Speed limiter?

IggDawg · Post by **IggDawg** » Tue Feb 25, 2003 2:03 pm

I was cruising down the last leg of my commute today, looking forward to the "hyperspace stretch" where an exit peels off the right lane (4 lane highway) for a mile or so. I take this opertunity to give my baby an italian tune up and make sure her boost fluid isn't going stale. I've never had her much above 100 before. This is one of the only stretches where I can get decent speed without worrying about hitting anyone or getting tagged by a cruiser. Today I got an early jump on hyperspace and had plenty of distance left after I hit 100. I decided to take her a little higher. when I hit 110 she bucked at me like I had an air bubble in the fuel line or something. She was still going strong and wanting to give me more. I don't think I hit 13 lbs. I'm set to 10 lbs and I'd been steady on the throttle and I don't think it was a spike. My speedo is laggy, so I could have been going closer to 115 or so since I was still accelerating at a decent rate.

The new Imprezas have a speed limit of 112 on the 4EATs, but I don't think the older ones did. do the 4EAT legacy turbnos have a speed limiter?

Post by **Legacy777** » Tue Feb 25, 2003 3:52 pm

I can tell you that I do not have a speed limiter on my auto legacy.

I wouldn't say routinely....but I've had her up to 120 several times.......and topped out at 130.

Is your redline 6250 or 6500.....like when does the car shift when it's floored?

IggDawg · Post by **IggDawg** » Tue Feb 25, 2003 4:06 pm

The redline is 6500, but she sems to shift at 6200-6300. I think the tach is off a little. most subaru tachs say "for entertainment purposes only" if you look real close

. the speed I shift at seems proper for the 6500 RPM redline. I'm pretty sure the gearing is the same as my 4EAT Impreza, and I shift 5-10 MPH higher in each gear.

I mean, it happened a little after it shifted into 4th. I could have gotten a boost spike between gears I suppose. I should try it again and see what happens :devil:

vrg3 · Post by **vrg3** » Tue Feb 25, 2003 4:59 pm

Well, Josh, your ECU is different from the turbo ECUs, so it's quite possible the turbos have speed governers while the N/As don't.

If it seemed to cut fuel around 115mph, I'd bet it is a speed limiter, because that's pretty close to the magic number where stock tires can start getting dangerous. My old '95 Honda Odyssey would cut fuel at 115mph too.

I haven't taken either of the turbo Legacies I've owned much past 100 so I can't offer any other experience.

The Torque Chip is supposed to disable the speed limiter by modifying the vehicle speed sensor signal to the ECU.

vypa · Post by **vypa** » Tue Feb 25, 2003 10:53 pm

ive personally been over 120.... but again NA... and a 5MT

Aaron's ej22t · Post by **Aaron's ej22t** » Tue Feb 25, 2003 11:31 pm

my stock legacy turbo except k/n filter only would pull 110 mph, although, i was going uphill and in 5th gear.........i didn't try it for very long.

STi_GUY · Post by **STi_GUY** » Wed Feb 26, 2003 1:26 am

Ive hit right over 122. Ive even got that saved into the Apex'i RSM I have. Although its in km/hr. I'm sportin' an NA w/ a 5MT. The day was cool and I-77 is really straight.

Unofficially, Ive been to 130mph

Post by **Legacy777** » Wed Feb 26, 2003 1:28 am

IggDawg wrote:The redline is 6500, but she sems to shift at 6200-6300. I think the tach is off a little. most subaru tachs say "for entertainment purposes only" if you look real close . the speed I shift at seems proper for the 6500 RPM redline. I'm pretty sure the gearing is the same as my 4EAT Impreza, and I shift 5-10 MPH higher in each gear.

I mean, it happened a little after it shifted into 4th. I could have gotten a boost spike between gears I suppose. I should try it again and see what happens :devil:

I'd say the tachs are pretty acurate at higher rpms mind you....lower....yeah they're just play numbers.

The gearing in the turbo legacy & your impreza are different. The gearing in the tranny may be different, but the final drive reduction in the turbo legacy is 3.9, compared to the impreza's 4.111

IggDawg · Post by **IggDawg** » Wed Feb 26, 2003 2:10 pm

Tru dat. tru dat indeed. I forgot about the whole 4.11 thing.

BUT, I figured out it's the fuel cut. first off, my boost gauge is about 0.05 bar off. the "zero" area on the WRX boost gauges is 0.05 bar (0.005 MPa) wide above and below the zero line. It sits at teh very bottom of this region. at full boost with the factory solenoid I'd get about 0.55 bar. I should be getting 0.6 .

Generally with my bleed valve she boosts to 0.7 bar. fuel cut is 0.9 (approx 13 lbs. that's where the FC hiots, right?) so the "0.7 bar" is actually 0.75 bar. all it needs is a 0.15 bar spike to hit the fuel cut, and I bet I'm getting spikes and not seeing them. there's a restrictor in the WRX boost gauge's line. I assume it's there to smooth out the readings. momentary spikes could be damped.

Sometimes I'll get surges to 0.8 or so depending on underhood temps. The bleed valve type MBCs are dependent on ambient temp. yesterday and today have been colder than usual, so I was running slightly higher boost than normal anyways. So it wouldn't surprise me that I hit fuel cut.

To test my theory I upped the boost slightly, and sure enough I was getting these lurches at WOT a lot sooner than any speed limiter would hit

. so now I'm at the very least looking for a less spikey boost controller. a boost monkey or at least a ball and spring valve instead of this home depot crap I've thrown together.

Thanks for all the useful info everyone!

vrg3 · Post by **vrg3** » Wed Feb 26, 2003 3:19 pm

Well, Igg, I'd still be interested in knowing if we have speed limiters. I know for a fact there's a fuel cut when a certain boost level is exceeded, but there still may or may not be a fuel cut when a certain speed is exceeded. Maybe try taking out your bleeder (to run stock or not-too-much-above-stock) boost and see if you can get faster than ~115mph?

I do seem to remember that the BF JDM Legacy GT wagons had speed limiters; they had to remove the limiter from the wagon that was doing the endurance race or whatever that was.

boostjunkie · Post by **boostjunkie** » Wed Feb 26, 2003 3:41 pm

I know for sure that my 5spd turbo doesn't have a speed limiter . . .

IggDawg, I would suggest the Joe-P MBC. I haven't had too many problems. Yes, I have spikes, however, I'm almost posititve it's a function of the wastegate/dp combination at 1.15bar.

Last time I saw this MBC, it was on sale for $30 or so . . . its a dual ball-spring type.

Post by **Legacy777** » Wed Feb 26, 2003 4:32 pm

I doubt you guys have speed limiters......I know the manuals don't.....however i still think the autos don't. I know mine doesn't.....we just need to find someone with an turbo.....auto......and have them go haul arse....hehe.

teaguespeed · Post by **teaguespeed** » Wed Feb 26, 2003 8:07 pm

i've gone 125 in my turbo, and its an auto.

Brat4by4 · Post by **Brat4by4** » Thu Feb 27, 2003 6:14 am

My Legacy hit 121 mph on the speedo... This is with WRX rims and tires which are slightly larger than OEM. My speedo also does the little pause then catch up deal with the needle. I don't know about Subaru speed limiters (don't have to worry about those in a Brat) but many manufacturers set it at 130 mph for the sake of the OEM tires. So I'll have to go out and see if it will cut out at 130 on the speedo.

Oh, by the way, I was pulling from a Audi Coupe 20 Valve Turbo when my speedo hit 121... a whole lot of good that extra valve did him.

boostjunkie · Post by **boostjunkie** » Thu Feb 27, 2003 2:52 pm

Hey Brat4by4, do the turbo legacy 5spds only weigh 2980lbs? I always saw somewhere in the range of 3100lbs.

Post by **Legacy777** » Thu Feb 27, 2003 3:18 pm

That may be dry curb weight, but they're no way it only weighs that much, considering my FWD legacy weighs about 3100-3200 lbs with full tank and me in it.

boostjunkie · Post by **boostjunkie** » Thu Feb 27, 2003 3:53 pm

That's what I thought, Legacy777. I'm guessing my car weighs something like 3400lbs with a full tank and me in the car.

Aaron's ej22t · Post by **Aaron's ej22t** » Thu Feb 27, 2003 4:17 pm

Everywhere i have found, the 5spd turbo sedan weighs 3,140 pounds. 3140-2980 = 160. it that is dry weight compared to everything in it except a person, then that is a big difference. do fluids really weight that much?

I weigh 160 and my car with me would probably way in at 3300. of course, if you take out the spare, jack and tools, etc.... then it is down to about 3250 with me in it. although, that weight can change also depending on how much gas you have in the tank.

Post by **Legacy777** » Thu Feb 27, 2003 6:44 pm

Easy solution......go to a truck weigh station......weigh your car.....very simple. I think it was like 8 bucks for the first weigh, and like 2 or 4 bucks for next 3.

So I weighed mine empty, around 1/2 tank, and full tank.

If you do it......get the car spaced evenly over the front and back weigh pads, that way you can get a front & rear ratio.

Brat4by4 · Post by **Brat4by4** » Thu Feb 27, 2003 10:27 pm

I weigh mine for free. On the way to work down the street from me there is a rock place that has a big scale. I go in and the lady tells me what it weighs. That was with 4 gallons of gas in it (i went and filled up right after). Full tank plus me takes the weight up to around 3226 (estimated). I weigh 150 and you figure around 8-9 lbs for every gallon of gas. Didn't mean to take everyone off subject with my signature.

Anyone had their 5-speed past the 130 mark? That would definitely settle the limiter issue.

boostjunkie · Post by **boostjunkie** » Thu Feb 27, 2003 10:54 pm

Brat4by4 wrote:Anyone had their 5-speed past the 130 mark? That would definitely settle the limiter issue.

Yes.

paf · Post by **paf** » Mon Mar 24, 2003 3:54 am

according to some website for mechanics that i ran into while looking for ecu codes for a 97 maxima... I forgot where it was
anyways it states that legacies only got speed limiters @ 180km/h in 1995-present
for you americans and british (sensibly named the metrick impaired) out there thats 113MPH

Its states
"'95 Legacies have a speed limiter that kills injection at 113 mph. So, a malfunctioning vehicle speed sensor that sends a signal indicating that number or higher will shut down the engine. If you want to go faster than that, we hope you do it somewhere far from us. "
by the way the page is http://www.parttrackers.com/library/1/93/106/ (found it by typing bits of it on google)
so I deducted that only 95 and later have the speed limiter
I could be wrong But i know one thing I hit 200 (125mph) with My 1990 legacy wagon (Base... no options at all, no A/C, Nothing at all not even tape player, well i finally installed one)

Mark Ward · Post by **Mark Ward** » Tue Mar 25, 2003 3:59 am

I have hit speed limiter 2 times. Once with the 2.2T and stock 5spd and once with the EJ20T and 5spd with 4.11. (the latter got there quicker

)

Both were 125 (200km/h).
Mark

entirelyturbo · Post by **entirelyturbo** » Sun Jun 20, 2004 9:24 pm

Holy old thread Batman!

To add some more input to this discussion, I thought I'd make the Dragon run a 100% complete test of my car's limits. Not only did I push the limits of the handling on the Dragon, but on the highway back, I decided to go for top speed. This is on I-75 in North FL about 11pm.

I hit 105 and Patti wanted to go more. So I kept going up until about 110. At that point the engine was about 4700-4800 revs, so it was just in its HP peak, should have had more to go. But a tiny bit past 110, the car just wouldn't go anymore. Further throttle application yielded no acceleration, even WOT. It didn't hit fuel cut or anything, it just wouldn't go anymore. So I do have the 112-mph speed limiter.

Post by **Legacy777** » Sun Jun 20, 2004 9:28 pm

No......you have no pre-defined speed limiter......what you do have is a drag vs. hp limiter.

The hp required to overcome the wind resistance at that speed was more then what your car had.

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Speed limiter?

Speed limiter?

Arrgh