ECU quick question

#1 10-07-2002, 10:55 AM

I have an svx manufactured in 91/7. It was purchased in canada, if it makes any difference. Would i still have the bead in the ECU? I dont want to waste half an hour taking the damn thing out only to find out that there wasnt any bead to begin with. Any insight?

Mr. Pockets · #2 10-07-2002, 01:23 PM

Quote:

Originally posted by Ticallion
I have an svx manufactured in 91/7. It was purchased in canada, if it makes any difference. Would i still have the bead in the ECU? I dont want to waste half an hour taking the damn thing out only to find out that there wasnt any bead to begin with. Any insight?

I assume you are talking about the famous resistor, which so many people feel the need to immediately 'crush' when they find that they have one.

Since you have such an early SVX, the resistor in question is most likely present on your ECU. But it is possible that a dealer service department already crushed it for you. Crushing the resistor was a solution to a serious hesitation issue eventually covered in a TSB issued by SOA. My car's ECU was altered in this fashion, but before the TSB was issued, the dealer tried all sorts of solutions first.

Call your local Subaru dealer and ask them to print up a service history for your car. It'll tell you everything that was done to it by any Subaru dealer in North America.

If the TSB was performed, then you don't need to disassemble your car and risk damaging your ECU. Even if it wasn't performed (I don't know what percentage of early SVXs this had to be done to), unless you have a serious hesitation problem when accelerating from a stop, I wouldn't bother. It won't magically add 100hp to your car's output and it won't grow hair back.

Aredubjay · #3 10-07-2002, 01:28 PM

When I looked into this, I found that my car had had the upgraded PROM installed. When I found this out, I decided NOT to crush the bead (known as the "Noise Supressor"), since it would also involve (according to the TSB) snipping a tan resistor. Too many iffies for my blood.

nvrmore100 · #4 10-07-2002, 07:21 PM

4 words....

COMPLETE WASTE OF TIME!

I have a 92, also made at the end of 91, which had the bead. I've done the crush mod on my ECU, and one that I had purchased just in case it decided to stop working after I did it. Both made absolutely no difference, aside from wasting my day and taking $50 for the extra ECU out of my pocket.

northernkanuck · #5 10-13-2002, 02:28 AM

"It won't magically add 100hp to your car's output and it won't grow hair back."

I feel a need to step in here. When I had my SVX I had this done, made a HUGE difference in the performance of the car and I would recommend anyone try this. My mechanic who is also a close friend did it for me and said it was fairly easy to do and he also commented on the improvement.

Now, 3 years later some of my lost hair is beginning to grow back, coincidence? I think not.

Keith

ensteele · #6 10-13-2002, 11:16 AM

Gosh, if it is helping grow your hair back, I might buy the extra one that nvrmore100 has for $50.00 and see if it works on my hair. I might have to change my handle to Curly93 though.

And now that I think about it, I have been a little tired. Maybe that extra HP that comes with it would give me some extra NRG.

Aredubjay · #7 10-13-2002, 12:52 PM

Seems that there have been a variety of results from the bead crush. Some "feel" it, some don't. People need to begin to compare note to see what the common factor of "feeling it" are. Since I had found that I had the upgraded PROM in mine, I opted not to do it. Again, those with positive results need to compare notes with those who had negative results and find a common denominator.

nvrmore100 · #8 10-13-2002, 01:13 PM

I'm basing my results on track times. Literally no difference. I also can't say I can "feel" it either.

Now adding my cone intake, which at the track actually slowed me 0.1s in the 1/4, DOES actually "feel" like you are going quicker. The extra growling grunt gives you that impression, but overall nothing good comes out of it.

- Ryan

#9 10-13-2002, 01:14 PM

That's probably because the cone filter sucks in hot air from the engine bay, as opposed to the drop in which still takes air from the fenderwell.

nvrmore100 · #10 10-13-2002, 01:15 PM

Quote:

Originally posted by Ticallion
That's probably because the cone filter sucks in hot air from the engine bay, as opposed to the drop in which still takes air from the fenderwell.

Exactly right, but I've been too lazy to build myself a heat sheild to encase the cone. If I'm going to bother with that, I would be better off just buying a K&N drop in filter for the stock airbox.

#11 10-13-2002, 01:18 PM

Yeah, nvrmore, just get the drop in and put the box in. The box is not restrictive anyway. Just make sure you get rid of the resonator. (remove the inner fender lining, remove front turn signal, and that will give you access to the proper bolts.)

northernkanuck · #12 10-13-2002, 08:11 PM

I wouldn't say there was an increase in horsepower by doing this. The problem I was having was when starting from a dead stop there was a hesitation, delay (call it what you like) of about 1 to 2 seconds from the time I pushed on the accelerator until the actual drive train engaged. This was very hard on the drivetrain as it would literally slam into gear on every takeoff no matter how careful you were, not to mention it wasn't overly comfortable. After having the mod done there was no hesitation, delay. The drivetrain responded immediately when the accelerator was pressed without slamming into gear in a manner I am used to with every automatic I have ever driven. As I mentioned my friend is a mechanic (Toyota master mechanic with over 20 years experience)had commented on the problem a few times before I found the TSB and had him do the fix. At first he was skeptical but afterwards he could not believe the difference. I realize others have done this and have not noticed a difference, I am just saying what have you got to lose? If it doesn't make a difference, 30 minutes of your time is lost. If it works like it did for myself it could save $$$ in repair costs due to the drivetrain slamming in gear and make your ride much smoother and more comfortable.

Keith

Stevebsy · #13 10-13-2002, 09:56 PM

I did it on my '93 and it made a world of difference. Before it hesitated to a disturbing degree right off the line. I was thinking I had a TPS with a dead spot in it when I first bought the car. After the crushing, it now behaves like a normal car. Oh, and yes, it is a PITA to get the thing out/in there

Any good feelings though that you get after this 'mod' are just an improved drivability off the line. It might feel like an increase in performance, but it is just the car acting properly.

northernkanuck · #14 10-14-2002, 12:16 AM

Any good feelings though that you get after this 'mod' are just an improved drivability off the line. It might feel like an increase in performance, but it is just the car acting properly.

Exactly what I was trying to say Stevebsy.

Keith

Aredubjay · #15 10-14-2002, 08:31 AM

Steve and Keith,
According to the TSB, you have described exactly what the bead crush was supposed to do: Elimintate Hesitation. The "noise supressor" was originally put there to add the hesitation, in order to keep overzealous drivers from putting too much torque to the drivetrain on takeoff. Obviously, drivers didn't like this function and complained . . . alot . . . prompting Subaru to put out the TSB. In short, the bead crush "mod" (noise supressor) was not supposed to increase performance, or horsepower, it was merely meant to remove the annoying hesitation (possibly dangerous, in some circumstances, where the hesitation seemed to elevate) on takeoff.