I agree, but the first time I dynoed my car (stock), it turned only 228rwhp. Seemed very low for a 6MT car, but it ran just as good as any other stock Z.

When we did my extensive NA mods (cams, exhaust, etc), I only hit low 260s for power. I was a bit ticked at first since others were hitting 270 - 280s. But, 260-228 = 32hp gain. 280-245 (more typical stock dyno) = 35hp gain. So, I determined the dyno I went to was just reading low. No biggie.

That's why I think we really need to see zachcrosen's stock numbers.

 

Yeah. I guess i will be in the same pickle if i ever do a dyno, cause i didn't have one stock. But i have felt an increase in power. I guess Zach should try another dyno and see how his numbers compare.

 

First one is 12-03-04, second is 12-06-04. At peak, you gained 5 rwhp and peak 9 tq. Your air/fuel ratio is fine. You gained serious torque between 3,750 rpm to 5,000 rpm after header installation. Eyeballing, it's about 30-35 torque. That is a huge gain.

Running an automatic, you will have significant drivetrain loss. I don't remember the exact numbers but it's about 15-20% loss when compared to 6MT. Overall, I don't see any loss, I see great gains.

You probably should get a technosquare at this point because of the quantity of your mods to clean everything up.

 

Oh, and, unless I'm missing something, I think you owe Z1 an apology.

 

hfm brings up a good point... header gains are going to be much more prevalent (as shown in the dynos) at the low end, not as peak numbers.

 

Yes. If you look at 3,500 rpm for 12-3-04 tq was at 175. On 12-06- 04 tq was at 200, that's 25 tq right from there. Zach gained so much tq that the hp/tq nexus moves from 4,700 rpm on 12-03-04 to 5,100 rpm on 12-06-05.

The 5 rwhp peak gain is exactly what I would expect from adding a header to previous intake/exhaust mods. And, this header clearly added great gobs of torque from 3,500 to 5,100 rpm. The final numbers are right about what I would expect from a 4AT with those mods.

Zach, you should be very pleased with that header installation. I would be.

 

I have heard from many companys that the drivetrain loss on a auto is around 10-15%, that being that most of them are about 10%. I had a auto turbo civic and dynoed it with my friends manual turbo civic that had all the same stuff as me at the time and I only dynoed 8hp and 5tq away from what he did. There was one difference through actually, he had a stage 3 clutch and I had a Level Ten torque converter. Mostly the same through. I would try dynoing it at 3rd and 4th and try out a couple of things. Did you reaset your ecu after all the installs. I have heard that helps.

 

They are not equal lenght right? You will gain mor epower with equal lenght headers, do you have a y-pipe also?

 

actually if you look at the torque side of the graph the numbers are not the same as on the hp side, at 3500 rpm for 12/3 was a little over 200 maybe 205 and on 12/6 at 3500 rpm it was just a hair under 215...still a good gain about 10.... this is why i don't like charts where they are not scaled the same cause it makes it look alot different than it really is... not tryin to be an *** or anything but i thought the same thing until i looked at the numbers on the torque side compared to those on the hp side, this is also the reason that they do not cross at 5250

 

So Zach, let me ask this: Can you FEEL any power increase? Personally, I will probably NEVER dyno my car but as long I can tell on the road, in real word situations, that my car is pulling stronger then the mods are worth it. Numbers are fine but if they don't translate into noticable gains on the street then I don't really care about them. Looks as if you should've picked up some good low end punch. Is that right?

 

and Zach, as far as the numbers being low, thats how Z1's machine measures. At their dyno day competition during their car show, several of us who normally dyno at another local shop dynod 10-25hp less on theirs. (I was WAY down, but can't count mine due to worn rings, however the 3 other guys were a consistent 8-10% below their normal dynos at the other shop.

 

How's the sound after the header install? I think $230 shipped for that much of a torque increase is well worth the money.

btw, I was under the assumption that n/a Z's dont react well if there is not enough back pressure?

 

Actually, you need to look at the plottings again as the rpm scale is not the same on each graph. There are still gains, just not as impressive as you mentioned above.

So far there has been a lot of BS flying around these threads. The drivetrain loss of the 5AT is not verified information. Do you know anyone who has dynoed their car with the AT, then installed the MT and redynoed on the same dyno with the same conditions? I didn't think so. Maybe my car is odd, but the only time I had it dynoed, I put down nearly identical numbers to a 6MT with nearly the same mods on the same dyno. Not exactly proof, but it makes me wonder if there is that 5-10% difference people want to think exists.

Back pressure and test pipes - the header design is the most important part of the exhaust. Once the exhaust gases make it past the headers, you want the least amount of resistance possible to make good HP. Different exhaust designs simply shift the HP/TQ curve, test pipes could decrease low end torque if a poor header design is on the car or if the A/F ratio is not correct after the install. If you look at serious drag cars, they have headers only with no other exhaust components!!

This car is particular about timing, especially the 5AT cars. From the experiences I have heard of, there seems to be massive timing that is getting pulled while some 5AT cars are on the dyno in 4th gear. Some have been able to dyno in 3rd gear and not have this occur. I had an ECU reflash when I dynoed so I did not run into this problem. I know of one person who couldn't even reach redline due to so much timing being pulled by the ECU. All of the cars I am speaking of had a number of mods but no ECU reflash. It would be nice if you could dyno with Consult II hooked up to see exactly what is happening to your timing. It should at least be in the upper 20s. Some of these guys had timing pulled back in the lower teens. That kind of timing retard is much like the torque management system that kills power by 30% when the ECU senses the brake and throttle being applied at the same time.

 

Please explain why I owe Z1 an appology? I never said anything negative about them nor will I. Lorca, Russel and John are great guys to work with. Like I said, explain why I owe them an appology.

 

No I dont have a Y pipe. I have the Injen true dual.

I dont know if they were equal length or not. I didnt look. I know the TopSpeed headers are identical to the DC Sports headers in that they have visually identical bends.

I think the car is a little louder after the install.

 

Here is a pic of the TopSpeed headers that I just installed.

Member Llare on here dynoed with the Injen dual exhaust (same as me), a popcharger and high flow cats. He then dynoed after the header install and gained 10 HP and 15 ft/lbs. And these gains were after 3 others mods were already done. Correct me if I am wrong here, but the more mods you have, the less cumulative gains you will see with each additional mod(law of diminishing returns). I have a vid of this dyno run with the TopSpeed headers installed if anyone would like for me to email it to you.

Thanks for all the constructive comments so far.

 

hey zachcrosen could you email me that video vanismo@aol.com, i'd like to see how it sounds since i'm getting the injen too and have hi flow cats. I'm waiting on the exhaust to get in before i install the headers. how's the car feel since you got it back?

 

So cool to see all you knowledgeable tuners weighing in.

 

I took this as a dig:

From what I've seen the people at Z1 know what they're doing. Saying that Z1 don't have a clue looked like a dig. If you have a good relationship and I misunderstood, then you obviously don't owe an apology.

 

I'll have to look at the graphs again later, been out drinking.

No, I don't know anyone who had an AT and installed the MT and redynoed. I don't think I've heard anyone who has done that and I suppose neither have you and so the question was answered before it was asked.

That is my understanding, it's supported by multiple dynos in California where MTs and ATs do their dynos at the same shop on the same day. If I'm mistaken, sorry, like I said, I don't know the precise drivetrain loss between AT and MT but those are the rumored numbers.