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| Fitting Fuel pump and fuel pressure regulator http://www.gt4dc.co.uk/forum/viewtopic.php?f=1&t=651 |
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| Author: | robbiemcvee [ Fri Feb 24, 2006 11:09 am ] |
| Post subject: | Fitting Fuel pump and fuel pressure regulator |
I wonder if you chaps can help me, not sure if you know but i have bought another GT4 St205, this is to replace the one i have as i dont have the time to modify it as much as i would like. The GT4 was uzthedentists, it has quite a few mods that have been aplied since the last tuning at Thor. These mods are: JUN cams and springs Hybrid CT26 stage 3 from fensport Aussie downpipe FMIC It come supplied but not fitted with the following: 280l hour fuel pump Aeromotive fuel pressure regulator. My question is - should i fit the above before the tuning and how difficult are they to fit? Also i'm looking to take it back to thor to remap the Apexi - how long do you think this will take? Cheers Rob |
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| Author: | MarkCL [ Fri Feb 24, 2006 11:30 am ] |
| Post subject: | |
 I didn't know Uz had sold his 'Four!? As to fitting the fuel system upgrades, well that depends on what you hope to be running with regard to power on this car after the re-map. If 350bhp or more then I'd say yes as even though really you ought to also be changing the injectors too, you could get round the immediate need for those by upping the fuel pressure a little so that the stock 540's are better able to deal with the fueling required at that level.
Cheers, Mark |
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| Author: | Kris [ Fri Feb 24, 2006 2:18 pm ] |
| Post subject: | |
A new uprated pumo would be a wise idea to fit. A guide on fitting this is available from the website www.gt4dc.co.uk 
FPR - personally I do not see a need for this, I'd want to fit larger injectors rather than up the rail pressure to compensate? For reliability, fitment etc I'd stay with the stock unit. |
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| Author: | TrackToyFour [ Fri Feb 24, 2006 2:27 pm ] |
| Post subject: | |
Rob, congrats on joining the double Four club 
AFAIK Uz's engine is still running standard internals (I bought a set of Ross forged pistons off him a while back) In stock form I wouldn't want to push it any further than 350bhp. Even at that level you want to make absolutely sure that the fuelling is spot-on. I'm producing similar power on the stock 540 injector's and fuel pump controlled by the MoTeC. You could go ahead and fit the 280l pump and Aeromotive regulator but IMO there would be no benefit. Is there something wrong with the Apexi mapping that you need to take it back to Thor? They have a reputation for accepting higher knock levels and ignition advance than some believe prudent but if you tell them what you want and are with them when they do the work then they should be fine. HTH |
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| Author: | robbiemcvee [ Fri Feb 24, 2006 2:40 pm ] |
| Post subject: | |
The trouble is that I don't really know what i want.. i'm going to have to go through a steep learning curve. Thanks for the advice - i wanted to see if i neededto fit these before i get it re-mapped. Are you saying that perhaps i dont need to? The mapping seems to be causing a problem on Idle, since fitting the JUN cams the car has a problem at Idle in that it switches between 700 rp and 2 rpm. If i don't need to take it back to Thor i won't i'll find the nearest and best tuning - from what your saying i dont need to take it back there? |
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| Author: | Diceman [ Fri Feb 24, 2006 7:16 pm ] |
| Post subject: | |
Rob, The cams will move the VE of the engine to a higher rev range and hence the fuelling will require adjustment - reduce at low & mid RPM and increase at higher RPM. You will also be moving the peak torque point and hence the ignition timing will require adjustment. From info I have heard and witnessed a knock of 35 correlates to the onset of very minor detonation, should be ok if it exceeds once in a while but I woudl not map a car to regularly exceed that. This number has been identified via det cans on a couple of vehicles now. It is however likely to vary between engine and knock sensor slightly. When tuning to that level I woudl want to know that all of the fuel system is capable of providing enough fuel CONSISTENTLY, bear in mind all these items are now circa 10-11 years old. IMHo I woudl change fuel filter, fuel pump & either replace injectors or get teh old ones cleaned. Old tired injectors after 60-100K miles are likely to have started to hose rather than spray mist. With teh cams you are likely to spend more time up in teh rev range and hence my personal opinion is that you will run out of fuelling with teh 540cc injectors. The stock setup appears to be ok for upto 1.25 bar at high rpm according to thor. you could probably get away with running high boost in teh mid-band as injector period is longer here. I know Don has managed 340-345 bhp on stock injectors at circa 1.5 bar and IIRC he has seen 80% duty cycle at 6K rpm ish when running his regular 1.3 bar? (I am sure Don will correct me if I am wrong  )
I woudl change to larger injectors, new fuel pump (walbro or sytec or wha have you) and replace fuel filter. I would leave the stock FPR in place - IIRC the higher pressure you run injectors ta the more likely they are to lock. I woudl alos then get the car remapped - where - I dont know (but all this is me and not you lol)
Good luck m8 |
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| Author: | GT4WRC [ Fri Feb 24, 2006 9:38 pm ] |
| Post subject: | |
I had a few idling issues with the HKS 264 cams after the rebuild which were essentially cured by fitting and mapping the Apexi Power FC. You will probably have to set the base idle at around 1000rpm depending on how 'lumpy' your cams are. Problem is that with the different timing it can be difficult to create enough vacuum at idle hence the rough running at those engine speeds. Gary |
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| Author: | MarkCL [ Sat Feb 25, 2006 9:28 pm ] |
| Post subject: | |
Just to note - I also have the HKS 264's on my engine and didn't notice any problems with idling or lumpy running  Since I'm still running the stock ECU on mine I would expect there to be "issues" if the cams could cause them, but since I have none I can only say that if they are correctly installed and set up/timed in then there shouldn't be any issues other than the need to adjust fuelling to optimise things as JP mentioned - this more than anything is why I need an ECU on mine....
Cheers, Mark |
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| Author: | GT4WRC [ Sat Feb 25, 2006 9:40 pm ] |
| Post subject: | |
Mine were 'correctly' set-up. Had two different experts check the settings etc. Could well be due to the nature of the gas flow through teh cylinder head which has been extensively modified. Gary |
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| Author: | Kris [ Sun Feb 26, 2006 1:31 am ] |
| Post subject: | |
Quote: Mine were 'correctly' set-up
How do you mean? Correctly as per the HKS settings, or setup for your engine? |
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| Author: | GT4WRC [ Sun Feb 26, 2006 6:54 am ] |
| Post subject: | |
As per the HKS spec sheet supplied. Remapping of the Apexi PFC has cured all the initial idling issues. Gary |
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| Author: | TrackToyFour [ Sun Feb 26, 2006 11:40 am ] |
| Post subject: | |
IIRC didn't Adrian at Fensport find that the guidance supplied with the HKS cams didn't work properly i.e. no perceptable power increase. At one stage they even went back to using stock cams
They eventually discovered by a process of experimentation that degreeing the HKS cams specifically for the 3S-GTE was essential to realise any performance gain. Getting the set-up info is quite difficult as most tuners adopt secret-squirrel mode to retain their IPR 
I suspect that any instructions supplied with the cams are for the 3S-GE NA engine. AFAIK the cams were actually designed for this NA engine NOT the turbo. Although I stand to be corrected on this as I've never bought a set of new HKS cams so don't know what info they are supplied with. My spare gas-flowed head has a set of HKS272's so I have a particular interest in this
I believe the JUN cams are the only ones specifically designed for the 3S-GTE although the new Piper cams may also be specific to the turbo unit. I think matgt4 was planning to fit those? Mat, any comment? |
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| Author: | robbiemcvee [ Sun Feb 26, 2006 9:53 pm ] |
| Post subject: | |
Thanks for all the info - very helpful as usual! These are JUN cams and springs, It seems like i should replace the fuel pump. The Aeromotive comes with a pressure gauge and is adjustable. But if i don't need it it won't be fitted. I will change the fuel filter too. So any reccomendations on RR tuning shops.. i know Thor, but if you don't think they do a good job i will take it elsewhere. This will be my daily runner too - should i be saying this to the tuners? |
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| Author: | tangcla [ Mon Mar 13, 2006 12:29 am ] |
| Post subject: | |
So no need to do the fuel pressure regulator?
i'm confused. I've heard that I should, as a basis for tuning in futre - and now you guys say no need! Help...
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| Author: | TrackToyFour [ Mon Mar 13, 2006 12:47 am ] |
| Post subject: | |
I think its more a case of monitoring the fuel pressure in the rail. AFAIK no-one has monitored this on an ST205 with a standard fuel pressure regulator. It follows that any advice regarding the suitability of a standard FPR in a tuned car is, IMO, without justification. It would appear that most tuners fit an adjustable FPR and I'd imagine thats for a very good reason. I've got a fuel pressure gauge on my data logger so once the weather warms up a bit I shall be on track testing the stock setup. I'm still running 540 injectors at 80% duty at around 300-330bhp on track so this should give me some good baseline data to move forward with my next engine build. |
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