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View Full Version : Need some help with deciding on my fueling in my BT setup



GetBoosted84
04-19-2013, 04:20 AM
Hey guys,

I'm trying to determine if I need to upgrade my fuel setup before I find some time to sit on the rollers to get some tuning done. I just want to make sure I get this sorted before I waste money by heading to the tuner & then paying to tune the car only to find I have a hardware limitation with my fuel setup.

Some background on the car. The last time I hit the dyno a few weeks ago, I put down 377whp / 341 ft/lbs tq and that was on a slightly modified base tune from Eurodyne (hell of a base tune for maestro if you ask me). I only modified it to pull back some timing because I was getting some pull and also to disable the MAF tables since I am unfortunately MAFless due to where my turbo sits in the engine bay (frankly can't fit one). Anyway, my current setup (fueling wise) is pretty basic. It consists of a Walbro in-tank 255 pump, EV14 840cc injectors, stock (but recently replaced) fuel filter, stock FPR, stock rail, stock lines, and a fuel pressure gauge just to make sure my base fuel pressure isn't dropping. During the run where I made the aforementioned power, my injectors were only at 63% duty cycle at peak so they still have a little ways to go even at the stock pressure.

Now to complicate things, I have several new parts that will be getting installed on the car prior to getting tuned so that the tuner will be able to work with not only the base tune but also bigger/better hardware. The hardware currently sitting on my shelf is as follows:
* Larger 2.5" IC piping
* SEM Intake manifold
* 034 Phenolic transition gasket (since I'm a small port AWM)
* Larger 80mm throttlebody
* Bosch 044 in tank fuel pump (not sure if I'm going to toss this in... feedback appreciated)
* Direct wired fuel pump via a painless relay
* Bolt down coils (mine are pretty new so I'm not sure if I would put these on before tuning but I have them if necessary)
* AEB head (have this sitting on the shelf... just not sure if I'm going to toss it in prior to getting tuned)
* Revolver cams

My goals when I go for tuning are the low to mid 400 range so I think that's attainable given that I already made 377 to the wheels on a base tune, I have more parts to throw on, and I have meth installed on the car.

So back to the original question... do I need to upgrade anything in my current fueling setup in order to support my power goals? I figure if I target my fuel system supporting 500 @ the wheels then that will be more than enough for any power I will make with the car as she sits. My main concerns with my current fuel setup are the lack of an adjustable FPR (for this, I was thinking about the 034 unit that installs right into the stock rail), and whether or not the stock rubber lines and the stock rail will support my goals. I'd prefer to not dump money into areas where they don't make sense unless I have to (ie. going with -6AN lines from the in-tank fuel pump all the way to the tail with an external FPR & bigger rail).

Seerlah
04-19-2013, 04:37 AM
Your stock lines should be just fine for 400whp. E85 is a different story. I personally went with an 044 drop in unit from the start to support anything I ever wanted to throw at it in the future. If you made 377whp off a base tune minus some timing, not sure why a custom remap from that base tune can't yield you your goals without any hardware changes.

I talked to someone who did quite a few testings when he was a tuner for a company, and he said that the small port head is rather ideal unless chasing more than 400whp. I think he said there were no real gains, only later spool with the larger port head. But obviously if pumping more air you need larger ports. But he said roughly 400whp is the limit for the small port head.

I am going to send you a PM. Also, what turbo you running?

M-Hood
04-19-2013, 08:47 AM
Chris if your goal is 500whp I would suggest upgrading the fuel lines and the fuel rail, you can still use the OEM type FPR by using an adapter cup. Injectors should be fine if you plan on sticking with 4 bar base fuel pressure, if you drop down to 3 bar to increase the flow of the fuel pump you will most likely want to upgrade to 1000cc or 1150cc Bosch injectors.

The issue isn't the small port head since others have gone beyond 450whp with it, problem is mainly the cams. What cams are your running at this point?


80mm throttle body is major over kill and will actually decrease power. The S4 guys have been testing the flow of the TB's lately. 70mm would be plenty for you or no longer then 75mm.



Your stock lines should be just fine for 400whp. E85 is a different story. I personally went with an 044 drop in unit from the start to support anything I ever wanted to throw at it in the future. If you made 377whp off a base tune minus some timing, not sure why a custom remap from that base tune can't yield you your goals without any hardware changes.

I talked to someone who did quite a few testings when he was a tuner for a company, and he said that the small port head is rather ideal unless chasing more than 400whp. I think he said there were no real gains, only later spool with the larger port head. But obviously if pumping more air you need larger ports. But he said roughly 400whp is the limit for the small port head.

I am going to send you a PM. Also, what turbo you running?

I think he wasn't able to make more because his limiting factor at the time was the small 2" IC pipes he still had on the car when he installed his extended tip Comp Turbo CT2-5156.

melomandn
04-19-2013, 09:36 AM
I talked to someone who did quite a few testings when he was a tuner for a company, and he said that the small port head is rather ideal unless chasing more than 400whp. I think he said there were no real gains, only later spool with the larger port head. But obviously if pumping more air you need larger ports. But he said roughly 400whp is the limit for the small port head.


I realize its not exactly cheap to do but why hasnt anyone gotten on the dyno and actually done runs on a BT car comparing the small port to large port heads? Everyone always talks about the small port "limit" and how its a waste to swap a large port head on anything making less than 400awhp. But people have been tuning this platform for over a decade and no one at all has tried to get real world evidence on this?

If there is some and I just cant find it, I would love to see it, I just think its crazy that after this long theres still no solid answer.

GetBoosted84
04-19-2013, 10:18 AM
Your stock lines should be just fine for 400whp. E85 is a different story. I personally went with an 044 drop in unit from the start to support anything I ever wanted to throw at it in the future. If you made 377whp off a base tune minus some timing, not sure why a custom remap from that base tune can't yield you your goals without any hardware changes.

I talked to someone who did quite a few testings when he was a tuner for a company, and he said that the small port head is rather ideal unless chasing more than 400whp. I think he said there were no real gains, only later spool with the larger port head. But obviously if pumping more air you need larger ports. But he said roughly 400whp is the limit for the small port head.

I am going to send you a PM. Also, what turbo you running?
Seerlah, thanks for the input. I replied to your PM. I am running a Comp CT2-5156 extended tip turbo as well.


Chris if your goal is 500whp I would suggest upgrading the fuel lines and the fuel rail, you can still use the OEM type FPR by using an adapter cup. Injectors should be fine if you plan on sticking with 4 bar base fuel pressure, if you drop down to 3 bar to increase the flow of the fuel pump you will most likely want to upgrade to 1000cc or 1150cc Bosch injectors.

The issue isn't the small port head since others have gone beyond 450whp with it, problem is mainly the cams. What cams are your running at this point?

80mm throttle body is major over kill and will actually decrease power. The S4 guys have been testing the flow of the TB's lately. 70mm would be plenty for you or no longer then 75mm.

I think he wasn't able to make more because his limiting factor at the time was the small 2" IC pipes he still had on the car when he installed his extended tip Comp Turbo CT2-5156.
Hi Mike, thanks for the heads up on the fueling info. My plan is to stick with the stock pressure unless necessary to change it. But I agree, if I do end up needing more volume then bigger injectors are going to be the ticket. I was hoping to run out the 840cc injectors & be able to reach my goals since they "should" be able to hit that according to the diagnostic report on the injectors. Right now the pressure is right around ~54 psi base so ~3.7 bar at idle according to my fuel pressure gauge for anyone who is curious.

As far as cams... good catch there. Right now they are the stockers. However I have a set of revolvers also sitting on the shelf that will be in the car before I hit the tuner.

And with regard to the throttle body, I ended up opting for the larger unit after going through this thread (http://forums.vwvortex.com/showthread.php?4690902) and doing some other research on it. I know that it sounds like overkill but those numbers were stunning. I figure I'll try it and if it ends up being a nightmare I can always dial back since I have the larger flange setup on the manifold.

Any yeah, I totally agree that the 2" piping is choking the crap out of my setup at this point from what I have researched (thanks for your help on that btw).

EV14 injector flow information from my diagnostic report...
Alternate flow:
* 900 cc @ 3.5 bar
* 960 cc @ 4.0 bar

Limits @ 3.5 bar:
* 504 bhp @ 90 duty .57 bsfc
* 448 bhp @ 80 duty .57 bsfc
* 522 bhp @ 90 duty .55 bsfc
* 464 bhp @ 80 duty .55 bsfc


I realize its not exactly cheap to do but why hasnt anyone gotten on the dyno and actually done runs on a BT car comparing the small port to large port heads? Everyone always talks about the small port "limit" and how its a waste to swap a large port head on anything making less than 400awhp. But people have been tuning this platform for over a decade and no one at all has tried to get real world evidence on this?

If there is some and I just cant find it, I would love to see it, I just think its crazy that after this long theres still no solid answer.
If you pay for the dyno time I would be willing to do it with mine :-). I have both now.

M-Hood
04-19-2013, 10:26 AM
Yeah right now you are most likely at the limits of the stock cams, Pete just put down about the same numbers with his CT4-5562 and he is also running stock cams but will be putting in a set of Piper Ultimate Road cams.

I think once you swap out the stock cams you should see a nice jump in peak power.

034Motorsport
04-19-2013, 11:14 AM
You're getting very close to the limit of that Walbro pump @ that FP.

If you have the 044 already, drop it in and you'll be good to 580whp on regular gas (race, pump, etc) with the stock feed and return lines from the tank. Upgrading to a larger feed line can extract some extra power capability, but at that point you're better off running a surge system of sorts and moving it close to the engine bay (think of the blowing through a 6" long straw and a 2 foot long straw).

But for 500whp on pump or race gas, all you need is an 044 in the tank.

For reference, I maxed out my single 044 and stock feed/return lines @ 580whp @ 4BAR on 750cc injectors @ 25psi. V6 but same thing.

b5a4gt28
04-19-2013, 12:30 PM
Yeah and Chris as you know I made 450+whp and only maxed out my injectors. I would recommend using that relay when you drop that pump in though.

Seerlah
04-19-2013, 01:00 PM
There is a thread in the B5 S4 section where I person eventually burnt his connections on the pump cap from running direct current from the battery (melted the plastic actually). Not sure what size resistors you would need to use to prevent that from happening. And it seems he only ran it direct when wanting to drain the tank.

http://www.audizine.com/forum/showthread.php/535617-PSA-All-E85-users-must-read

b5a4gt28
04-19-2013, 01:12 PM
even with using the relay?

034Motorsport
04-19-2013, 01:18 PM
Why wouldn't you just use the stock wiring?

M-Hood
04-19-2013, 01:22 PM
There is a thread in the B5 S4 section where I person eventually burnt his connections on the pump cap from running direct current from the battery (melted the plastic actually). Not sure what size resistors you would need to use to prevent that from happening. And it seems he only ran it direct when wanting to drain the tank.

http://www.audizine.com/forum/showthread.php/535617-PSA-All-E85-users-must-read

I have never had that issue and run direct power from the battery thru my pump cap.

b5a4gt28
04-19-2013, 01:46 PM
Why wouldn't you just use the stock wiring?

Using the stock connector was kind of restricting my pump. Not really sure why it was, but running a separate relay and wiring the pump by itself helped my pump when it was having issues keeping the fuel pressure supplied. Call me crazy but when I did that it fixed my fuel pressure issue. The guy at my local performance shop says he does almost every BT car like that. Kinda like the tiny hole in the TB to get it to idle better. Just a little trick he had. I guess it helps supply a consistent, more direct amount of power??? I'm not a wiring genius but all I know is it helped in my situation.

GetBoosted84
04-19-2013, 04:03 PM
There is a thread in the B5 S4 section where I person eventually burnt his connections on the pump cap from running direct current from the battery (melted the plastic actually). Not sure what size resistors you would need to use to prevent that from happening. And it seems he only ran it direct when wanting to drain the tank.

http://www.audizine.com/forum/showthread.php/535617-PSA-All-E85-users-must-read

This is a good post because it shows what can happen when you don't use a circuit breaker or a fuse before the relay (or directly wired to the pump). That's why they include those in the kit. You just pop in the 30 or 40amp breaker that comes with the kit and then that will prevent those issues since there can be voltage fluctuation in the line.

I run a relay on my RX-7 because I had some issues with the fuel supply because the voltage was dropping that old car.

You guys are probably right & don't need to use the relay setup but I already have it and it's not a big deal to toss it in there to avoid a potential issue especially since John hit the same problem on the rollers and I want to avoid that if possible.

b5a4gt28
04-19-2013, 04:10 PM
Im currently running an inline 20amp fuse under the knee bolster to the relay. The closer the relay to the pump, the better. Less distance to fluctuate? All I know is its working damn good for me and fixed my problem.

GetBoosted84
04-19-2013, 04:31 PM
To the takeaways I have are:
* Fuel pump may support my goals but since I have the other pump, might as well upgrade
* The lines are probably ok but maybe not (different opinions on the topic)
* Fuel rail is probably ok but maybe not (different opinions on the topic)
* Fuel pressure regulator I probably don't need as long as I stick with the same pressure
* Injectors are ok for my power goals at my current target fuel pressure

Does that about sum it up so far?

M-Hood
04-20-2013, 04:02 PM
To the takeaways I have are:
* Fuel pump may support my goals but since I have the other pump, might as well upgrade
* The lines are probably ok but maybe not (different opinions on the topic)
* Fuel rail is probably ok but maybe not (different opinions on the topic)
* Fuel pressure regulator I probably don't need as long as I stick with the same pressure
* Injectors are ok for my power goals at my current target fuel pressure

Does that about sum it up so far?


Pretty much, so it is up to you to do what you want. lol

GetBoosted84
04-20-2013, 07:38 PM
lol, damn. I was hoping for more definitive answers. Oh well.

M-Hood
04-20-2013, 10:04 PM
lol, damn. I was hoping for more definitive answers. Oh well.

Oh I thought you had already figured out which way you were going. Upgrading the fuel pump, fuel lines and fuel rail will need to be done at some point anyway.

GOODBYNAAIR
04-21-2013, 12:50 PM
This is a little off for the OP but same thing really. I am looking to make about 300whp I have 630cc simians and 034 fuel rail. A new filter will go in and plain on keeping my stock pump and lines, do I need a different FPR. What would be the best set up really, want to do it right if I can. thanks car 2001.5 QTM

GetBoosted84
04-22-2013, 04:55 AM
Oh I thought you had already figured out which way you were going. Upgrading the fuel pump, fuel lines and fuel rail will need to be done at some point anyway.
Well it sounds like it could go either way depending on different opinions. I'm going to think it over & decide which way to go. Probably will end up just doing everything at once to avoid having to pay twice on the dyno though.