received 0 Likes
on
0 Posts
I have read the threads on Dawes devices and also on Superchips with interest.
Many years ago I used to own an RST, to which I fitted a Superchip. This took the power from about 133 BHP to 185 BHP - not far short of a 40% increase, which totally transformed the car. Yes I got through front tyres quickly, yes traction and torque steer was a problem, and yes it was a crappy Ford after all...but it was also fun to drive, and on the odd occasion when I actually got traction (for that read sunny day, sticky tarmac, and third gear!).....it really did go well. I used it everyday for 2 years and 40,000 miles with no engine problems at all, so I was initially surprised to see the bad press Superchips has here, although after a little research I do understand why.
What I remember most after having it fitted was the solid push in the back that never seemed to end. I've been looking for a way to get my Scooby to do the same. I will probably never buy another Ford, and I would buy another Scooby....but I would like just a bit more grunt, if you know what I mean? and without spending £1,000 on a Link etc
I've recently fitted a Dawes Device, and before fitting it I fitted a boost gauge onto my MY99 UK car (unmodified except for Scoobysport backbox). I was quite surprised to see how little boost the car uses at a constant throttle opening, in everyday cruising say on the motorway it is frequently below zero bar. I went up Shap on the M6 at 3500 rpm with (- 0.25) boost i.e. with
partial depression in the manifold. Positive pressure is only generated on acceleration, the boost briefly hits 1.1 bar and then settles at 1.0 bar on full throttle on my car, as standard.
What have others found..is this typical?
Initially I fitted the Dawes unadjusted (as it was delivered) and had 0.5 Bar boost i.e. half that of the standard car. It was not quick! After Winding three full turns on the adjuster, boost was up to 1.0 bar, it did not peak at 1.1 like the standard car, just rose to 1.0 bar and sat there. It did not feel as quick as the
standard car either and the needle on the boost gauge did not seem to rise as quickly, this surprised me as I was expecting the opposite as with the Dawes the wastegate is effectively
closed for longer. Another full turn on the adjuster and my boost gauge was showing 1.2 bar...full thottle in 5th on the motorway did not show any sign of fuel cut...at this point I began to wonder how accurate the gauge was. So I wound on another full turn on the adjuster, went back on the motorway and had 1.3 bar for a few seconds followed by a fuel cut. Guess the gauge is right then! with fuel cut being at about 1.25 bar on MY99 UK car according to the posts here. My final setting is just slightly under 1.2 bar, about 1.18 bar which seems to be the maximum
available without triggering a fuel cut, which is the last thing anyone wants when overtaking! I've not enlarged the bleed hole.
So my car is a bit faster...as far as I can see I've got the best out of the Dawes, and it has made a difference, but not by an earth shattering amount, although it is certainly more responsive and a cheap mod.
I've not yet checked the fueling, but intend to do this soon. I went to Maplin to buy the bits for the DIY AFR meter (thankyou to john banks) but they were shut. In all honesty I would be surprised if there was a problem, this is obviously my subjective opinion and not a scientific statement, but the increase in performance doesn't seem big enough to cause a problem. It is
certainly nothing like the 40% increase I saw with the Superchip on my old RS.
When I had adjusted the Dawes to give 1.3 bar and hit the fuel cut, I have to say that the car was still not vastly different...it wasn't as if I was asking the car to do something that would obviously cause it to break. It was not suddenly outrageously ultra rapid, just a little bit faster than before. I suspect that the fuel cut is set at that level by Subaru purely as a safety precaution in the event of a fault e.g. the wategate hose coming off.
That is a good thing of course and could save a few engines, not to mention some profits for Subaru through warranty claims. But I can see that the removal or raising of the fuel cut limit by Superchips is not necessarily such a dangerous thing as is suggested in some threads. The standard fuel cut limit seems quite conservative. I am not fully familiar with fuel cut defenders etc but would be interested to hear what boost people have safely run with standard fueling. I would like to raise the fuel cut limit a little and then see what boost I could safely run, obviously checking the fueling carefully.
Is there any point adjusting the wastegate, I assume I will still just come up against the fuel cut limit...
I'd also be interested to hear if anyone has found a variation in the boost that UK cars run as standard i.e. are some quicker than others?
Cheers
Paul
Many years ago I used to own an RST, to which I fitted a Superchip. This took the power from about 133 BHP to 185 BHP - not far short of a 40% increase, which totally transformed the car. Yes I got through front tyres quickly, yes traction and torque steer was a problem, and yes it was a crappy Ford after all...but it was also fun to drive, and on the odd occasion when I actually got traction (for that read sunny day, sticky tarmac, and third gear!).....it really did go well. I used it everyday for 2 years and 40,000 miles with no engine problems at all, so I was initially surprised to see the bad press Superchips has here, although after a little research I do understand why.
What I remember most after having it fitted was the solid push in the back that never seemed to end. I've been looking for a way to get my Scooby to do the same. I will probably never buy another Ford, and I would buy another Scooby....but I would like just a bit more grunt, if you know what I mean? and without spending £1,000 on a Link etc
I've recently fitted a Dawes Device, and before fitting it I fitted a boost gauge onto my MY99 UK car (unmodified except for Scoobysport backbox). I was quite surprised to see how little boost the car uses at a constant throttle opening, in everyday cruising say on the motorway it is frequently below zero bar. I went up Shap on the M6 at 3500 rpm with (- 0.25) boost i.e. with
partial depression in the manifold. Positive pressure is only generated on acceleration, the boost briefly hits 1.1 bar and then settles at 1.0 bar on full throttle on my car, as standard.
What have others found..is this typical?
Initially I fitted the Dawes unadjusted (as it was delivered) and had 0.5 Bar boost i.e. half that of the standard car. It was not quick! After Winding three full turns on the adjuster, boost was up to 1.0 bar, it did not peak at 1.1 like the standard car, just rose to 1.0 bar and sat there. It did not feel as quick as the
standard car either and the needle on the boost gauge did not seem to rise as quickly, this surprised me as I was expecting the opposite as with the Dawes the wastegate is effectively
closed for longer. Another full turn on the adjuster and my boost gauge was showing 1.2 bar...full thottle in 5th on the motorway did not show any sign of fuel cut...at this point I began to wonder how accurate the gauge was. So I wound on another full turn on the adjuster, went back on the motorway and had 1.3 bar for a few seconds followed by a fuel cut. Guess the gauge is right then! with fuel cut being at about 1.25 bar on MY99 UK car according to the posts here. My final setting is just slightly under 1.2 bar, about 1.18 bar which seems to be the maximum
available without triggering a fuel cut, which is the last thing anyone wants when overtaking! I've not enlarged the bleed hole.
So my car is a bit faster...as far as I can see I've got the best out of the Dawes, and it has made a difference, but not by an earth shattering amount, although it is certainly more responsive and a cheap mod.
I've not yet checked the fueling, but intend to do this soon. I went to Maplin to buy the bits for the DIY AFR meter (thankyou to john banks) but they were shut. In all honesty I would be surprised if there was a problem, this is obviously my subjective opinion and not a scientific statement, but the increase in performance doesn't seem big enough to cause a problem. It is
certainly nothing like the 40% increase I saw with the Superchip on my old RS.
When I had adjusted the Dawes to give 1.3 bar and hit the fuel cut, I have to say that the car was still not vastly different...it wasn't as if I was asking the car to do something that would obviously cause it to break. It was not suddenly outrageously ultra rapid, just a little bit faster than before. I suspect that the fuel cut is set at that level by Subaru purely as a safety precaution in the event of a fault e.g. the wategate hose coming off.
That is a good thing of course and could save a few engines, not to mention some profits for Subaru through warranty claims. But I can see that the removal or raising of the fuel cut limit by Superchips is not necessarily such a dangerous thing as is suggested in some threads. The standard fuel cut limit seems quite conservative. I am not fully familiar with fuel cut defenders etc but would be interested to hear what boost people have safely run with standard fueling. I would like to raise the fuel cut limit a little and then see what boost I could safely run, obviously checking the fueling carefully.
Is there any point adjusting the wastegate, I assume I will still just come up against the fuel cut limit...
I'd also be interested to hear if anyone has found a variation in the boost that UK cars run as standard i.e. are some quicker than others?
Cheers
Paul
26 January 2002, 07:06 PM
#2
Scooby Regular
Join Date: Mar 2001
Location: uk
Posts: 1,998
Likes: 0
Received 0 Likes
on
0 Posts
I think you have a good car as my decatted MY00 peaks at 15psi and holds 13/14psi,I do not think the gain will be as large with the Dawes as you have decent boost already.we fitted one to a m8's standard X reg with great results on road and at a recent rolling road day.the Dawes also helped my car as I was able to peak and hold 16psi,well away from fuel cut.
any chance of you looking at the ECU and post the label colour and date from the seatbelt as you do have good boost for a car with fairly standard breathing.
Edit-john banks got good results adjusting the wastegate rod.
[Edited by T-uk - 1/26/2002 7:08:53 PM]
any chance of you looking at the ECU and post the label colour and date from the seatbelt as you do have good boost for a car with fairly standard breathing.
Edit-john banks got good results adjusting the wastegate rod.
[Edited by T-uk - 1/26/2002 7:08:53 PM]
26 January 2002, 07:36 PM
#3
Scooby Regular
Join Date: Nov 2000
Location: 32 cylinders and many cats
Posts: 18,658
Likes: 0
Received 1 Like
on
1 Post
I think your expectations are too high for the standard ECU compared with what you acieved on your RST. I have been running 19PSI but turned it back to 18PSI as I did not want to dice with fuel cut (I have a PPP ECU - fuel cut is between 19 and 20PSI held for about 4 seconds - so about 2 PSI more than the standard ECU), and also I really do not think there is any point in going higher on the TD04L turbo which only makes a lot of hot air and not much power when you yank up the boost over 18-19PSI. All you will do is go nearer to detonation, get lots of ignition retard, high in-cylinder temperatures and not much extra performance as you are falling off the compressor's efficiency islands.
I am surprised thought that the Dawes did not make a big difference. It made a considerable difference to mine and I was already running 17PSI with a Prodrive Pack and full exhaust system. The spool up is much quicker, comes in earlier and holds more up top.
You could fit a Superchip and go up to say 18PSI, but I would not go higher. There is the concern of no fuel cut as you mentioned.
You could source a fuel cut raiser rather than defender and increase your fuel cut to say 19 or 20PSI, obviously checking AFR and knock as you go, but I don't know of suppliers apart from HKS.
But if you want the same sort of gains you got on the RST, then get a new turbo from the VF series, front mount intercooler and Link or similar remappable ECU. You are looking at £2000-3000. I am resisting doing this as I and others think the rest of the car is not up to it and I would be better buying an Evo 7 - on that you can increase from 17 to 20PSI and get a massive increase in power. 371bhp with a Dawes and an exhaust if you believe a rather optimistic rolling road printout that rated my Scooby at 257bhp with 17.5 PSI. Since I have tightened the actuator and turned things up a bit, and think it now might be 267bhp on this RR which is known to be conservative for Scoobys - standard cars do tend to get 215 to 220bhp. So my peak power is increase only by 20-25%, but midrange punch and spool up is much improved.
I am surprised thought that the Dawes did not make a big difference. It made a considerable difference to mine and I was already running 17PSI with a Prodrive Pack and full exhaust system. The spool up is much quicker, comes in earlier and holds more up top.
You could fit a Superchip and go up to say 18PSI, but I would not go higher. There is the concern of no fuel cut as you mentioned.
You could source a fuel cut raiser rather than defender and increase your fuel cut to say 19 or 20PSI, obviously checking AFR and knock as you go, but I don't know of suppliers apart from HKS.
But if you want the same sort of gains you got on the RST, then get a new turbo from the VF series, front mount intercooler and Link or similar remappable ECU. You are looking at £2000-3000. I am resisting doing this as I and others think the rest of the car is not up to it and I would be better buying an Evo 7 - on that you can increase from 17 to 20PSI and get a massive increase in power. 371bhp with a Dawes and an exhaust if you believe a rather optimistic rolling road printout that rated my Scooby at 257bhp with 17.5 PSI. Since I have tightened the actuator and turned things up a bit, and think it now might be 267bhp on this RR which is known to be conservative for Scoobys - standard cars do tend to get 215 to 220bhp. So my peak power is increase only by 20-25%, but midrange punch and spool up is much improved.
26 January 2002, 08:05 PM
#4
Scooby Regular
Thread Starter
Join Date: Apr 2001
Posts: 258
Likes: 0
Received 0 Likes
on
0 Posts
T-uk: ECU has a black label and is type AE800. Seatbelts are stamped 0798 (presumably July 1998) and the car was registered January 1999.
John - I wasn't expecting to get a similar increase, particularly as the Dawes costs next to nothing, but I was expecting a little more through increasing the boost by nearly 20% (1.0 to 1.18 Bar). The car is better, but we all like just that little bit more don't we
Maybe some cars respond better than others.
It does make me think that the 40% power hike I got through that old Superchip was good value, even if the electronic components were only worth a few quid. I too think that £2-3000 would be better put towards a new car, agree EVO would be a good idea, maybe a TVR also?
Am I correct in thinking that adjusting the actuator makes the wastegate open slightly later and so would increase mid range power?
John - I wasn't expecting to get a similar increase, particularly as the Dawes costs next to nothing, but I was expecting a little more through increasing the boost by nearly 20% (1.0 to 1.18 Bar). The car is better, but we all like just that little bit more don't we
Maybe some cars respond better than others.It does make me think that the 40% power hike I got through that old Superchip was good value, even if the electronic components were only worth a few quid. I too think that £2-3000 would be better put towards a new car, agree EVO would be a good idea, maybe a TVR also?
Am I correct in thinking that adjusting the actuator makes the wastegate open slightly later and so would increase mid range power?
26 January 2002, 08:07 PM
#5
Scooby Regular
Join Date: Nov 2000
Location: 32 cylinders and many cats
Posts: 18,658
Likes: 0
Received 1 Like
on
1 Post
More the top end - your Dawes will do the deal in the midrange. Don't adjust it if you get 14.5PSI (1 bar) at 6000rpm. I wasn't and other cars did, so mine was set "soft". My boost was dropping excessively from 4000rpm compared with other cars which hadn't had their actuators adjusted.
27 January 2002, 12:38 PM
#6
Scooby Regular
Join Date: Sep 2001
Posts: 191
Likes: 0
Received 0 Likes
on
0 Posts
Paul,
Having read your thread with interest, I to have to admit owning an RST in the past and R5 turbo for that matter, so I can appreciate what you are saying.
I noticed that you only have a stainless rear box fitted at present. I have just fitted a de-cat down pipe and de-cat mid-section. Your RST was never fitted with a cat, hence there wasn't a restriction holding it back. Loose the cats on a scoob and it becomes a different car!
I'm yet do any boost mods yet but, will be speaking to John soon about them. As far as value for money, I think a replacement exhaust system is well worth it.
Chris
Having read your thread with interest, I to have to admit owning an RST in the past and R5 turbo for that matter, so I can appreciate what you are saying.
I noticed that you only have a stainless rear box fitted at present. I have just fitted a de-cat down pipe and de-cat mid-section. Your RST was never fitted with a cat, hence there wasn't a restriction holding it back. Loose the cats on a scoob and it becomes a different car!
I'm yet do any boost mods yet but, will be speaking to John soon about them. As far as value for money, I think a replacement exhaust system is well worth it.
Chris
Thread
Thread Starter
Forum
Replies
Last Post
Mattybr5@MB Developments
Full Cars Breaking For Spares
28
28 December 2015 11:07 PM
Sam Witwicky
Engine Management and ECU Remapping
17
13 November 2015 10:49 AM