Since you've tested "TONS" of exhaust systems for companies you'd probably say B.S. that my '03 Cobra went from 382 peak rwhp completely stock (as delivered from SVT) @ 1500 miles to 415 peak rwhp @ 2000 miles with only the addition of a Magnaflow Catback and a UPR CAI Kit. 33 rwhp and the temperature on the day of the modded test was higher with higher humidity to boot.
I'll gladly perform the same little comparison with my GXP. I need to get the car to MC Racing in KC for the baseline (with K&N drop-in) and then after I get the Magnaflow on I'll return to MC Racing and have a re-dyno (with atmospheric conditions as close as possible). I have a gut feeling that I'll be seeing quite a bit more than 6 peak rwhp difference between those runs. I'll even make sure that several hundred miles of "learning" miles are acrued on my GXP "after" addition of the Magnaflow Catback to rule-out the possibility of the computer not having had enough time to make its "supposed" adjustments.
The baseline won't happen next weekend but it will probably happen the following one (June 23rd). Then it'll be a bit for me to get rest of my $$$'s together so I can add the Magnaflow exhaust but I'll try to have the re-dyno completed by the middle of July. That's the best I can do but seeing that no-one else has taken the time to make proper comparisons that's all I can do.
This way it's same car...same dyno...same dyno operator...as close to same conditions as I can make it (right down to tire pressure and fuel-type and weight of car).
You are completely missing the point. You are not assuming that exhausts dont do anything. What does your '03 cobra have to do with any of this? BTW, I was just faxed this from someone who just had their GXP dynoed with the Magnaflow exhaust.
I guess he felt it was pointless trying to explain things to people on the forums.
pretty simple guys, butt dyno means nothing and dyno dyno means nothing
time logs...that's all that matters
stock does a lttle over 5 second 0-60's
when someone cracks 5 seconds that's when we'll know it does somehing
That is where you are wrong. You can dyno test and keep things the same, time testing is harder to get everything the same. Driver error can cause problems with time test, you do not have that problem on a dyno.
__________________
John Higgins
2001 Z24 5 spd
M45
That is where you are wrong. You can dyno test and keep things the same, time testing is harder to get everything the same. Driver error can cause problems with time test, you do not have that problem on a dyno.
I agree. When I took my mr2 out, I was runnin 15s, 14s, then an 11.9 when I finally got my launch down.
We do whats called an "intertia test" on our dyno to give us the most accurate results possible. At the gear we dyno in, we put load on the car from 1000rpm to 3000rpm, then at WOT, let the dyno bring the car back down to 1000rpm. On the dyno graph, accel and decel must match, and thats how we can tell the proper inertia settings are in place.
That is where you are wrong. You can dyno test and keep things the same, time testing is harder to get everything the same. Driver error can cause problems with time test, you do not have that problem on a dyno.
time logs on auto transmission, done with a computer log like dashawk and you log from wot
I don't think in any scenario with the mods you are gonna get bellow 5 seconds, yet without mods we get right to it
is there even a best case scenario where a modded exhaust gxp logged in the 4's?
Oh well, on an auto, thats totally different. Best way to be consistant is with an auto just mashing the pedal.
ya and that's what I meant, this is much better then dyno and as I say, there is nobody logging below 5 seconds...how can anyone make a claim of gain if they can't get even one or two tenths of a second
ya and that's what I meant, this is much better then dyno and as I say, there is nobody logging below 5 seconds...how can anyone make a claim of gain if they can't get even one or two tenths of a second
Well, rather than drawing out the argument forever. We have come to a logical explanation.
You are completely missing the point. You are not assuming that exhausts dont do anything. What does your '03 cobra have to do with any of this? BTW, I was just faxed this from someone who just had their GXP dynoed with the Magnaflow exhaust.
I guess he felt it was pointless trying to explain things to people on the forums.
The dyno chart you used for reference doesn't compare anything. I'm hoping that you're not claiming it to represent a comparison between a GXP with Catback vs the same GXP without Catback since the runs were made only 3 minutes and 6 seconds apart.
I'm sorry but I don't think you're going to remove a stock exhaust and replace it with a Catback in 3 minutes and 6 seconds.
If you're only showing peak rwhp; again it proves nothing since some cars are much weaker than others or vice versa.
Please clarify what you are trying to show with the dyno chart you posted.
Thanks
Current Mods:
1. K&N Drop-in Panel Air Filter (until problems w/CAI's get resolved)
2. Solo-Performance Street Race exhaust
3. BSR Tune
4. GMPP CAI Kit Planned Future Mods:
1. High Efficiency FMIC
2. Improved IC Tubes
3. Upgraded Turbocharger Kit from Hahn Racecraft and BSR Stage II or III Tune to accommodate the modifications.
The dyno chart you used for reference doesn't compare anything. I'm hoping that you're not claiming it to represent a comparison between a GXP with Catback vs the same GXP without Catback since the runs were made only 3 minutes and 6 seconds apart.
I'm sorry but I don't think you're going to remove a stock exhaust and replace it with a Catback in 3 minutes and 6 seconds.
If you're only showing peak rwhp; again it proves nothing since some cars are much weaker than others or vice versa.
Please clarify what you are trying to show with the dyno chart you posted.
Thanks
Both runs were a stock GXP with just Magnaflow exhaust. Again guys, there is no point arguing. Just like the whole explanation with the CAIs people are buying. We proved it over and over again on the dyno but people are still in denial. We proved it yet again at the Battle of the Kappas when we dynod a redline with the hood closed and with it opened. Have a nice day everyone!
It sounds like from what you have said, you've dealt with a few people on the phone at magnaflow that don't know either exactly what platform (standard 2.4 or turbo'ed 2.0) you were asking about or are just not informed. Trust me, I've called other mfg. before (ACT) about stuff and their tech guy knew little about the specifics of what I was asking... and gave wrong info accordingly. 6whp gain on a n/a car I can believe. 20whp on a turbo car I can believe as well.
In the dyno chart posted, there are two post-catback runs (unless the guy managed to install a cat-back in 4 minutes). That tells us nothing really. I see a light line on the chart which is not shown down below in the runs legend; is that the baseline? If so then there was a rather large increase in the lower part of the power band.
Second, I don't think you're being attacked here. I think if you get some more experience tuning with the turbo kappa ecu you will know there's a lot more at play with this ecu than the standard kappa ecu (completely different btw) It has a logic subsystem based on atmospheric conditions and limits boost accordingly. It has a torque management system that will limit overall torque, and a MAF that likes to cause the car to go limp at high mph runs. A boost control system that causes boost to taper off mid-range and then comes back up at top end. It's a real mess stock. The screen shot you show is of the N/A kappa, and the beta software I have of hptuners shows a completely different set of tables for torque management... so they're not the same system by any means. We are talking about the turbo kappas here I assume.
Lastly, I agree that without a tune, nobody will be able to take full advantage of the power a less restrictive cat-back, downpipe, or can provide. Yes, you can add me to the list of people who have had experience tuning and racing cars in both GM and Subaru worlds, as well as including hptuners for the GXP. Yes I did baseline my car at 230rwhp. No I haven't been back on the rollers since mods, but I'm sure I'm close to around 260 wheel now from a conservative 1/4 mph estimate. Should I be seeing more? I think so! With a good tune and less ECU restrictions I think 300whp is possible indeed! You wont get there though without a less restrictive cat-back, that's for sure.
I'd assume you'd have a before and after chart yourself to back up your claim but I haven't seen one yet. Remember the ecu needs to re-learn the increase in low end torque; a power robbing agressiveness I've never really seen until this new gxp.
Those dyno sheets are from my car.Everybody seems to think that the stock motor puts out about 216 whp stock. So if mine dynoed at 217 whp with the 3 " magnaflow, what would your guess be without the exhaust?About 190??? The exhaust had been on the car for approx. 800 miles,so had plenty of learning time I expected a little more, got a little less. No big deal. Just trying to show that there was no 30 hp gains. If its there i sure cant feel it. Maybe twords fall i'll put the stock exhaust back on and go try it again,just to keep everyone honest
I guess he felt it was pointless trying to explain things to people on the forums.
Did you also do a dyno before installing the exhaust? That would of answered a lot in this topic we're having.
Take a look at the dyno in my sig, thats the reason why i dont believe the 6hp gain you were told.
we have seen torque management bring power back from a 14whp gain to 6whp gain.
with some GREAT snark going at the end of the post;
Quote:
Originally Posted by rpipower
if you buy an exhaust from John at Hotexhaust, you'll get 22whp max and 30whp peak. If you buy a Magnaflow from us, you'll get about 6whp gain. Those who want the most power should buy it from Hotexhaust as they have the more powerful 3" systems.
then you answer some real life questions, this answers it best;
Quote:
Its the same thing we experience with the Lotus Elises. Headers, intake, exhaust will generally give a nice increase in power. The guys drive it around for a month or so and then their cars are dynoing less than stock. The ecu learned and made its adjustments.
Did you also do a dyno before installing the exhaust? That would of answered a lot in this topic we're having.
Take a look at the dyno in my sig, thats the reason why i dont believe the 6hp gain you were told.
Was that dyno done on your car, with you watching, and not a dyno from a vendor and their test vehicle?
I'm not saying your gains are false, but just curious.
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