Z1 Performance

iTrader: (564)

I'd almost put money that it would be a significant difference vs what you've got now. I got the ones I use on my car used in the classifieds here for a good price...maybe keep your eyes opened.

If it were my car though, I'd look strongly into having a proper set of long tubes done for you by a header builder that knows his stuff (there are quite a few out there...should be relatively easy to have done in your neck of the woods, though I suspect the person you find is more used to doing Vettes, Mustangs, Vipers, etc). In the NA world the relationship of the valve opening and closing, and the header are paramount above just about all else - don't underestimate it

Z1 Performance

iTrader: (564)

I hear what your saying, but look at what his torque curve looks like, and then for comparison look at mine. He makes a bit more peak but look at the shape of the curves - he's got alot more going on than a simple exhaust swap is going to fix Saying car A with a true dual pulled better than car B with a Y pipe + catback, even with identical mods, does not really prove anything. Take the same car, swap exhausts back to back on the same day, re-tune each, and redyno, and show me the results. I bet I can tell you what they will be. The sound will be different, the weight can be different, the look will be different, and the pull up top might be slightly different - but the differences are by no means night and day, or even significant. Certainly not to the point where there is a clear choice in my book. Everyones opinions might vary, and that's fine.

The idea of an H pipe based system certainly has its merits, which is why they have existed for so long with domestics - but it tends to do more to shift the curves around vs changing the out and out peak values, as you mentioned. But, in this case, it all starts with the header - its really important to get the header design matched to the cam.

Rednez - Was there any work done to the heads or were they used out of the box?

Finding the ideal exhaust diameter for a given application is relatively easy to do - rednezz, if you don't already have it, have someone buy you the Automath book for Christmas - its invaluable!

warmmilk

iTrader: (5)

why is there such a big torque dip around 2k rpm?

Hydrazine

iTrader: (53)

Gotta respectfully disagree here Adam.

Aside from what headers may or may not gain, I've dyno tested the Nismo Vs Stillen and the Nismo was not as good. Short by ~3 HP. And considering the Nismo is good for about +8 HP, 3 more HP is almost a 40% increase.

Nismo is a chambered muffler design whereas most other high performance exhausts are straight through designs.

If was looking to get the most HP for a dyno shoot out, I personally wouldn't be running a Nismo exhaust.

Z1 Performance

iTrader: (564)

you guys are missing what I am saying completely.

3 hp? We're talking about a ~1 % difference in overall power figures .

Tony, you can give me all the voodoo math ya want 8 whp, 11 whp...it's all the same oatbag. Show me where one exhaust makes 2 whp and another makes 20 whp and then you've got a difference worth mentioning IMHO

He can change it out if he wants...its his $. But his improper header selection is costing him big time - far more than 1%, and its affecting every single rpm point as well

rednezz

iTrader: (1)

The dips in the torque are caused by improper cam advance and the 3" MAF housing not completely fined tune...ran out of time. With proper cam advance the torque will smooth out...it was worse before we started tuning it. I just didn't have the correct advance angles when we were tuning it this Saturday to set them in and I didn't have alot of time on the dyno.

Z1...I will definitley see if I can look into someone making me some good headers. I know alot of domestic guys always get a good set of headers when doing cams...it really improves scavenging and wakes the motor up with a good cam.

Hydrazine

iTrader: (53)

I'm not arguing with with you Adam, but I never said anything about 20 HP.
Like I said earlier in the thread, there are a few more HP to be made.

If 294 is the current mark and 300 WHP is the goal, 3 more HP (that can be so easily made) is worth doing.

I would also bet that what is good for 3HP on a modestly modified Z Vs a heavily modified NA Z (like rednezz), that 3HP is more likely to be 4 or possibly more.

If I were Rednezz, I would change the exhaust out and also research better headers.

As you already know, it takes a lot of work and $$$ to get into the 300's. With Rednezz being this close to the elusive 300 WHP mark, its a relatively easy and low cost change to make.

TheJerk

I'm having this same (respectable) argument with Adam right now. I'm not sure what is right anymore.

Z1 Performance

iTrader: (564)

Again, you're completely misunderstanding what I am writing....go back and re-read

A 3 whp change is so small its not even worth mentioning IMHO - you're going to tell me that swapping out exhausts, be it $500 or $1000 for 3 whp is a worthwhile change to make? He could unplug the ecu, go out to lunch, come back and redyno the car and see a 3 whp change also, and that doesn't cost him anything. There are other, more important reasons I suspect his car is not putting down what it should given his parts - the header is one such area, and is going to net a FAR bigger change than swapping one exhaust for another IMHO. The right header to cam relationship is absolutely essential, and right now, he doesn't have it.

His car, on paper, should be making significantly more power than mine given his heads (larger valves), and his cams, and his dyno (Dynojet vs mine being on a Dyno Dynamics). My point is that there are important reasons I am sure it's not eclipsing mine, and the exhaust he is running is at the bottom of the list as far as I'm concerned

I've been around these cars long enough to know one thing - the exhaust choice you make, be it a true dual or a Y pipe + catback, in the grand scheme of things is a minor differential in power, both under and over the curve. That is not to say there may not be a difference, but it is so miniscule, it's not important in my book. I am not running a true dual on my car - and given my dyno, my car isn't asking for one either (nor would I install one, as they are too heavy, and I can't stand how they sound or look)

TheJerk

2.5inches or Greater have shown great results on these cars. Throw in a Higher red line, some tuning, and I could see more than "3hp" being made. Not to mention a better overall powerband.

Audible Mayhem

iTrader: (48)

to solve it, all you have to do is unbolt the exhaust at the end of the y pipe and then unbolt the y pipe on the dyno.

i think i am going to build another NA motor here soon

rednezz

iTrader: (1)

Thats what I plan on doing...as soon as I get a chance.

Hydrazine

iTrader: (53)

Yes, I did go back and re-read. Maybey you misunderstood what I wrote?
Your point evolved from the first (and my only) point of contention. I said changing out the Nismo would be worth a few more HP and you wrote:

That's what I disagreed with. We don't disagree about headers, and without digressing from the Nismo exhaust, my point was to offer Rednezz advice on what he can do to get closer to the 300 WHP mark.

Changing the Nismo out is good for a few more HP.
If you don't agree with that... well... we disagree.

Hydrazine

iTrader: (53)

Run open test pipes and HP above 2500 RPM will jump up real nice.
Good for another 10+HP.

And insanely loud!

Z1 Performance

iTrader: (564)

Good, we're back on the same page

I'm a firm believer in changing things only when they need changing. The NISMO exhaust will support all the NA power rednezz's car will put out IMHO. It is not the bottleneck in his setup IMHO.

I look at it like this - if there was a widget on the market being sold for $700 that made 5 whp, proven on a variety of different dynos, with a sampling of 50 cars, I still would not consider it a worthwhile mod. I look at the true dual vs Y pipe + catback scenario the same way: 6 of one thing, half dozen of another.

rbfd

iTrader: (18)

Not to high jack the thread but there seems to be alot of knowledge being tossed around in this thread. Z1, You seem to know alot about the cam to header relationship and how they effect the cars overall power. I have the Nismo R cams and Nismo headers, when I go to tune my set up probably via OSIRIS are these two parts going to work well together? I am running a MUCH smaller cam than Rednezz so should the nismo headers, which im guessing were designed to work with the nismo cams, going to help or hurt me? Is Z1 offering and NA engine building services yet? You seem to know a good amount of very in depth information that most other shops brush off.

1cockyZ

iTrader: (46)

287 lower plenum. Go back and check when audiblemayhem did his na build peaked at 6200 swapped in revup lower and changed the whole curve. I am not saying use a revup lower but an mrev2 or even 1/2" spacer. I mean those two things make more power on cars without cams, heads, or higher cr. Is the exhaust a restriction? its 4 bolts to undo the y pipe. I am going to throw the nismo exhaust is a restriction crew under the bus, how come those LS1 f body guys can't make power with those stupid 3" single exhaust with a chambered rear muffler with dual outlets. I mean over 500rwhp with 3" pipe, flow is flow. 5hp or 6hp back to back on a dyno on a 300hp car 5 or 6 hp is acceptable error. If the best run was 294 what were the rest? I want you to break 300 it helps the rest of us save time and money everytime someone does cause it rules out what works and doesn't. Good luck

Z1 Performance

iTrader: (564)

we will not be offering any built motors, sorry - we just sell parts, we have no interest in offering fully built solutions.

the general Nismo R tune cams will work well with the Nismo headers yes

I'd still recommend a UTEC for tuning - I am not an advocate of mail order based retuning

__jb

iTrader: (3)

Congratulations on your 294 horsepower dyno run. That's amazing for an NA VQ!

If you decide to get a set of Crawford headers, you might want to order them with the Jet-Hot coating. Doug offers Jet-Hot coating as an option and sends the headers out as part of the deal.

I have Crawford headers with the Jet-Hot coating and like them a lot. I'm probably nowhere near your horsepower level, but I'm working on it.

TheJerk

This is stupid logic.

A Bottle neck is a Bottle neck. I never understood someone saying Things like "in your build, its not worth it" The Nismo Exhaust most likely doesn't make power, and as RPM rise, he could be losing out on a broader power curve. I'm with Tony and Alberto on this one (big surprise)