High HP 914? |
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High HP 914? |
d k |
May 3 2011, 10:59 AM
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#1
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Newbie Group: Members Posts: 7 Joined: 2-May 11 From: Miami Member No.: 13,014 Region Association: None |
Hello people.
I'm a noob here, but been around cars for awhile. Recently acquired a 75 914 that is very clean and going to do the Subaru conversion. Car will be used mostly for track events and some odd miles on the street. The question that I had, is how does this car respond to high horsepower? In stock form, the EJ257 will put out 300 at the crank and I'm wondering if it makes sense to tweak it a little more.... I've seen a few conversions done here and read through a ton of threads. Some very helpful info here, but I haven't read anybody's feedback on what the chassis will do if throw 500hp at it? Besides all the supporting mods necessary to handle the power, what will the driving dynamics be?? Maybe it's not worth to do anything except just the engine swap, but since it's going to get a full cage, big brakes and aero, maybe go big (IMG:style_emoticons/default/driving.gif) David |
stewteral |
May 5 2011, 10:35 PM
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#2
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Old Member Group: Members Posts: 384 Joined: 4-December 07 From: Camarillo, CA Member No.: 8,424 Region Association: Southern California |
Hello people. I'm a noob here, but been around cars for awhile. Recently acquired a 75 914 that is very clean and going to do the Subaru conversion. Car will be used mostly for track events and some odd miles on the street. The question that I had, is how does this car respond to high horsepower? In stock form, the EJ257 will put out 300 at the crank and I'm wondering if it makes sense to tweak it a little more.... I've seen a few conversions done here and read through a ton of threads. Some very helpful info here, but I haven't read anybody's feedback on what the chassis will do if throw 500hp at it? Besides all the supporting mods necessary to handle the power, what will the driving dynamics be?? Maybe it's not worth to do anything except just the engine swap, but since it's going to get a full cage, big brakes and aero, maybe go big (IMG:style_emoticons/default/driving.gif) David Hi David, So much to consider! I've been running my 914 V8 with 500 HP (built 383) for some 8 years and have learned a lot in developing the car: -Mine is a Track Car = Willow Springs Raceway, not a slalom car. If you plan to run slaloms, you will not be able to get your tires warm enough to put the BIG power down. I run 315/35-17 DOT Hoosier slicks and when I drive on the street, I can just light up the rear by opening the throttle in 1st, forgetting that I take a full lap on track to warm the tires and get traction. -While you could tune a Subie up to 400 HP, you would be likely pushing the limit of the block. You can do it, but how long would it stay together? If you love rebuilding engines and have lots of $$, go for it! I'd suggest getting deeply into Subie forums to learn what can be done reliably. -When you get big power (400 and up) You MUST have a full rollcage with tubing bracing all 4 suspension top load points. This gives you a RIGID Chassis. The original chassis is a true Flexy-Flier! -It is important to STAY with a pancake engine to keep the CG low. The chassis is designed around a low CG and low body roll. My V8 has caused me a lot of work in getting the car to handle due to the tall mass (I've posted extensive info on the roll vs. toe change of the rear suspension through the arc of travel). -At 500 HP, the game completely changes: -You MUST get a stronger trans. I have a 930, but Pantera ZF, Porsche 993 will work ($3000 - $8000), 911/930 half-shafts, 930 CV joints, LSD Differential, full bracing of inner and outer rear suspension mounting points and shift-linkage -Then don't forget BIG brakes, dual-master cylinder + balance bar. -Last issue is COST, I got 500 Chevy HP for $4500, I have no idea what that would cost in Subie. So while I'm hoping to be helpful, I'm also hoping you are taking a step back to look at your plan before jumping in. I started my project with an Excel spreadsheet. (IMG:style_emoticons/default/smile.gif) Best of luck, Terry |
d k |
May 6 2011, 08:24 AM
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#3
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Newbie Group: Members Posts: 7 Joined: 2-May 11 From: Miami Member No.: 13,014 Region Association: None |
WSIR with a V8 914 would be a scary proposition...
What kind of times are you turning? When I raced there with my S2000, we were at the 1:28 range on R compounds and 260hp.... I don't know what you must do there, 1:19? Although I love the torque of a V8, I think that the 914 would benefit most from a high compression flat 6... Some videos of the 914 GT, the sound and feel is just awesome.. D Hello people. I'm a noob here, but been around cars for awhile. Recently acquired a 75 914 that is very clean and going to do the Subaru conversion. Car will be used mostly for track events and some odd miles on the street. The question that I had, is how does this car respond to high horsepower? In stock form, the EJ257 will put out 300 at the crank and I'm wondering if it makes sense to tweak it a little more.... I've seen a few conversions done here and read through a ton of threads. Some very helpful info here, but I haven't read anybody's feedback on what the chassis will do if throw 500hp at it? Besides all the supporting mods necessary to handle the power, what will the driving dynamics be?? Maybe it's not worth to do anything except just the engine swap, but since it's going to get a full cage, big brakes and aero, maybe go big (IMG:style_emoticons/default/driving.gif) David Hi David, So much to consider! I've been running my 914 V8 with 500 HP (built 383) for some 8 years and have learned a lot in developing the car: -Mine is a Track Car = Willow Springs Raceway, not a slalom car. If you plan to run slaloms, you will not be able to get your tires warm enough to put the BIG power down. I run 315/35-17 DOT Hoosier slicks and when I drive on the street, I can just light up the rear by opening the throttle in 1st, forgetting that I take a full lap on track to warm the tires and get traction. -While you could tune a Subie up to 400 HP, you would be likely pushing the limit of the block. You can do it, but how long would it stay together? If you love rebuilding engines and have lots of $$, go for it! I'd suggest getting deeply into Subie forums to learn what can be done reliably. -When you get big power (400 and up) You MUST have a full rollcage with tubing bracing all 4 suspension top load points. This gives you a RIGID Chassis. The original chassis is a true Flexy-Flier! -It is important to STAY with a pancake engine to keep the CG low. The chassis is designed around a low CG and low body roll. My V8 has caused me a lot of work in getting the car to handle due to the tall mass (I've posted extensive info on the roll vs. toe change of the rear suspension through the arc of travel). -At 500 HP, the game completely changes: -You MUST get a stronger trans. I have a 930, but Pantera ZF, Porsche 993 will work ($3000 - $8000), 911/930 half-shafts, 930 CV joints, LSD Differential, full bracing of inner and outer rear suspension mounting points and shift-linkage -Then don't forget BIG brakes, dual-master cylinder + balance bar. -Last issue is COST, I got 500 Chevy HP for $4500, I have no idea what that would cost in Subie. So while I'm hoping to be helpful, I'm also hoping you are taking a step back to look at your plan before jumping in. I started my project with an Excel spreadsheet. (IMG:style_emoticons/default/smile.gif) Best of luck, Terry |
brant |
May 6 2011, 11:19 AM
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#4
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914 Wizard Group: Members Posts: 11,640 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
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d k |
May 6 2011, 01:31 PM
Post
#5
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Newbie Group: Members Posts: 7 Joined: 2-May 11 From: Miami Member No.: 13,014 Region Association: None |
I said high comp flat 6, not 500hp/high comp/flat 6 (IMG:style_emoticons/default/smile.gif)
I agree, not very realistic. As it is with track cars, sometimes driveability and response can be worth giving up 100+ hp. D Although I love the torque of a V8, I think that the 914 would benefit most from a high compression flat 6... D 500HP = "high compression flat 6" Not a phrase that is very realistic... its possible, but not a good value and not easy. |
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