Mine was just a cat back... I don't think test pipes would benefit much just because you would loose back pressure I would assume... I am not sure but just guessing...

 

Mine was just a cat back... I don't think test pipes would benefit much just because you would loose back pressure I would assume... I am not sure but just guessing...

 

The biggest loss on the HR exhaust is the stock cats. Replace those with HFC or test pipes and you will get a good gain.

 

If I could find some used ones in good condition for the right price I would pick em up.

 

well honestly I haven't seen anybody using osiris with the same setup A.H. is running. (headers, test pipes, exhaust, injens)

you can "squeeze" some extra power on the dyno running a bit leaner, something that you want to avoid if you track your car.

on the other hand.. to compare apple to apple... you should dyno on the same dyno. both baseline (better the same day) and both tuned (again better the same day) because is not about absolute power, it's about gains.

a car like a Z could have a tolerance of +-5% in the baseline performance and still be considered good for production. and with that kind of WHP we are talking of a range a little short of 30whp.

 

Well eventually my car will have all those mods (not sure on the headers though), but everything else. My car is getting dynoed and the tune adjusted for the HFCs since I had them installed this Sunday at UPREV. The HFCs did something to my A/F that is causing it to act a bit hesitate at low rpms now.

And it is about the mean average of the power. If you gain more power over the mean average of the power curve, your car will be faster. PEAK power means nothing if it only gains at the peak area of the power band but you gained nothing throughout the powerband. So your car is really not faster. The car with the most mean average gain throughout the powerband will be the faster car.

 

Key = used part of the power band. If you are on a road course with slow corners that is true, if you are on a high speed course or a drag strip, anything below 4500 can pretty well be ignored because you downshift and avoid those RPM's.

 

There is a reason why the Motordyne spacers work so well on these cars and his products. Because he uses the mean average and gets power throughout the powerband, not just peak power. And it does show in the 1/4.

Peak power is near redline on our cars anyways, if you wanted more peak, it would only be near redline and that doesn't last very long, maybe 1 sec.

 

even with fast corners you still don't know... depends on the speed you can keep on the gear and which is going to be the exit speed.
and in high gears the 350z isn't that great as ratio.

if I remember correctly you hit 210/220 in 4th and way over 250 in 5th... the 6th is there only for fuel economy.

except in some cases when you decide to use 3rd gear instead of 2nd (slipping, more control, bla bla bla) where the powerband around 3K rpm could be really useful... you still run over 4K anywhere

and you want to have good power there around... peak at 7K doesn't really help. unless you like the VTAK!

something that I'd like to see, will be using the SG performance long tube stepped headers. but they are in dev for the VQ35DE, so I can see fitment issues for the HR.
that, with a nice set of matched cams will be really nice to have the engine breathing right.

even if you get 320 whp with a nice powerband you'll have enough power on the track to mess with a lot of cars...

 

I was waiting for you to test with them... than I can tune my superloud nismo!

 

So let me get this straight..

you put down 281whp before the tune..

and then after the tune you put down 283whp??

 

We don't know what my actual base line is being that I didn't base line with the stock exhaust. I am going back on the dyno when and if I can find some cat's or nitrous. Your not going to see huge crazy gains if your pretty stock. The factory tune starts get thrown out of wack when you have a few more mods then just a cat back.

 

If i remember reading correctly that a stock HR dyno at around 260-267??

 

260hp is the norm for a HR.

 

So, the point is to get 28X just from a cat back and tune is pretty freak en awesome! That is why i said i wonder what it would do with test pipes added to it.


edit: I also think maybe with the test pipes it could be possible to reach into the 29X area.

 

I just got back in from UPREV in Austin, TX. WOW! What a day.

My car has officially woken up. The HFCs I got caused my car to lean out a bit too much. Remember my stock tune with K&N's drop ins was 260hp back when I had it done, I forget the TQ off hand but high 220s.

My first dyno today was 265 and low 230s tq. After they adjusted my car for the cats, it went up to 273 hp and 245 tq on a hot car after running back to back dyno runs with no cool down. The car made a good amount of power from just the cats!

We had two other NISMO's like mine. One was stock, the other had a NISMO intake. Both dynoed identical to each other 254-255 hp, and 225~ tq for stock other than the intake on that one which did nothing other than screw up his A/F. He needs a tune. So comparing my car to theirs the same day, my car is making 20 hp more and around 25 more ft of tq over stock! And this is peak. It gained throughout the whole rpm range.

15% drivetrain loss this is around 346~ hp to the crank. I am happy. No dyno sheet yet till they email it to me. They had many other dyno runs to finish that day.

 

^ nice..so how much would it cost me if I wanted to get the same tune you got?

I'm not interested in different maps and all that mess, just thought it would be nice to adjust my a/f ratio..

 

I am not exactly sure. Their pricing confuses me a little.

I think $400 or the $700 package depending what you want. It's on their website.

The different maps come with the package. That is the way it goes.

 

basically you got 7 peak hp and 15 tq retuning for the hfc... that's not bad.

 

Just a update guys about my Dyno Sheet.

UPREV is having difficulty getting me my dynosheets where I can view them properly. They are in contact with the Dyno people to resolve the problem. Once I get my dynosheet I will post it up!

So please be patient on the PMs.