this is sounding promising!!!

 

The newly designed headers work!!

I gained almost all of my lost lowend tq/hp. I think I lost 3-5 hp/tq down low and up top with the new headers nothing you can really feel, but losing 15-20 you can feel.

Went to the track last week with the old design in warm weather I couldn't go faster than 13.9@102 with 2.2-2.3 60fts. Modded 350Zs were only trapping 97-98 that night for comparison.

The fastest I've went with the old headers was 13.5@105 with slicks in cold weather.

I went again last night with the new headers in the same weather conditions my slowest was 13.8@102 and my fastest was 13.4@104.

My slowest 60ft was 2.13 and my fastest on street tires was 2.05 for the night.

The final numbers were almost the same 271/241 with new headers and 272/242 with the old headers.

I will post up the dynos later, I have sheets comparing new to old, new to before LTH w/cams installed, and new to before cams and LTH.

 

So you are saying that you restored your bottom end to levels comparable with the momentum headers and art pipes while maintaining the top end in comparison to the other PPE headers?

 

yes

 

new headers vs momentum headers, ART pipes, stock cams


non-stepped 1 3/4 vs stepped 1 3/4- 1 7/8. I lost my lowend with the stepped headers


new headers vs momentum, ART pipes JWT cams



new headers no step

 

This all looks great. It seems to me that the latter design is much better for your application... And perhaps mine as well. But, I can't help but wonder if the intake manifold and S1's weren't well matched to the last set of headers. I wonder if they have a place on a more radical VQ... Say a cosworth intake equipped engine with C8/C8R's. As an auto driver u would need a helluva converter to get out of the hole with that. As an 6m guy, I think it would be fun.

 

Good results and glad to hear you are back to a state you are happy with. That merge collector you have there looks very similar in design to the one that SG uses, expanding from what looks like a 2.25 to 2.5. I wonder if that is more the culprit rather than the stepping.

I am really surprised that the lowend affected your quarter mile time and trap speed by that much. Perhaps it's because you are auto.

 

Furthermore, I say this because you lose a lot of area under the curve in the low end with the step headers that I don't see even remotely being redistributed to the top end anywhere. It just seems that our intake system tapers off after 6300. Even stock revups do it, though its not as pronounced. I have decided to get a set of these, but I just have to figure out which ones. I really wonder if I would be better off with the first set and a cosworth, or your current set with my mrev2+spacer. The car is a nitrous car for now... it seems that your current setup would kill it on the spray in the 3500-6500 range... as would mine... the gains over the momentum's and art pipes ARE the vast majority of that powerband haha.

 

My theory is that the intake is limiting - and because of the 60* bend it makes coming into the manifold. A much better design would significantly help. Seems like this was Sasha's conclusion when he redisgned his upper manifold as well.

I like your gains here - the non-stepped def look to have much better low-mid and keep the top end the same. Looks like a winning design

 

Yes it is similar to SG 2.25 expanding to 2.5. I can't launch higher than the lowend drop 6mt will have no problem.

Gabe try launching with 15-25tq/hp less from your launch RPM you will be slower.

Before installing the new headers I installed collector reducers and saw gains. I'll post that sheet up later.

 

In regards to the intake being the limiting factor, I couldn't agree more. I'm looking at all sorts of options. I know there is that LS2 tb made by hitachi that is "plug and play" at least in regards to function... the connector may have to be swapped... i really dont know for sure. i just remember reading about it on my350z. combine that with the front mount tb mount version of the cjm intake and you have something that wont fall on its face at 6500. I'd really like to develop a 7000-7500rpm capable combination and spray/boost the **** out of it. would i spend 3k on an intake manifold... well yes, if it allowed me to make power with my current shortblock by revving as opposed to having to build significantly bigger in terms of displacement. that, and i would already have a fantastic intake foundation when i went to boost it. the only issue i see here is plenum volume... optimizing it for na or fi kinda screws you while doing the other.

 

are both sets of headers going to be available for purchase through ppe? what did you do with the prototype ppe stepped headers?

 

I installed my PPE headers today. They are the original prototype design with the step. I can't say I noticed any low end loss, they feel great on top end though. I will be going in for a re-tune soon, just wanna change plugs first.

I'm also still on stock cams, the Tomei 272s will have to wait and collect dust for a bit. I decided I'm going to be replacing my motor. My current one suffers from too much oil consumption, and I'd like to have a stronger bottom end so I can rev to 8k rpm.

 

REALLY interested to see what these do on a DE with stock cams. Even better would be if you had gotten a before dyno to compare the PPEs to the Nismo headers/ART pipe combo.

 

i just wanted to make it known that there is a group buy going on for these headers on my350z.... there seemed to be a lot of interest over here... i need three more...
http://my350z.com/forum/intake-exhau...s-finally.html