1999 Nissan Maxima SE-L
Car Now Has 103,993 miles on it
Car is a California Spec car
JWT Popcharger
Sun Automobile Hyperground System
Warpspeed Y-pipe
Catco High-Flow Cat.
Greddy SP Catback
Car Ran 15.129@93.12MPH prior to exhaust install
Run Conditions 86.26 degrees F,29.82 in-Hg, SAE: 1.01
176.03WHP@5500RPM
190.86WTQ@4500RPM



So obviously i was very upset and decided to trade the car in because i hated it. went to nissan. worked out a great deal they were going to give me $7500 for the max. $2500 down and 4% financing, payments were $186 a month.
Then it happened i test drove it. interior was very cheap looking, i could feel the power diffrence and i was like what am i thinking so i kept the maxima. i did envy the SE-R's brembo brakes and limited slip but the interior quality is terrible. cheap looking. so my question is WHY is my car so WEAK i should have 185whp like everyone else. anyone have any idea why this thing hates me and i love it so much. all i want is my 10whp or are cali spec cars just weaker?

 

Is your knock sensor dead?

 

No knock sensor is brand new
car had a full tune up
New Plugs- NGK Platinums
Coolant flush
Oil changed

Car runs respectable 1/4 mile times does't know why it is so weak

 

Ever think it was the dyno? Your TQ seems right.

 

it wasn't the dyno my brothers 6speed G35 coupe laid down 240WHP and 235WTQ dead on what it shoudl be stock

does anyone know what calispec cars with my mods lay down?

 

You are about 6-8hp off max.

How old is your Air filter? and Fuel Filter? Also what kind of gas are you using.

 

ur numbers seem right could have been weather or anything holding just a lil bit back...what was ur AFR

 

Looks completely normal to me. I don't see why you're so upset. Your ET/MPH seem normal too. Are you really worried about 3-4whp? Seriously, most 5 speed Maximas with your mods put down ~178-180whp/188-190wtq. Simply hot weather could be causing such a minimal loss.

 

i guess you guys are right. but if you guys coud see how well i take care of this thing you would know what i am talking about.
i average about 22MPG city and highway driving and i drive very agressively.
that was what i forgot the fuel filter was also replaced when the tuneup was done.

the air fuel ratios are on the same graph
i was told by the air fuel guys that if i could adjust my airfuel to 13:1 i could pick up some hp if you can look at the graph its down at about 12:1 most of the run

i am thing maybe because my car is a 99 may my coil packs are bad, the car has no check engine lights or any sort of issuse, runs and drive great. i just wanted 180+ whp like all the other guys.

 

Who cares what a dyno says? Really, a dyno is used for comparing modifications on the same car, not comparing what another maxima happend to dyno somewhere else. It's all relative.

 

you wanna get ore HP, get a MEVI or a VQ35.
there I garantee you will get alot more then 8fwhp
my car is doing 165fwhp and 177tq, I'm happy with it right now, because I have a 33.5 mpg HYW fuel economy.
BTW I was at the maxima dyno meet this past spring, I remeber you, but I think you should keep you maxima. and get the MEVI. then we can both install it and help each others.

BTW I'm getting a MEVI

Man this was my most confusind post I ever posted.

 

yeah MEVI is not in my future due to the lack of way to raise the REV limit and restore the low end that may be depleted. i love the torque. the thing pulls hard. i guess over all i am happy. i am hoping SSR does that inttake manifold i would get it. i really wish i could do 200whp NA but 24hp is alot to go and i am outta mods other than. under drive pulley except for cams and headers which are more than i am willing to spend for what they will give condering they may be $3000 combined when installation is added in. i may just get nos. i was looking at the ZEX 55 shot wet kit. $550 isn't bad.

 

An MEVI won't increase peak hp much.

 

Any suggestions on additionaly mods that i can do that may add some power, i am open t o suggestions

 

It's a Cali spec so the 6-8hp difference is nothing to worry about.

 

yeah maybe at this point there is nothing i can do anyway. at leats i have some torque

 

Your Cali spec has pre cats which accounts for a few less HP then non Cali spec Maximas.

There is a member on here who has sucessfully removed the pre cats on his Cali spec and tricked the ECU by relocating the o2 sensors behind the main cat. You might want to search around and see if you can find him or do a little creative thinking and come up with your own idea on removing the pre cats. An exhaust shop might be able to help you out. Just get a non cali spec Y pipe on the car and 10 HP should around easily.

 

i think i will look into this but i am really excited about the SSR intake manifold. If not i think i will just get some NAWSS. i like the simple bolt ons...

thanks guys for the info

 

Zack your car is only 5 hp away from my '96 that I dynoed last April. Granted the numbers you got last time werent that good, I think your numbers are right on now. Mine put down 181 HP and 190 TQ and not to mention your TQ and HP curves are alot smoother than mine. Also keep in mind your car is cali spec with its swirl valves and extra pre cats, I think your car is right on with its power figures.

Also if you want to lean out the A/F ratio to 13:1 you might want to look into a SAFC of some sorts. You cant get a ECU but with a SAFC it can help some what.

 

Yeah i have considered tuning with the SAFC i even started a thread
http://forums.maxima.org/showthread.php?t=328482

i was told by a friend that i should replace all my 02 sensors because they maybe getting old. my car does have 104k now. i am much happier with the results and improvements from the last time it was dynoed, i was really hoping on 180+ whp thats all. my next mod granted that it is developed is the SSR intake manifold.

what mods were on your car that time when you dynoed?

 

Did you disable your swirl valve yet? It won't help on your peak HP/TQ but it sure helps in 1/4 time.

 

no i didn't can you elaborate?

 

Look here.

http://public.fotki.com/1max2nv/1max...ali-spec_swir/

Pull the vacuum hose. Plug BOTH the hose end and the valve end. You can pick up those rubber plugs at your local advance auto parts.

Test drive the car and get back to me. If you like it, paypal me $5

 

that sounds about right i wouldnt be too worried maybe it was the hot weather.

 

A 12:1 afr is ridiculously low for a normally aspirated engine, and will cost you some power. It may just be that their wideband needs to be recalibrated - find out when was the last time they did that. If they stand by their numbers, then you could probably pick up a few hp by leaning out to 13:1.

 

yeah i had faulty o2 sensor when i dynoed with about the same mods you have and i was running rich around 11:1 and i got 158/167. i replaced the o2 sensor and i felt a dramtic increase in power. i will get new graphs soon to see where i stand now.

 

Surprisingly, most 4th/5th gen VQs hover in the 12:1-12.5:1 A/F ratio at WOT. I don't see anything I haven't seen 20 different times.

 

You know, I just checked my own dyno from before I was boosted, and it shows a low of 12.3:1 at about peak torque, which rises to 13.02:1 at peak hp, and then lowers back to 12.24:1 at redline. I got 195 tq and 185 hp with about the same mods as Zack.

Maybe Zack's afr isn't abnormally rich after all compared to other NA Maximas. It seems that way to me, though, since the conventional wisdom among boosted people is to tune to a low of 12.5:1.

 

no i think his car just dont like being dyno'd.

 

i have seen many dynos of n/a 5th gens in the 13:1 range so i figured thats where i should be as well

so 12:1 range is pretty normal???

 

I dunno, still seems pretty low to me. But it may not be worth the two bills for an SAFC to raise it just to gain a few hp.

 

So this is what i know , their air/fuel gauge at the dyno was in good working order. my brothers 6speed g35 coupe dynoed 240whp/235wtq and a perfect 13:1 air fuel ratio all the way across. i will scan this and post it later. my O2 sensors maybe on the way out i replaced one about 3 months ago but i have had no CEL's to indicate anything. the car doesn't REALLY like me and i am good to it. but its not too bad. i guess there can be a bunch of things to explain my lower HP #'s the car is a cali spec, the front tire pressure was low at time of dyno and it was a pretty hot day. My plan of action is wait a while and see what comes up. i saw that someone mentioned that unichip can do an ECU for the 98-up maxima's so if this is the case, ECU and MEVI it is or if SSR actually does make an intake manifold then intake manifold and either SAFC or EMANAGE to tune . as for the car its a good car. good gas mileage for the ways i drive 22mpg city/highway with way too much redline passes. and i like it so i will keep it and work with her. i just hope some of this stuff comes a reality because my hopes are up...

 

any thoughts

 

ditto

I know it was already mentioned, but I'll say it again just to reinforce. The 99 Cali-specs use the 5th gen Y-pipe design which does not give you as much power. 95-98's can gain 12-15 whp or so vs the 99-01's which is somewhat less. Maybe 8-10 whp/wtq? So there is your missing power vs other 4g's with similar mods. Try the 95-98 y-pipe retrofit and O2 sensor relocate, and also 1MAX2NV's swirl control valve disable. As it goes with 4th gens, the newer they are, the worse off they are for modding. 95-96's rock (ECU w/rev limit hack). 97's aren't as good but still decent (ECU but no rev limit hack). 98's are near the bottom (no ECU but at least use the older y-pipe setup). 99's are rock bottom. Newer crappier y-pipe setup, more emissions garbage, and even the S/C install is a major PITA vs others from what I've read.

Naturally, I have a 99 and didn't know any of this before I got it. But that's okay because it's just a nice daily driver for me and I never really planned on doing much to it anyways. I have a 20th AE shift **** on it b/c the OE one wore out and the leather stitching starting tearing into my hand, and that's it. Does that mean I get 37hp extra too?

 

yeah i had done some research prior to buying the 99 but nothing so indept. i had planned on a 97-99 car because i liked the front end better. then i saw my car, never seen a green maxima before and it was an SE-L and such a good deal i was like ok i will get it. then i realized what i had done. welll i guess my car is right aroudn what it should be a for power numbers. around town and normal driving its pretty quick but i feel as if i need some more power on the highway. i am keeping my eye open on a couple options that' may give us 99 guys a fair shot.
Disabling the swirl valves aren't going to negitvely affect anything else will it? and what exactly is this going to do for the power band some low end or some topend or just all over? thanks for all the info guys

 

I forgot what the exact spec of when the swirling valve is closed. I believe it's something like below 2500rpm regardless of the throttle position. But unplugging the vacuum hose and cap both ends. You will keep it open at alll time. It's still there in the way of air path so if you really want. You can take off the upper intake manifold and remove it off the lower intake manifold.

 

i am all about the easy stuff. i will do what you showed me for now and wait to see what SSR comes up with and if that doesn't become a reality i may just get the MEVI and a UNICHIP tuned piggy back ecu