Dont feel too bad. I dynoed with the same mods as you and ONLY got 232 HP and 231 ft lbs!!

 

people were telling me that my 19s might make me lose power on the dyno dont really understand how but i guess so, ill know again for sure b/c im gna bring my car to the dyno on jan 22nd and see what it does but im gna buy an safc 2, BIG QUESTION do you guys think the safc2 will solve some problems for me or will i have wasted like 300 dollars, be honest please b/c im gna buy it this week if you guys think its worth it

 

I don't think wheels will change your peak HP much, just your accelleration HP

 

I think that the SAFC only modifies your AFR and nothing else. I think this would help you if your poor numbers were due to bad AFRs. Otherwise, it may not be a worthwhile mod. Dont take my word as I dont know very much about this topic. Like I said, I am experiencing similar results.

Do you have a 5AT or a 6MT?

Zach

 

Dynos measure hp by the speed/force your wheels/tires can rotate those cylinders on floor. The assumption is that the bigger the wheel, the heavier it is, and the more force is needed to rotate the cylinders, which results in a lower hp reading. I have not seen dyno results comparing wheel sizes/weights, but the theory is sound.

However, remember that hp numbers can vary for a number of reasons (machine calibration, room temperature, etc.), and that the number can vary as much as 30hp. Therefore, you shouldn't worry to much about how many hp your wheels are "losing" you, cause in the end the engine is making the SAME hp, it is just harder for the dyno to record it because of the heavier wheel, and ifyou were to take it to another dyno machine your number could be higher or lower. What you need to do is compare that dyno with future dynos done at the same dyno machine after youve done other mods. The difference between those dynos is relevant - comparing your dyno numbers to other Zs done in other machines is pointless...

 

I was told by my dyno guy that he uses DynoJet dynos because they're the most consistent from place to place. That that's why Nascar uses them cause they have to make sure their cars are within spec of the race they're doing.

Also I thought SAE correction factored in some of the temps, altitude, and air density stuff?

I'm trying to learn more.

Before going to the dyno I was happy with my car aside from the check engine light. A lot of guys with less or similar mods than me are putting down almost 30 more rwhp than me according to this site. That concerns me that something is wrong with my car - especially since I have a check engine light.

I know that mustang dynos give you a higher dyno number, but I was told it's more like 10 rwhp than dynojet.

A sorta interesting story happened when I was at the dyno. Some guy had some sorta mustang cobra and replaced the supercharger on it and went from 500-510hp and was pissed from such a small gain after spending thousands of dollars.

He sold the new supercharger to a friend who had a regular mustang while he went back to the stock supercharger. His friend started putting down 517hp with his "lower end" car.

I'm wondering if my engine is weak. One time I missed a shift and the RPM's mus've been at like 9k for about 2 sec. I've been running beyond lean for about a month now - detonating and not even knowing it. Maybe that weakened my engine and reduced my power?


maybe my car just sucks... "I need NOS"

 

my car is a 6mt, i feel a little better after what you guys have said but its like i love my car but its tempting to buy a corvette lol and mod and get more power you know, but i dont really know if i could get rid of my z im too obsessed with it haha

 

I have yet to see anyone make serious, repeatable power without doing some form of ECU upgrade...whether it's a reflash or a full replacement.

The engine has the potential to make good power in NA trim. Look at the Grand Am Cup cars...they make 80 hp more than stock. I don't believe they have any serious internal engine work done...just cams (possibly valve train, but I can't remember). They're running a full Motec ECU though, so they can extract power. That's the difference.

If you want to make it faster, start stripping weight off of the car. Every lb you shed will make it accelerate, turn, and stop better. In terms of acceleration...power to weight ratio is key...not taking gearing, etc. into account.

McDuck put this together ages ago...ratio is relevant column.

......CAR.........WEIGHT...HP....RATIO...PRICE.....POWER VALUE
Mustang SVT........3665....390....9.40....$33,300....0.320
Trans Am ('02).....3495....310...11.27....$28,025....0.316
Subura WRX........3085....227...13.59....$24,195....0.304
Honda S2000.......2810....240...11.71....$32,600....0.262
Porsche Boxter S..2911....258...11.28....$51,600....0.172
BMW M5..............4024....394...10.21....$70,400....0.139
911 Carrera 4S...3240....315...10.29....$81,800....0.119
911 Turbo...........3388....415....8.16...$116,200....0.105
Acura NSX 3.2L...3153....290...10.87....$89,000....0.103

E46 M3 3458/333= 10.38
300ZX TT 3480/300= 11.6
RSX Type S 2808/200= 14.04
MKIV Supra 3450/350=9.86
FD RX-7 2694/240= 11.22

Stock 350Z: 3200/287= 11.15 lbs. / hp
Put the Z on a diet, and factor in your extra 20 hp: 3000/307= 9.77 lbs. / hp. That would put you at a better ratio than most of the cars on this list...not too shabby if you ask me.

 

Honestly, your dyno results is what i would expect from the mods you have. Its been known that the 350z dont really respond to bolt on mods well without a ecu modification. If you had listed just your mods but not how much you dynoed, i would probably guess somewhere around 254-256 rwhp. So i dont really see anythign wrong with your dyno results. Your car is fine and doing what its suppose to do. I think you just had your hopes up too high on what your bolt on mods were going to do for you. A TS ecu reflash would give you atleast another 10-13 rwhp. Maybe even more. So i would look into that if i were u.

 

Those guys with 30hp more, was it measured on the same dyno you used? If not, any comparison is invalid. Also, if you are running lean, you absolutely need a reflash, according to what i have read.

 

yeah i'm still lean

TS bumped me around 2 points richer - still too lean

I gained about 8 or so HP in the midrange from that correction - and I can feel it cause it feels like the wheels wanna spin out earlier if I floor it in first (with stock tires they usually spin out around 5500rpm at WOT)

Now it feels more like 5000rpms

TS wrote me saying they can flash me back to stock, but that lots of customers have been getting misfire codes... I dunno who to believe. Flashing to stock is about the only thing that'll begin to properly troubleshoot my car - and also I could dyno without TS to see what the stock ECU does - bla

 

Wait a minute. Isn't the reflash supposed to correct the lean condition? What good is their reflash if it doesn't properly tune your car??? What did you get for your $600??? What good is a rev limit increase if my car is detonating?

 

I dynoed 231 RWHP on a dynojet with a pop-charger. A year later, dynoed 278 RWHP; same dynojet! Used an xede to tune A/F ratio's.

 

TS seems to want to be working with me to get the right A/F

I just wonder how many times it's going to take and how much more power they can give me

but I really do want to know what is actually CAUSING my engine to misfire. It sounds very suspicious to me that it started misfiring AFTER the TS flash

they said it was my tilton, but there's a lot of tilton drivers with no misfire code...

 

hey 287hp, i figure i should buy something to tune my car and iwas gna get teh safc but now im told my not do what i need, i want to tune my car so it can run normal, and be a little faster, but basically run normal and give more fuel to the car since im pushing alot more air then i was b4, what did the xede do for you ?????

 

you're one of theguys getting big NA numbers - you got 278 with your current mods with proper tuning? Or was that a year later with the popcharger still? I just want to double check cause maybe that dyno i'm using just isn't showing high numbers...

I figure most stock 6mt Z's are around 230ish give or take a few hp so your base dyno sounds dead on

 

The 278 was with all of the mods in my sig!

 

For those of you doubting the reflash, well your just plain wrong. This engine is very picky in N/A form as it relates to both timing and A/F ratio. Many of you are talking A/F, which yes has an impact, but so does timing. Once TS nails the flash, which needs to be tailored to your car with your mods, then you will see very good results. I dyno'd in the mid 270's with my 19s on and an A/F ratio in the low 12s. There was some timing advance as well. I sent the ECU back into TS and had them make some minor A/F changes and some timing adjustments. Unfortunately I haven't made it back to the same dyno as it is 11+hrs away, but I gained 3+ mph in the quarter and dropped 0.2seconds off my time slip. There is no doubt that proper tuning will make a difference. It is just not that easy to get it right through the mail. I personally was discouraged at first but kept working with TS, who was great to work with, and now I couldn't be happier. I had three flashes before it was where it is now.

As far as bigger heavier wheels go. It has been shown in quarter mile runs and on the dyno that they increase times and decrease HP/TQ read outs. By pushing more weight to the outside of the wheel, you are in effect increasing unsprung weight, which the rest of the drivetrain has to overcome. Smaller wheels will allow more HP/TQ to make it to the ground. A large yet light wheel is still worse than a small heavier, within reason, wheel because that weight is being pushed to the outer part of the wheel more.

 

Well. I got 276 rwhp with the mods in my sig (I don't have the camshafts yet) and no ECU reflash or tuning of any kind. However, comparing my number against anyone's number done on another dyno is completely POINTLESS. My car done in six different dynos will give me six different numbers which can vary as much as 30hp.

Since my A/F ratio numbers looked good and my hp numbers looked good and my car felt GREAT, I felt an ECU reflash was a $600 waste of good money. I have a 2004.5 with the newer ULEVII ECU. Don't know if that makes any difference, but I would definitely dyno and get good A/F readings before I assume a reflash will increase my hp numbers dramatically. And if I am off 10-15 hp from my "expectations", I wouldn't worry too much since that is well within the margin of discrepancy between dynos.

My $.02

 

very very well put ZBoater