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#31
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Re: If you had a 400HP engine........
One last question before I post my conclusions. What is the "no kidding" top speed of the stock SVX? I have seen 143MPH posted at several locations. However, peak HP occurs at an RPM that corresponds to 158MPH and I have also seen several people claim that they got their SVXs up to the 150s. What wasn't clear was whether or not they had a manual transmission and/or performance modifications. Does anyone have a definitive answer to this question?
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Tony 1996 Polo Green Subaru SVX LSi, 168,XXX miles, Redline D4 ATF, Redline 75W90 gear oil, K&N HP-4001 Oil Filter, Mobil 1 5W50 FS (3qt) and 5W30 High Mileage (4qt) Oil Blend, Motul RBF600 Brake Fluid, AC Delco A975C Air Filter, NGK BKR6EIX-11 plugs, Centric Rotors, Power Stop Evolution Carbon Fiber Ceramic Brake Pads 2005 Gray Acura RL, 165,XXX miles, Redline D4 ATF with Lubegard Platinum Protectant, Mobil 1 5W20 High Mileage Extended Performance Oil 2009 Red Toyota Venza, 123,XXX, Mobil 1 5W30 High Mileage Oil 1992 Red Ferrari 348 ts, 82,XXX, Redline everything |
#32
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Re: If you had a 400HP engine........
92 is supposedly limited to 155mph. Later years tested much lower in top speed, but I'm not sure why.
Low frontal area and CD make some huge strides for the lack of power. |
#33
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Re: If you had a 400HP engine........
I'm looking to make that kind of power out of my built motor, and the trans I chose was a 2005 WRX 5 speed with the 1-4 gears, main shaft, and synchros swapped to those of the Legacy GT. I didn't go with a 6 speed mainly because of cost and because I bought my car already set up and converted for a 5 speed so I had the parts already to just bolt it in.
Theory is that LGT gear are the same as earlier JDM STI non RA gears. Exactly the same ratio and thickness, at least. |
#34
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Re: If you had a 400HP engine........
Yeah but those were based on claims people made, as far as I can tell. I would like to hear from someone that actually has achieved those speeds in a stock SVX. Or perhaps an official claim from Subaru that it was the top speed of the stock SVX.
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Tony 1996 Polo Green Subaru SVX LSi, 168,XXX miles, Redline D4 ATF, Redline 75W90 gear oil, K&N HP-4001 Oil Filter, Mobil 1 5W50 FS (3qt) and 5W30 High Mileage (4qt) Oil Blend, Motul RBF600 Brake Fluid, AC Delco A975C Air Filter, NGK BKR6EIX-11 plugs, Centric Rotors, Power Stop Evolution Carbon Fiber Ceramic Brake Pads 2005 Gray Acura RL, 165,XXX miles, Redline D4 ATF with Lubegard Platinum Protectant, Mobil 1 5W20 High Mileage Extended Performance Oil 2009 Red Toyota Venza, 123,XXX, Mobil 1 5W30 High Mileage Oil 1992 Red Ferrari 348 ts, 82,XXX, Redline everything |
#35
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Re: If you had a 400HP engine........
The old Brochures clam 146 MPH I read where the newer ones 1994 and up had a speed limiter . Anyone know if that was engine or transmission .
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#36
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Re: If you had a 400HP engine........
Quote:
I remember reading that there was a guy in Germany that got his into the 170s on the autobahn. But I don't know if that was stock or not, and there's no way to know for sure if it actually happened.
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'94 Laguna Blue LSi ~159k.......JDM ultra short-geared 3.900 STi Version 7 6-speed w/ Cobb shortshifter, ECUtune 244,8.1mm/256,9.1mm i/e cams, group N motor mounts, '97 grille, JDM clear corners, Momo JDM Legacy GT steering wheel, apkarian's LED tails, silver STi BBS wheels, PWR radiator, redstuff pads f/r, drilled/slotted rotors, bontragerworks rsb #18, Koni/GC 450f/375r coilovers, Megan Racing adjustable lateral links, KMac c/c plates, Stebro exhaust, ECUtune 1v5, Optima battery in the trunk where it belongs. Turbo project '97 Ebony LSi ~137k #036.......Power mode mod, JDM clear corners, BBS wheels. AUX/pocket mod Now a mod "over there" ............Photo album |
#37
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Re: If you had a 400HP engine........
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I can believe a 92 SVX in proper shape could do 155. Good tires, well balanced unbent rims, engine in proper shape, good highoctane fuel, etc. My 94 SHO with roughly the same power could get upto just over 140mph. This is with a larger frontal area, higher CD, and worse gearing. I wonder though if top speed is best found with the torque converter locked or unlocked. |
#38
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Re: If you had a 400HP engine........
OK, here's the deal. I was intrigued by the engine that EFI Logics modified and is now selling. It is normally aspirated and produces approximately 416HP at 6650 RPM and 420HP at 8100 RPM. The power curve is very flat from about 6400 RPM to 8100 RPM. The stock redline is around 7000 so I don't know how comfortable I would be running it out past 8000 even considering the upgraded interiors.
I decided to use the 143 MPH number as the reference point for the stock car. After looking at the stock power curve, I estimated the power to be about 215HP at 4890 RPM where one would see 143 MPH. That's the reference point. The power curve for the EFI engine can be seen in the attached file. This was measured with the engine in an Impreza with a manual tranny so I scaled these using an assumed tranny efficiency of 76% to get the engine numbers. The attached spreadsheet shows estimates for the top speed that can be achieved in the SVX, with this engine, for both an automatic and manual transmission. I used 66% for the assumed efficiency for the automatic transmission. I calculated what the optimal final drive ratios would be for each type of tranny (Max Speed RPM = Max HP RPM) and then selected the closest ratio among the trannys I have heard discussed on this forum. Then I calculated what the actual RPMs would be at the calculated top speeds for each tranny type. You can see that the RPMs end up a little higher than the RPM at which the first peak in the HP curve occurs but it is within the flat region of the curve so the impact on top speed is minimal. These RPM values are also right around stock redline so that is convenient. The conclusion is that this engine in an SVX with an automatic tranny can reach approximately 178 MPH and it could reach 187 MPH with a manual tranny.
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Tony 1996 Polo Green Subaru SVX LSi, 168,XXX miles, Redline D4 ATF, Redline 75W90 gear oil, K&N HP-4001 Oil Filter, Mobil 1 5W50 FS (3qt) and 5W30 High Mileage (4qt) Oil Blend, Motul RBF600 Brake Fluid, AC Delco A975C Air Filter, NGK BKR6EIX-11 plugs, Centric Rotors, Power Stop Evolution Carbon Fiber Ceramic Brake Pads 2005 Gray Acura RL, 165,XXX miles, Redline D4 ATF with Lubegard Platinum Protectant, Mobil 1 5W20 High Mileage Extended Performance Oil 2009 Red Toyota Venza, 123,XXX, Mobil 1 5W30 High Mileage Oil 1992 Red Ferrari 348 ts, 82,XXX, Redline everything |
#39
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Re: If you had a 400HP engine........
Tony, I believe you have just proved that you are constantly bored throughout your everyday life .
In all seriousness though, are you purchasing that engine?
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Cam '92 Ls-L Dark Teal 11:1 CR ECUTUNE pistons ECUTUNE .256 duration intake/exhaust cams ECUTUNE STAGE 2AV1 ECU Z32 MAF/SR20DET injectors Balanced & Blueprinted |
#40
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Re: If you had a 400HP engine........
Quote:
I'm honestly not all that interested in top speed. You just can't go that fast under anything resembling normal circumstances.
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'94 Laguna Blue LSi ~159k.......JDM ultra short-geared 3.900 STi Version 7 6-speed w/ Cobb shortshifter, ECUtune 244,8.1mm/256,9.1mm i/e cams, group N motor mounts, '97 grille, JDM clear corners, Momo JDM Legacy GT steering wheel, apkarian's LED tails, silver STi BBS wheels, PWR radiator, redstuff pads f/r, drilled/slotted rotors, bontragerworks rsb #18, Koni/GC 450f/375r coilovers, Megan Racing adjustable lateral links, KMac c/c plates, Stebro exhaust, ECUtune 1v5, Optima battery in the trunk where it belongs. Turbo project '97 Ebony LSi ~137k #036.......Power mode mod, JDM clear corners, BBS wheels. AUX/pocket mod Now a mod "over there" ............Photo album |
#41
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Re: If you had a 400HP engine........
Double post...the phone strikes again
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Cam '92 Ls-L Dark Teal 11:1 CR ECUTUNE pistons ECUTUNE .256 duration intake/exhaust cams ECUTUNE STAGE 2AV1 ECU Z32 MAF/SR20DET injectors Balanced & Blueprinted |
#42
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Re: If you had a 400HP engine........
Quote:
Keith |
#43
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Re: If you had a 400HP engine........
I'm still trying to sort out what you're trying to do! Is this supposed to be streetable? Pump gas or race gas? Only to set a known top speed? A term paper? Drunken math experiment?
Start backwards. Sort a power to speed requirement curve. <Here> is some handy info, and a wicked Caprice to boot. Frontal area and drag are on the web somewhere; I've found them before. You're going to want to establish a maximum distance to achieve this speed, as well, unless you've got a ten mile long private straight to work with. This'll get some acceleration requirements defined for your gearing. REMEMBER TO UPGRADE YOUR BRAKES.
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Disclaimer: The above post is on the internet. |
#44
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Re: If you had a 400HP engine........
Quote:
At least I am not sad enough to post a message about my birthday to solicit well wishes. (Not talking about you Cam) Quote:
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Tony 1996 Polo Green Subaru SVX LSi, 168,XXX miles, Redline D4 ATF, Redline 75W90 gear oil, K&N HP-4001 Oil Filter, Mobil 1 5W50 FS (3qt) and 5W30 High Mileage (4qt) Oil Blend, Motul RBF600 Brake Fluid, AC Delco A975C Air Filter, NGK BKR6EIX-11 plugs, Centric Rotors, Power Stop Evolution Carbon Fiber Ceramic Brake Pads 2005 Gray Acura RL, 165,XXX miles, Redline D4 ATF with Lubegard Platinum Protectant, Mobil 1 5W20 High Mileage Extended Performance Oil 2009 Red Toyota Venza, 123,XXX, Mobil 1 5W30 High Mileage Oil 1992 Red Ferrari 348 ts, 82,XXX, Redline everything |
#45
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Re: If you had a 400HP engine........
What about... a local car with a 5-speed installed but no engine?
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Disclaimer: The above post is on the internet. |
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