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Old 08-31-2006, 03:39 PM   #1
drfrink24
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Default Can 400+ whp be safer than 350 whp?

Lets assume you are making 400whp with a rotated and EWG'd setup, lets say, at 18psi or something.

Now, lets say you are running 350whp 20g/fpgreen IWG and 21+ psi, with more timing and lower VE.

Would the 400whp setup still be more stressfull to the longevity of your engine? Could we take it even a step futher and say that a 300 whp vf-39 setup isn't as safe as a 350whp 20g ewg setup?
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Old 08-31-2006, 04:11 PM   #2
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depends but usually you will see a 400+ setup on a car that has alky injectoing which makes the car even safer !
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Old 08-31-2006, 04:15 PM   #3
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its all in the tune.
someone can have a 325whp tune with a 20g on 91 octane, and it can potentially run far far worse than a GT35r STi making 475whp on 91octane.

Its ALL in the TUNE. 99% of it.
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Old 08-31-2006, 04:58 PM   #4
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Your referring to just the motor right?
The tranny might have something different to say.
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Old 08-31-2006, 05:19 PM   #5
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same thing with tranny... its how u drive.... paintballguy has 390WHP on his car and stock tranny and clutch.... no problems
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Old 08-31-2006, 05:45 PM   #6
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Quote:
Originally Posted by xfactor23 View Post
same thing with tranny... its how u drive.... paintballguy has 390WHP on his car and stock tranny and clutch.... no problems



Stock tranny and clutch are holding great.... Clutch NEVER slips even with 5k launches.

Its all in how you drive it. Although I'm still getting PPG's.
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Old 08-31-2006, 06:22 PM   #7
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Quote:
Originally Posted by WrxRick View Post
its all in the tune.
someone can have a 325whp tune with a 20g on 91 octane, and it can potentially run far far worse than a GT35r STi making 475whp on 91octane.

Its ALL in the TUNE. 99% of it.
I understand that a horrible tune on even a stock car can pop an engine, vs a great tune on an extensively modified turbo system.

Lets assume you measure all aspects of a tune that are destructive to a vehicle. Cylinder pressure, EGTs, knock resistance of a tune, etc... (ignoring driveline).

If you set varibles for each and every one of these important aspects, and don't want to exceed 10 of X, 9 of Y or 11 of Z, is there a great possibility that the worlds best tuner, given the same vehicle, could not satisfy those safety measures with a vf39 and 300whp, but could acheive those safety measures with a GT30r at 400whp, with the right supporting hardware (not counting balanced and forged internals, or exotic intake/intercooling)?

Last edited by drfrink24; 08-31-2006 at 06:27 PM. Reason: clarification
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Old 08-31-2006, 06:28 PM   #8
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it all depends on what components u are pushing just like u said the guy with the stock turbo making 312WHP his turbo is going to blow soon i bet if u take a 20G and make the same power ur not put as much pressure on it ......
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Old 08-31-2006, 06:39 PM   #9
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Quote:
Originally Posted by drfrink24 View Post
I understand that a horrible tune on even a stock car can pop an engine, vs a great tune on an extensively modified turbo system.

Lets assume you measure all aspects of a tune that are destructive to a vehicle. Cylinder pressure, EGTs, knock resistance of a tune, etc... (ignoring driveline).

If you set varibles for each and every one of these important aspects, and don't want to exceed 10 of X, 9 of Y or 11 of Z, is there a great possibility that the worlds best tuner, given the same vehicle, could not satisfy those safety measures with a vf39 and 300whp, but could acheive those safety measures with a GT30r at 400whp, with the right supporting hardware (not counting balanced and forged internals, or exotic intake/intercooling)?
Its because of the much larger flow capacity of the GT30R compared to a VF39. The tuner doesnt have to push the engine as much as the VF39 shooting for 300whp. You would have the 400whp 30R running convservative timing with basically no chance of knock and the VF39 with aggressive timing and a higher possibility of knock.
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Old 08-31-2006, 07:17 PM   #10
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Quote:
Originally Posted by Paintballguy View Post
Its because of the much larger flow capacity of the GT30R compared to a VF39. The tuner doesnt have to push the engine as much as the VF39 shooting for 300whp. You would have the 400whp 30R running convservative timing with basically no chance of knock and the VF39 with aggressive timing and a higher possibility of knock.
Assuming a strong engine though, you're making a pretty bold statement. You're saying that everyone around here running the common stage 2 300whp protune by respected tuners, are actually doing, or, have the ability, to do more damage than a "conservative" 400whp GT30r.

If this is mutually accepted, then, heck, I'm getting my EWG 30r rotated setup, tellling my wife that it would be dangerous NOT to.
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Old 08-31-2006, 07:26 PM   #11
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LOL. If I had the money asap I'd do it too. College expenses suck!

But yes, of course more whp will eventually cause more wear and tear on all parts of the car...engine, tranny, suspension, brakes..to an extent.

Stock 6speed transmission ive heard holds up to about 600whp. Although I may look into different gears for the dragstrip.
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Old 08-31-2006, 07:52 PM   #12
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Quote:
Originally Posted by drfrink24 View Post
Assuming a strong engine though, you're making a pretty bold statement. You're saying that everyone around here running the common stage 2 300whp protune by respected tuners, are actually doing, or, have the ability, to do more damage than a "conservative" 400whp GT30r.

If this is mutually accepted, then, heck, I'm getting my EWG 30r rotated setup, tellling my wife that it would be dangerous NOT to.
No I'm talking about someone pushing a smaller turbo to hit a certain number. Not talking about a run of the mill stg 2 protune.
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Old 09-01-2006, 10:30 AM   #13
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Quote:
Originally Posted by Paintballguy View Post


Stock tranny and clutch are holding great.... Clutch NEVER slips even with 5k launches.

Its all in how you drive it. Although I'm still getting PPG's.
Good call.
The first serious mod I did was PPGs and I don't regret it what-so-ever.
- Eric
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Old 09-01-2006, 11:41 AM   #14
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Exactly correct. Though I would say your example is pretty extreme, but possible nonetheless.

Quote:
Originally Posted by WrxRick View Post
its all in the tune.
someone can have a 325whp tune with a 20g on 91 octane, and it can potentially run far far worse than a GT35r STi making 475whp on 91octane.

Its ALL in the TUNE. 99% of it.
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Old 01-23-2008, 04:16 PM   #15
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Quote:
Originally Posted by Paintballguy View Post
No I'm talking about someone pushing a smaller turbo to hit a certain number. Not talking about a run of the mill stg 2 protune.
I'll try to put this in lamen's terms for the newbies..

You can't "push" a turbo farther than its mechanical limits. What you have to do is push the engine harder to try to make up the numbers the turbo can't. Technically it's better to have a larger turbo that doesnt force a tuner to run ridiculous timing to make that magic number you're looking for... but more air + more gas = more explosion = your engine is not going to last as long.

Your best bet is to figure out how much money you're willing to spend TOTAL. Figure out the most well-rounded setup that can be had for that $$ amount, then get tuned to the best of that setup's ability... don't tell the tuner to hit a certain number, just let him do his thing.
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Old 01-23-2008, 04:22 PM   #16
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A bad tune on 350whp is definately more dangerous than a good tune on 400whp.

If the tunes are equal quality, 350whp will most definately be "safer" than 400whp.




Basically, if you want 400whp, you need to accept that blowing the motor is an entirely reasonable possibility. It may make it 100k, it may make it 5k. Even on the best tune out there, 400whp is right around the limit for most 2.5L subbie motors and you are taking your chances. Obviously a great tune pushes it more in your favor, but one spot of bad gas at that power level has the possibility of taking out a piston. Or not.

What I am saying is that you should be comfortable with the fact that it CAN happen. If you cant accept the possibility of it blowing up, you should stay well below that power level.
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Old 01-23-2008, 06:26 PM   #17
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<------- stock clutch on a GT35R for 6 months now but i dont drive like a idiot!
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Old 01-23-2008, 06:37 PM   #18
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good thread! ive always thought about this in the back of my head.
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Old 01-23-2008, 07:23 PM   #19
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If both tunes were spot on, then the high-powered car would have more damage in the long run.

It's as simple as extra load on the engine's internals.
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Old 01-23-2008, 11:19 PM   #20
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^^ seems to me that'd be the case. but it'd be more fun even though you'd lose a few lifetime miles
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Old 01-24-2008, 01:17 AM   #21
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It's stressful on the car when its completely stock and you're beating on it. When tuned with aftermarket parts though depends on aggressive tune or conservative. Common sense though the more power you have the more stress on the internals. That's why there is UPGRADES WOT!
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Old 01-24-2008, 03:36 AM   #22
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Engine longevity is directly related to engine wear. And engine wear occurs from a number of things, but mainly from friction and loading.

Stock engines are developed by their manufacturer to withstand the load that can/will be placed on the oem components and the wear of these components regardless of driving style. Each component would have been tested by the manufacturer to find its "break point" and then the engine and tune would have been developed to ensure the "break point" is never met.

If you increase the power 100-200% above factory, the extra load placed on bearings, rings, fasteners etc is increased exponentially. This extra load will wear these components much more rapidly - and if the load is above the load rating of the components (break point) then the components will fail and your engine will eat itself up from the inside

It isn't all doom and gloom though, as most manufacturers over engineer the engine components so they last under different conditions in different markets using different fuels and lubrications. This over engineering gives extra headroom and is why you can mod your car and make more power without replacing engine components.

Just keep in mind that the more power and load the engine components are under the more chance they will wear/break. So pay special attention to experienced Subaru tuners and those members who have modded their engines/cars and found the operational limits of the engine components. There experience and knowledge is vital in assisting you to make a safe amount of power from your modded "stock" engine wrx.


Anyhoo. Moral of the story, make sure your tune is good and make sure you don't take the components above what others have proven is the break point.
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Old 01-24-2008, 03:47 AM   #23
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det can make short work of a stock engine
but if you have a good safe tune then you should have no det...

we also have heat and pressure

by tuning for more power we are also making more heat and pressure on the top of the piston just after TDC

the alloy of the stock cast piston will reduce in strength as the temperature rises toward its critical temperature (not sure what this is, but raw aluminium melts at mere 660deg C)

also the expansion of the pistons also increases as the temperature rises
The tolerances of the stock piston in the bore are already very "tight"
if the piston expands enough to become to too tight then I guess it could easily break the ring land

what I am getting at is the temperature of the piston is a big factor

if you are taking out timing to reduce det then the exhaust gas temperature goes up
this means that the piston is subjected to higher gas temperatures for a longer period of time...

the safest way to make power is to have a better turbo setup.... cooler intake charge and less residual exhaust gas left in the combustion chamber

parts required:
bigger exhaust housing
more efficient compressor (at higher flow rates)
bigger intercooler
tuned length headers
lower pressure drop exhaust piping
+ a good safe tune

If you are trying to hit 350wHP by simply using small exhaust housing turbo with larger compressor (ie. TDO5-20G or variant) and then winding up the boost
then I would think this is most likely much less "safe" than 400whp with a full turbo/ system parts upgrade
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