Well it is off eBay but I paid £24 for it. It's a ball type manual controller. Yes a Dawes device.
boost problem with dawes device
- Thread starter Perrin21
- Start date
@gtirx2 the way your boost curve does the opposite of your hp curve at high revs makes me wonder if it's nothing to do with your boost control but you have an air leak somewhere on your intake? Just another option to look for.
geoff pine
Well-Known Member
I should have asked you this question was it made by dawes cost is not relavent if its a copy its a copy .
I wasn't aware Dawes was a brand name in itself. I thought it was a referral to the type of ball based pressure release mechanism on a manual boost controller as opposed to the inferior bleed type. My bad?
This is the one I have http://www.ebay.co.uk/itm/NEW-MANUA...CarParts_SM&hash=item2c5eead2e9#ht_1049wt_689
gtirx2
Active Member
Thanks mate,yep the power curve does look pretty suspect with the big dent in the middle then it climbing back up with the boost dropping.
Not to sure what that problem was tbh as you used to be able to feel the dent between 5-5.5k(once i knew it was there) then it would pick back up.
I think it even used to do it when my car was almost completly stock with just an exhaust and filter.
I think i thought it was normal to feel like that as it still done it once the engine was rebuilt,it was not until after the dyno that i knew it was not quite right.
It did not really feel like a dent/flat spot when driving it,more of a sudden surge of power at the top lol
Then the engine was then rebuilt yet again after that dyno run and at the same time i rebuilt the inlet manifold and i think after that rebuild it seemed to cure the dent between 5-5.5k(or at least i think it has as i dont think i could feel it anymore),but i was still getting the boost drop at the top?
Strange one really as i had pressurised the system and checked for leaks a few times in the past but never found anything.
God knows, i need to get back on the car and fix it tbh as its been a couple of years now that its been sitting,the dent will proberly be back next time i drive it lol.
Sorry for the hijack perrin!
The inlet manifold gasket is meant to be re-usable but I had a leak on mine that meant it held boost but lost air flow at high revs. After that I always got a fresh gasket for the sake of £5 whenever I took the manifold off. The dent would be easier to understand if you had an AFR shown against your dyno plot. If you get an air leak after your MAF then the AFR will go rich. When I mapped mine I mapped around the air leak. When I fixed the air leak I had to re-map the car again :doh:
gtirx2
Active Member
Thanks for the reply mate,its definatally a very good heads up for me to be extra certain of no leaks when i put it back together.
What you are explaining sounds like i could have a leak,i just wish i could be sure that the feeling of the dent in the revs had gone on its last outing now lol.
It could well still be there as the more i think about it, i think i could have had it on and off from proberly since i brought the car.
It was mentioned to me and i thought that it could be the ecu pulling the timeing every now and then for some reason,thats if the stock ecu can even do that?
I am pretty sure it was pulling smoother after the 2nd rebuild though, but if i am honest i did not do many road miles in it after it was rebuilt,and i was not really looking for it on the qtr miles or the track day i did.
I am 100% certain the boost was still dropping though,and this could proberly mask the dent a little.
Thing is i am pretty sure that the dent was also there back in my near standard days,and its been through alot of changes over the time including engine block,heads,inlets combos, everything really lol.
I can remember that it used to feel like it pulled extra hard at the top and looking back that was proberly the 5-5.5k dent making it feel like its coming alive at the top.
But saying that that was all measured with my arse dyno and poor memorylol
It never used to lose the boost at the top back then though,And i am sure it only started happening ofter the actuator change,or even possibly after the intercooler.
Argh i cant remember know lol,think i may have fitted the actuator around the same time as the intercooler.
As i can remember i was also a little bit suspect of the larger intercooler causeing a pressure drop at the time,but over the time come to the conclusion it was the actuator.
I think there is proberly a couple of issues in that dyno plot though, as i am not sure if the dent is connected to the boost drop at the top?
Heres the afr and other graph...
Unfortunately Spikey was unable to replace the spring in the actuator as forge didn't supply me with the correct seat for it. He had the old spring out of it within 5 mins though so kudos for not needing to remove the turbo. Going to try get hold of the seat for the actuator before Wednesday. Found another boost leak though so were getting closer. Thanks Spikey Ur a star.
@gtirx3
Your fuelling between 4.5K and 5.35K is spot on so the car in the lump. It gets a bit rich around peak power and at 7K the afr is nearly 10 which is too low.
If you're on a standard ECU then it can't pull timing in the way people describe.
The leak causing boost to drop could be on your exhaust side?
When I first got my car the piper cams had been shimmed very badly and that gave it a feel of coming on cam around 5K. I never dyno'd it but the car did feel a lot smoother at the top end once it was sorted.
Your fuelling between 4.5K and 5.35K is spot on so the car in the lump. It gets a bit rich around peak power and at 7K the afr is nearly 10 which is too low.
If you're on a standard ECU then it can't pull timing in the way people describe.
The leak causing boost to drop could be on your exhaust side?
When I first got my car the piper cams had been shimmed very badly and that gave it a feel of coming on cam around 5K. I never dyno'd it but the car did feel a lot smoother at the top end once it was sorted.