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View Full Version : Need help understanding current issues facing FI svx's


SVXMAN2001
12-01-2007, 04:38 PM
Ok guys so I have been keeping close tabs on the progress that has been made in regards to Forced Induction in our svx's, which I know many other's of this board have been as well...instead of cluttering the current thread started by Tom I figured i would start my own....

First off for the supercharger offered by LAN, apparently the users are experiencing a timing issue due to the knock sensors sending the ECU an inaccurate reading due to the vibrations caused by the supercharger. Secondly, I recall some citing belt slip as an issue on the supercharger...is this issue still occurring?

I have also noticed that those seeking higher hp goals are disregarding the supercharger route and seeking the turbocharger.

So that being said, what hp/torque numbers is the supercharger producing on the svx. Also I would assume that its safe to say that the supercharger is not reliable due to the knock sensor issues, correct? In addition, what other hurdles are we facing in regards to the supercharger, is LAN working towards overcoming these issues?


So that does it for the supercharger....now on to the turbocharger route.

When turbocharger, can one still use Lan's ecu programs? I've heard of some members having to institute a standalone to properly utilize a turbocharger...why is this?

Also are custom intake manifolds required for turbocharger? Or is that just above a certain PSI?

That's about all i can think of for now, I working towards building up my engine and am just trying to determine what route (sc or turbo) would be the most effective for considerable AND reliable hp gain.

thanks, chris

sicksubie
12-01-2007, 05:11 PM
I did have severe belt slip when I was on the dyno (lost about 35% of my boost) I have since put on a gatorback belt that is about .5 inches longer and alows me to get really good wrap. I can now say very confidently that I have no belt slip. On 9psi with 5.5~psi (should have been 9psi) I hit 231whp. 9psi with no belt slippage probably would be 270~whp.

The 12psi pulley is a whole different story. Here are some quick facts on it. 12psi is at the high end of the blower's efficiency range (Lysholm 1600AX). This now means that the blower is working very, very hard (HOT intake temps now). Intake temps are around 220degrees with the 12psi pulley. Also, the blower is obviously spinning faster to generate the 12psi and this increase in rotations is what we believe is causing the knock sensors to pick up what they think are "knock", but is actually just vibrations from the motor. There have been no dyno runs on 12psi yet. I would think that the stage 3 on 12psi and methanol would be approaching 380whp. This is based on correcting the false knock issue though. There is no way IMHO to run more boost than that on the stage 3. You could tweak it in other ways (fuel, meth, etc) but you will be limited to that max boost of 12psi.

NikFu S.
12-01-2007, 05:15 PM
That's about all i can think of for now, I working towards building up my engine and am just trying to determine what route (sc or turbo) would be the most effective for considerable AND reliable hp gain.

thanks, chris

How much power are looking to create?

SVXMAN2001
12-01-2007, 06:30 PM
sicksubie, so the supercharger offered by LAN maxes out at around 12psi, I recall other members running a side mounted sc, by relocating the battery and placing the sc there. Does that sc offer increased power? Also seeing as that with the increase of psi, there is obviously an increasing in operating temp thus creating the need for additional cooling correct? I know in turbo applications, an intercooler assists in keeping things within operative temp's. For LAN's sc is additional cooling required? If so what type of setups are available, how does the cooling process differ from that of a turbo application?

NikFu, as for the power i am looking to create, seeing as i am going to be building the engine and spending a significant amount of money to do so I am looking to get somewhere between 400 - 500 reliably...it is my understanding that we are now at the point where a built engine will support this amount of power, now it is a thing of addressing adequate cooling, and i suppose other unforeseen troubles such as the knock sensor issue popping up throughout the process...

Crazy_pilot
12-01-2007, 06:38 PM
svxfiles is running a centrifugal (or centripital, whatever word we're using today:rolleyes:) SC, with intercooler. I don't know if Tom's ever dyno'd his though. I did find a video of 0-60 runs, at around 5 seconds.

NikFu S.
12-01-2007, 07:15 PM
somewhere between 400 - 500 reliably..

At the wheels?

SVXMAN2001
12-01-2007, 07:23 PM
yes at the wheels so the way i figure at the crank (assuming a 25% drivetrain lose) i would need/want 500 - 625...

Would LAN's ecu stage two chip work for a turbo application?

NikFu S.
12-01-2007, 08:41 PM
I'm just wondering how you're going to make a 600hp or so SVX "reliable". I'd want to figure that out before starting on power.
What are you doing for a transmission?

Theoretically LAN's stage 2 is tuned for your needs (500chp max, actually, so maybe not) but it's actually never been used to this extent. Your guess is as good as anyones. As with the stage 3, with stage 2 you'll be hitting that wall that Tom and the others have hit.

SVXMAN2001
12-01-2007, 08:55 PM
good point, i suppose because of reliability i would have to sacrafice raw hp. As for transmission I'll be using LAN's rebuilt auto.

The reason i ask about the ecu stage 2 is because other members in the other thread have stated that they would need a standalone or need to create/format their own software.

nextse7en
12-02-2007, 06:34 PM
While I am no expert, there are a number of other walls that are being hit that are not addressed yet, now that we have the ECU open, we can make some useful conjecture.

Our ECU pulls timing at the drop of a hat. Even without the knock sensor issue, we are seeing that the ECU pulls timing at varied intervals starting in the 4000 rpm range. While many are working on a way around this, some who are seeking a lot of horsepower have decided to throw in the towel when it comes to the stock ECU.

I belive we would see an immediate benefit in quarter times and 0-60 runs on a totally stock engine simply by switching to a standalone system that didn't have a timing map based on voodoo and one that was not trying to constantly play kiss ass with the TCU.

Once a standalone system is in place, the EG33 simply becomes an engine again, not a logic puzzle only completely understood by Subaru programmers, it has always been a let down that we could plug known horsepower figures, gear ratios, weight and rolling diameter into a quarter mile time estimator, and would ALWAYS end up with a time higher than that.

Color me standalone, FTW

TomsSVX
12-02-2007, 07:50 PM
I am selling my stage 3 for a couple reasons.

1. It ran pretty good and made about 270 AWHP with matching torque numbers when I was done. Ran great on 9psi on a stock motor with the headers. With the built motor it seems to need a re-map, which I have not heard of any progress on.

2. The "kit" aspect for me never arrived. I got all the parts but no kit feeling as I constantly was adapting it or my vehicle to make it work properly.

3. I am finished supporting by buying from ECUtune. Every time I report something that I found as a fault with their products means that I have a vaccum leak or some other diagnosis of an invisble and undiagnosable issue.

With a huge lack of technical support (from listening to the people who have their parts installed or built) ECUtune has done nothing for me except accept my payments and sent me parts without backing them once I diagnose issues with them. The stage 3 needs to be tuned on a dyno not at a computer desk. One tune does not support different conditions. Overwhelming evidence that I have provided about our new cams not allowing a good idle is apparently not enough evidence that they are nto working properly. I am through. I have had enough of trying to get through. I will be working on doing it all myself now using a standalone and having it dyno tuned rather than what we have now. Thats my story, their just happened to be too many straws on the camel's back this week.

Tom

redlinedeath
12-09-2007, 02:52 PM
I am selling my stage 3 for a couple reasons.

1. It ran pretty good and made about 270 AWHP with matching torque numbers when I was done. Ran great on 9psi on a stock motor with the headers. With the built motor it seems to need a re-map, which I have not heard of any progress on.

2. The "kit" aspect for me never arrived. I got all the parts but no kit feeling as I constantly was adapting it or my vehicle to make it work properly.

3. I am finished supporting by buying from ECUtune. Every time I report something that I found as a fault with their products means that I have a vaccum leak or some other diagnosis of an invisble and undiagnosable issue.

With a huge lack of technical support (from listening to the people who have their parts installed or built) ECUtune has done nothing for me except accept my payments and sent me parts without backing them once I diagnose issues with them. The stage 3 needs to be tuned on a dyno not at a computer desk. One tune does not support different conditions. Overwhelming evidence that I have provided about our new cams not allowing a good idle is apparently not enough evidence that they are nto working properly. I am through. I have had enough of trying to get through. I will be working on doing it all myself now using a standalone and having it dyno tuned rather than what we have now. Thats my story, their just happened to be too many straws on the camel's back this week.

Tom

tuning and such on a stand-alone, is it difficult as all hell, or is it like geting a pcIII or someting similar on a bike? (not including differances from going from a bike to a car)

TomsSVX
12-09-2007, 02:58 PM
I personally do not know for sure. I need to try it. I am always willing to do things I have no experience with and there are members (at least one) running their own who I may have to ask questions about. That said, it may not happen tomorrow but it should happen eventually

Tom

Myxalplyx
12-11-2007, 10:35 AM
Really good thread. I like reading about the honest results. Thanks for asking and for those of you who are posting. Tom, I really like your honesty in answering what you have experienced.

I do not have a lot to add to this as I have not had any experience around these issues. The turbo issues have always had me wondering. I am happy with my SVX the way it sits but 5psi would be cool with me as well. I will be reading this thread closely. :p