| Author | Topic |
|---|
On Probation
Location:
Sydney
Registered:
April 2005
|
|
3sgte group A fuel rail
|
Sat, 16 April 2005 01:52
|
 |
Is the 3sgte 185 group A fuel rail larger/ better than the 185 fuel rail. Can it flow more than 12psi of fuel.
This is a real problem for me as a halttech is going in the celica and i want to run a possible bar of boost but cant with until the fuel is upgraded.
what should i do?
|
|
|
Location:
Adelaide
Registered:
May 2003
|
|
Re: 3sgte group A fuel rail
|
Sat, 16 April 2005 01:55
|
|
Given that most EFI systems run almost 60psi of fuel pressure i daresay it would be able to run 12psi
|
|
|
Toymods Vice President
Location:
Sydney
Registered:
May 2002
|
|
Re: 3sgte group A fuel rail
|
Sat, 16 April 2005 06:46
|
|
Mate didn't you claim to have a built engine worth $15000? Why would you be asking about whether the standard fuel rail is good enough to run 1 bar of boost if you have an engine like that?
I'd be recommending getting a decent fuel system for it with a top feed rail and injectors. The other option is to bore out the 185 rail and run bigger side feed injectors.
|
|
|
On Probation
Location:
Sydney
Registered:
April 2005
|
|
Re: 3sgte group A fuel rail
|
Sat, 16 April 2005 08:24
|
|
yeah my engine cost that much. Most good engine rebuilds are within that price range that included the rebilt turbo (hybrid) and new transmission. But on topic... the 185 stock rail doesnt flow more than 12psi of fuel and can cause serious leaning out in cylinder 2 and 3. If you didnt know that now you do.
So i will refine my question.
What ways can i improve the flow of fuel across the rail without spending another fortune? And the orignial question, is the Group A fuel rail beter?
Justen suggested the 3sge or 5sfe fuel rail will flow more fuel.
How much roughly will it cost me to bore it out. It sounds like a funked up job.
Thanks.
|
|
|
Location:
Brisbane, Queensland
Registered:
January 2004
|
|
Re: 3sgte group A fuel rail
|
Sat, 16 April 2005 08:35
|
|
i would suggest you do your research instead of asking people here. This has been covered in depth.
But ill give a quick summary-
The Stock rail with the Stock injectors are fine for around 16psi of boost pressure with a slight tweak in fuel pressure. Probably more but i wouldn't go that far.
The problem arises when you use the Stock rail, and larger injectors. It can't flow enough and you get a large pressure drop on injectors 3 and 4.
Dual feed or Centre feed are the easiest approches. Along with having the rail bored out. Other then that you can try the 5S-FE rail and switch to top feed, or purchase a highflowing rail.
Visit MR2OC.com and have a look at how they fuel there engines.
|
|
|
Toymods Vice President
Location:
Sydney
Registered:
May 2002
|
|
Re: 3sgte group A fuel rail
|
Sat, 16 April 2005 13:04
|
|
I know quite a bit about the limmitations of the ST185 fuel rail. It flows a hell of a lot more fuel than 12 psi though. Considering the standard pressure regulator is around 40psi. If your assertion is that the standard fuel rail doesn't flow enough fuel for use with a CT26 running 12 psi of boost then I beg to differ. If your concern is the leaning out in cylinders 2 and 3 then you are barking up the wrong tree looking at the fuel rail, take a look at the flow figures for the intake manifold.
I answered your question of how you can improve the flow without spending a fortune, bore out the standard fuel rail. All this costs is a couple of drill bit's, one of which would have to be ~12 inchs long, a tap and a grub screw.
If you want some more info on the flow characteristics of the standard fuel rail take a look at WolfKatz Fuel Rail testing.
|
|
|
Location:
Parramatta
Registered:
July 2002
|
|
Re: 3sgte group A fuel rail
|
Sun, 17 April 2005 05:27
|
|
if you havent maybe changing the fuel regulator might give you a bit more i ran 18psi on the std inj and rail. If you cant get 12 psi out of the std rail there is something wrong with your car or ECU/tuner.
If not i have a spare hks rail for 300$ brand new. however it is to suit the gen 3 motor.
|
|
|
Location:
Adelaide
Registered:
May 2003
|
|
Re: 3sgte group A fuel rail
|
Sun, 17 April 2005 06:11
|
|
|
Far out guys. As we have already said the stock rail will flow 40PSI of FUEL easily. 12psi of FUEL is rubbish.
|
|
|
Registered:
May 2002
|
|
Re: 3sgte group A fuel rail
|
Sun, 17 April 2005 06:46
|
|
Group A fuel rail is exactly the same as a normal GT4.
What you are trying to say is (correct me if Im wrong) is will the standard fuel rail support a CT26 running 12 psi of boost. The answer is yes.
|
|
|
Location:
Redbank Plains,near Ipswi...
Registered:
May 2002
|
|
Re: 3sgte group A fuel rail
|
Sun, 17 April 2005 07:08
|
|
|
can I add somehting here...there are 2 issues I have observed in building high performance engines, including lots of 3S's.The first is structural failure of the rail from getting it too thin. I have only seen this once from a back-yard "rebore". It almost impossible to keep a long drill central. There are plenty of "large bore" rails around. Unmodified, the rails are capable of pressures well over 100psi/700kpa. next is bad fuel flow to one or more injectors. As indicated this happens when monster injectors are used on a "small" rail, and the internal losses mean flow progressively drops off away from the feed. These losses increase with the square of the pressure. Central feeds do not always fix this as the loss from the fuel hitting a wall at the T junction, are equal to metres of straight pipe. This is a basic hydraulics issue. The "best" I have ever seen is a properly dedsigned central feed with a "Y piece, coupled to a large bore rail. maybe this is food for thought for some of you.
|
|
|
On Probation
Location:
Sydney
Registered:
April 2005
|
|
Re: 3sgte group A fuel rail
|
Sun, 17 April 2005 08:32
|
|
Takai: 12psi of boost. Not fuel.
Ok well at least i did my reasearch before blowing something up. Beter safe than sorry.
|
|
|
Location:
Vancouver
Registered:
June 2004
|
|
Re: 3sgte group A fuel rail
|
Sun, 17 April 2005 21:14
|
|
Pressure as measured in any units, such as psi for this discussion, is a measure of pressure, NOT flow. Pressure develops as resistance is presented to some attempted flow; saying some object can "flow 40psi", "flow 12psi", or "flow a million psi" is an illogical statement.
Flow is measured in volume per unit time, not pressure. (such as 45gal/min, or 1000c/min, or 20lbs/hr)
Thank you for the cooperation...
Anyhow, I would say that if you've gone to all the work of building a nice motor ($15,000 is probably a pretty wicked motor I'm guessing), I'm of the opinion that you should spend a few bucks and get a piece of large bore fuel rail extrusion similar to this stuff...
http://www.rossmachineracing.com/extrusion.html
...and build your own fuel rail to prevent both the fuel flow problems that everyone has mentioned with the stock fuel rail, and the questionable strength issues with the modified stock rail. The last thing you want is gasoline squirting everywhere on a hot motor (that was a pun, get it? ha ha ha).
|
|
|
Location:
Adelaide
Registered:
May 2003
|
|
Re: 3sgte group A fuel rail
|
Sun, 17 April 2005 21:23
|
|
| ralfross wrote on Sat, 16 April 2005 11:52 |
Can it flow more than 12psi of fuel.
|
| ralfross wrote on Sat, 16 April 2005 18:24 |
But on topic... the 185 stock rail doesnt flow more than 12psi of fuel
|
|
|
|
Location:
Sydney
Registered:
October 2003
|
|
Re: 3sgte group A fuel rail
|
Sun, 17 April 2005 23:38
|
|
|
|
|
Location:
Adelaide
Registered:
July 2002
|
|
Re: 3sgte group A fuel rail
|
Mon, 18 April 2005 00:30
|
|
my sneaking suspicion is that ralfross is a 16yr old tosser with a pink st182 celica who wishes he had a 15k motor. If you have just spent 15k on a motor why would you 1) not already have a bigger and better fuel rail and 2) complain about a couple hundred dollers for a better fuel rail.
fuel rail will also not be the limiting factor, as it has been mentioned there are two things to consider 1) pressure as measured in PSI ie 44psi fuel pressure. and 2) flow ie 4x 540cc injectors will flow at 80% duty cycle around 1.8Litres/minute. so you will need a fuel pump capable of flowing that much liquid and also be able to provide it at the required pressure.
|
|
|
On Probation
Location:
Sydney
Registered:
April 2005
|
|
|
On Probation
Location:
Sydney
Registered:
April 2005
|
|
|
Location:
Adelaide
Registered:
May 2003
|
|
Re: 3sgte group A fuel rail
|
Mon, 18 April 2005 12:08
|
|
| ralfross wrote on Mon, 18 April 2005 21:32 |
hunty if your gelous that i have an immaculate example of a celica GT4
|
| ralfross wrote on Mon, 18 April 2005 21:47 |
Here is my pink 182 hunty!
|
|
|
|
Registered:
April 2005
|
|
Re: 3sgte group A fuel rail
|
Mon, 18 April 2005 12:23
|
|
Nice car 
|
|
|
On Probation
Location:
Sydney
Registered:
April 2005
|
|
Re: 3sgte group A fuel rail
|
Mon, 18 April 2005 13:01
|
|
|
thanks
|
|
|
Location:
Adelaide
Registered:
July 2002
|
|
Re: 3sgte group A fuel rail
|
Mon, 18 April 2005 23:43
|
|
so now the whole car has cost u 15k? ur story keeps changing every 5 minutes man. First off you bought the engine for 15k and not knowing much about it, then you had the engine built by someone, (i'd like to know who), and now your saying that the whole car and engine conversion has cost u 15k
i still think that ur full of it, but thats just my opinion
i would really like to see a dyno sheet of your gt4 with its ct26 running 25psi and making 500hp on what? stock injectors?
and dude its spelt Jealous and chassis
oh and i'm not jealous i'm quite happy with my mr2  its no 500hp powerhouse like yours tho
|
|
|
On Probation
Location:
Sydney
Registered:
April 2005
|
|
Re: 3sgte group A fuel rail
|
Tue, 19 April 2005 04:28
|
|
| ralfross wrote on Sat, 16 April 2005 18:24 |
yeah my engine cost that much. Most good engine rebuilds are within that price range that included the rebilt turbo (hybrid) and new transmission.
|
First mention of rebuild.(above)
I think your confused with another guy that started the "3SGTE" post.
http://forums.toymods.org.au/index.php?t=msg&t h=63690&start=0&rid=10103&S=ae70bf502d fab262883f0b57464e96ba
Learn to read posts carefully before shooting down the wrong guy. I never said my car has 500hp and to be hosest i never think that it will.
Quoted above is what i said. Never changed my story.
For the last time dont make me out to be a fool!!! Because im not!
Sorry for the spelling if it upsets you so much. Have a panadol and a lie down.
|
|
|
Location:
Adelaide
Registered:
July 2002
|
|
Re: 3sgte group A fuel rail
|
Tue, 19 April 2005 04:47
|
|
| Joshstix wrote on Sat, 16 April 2005 16:16 |
Mate didn't you claim to have a built engine worth $15000? Why would you be asking about whether the standard fuel rail is good enough to run 1 bar of boost if you have an engine like that?
|
thats what lead me to beleive to it was you who had that 500hp motor.
My apologies.
|
|
|
Location:
Brisbane, Queensland
Registered:
January 2004
|
|
Re: 3sgte group A fuel rail
|
Tue, 19 April 2005 07:30
|
|
|
Nice car, what wheels are they (size and offset if you wouldn't mind)
|
|
|
Registered:
January 2004
|
|
Re: 3sgte group A fuel rail
|
Tue, 19 April 2005 07:57
|
|
|
Ralfross, nice car man ....!!
|
|
|
On Probation
Location:
Sydney
Registered:
April 2005
|
|
Re: 3sgte group A fuel rail
|
Tue, 19 April 2005 11:03
|
|
Thanks guys.
They wheels are 18" Advanti Raptor 5s
Sorry not sure about off set.
Its ok hunty, I realised your mistake very quickly. No 500hp motor in my car. I wish
|
|
|
Location:
Brisbane, Queensland
Registered:
January 2004
|
|
Re: 3sgte group A fuel rail
|
Tue, 19 April 2005 11:13
|
|
|
phat.... you must be running some super lower profile tires!
|
|
|
Registered:
May 2002
|
|
Re: 3sgte group A fuel rail
|
Tue, 19 April 2005 11:40
|
|
|
Wow, your car has been nicely modified.....you cant beat photoshop !
|
|
|
On Probation
Location:
Sydney
Registered:
April 2005
|
|
Re: 3sgte group A fuel rail
|
Tue, 19 April 2005 12:56
|
|
HA no photoshop promise.
The profile is 35.
|
|
|
Location:
Brisbane, Queensland
Registered:
January 2004
|
|
Re: 3sgte group A fuel rail
|
Tue, 19 April 2005 13:14
|
|
| ralfross wrote on Tue, 19 April 2005 22:56 |
HA no photoshop promise.
The profile is 35.
|
width?
|
|
|
On Probation
Location:
Sydney
Registered:
April 2005
|
|
Re: 3sgte group A fuel rail
|
Tue, 19 April 2005 13:54
|
|
215/35/r18
|
|
|
Location:
Dubbo
Registered:
April 2005
|
|
Re: 3sgte group A fuel rail
|
Thu, 21 April 2005 12:34
|
|
hope u got a frount mount, or a ST205/Group A W/A charge-cooler, otherwise you will be sorta wasting your time with hihger boost levels through the standard top mount
That said tho i have seen someone achieve 390hp with the top mount, but 1 person is a bit of statistical anomaly.
|
|
|
On Probation
Location:
Sydney
Registered:
April 2005
|
|
Re: 3sgte group A fuel rail
|
Thu, 21 April 2005 14:07
|
|
Water injection. Its on the way.
Hope that helps.
|
|
|
Location:
South Australia
Registered:
July 2002
|
|
Re: 3sgte group A fuel rail
|
Thu, 21 April 2005 15:09
|
|
It's pretty rare that the fuel pressure itself will cause the rail to 'fail'...boring out the fuel rail isn't recommended (I know an engineer who specialised in drilling to depths of 100 times the diameter and getting a good level of accuracy is a PITA no matter what the scale is). As you bore out the rail, make sure you drop the maximum pressure that it runs at (in this regard, you may run into flow problems anyway).
If you are leaning out cylinders 2 & 3, you might want to check your injectors!
TerryOBeirne -> would pressure loss occur along the rail only if the injectors (the sum of them) are capable of out flowing the rail (for given duty cycle etc)?
|
|
|
Toymods Vice President
Location:
Sydney
Registered:
May 2002
|
|
Re: 3sgte group A fuel rail
|
Fri, 22 April 2005 03:25
|
|
Cylinders 2 and 3 lean out because the Gen 2 intake manifold flows a good 10% - 15% more air to those cylinders than it does to the outer two.
|
|
|
Location:
Dubbo
Registered:
April 2005
|
|
Re: 3sgte group A fuel rail
|
Fri, 22 April 2005 10:48
|
|
holy cow!  10-15%?! thats heaps!!
i knew its flow characteristics were bodgy but that is ridiculous
|
|
|
Location:
South Australia
Registered:
July 2002
|
|
Re: 3sgte group A fuel rail
|
Fri, 22 April 2005 14:17
|
|
|
I'd highly doubt that they flow 10-15% more air during operation though, maybe at maximum flow rate they might be able to flow larger amounts of air - but volumetric efficiency of the cylinder head etc would be pretty consistent across all four cylinders and that would be a more important factor methinks.
|
|
|
Toymods Vice President
Location:
Sydney
Registered:
May 2002
|
|
Re: 3sgte group A fuel rail
|
Mon, 25 April 2005 09:34
|
|
The intake manifold flows less than the head though. You will max out the intake manifold flow without maxing out the head flow when using a gen2 manifold.
|
|
|
Location:
South Australia
Registered:
July 2002
|
|
Re: 3sgte group A fuel rail
|
Mon, 25 April 2005 11:20
|
|
That sounds sus to me but I don't have the knowledge on hand to prove it.
Maybe your definition of out-flow is different to my definition.
|
|
|
Toymods Vice President
Location:
Sydney
Registered:
May 2002
|
|
|
Location:
South Australia
Registered:
July 2002
|
|
Re: 3sgte group A fuel rail
|
Tue, 26 April 2005 05:25
|
|
Nah that's all pretty much in agreeance with what I would think, the path through the head (without valves) is quite short compared to the path through an intake manifold - hence the difference in flow, and the reason that flow drops even further with the manifold attached would also be related to the increased length. I'm just surprised that toyota would design the manifold in such an uneven fashion, I'm assuming that it's a case of the pipes being shorter in the middle than the outer ones? I haven't seen any gen 2 manifolds up close.
I still reckon that valves would place the greatest restriction on flow as opposed to intake manifold. So even if the manifold was a good half of the restriction, then chances are it's only a difference of about 5 to 7.5% in operation between inner and outer cylinders, if that.
|
|
|
Toymods Vice President
Location:
Sydney
Registered:
May 2002
|
|
Re: 3sgte group A fuel rail
|
Tue, 26 April 2005 07:27
|
|
| RWDboy wrote on Tue, 26 April 2005 15:25 |
I still reckon that valves would place the greatest restriction on flow as opposed to intake manifold. So even if the manifold was a good half of the restriction, then chances are it's only a difference of about 5 to 7.5% in operation between inner and outer cylinders, if that.
|
I don't think I've ever seen head flow data for a head with no valves. I do know that a stock Gen2 head at 0.350" valve lift will flow a god 20cfm more than the intake manifold does.
A fair amount of the problem is that the air is dumped in "straight down" the centre runners and has a less direct route involving another 90 degree turn to get into the outer two runners.
Mind you I can't say I'm too concerned since I've got a Gen3 setup and my head flow characteristics are nothing like a Gen2 especially with 1mm oversize valves, tidied up throats and 0.400" lift cams. I was just offering the info to save a misunderstanding of the basic principals from costing the person who started the thread an engine.
To be safe you could just add a little more fuel to the centre two pots to keep A/F ratio even across the board. I know I'll be doing this with my engine.
On the otherhand some testing with individual oxygen sensors in each exhaust runner would put this kind of discussion to rest. I believe there are a couple of MR2 owners working on this at the moment.
|
|
|
Location:
Colac, Victoria
Registered:
May 2002
|
|
Re: 3sgte group A fuel rail
|
Tue, 26 April 2005 09:30
|
|
ot a little but has anyone thought about inporoving the design of the intake manifold to overcome the leaning ?
Im a little bit underskilled in this area of work - but well aware of this leaning problem as well - and in the future id like to rectify it without having to revert to a gen3 headswap
|
|
|
Toymods Vice President
Location:
Sydney
Registered:
May 2002
|
|
Re: 3sgte group A fuel rail
|
Tue, 26 April 2005 09:34
|
|
I have seen flow numbers for a Gen2 manifold that was extrude honed with the aim of balancing flow and it had a 2% diffence between the highest and lowest flowing runners. It also had about a 10% improvement in over all flow for the middle pair of runners and obviously bigger improvement for the outer pair.
Specialised Power Porting in Victoria would probably be able to sort something out for you in this department.
|
|
|
Location:
Brisbane, Queensland
Registered:
January 2004
|
|
Re: 3sgte group A fuel rail
|
Tue, 26 April 2005 09:34
|
|
|
extrude honing will get all the runners to flow within 3% of each other. if tahts oging too far, then you can run more fuel for the runners which run leanest.
|
|
|
On Probation
Location:
Sydney
Registered:
April 2005
|
|
Re: 3sgte group A fuel rail
|
Tue, 26 April 2005 11:00
|
|
Gen 3 head.  Thats what i should of done!
All these probs gone!
|
|
|
Location:
Brisbane, Queensland
Registered:
January 2004
|
|
Re: 3sgte group A fuel rail
|
Tue, 26 April 2005 11:07
|
|
| ralfross wrote on Tue, 26 April 2005 21:00 |
Gen 3 head. Thats what i should of done!
All these probs gone!
|
Gen3 head is all well and good, but as has already been said, the largebore gen2 head is much better once you get up in the power band.
|
|
|
Location:
Colac, Victoria
Registered:
May 2002
|
|
Re: 3sgte group A fuel rail
|
Tue, 26 April 2005 11:47
|
|
you gotta ask yourself how much power are you aiming for too - do you want a street car or a race car ?
for the street - work with what you have - it will work out alot cheaper + wont be a total pig to drive ..
|
|
|
Location:
South Australia
Registered:
July 2002
|
|
Re: 3sgte group A fuel rail
|
Tue, 26 April 2005 13:10
|
|
Hahah shows what I know
I suppose that when I think about the path that the air has to follow I'm not *hugely* surprised. Except for the fact that I'd expect alot more resistance from the valves where the flow would be under higher pressure and turbulence. But you can't argue with results can you?
If it was flowing 10-15% more air through the middle two *cylinders* and the EGO measures the total of all four (and it is supposed to run at say 11.0:1 A/F ratio) then two cylinders will be running 10.2:1 and two others will run 11.8:1 (approximately).
eep!
|
|
|
