Jamie@dundonmotorsports

Akra's race setup results on 991 GT3 show about 10-12whp gain

http://www.akrapovic-shop.de/akrapov...tion-race.html

GT3 KSA

That would mean my car at stock in 4th gear would show about 411 whp and in 5th show 422 whp. I am sure everyone finds those numbers hard to believe for a stock GT3.

According to Akra's website it is 26 hp gains to the engine and 37 tq gains to the engine, which if converted i believe give about 22 whp and 31 whp. I normally don't believe website numbers but if we did then that would mean in 4th my car at stock would be at 401 whp. I am just a consumer and i have only had my car for a month. I am probably the least knowledgable person on this forum. This is why before i posted my numbers, i was asking what are realistic stock GT3 numbers on a mustang dyno

I doubt running Motul oil and installing BMC air filters gave me gains but if they did then great! I am also not trying to say this system is better than X, Y or Z i am merely sharing the numbers it put down in case anyone wanted to go for this system they have an idea.

I was surprised myself when i saw the numbers but then again i don't have a baseline ... until then i can't really know what gains did i get

Jamie@dundonmotorsports

This is from there website for the akra race setup.

DATA

UNIT STOCK AKRAPOVIČ MAX GAIN
maximum
power
HP (m) 470.0 / 8450 rpm 481.6 / 8400 rpm + 27.1 / 3950
HP (i) 463.6 / 8450 rpm 475.0 / 8400 rpm + 26.7 / 3950 rpm

maximum
torque
lb-ft 314.3 / 6450 rpm 322.1 / 6400 rpm + 37.3 / 3900 rpm


Notice the rpm quoted. 8450rpm HP gain is 11 bhp. The numbers you're quoting are at 3950rpm and partly due to the lack of flaps on the race system.

If akra made 60whp over stock they would shout it from the roof tops...

I think more likely is that the dyno is reading a little optimistically. Hopefully someone with a stock car can help you and run on the dyno for a baseline!

GT3 KSA

The max gains according to Akras site are at around 3950 for hp like you said and 3900 for tq. This would explain why i felt the mid range having much more power than before.

My ultimate goal is to achieve 500-520 hp at the crank and 350-370 tq at the crank, so you can imagine the feeling i got when i saw the dyno numbers on Saturday but right away i said it can't be possible that i hit my goal that easily.

I am sure nobody is as obsessed with finding out the DELTA more than i am. I will not tune the car until i can compare my current numbers with a stock GT3.

I am sure you and Charles are probably thinking, if that was his goal, he should have just bought our headers but like i said, the reason i went with this system is it was already here, got an awesome deal on it and mainly was able to get it installed while i was on vacation out of the country. Not to mention the weight savings and some hp / tq gains as well.

It made sense for me and that is why i went for it. Now the mission is to find a stock GT3. Will keep everyone posted when and if that ever happens.

PS Dumb question but is 11 bhp the same as 11 whp?

Charles@dundonmotorsports

really the number the dyno puts out is pointless. The % gain is all you need to know.

11bhp is crank engine hp. Whp is after drivetrain loss. 11bhp will show to be about 8whp in the dyno I use. May show as 9-10whp in the one you used.

If a dyno reads really low then the power gains will be low. If the dyno reads high then the gains will be high. Again the number does not really matter.

If your baselines say 250whp, and you install the akra, 11bhp will be about 5whp so it will show 255whp. +5whp

If you baselines 398whp, install and 11bhp means 406whp +8whp

If you baselines 424whp and install, then that 11bhp means 433whp. +9whp

All of those gains are different numbers, but you will notice that no matter what the HP number is, the gain is still 2%

This is my theory on why so many dynos are not calibrated and read high. People like to see huge numbers and huge gains no matter what. It's just human nature that people want to see huge gains and think that their car is making more power than everyone else's. I should call these dyno heart breakers as when those cars run against ones that have "less power" a lot of the times they are proven to be much slower than said to be.

Nick Yoskin

HERE IS WHAT I HAVE ALWAYS SAID ABOUT DYNO NUMBERS

"DYNO NUMBERS ARE ONLY GOOD FOR SELLING PARTS!"

Sorry for the yelling but its common for a newbie to get all caught up in the #s.
This is why I have said repeatedly, take it to the dragstrip or use a VBox. Thosse numbers don't lie.

OK I will leave now.


Nick

Charles@dundonmotorsports

Jamie has one now i believe and he is heading to the track with a few other cars, maybe we can get some good video footage on friday

911_RS

Dyno numbers can be confusing... I'm looking forward to a more conservative dyno chart, that's more accurate and doesn't lie just to make the customer smile and think the gains are huge. So what I did was I went head to head with a 458 Speciale (605hp 1,300kg) and surprisingly I pulled off at least 3 cars! I even let him jump start and still same result... So right now dyno charts didn't really matter for me, I'm now a 100% sure that the car is faster and drives way better than before. Even though I knew that from the moment I left the shop with the DMS system, it made it more legit after racing the Speciale. Too bad no videos, I'll try out another Speciale (with full catless exhaust) really soon!

Jamie@dundonmotorsports

Sent it to Matt, I can hook up my Aim Solo and get the the same acceleration results, just not against altitude....

GT3 KSA

well I did race a v12 Ferrari 599 on Saturday. No idea if my GT3 at stock is supposed to be faster or slower though. He beat me a few times and I beat him a few times but most of the time we were neck and neck. The problem was we were counting while on the phone with each other but there was always a delay so before he would say "go" I would see him already going forward. We tried a few with the honks but because our cars were so loud again I would see him go before I hear the 3rd honk. We did not find a "light" to settle it but again I don't know the stats of his car

Charles@dundonmotorsports

with high HP cars, you will have to be comparing at higher speeds, such as 80-160+. At lower speeds the HP differences are minimal by comparison. I mean a 400hp car can do 0-60 in 4.0 seconds flat and a 750hp car can do 0-60 in 3.0, then you can find a 420hp car that can do 0-60 in 3.3, those few tenths of a second are just a few feet difference in distance.

Going from say 60MPH up to 160-180MPH is a much better, more comparable difference, and any "slight jump" shouldnt matter, if someone jumps and pulls half a car ahead, if the cars are same HP performance wise, then that 1/2 car difference will stay there, if the car that got a 1/2 car jump pulls 5 more cars ahead, then the jump really didnt matter as he only pulled 4 1/2 lets say. but if the other way around, the other car pulls 1/2 car jump at the start, and you wind up pulling away from him, that is a feat.

When they are the same or give or take its hard to say And anything from lower speed below 60mph is just a waste, so many varriables that just a little will throw it off. The only thing that wiill kill top end comparisons is if your car has A LOT of drag or A LOT of downforce (like a 991RS)

GT3ZZZ

Do you have any CEL with this setup?

GT3 KSA

Actually we did race from about 30 km to 200 km the gap stayed pretty much the same but i would feel like i would close in on him more and more even when he got the jump but when i got the jump i felt the gap did not get any smaller.

Anyway i'm not in a rush the hp / tq gain numbers will come sooner or later

Charles@dundonmotorsports

exactly, it ill happen. If you are happy with this setup then that is all that matters, if you decide later that you want more power, you know how to get a hold of Jamie or myself we have a lot more stuff in the works....

fxz

and with Charles you'll have for 7k a custom obesessed hand made exhaust rather than a fit for all exhaust of course made in titanium (which one btw? there are low cost titanium as well as those i used in my bike frames in the past
)