I also have the Stillen stage 3 & am contemplating on purchasing the headers along with high flow cats.The only problem is that when I install the headers & cats,I will supposidly loose boost.I'd like to see some dyno runs from your car knowing you have the headers.Anyways,I love the power.I was able to beat the hell out of my SCed G35 at Willow Springs with no problems besides the glazing of all my rotors & the wear on my tires(which literally turned blue from the heat). I'm starting to think the hood & bumper aren't so bad after all.

 

You may lose a little boost but you will gain power from the header and cats . Dont go with the RT cats though . Alot a them going bad on this motor

 

you loose boost with a set of EL headers???

how does this translate into 'gaining power'?

i am on the header fence, yet again......

 

Thanks for posting your stock hp numbers. Was this done on the same dyno? If so it confirms my earlier statements.

Nice times by the way. I did a 13.1 at 104 (stock worn tires etc) my only time at the track with my Z. The main difference with me is that I had to (auto)shift at 4.5 rpms because the tcm didn't know what to do with the power of the S/C. Since than I have fixed the shifting (plus added some serious power) and will be looking for a low 12, maybe high 11 sec run.

 

The losing boost part isn't right. Do you really think guys would add a plenum and headers if it decreased boost? It would not make sense. 12 sec (AKA) Max has both headers and a plenum and is making more boost than me using a lower rated psi pulley.

I haven't heard this rumor since the ATI kit came out. Many thought that since they weren't making full boost that it was the fault of the plenum, headers or cats but has since been proven incorrect. There are many other resaons you may not be making full boost. Believe me I know, I am looking for them right now

I 110% agree about the RT cats...

 

btw, i am now at 8lbs solid, (although its revv-limiter time very soon thereafter!)

after some belt adjusting, and BOV adjusting, i was able to eclipse the 7 mark....

now, if that new puck would just get here.......

 

Yes this was done on the same dyno. Your car should be in the low 12's or high 11's for sure. good Luck...

 

esemes,
I'm glad you solved your PSI issue. It sounds like it could have been the bypass/blow off valve that was causing your problem. Hopefully mine is that simple.

DBZ33,
Thanks, it sounds like you will be there soon enough. What exhaust, headers, test pipes are you looking at? May I also reccomend a plenum...It also sounds like you need to get new tires I've been researching this lately as I have been told my tires are practically bald. Back in the supra days the best tires guys ran (street and track) were the BF kw/kd. They are not so good in the wet weather but they are amazing on dry pavement. There is a another tire made by Goodyear that is supposed to be almost as good in the dry weather but much better during rain. Its called the G3 something. Good luck and let me know if you want any advise on the other bolt ons.

 

whosdady...The guy thats tuned my car is the one who told me about the losing psi after header and exhaust install...He said he has seen it happen many times.....He told me he would dyno a guy and they would come back weeks later with a new exhaust and headers and dyno again.....but would be confused because they didnt make as much boost but made more hp . He has been tuning race cars for 25 years...so Im sure he has seen alot . Now if thats not the case here ...so be it...but I think it could be a possibility

 

boog--

i wonder if its due toi the ecu trying to return to a factory ideal range of operation....

with the piggy, can we keep fooling it (with headers?))

interesting; i will ask my tuner next week, when i remapp for the new goodies (got the belt today, but, the fatty gates is still longer than 93") (rated ½" shorter than the goodyear thinskin however......

 

Psi is basically a restriction of pressure in the intake manifold because the motor can only take so much boost in. So if u have better headers or intake manifold u should see less boost on ur gauge because there is more psi getting in and out of the motor hence the extra power u see regardless of the boost reading(most likely lower on a SC'd car). Most SC guys tend to put a smaller pulley to raise the boost levels after headers, cam, and intake manifold ,etc… because more air is entering the engine.

 

I agree with you 100% about this theory... If the pressure decreases enough this could happen. However, I don't think there are enough bolt ons (made for our car) effect that much pressure. Maybe it requires more boost or a car that has serious stock restictions like a V8 Mustang or Camero?

Booger, you are running basically test pipes since you hollowed out your RT cats. (This eliminated a lot of pressure) Did your boost go down? To my knowledge, all of the guys that thought they had this problem learned it was something else that was lowering the boost. If I'm not mistaken, esemes is putting an exhaust on his car soon and I would not predict a decrease in his boost. Ask your shop if they have seen this occur with a G or Z.

There is a guy in NC that has every bolt on possible (including cams) to free up pressure and he is boosting the highest PSI out of anyone with the stock 9pis pulley size. So go figure.

Again, I know this is theory is true for other cars but it is more like a rumor with the 350Z/G.

 

whosdady-- (what is your name anyway??lol)...

tomorrow i am installing the fuji exhaust and Y alomg with crawfoird h/f cats..... i havent gottent the new pulley in yet, so 'ill have a direct comparo to make on the boost readings.... (also will have the mapping fine tuned to further exploit the new exh. gas flow)..still no headers for now!

-eS

 

My first name is Scott. I kind of inherited the screen name as it was a joke back in college and my friends still refer to me by this sometimes. It has kind of stuck. My wife hates it Since my second child, my wife wants me to change it to imadady. I guess I still use it (whosdady) because it makes me laugh as well. Also a lot of others know me by this name on other forums.

I will bet money your boost doesn't change at all. With more mods maybe slightly at first but would probably adjust quickly. I don't mean to sound like that theory is impossible to occur but I have yet to see/hear about it on our cars.

 

i actually heard from a Z owner that he pulled 8.5lbs (stock vortech) with a catback.... (not sure if there were headers)

either way, im hoping for gains of some regard (even if only audible)

(scott here too)

anyway, i have drifted this topic out to sea....... wilson????



-eS

 

If the boost readings doesnt change after exhaust or headers install then u guys have a good set of stock headers and exhaust from the factory. What are the gains N/A from headers and exhaust to the wheels? I guess its around 10-20rwhp right?

 

Yes gains have been seen anywhere from 10-25rwhp from headers and exhaust on this car while N/A. With the plenum adding even more, when used in conjunction with the others.

I can take a piture of my old stock headers. They look poorly designed. Especailly when you put them next to a set of Crawford headers.

The stock exhaust is not much better but gains are shown there as well when you upgrade. I will take a wild guess and say esemes will gain about 12rwhp after exhaust and h/f cats from his stock dyno. (boost will stay the same right at 8 PSI) If he added headers, I think he would gain another 13rwhp on top of that and his boost would stay pegged at 8 PSI.

Again, every car reacts slightly different to mods (and some dynos are more generous or greedy than others) but that seems like the average I have seen.

 

I think my next mod is gonna be a 5' tall hi-flow fan (with trailer!!) to pull infront of my car at dyno shoot-outs......

:^)

 

That and a few bags of ice and also a little co2 or nos to spray on the intercooler

Just so you know, I have never used any of these items while dynoing my Z. But it was normal for guys to use this stuff while dynoing supras. Supras are notoriuos for being dyno queens. I have personally seen a couple supras make 900rwhp.

 

lol

hadnt thought of the ice......

maybe i can turn my car into a good humor mobile??

hey scott---

i just got off the phone w/ a company that will sell me the walbro 190l pump (new, with filter and o-ring) for 90$ shipped.....

thoughts on this fitting w/o shaving the clip??? i think ma upgrade this, to help ensure the new puck will be a smooth transition (even though im going to remap, i dont think i want to rely on the stock pump to pull fuel out of the tank anymore ... i know the aux unit will be okay, but im still limited by the effectiveness of the oem pickup)

-scott

ps- time to start a new thread, after my sstuff arives today (not even sure wtf this thread is about anymore!)