janrx7

hi i am wondering about some non sequential turbo myths i have heard. For insteance. Is non seq turbo much faster than stock? does this shorten the life for turbos or engine? is non seq, only recommened for fd with boosting problems?

my fd has no boosting problems, i managed 290 whp @14psi but want more without going single(not yet anyway). wondering about non seq turbos but only fd i know took this route, broke engine.

any inputs?

Mahjik

iTrader: (1)

Non-seq can provide better flow if done properly. The sequential system becomes a hinderance past 370'ish rwhp. If you aren't at that level, you have plenty of room to spare with the sequential setup.

fendamonky

iTrader: (6)

What kind of a dyno were you making 290whp on? That seems kinda low for 14psi..

If you were on a Dyno Dynamics Dyno (Australian) than you may want to add 18% for clarification to the rest of the board (would put you at 340ish).

Personally I've still got my turbo's running in Sequence, and I see no reason to change them.

janrx7

don't know what type of dyno but certainly not aussie.... i found it low also for 14psi....could it be tuning? afr was 11.6, not sure on injector duty cycle. still have to check if car has downpipe(cause i bought the car light mod) ......what hp should i have with 14psi?
-intake amemiya,powerfc, catback,midpipe,boost controller,......should i add injectors?

beqa16v

is it safe to run stock twins in paralel with stock ECU?

Zhé

iTrader: (2)

wouldnt try it

and as for the non seq myth, it has greater potiential to be faster only if done right, and its not only recommended for fds with boostin problems, goin full non seq gets rid of like 60 vac lines which makes the system alot simplier

Prophet7000

Yes, as long as you can maintain boost at 10 psi or lower.

dgeesaman

iTrader: (7)

Yes, if your boost is set appropriately.

Dave

RLaoFD

iTrader: (6)

Downpipe will hinder flow drastically, but @ 14 psi and 11.6 afr (getting unsafe) u should have made way more whp with the mods that you have.

Randy

janrx7

going to check for downpipe.... so adding bigger injectors is going to help me make more power?

RLaoFD

iTrader: (6)

It will open the possibility to make more power. You have to tune for it. Your Injector Duty Cycle is most likely 80% or above, which would make me a little nervous.

Randy

Sukai94

What are everyones thoughts/experiences/recommendations with the "poor mans" non sequential?

mdpalmer

iTrader: (24)

This is coming from a full non-seq person, sub 300 whp level:

One thing to remember: the human body is sensitive to ACCELERATION and that means you're going to FEEL the torque of the motor. If you have a non-seq car or a big single car, torque below the boost threshold of the engine-turbo system will be nearly that of an NA rotary. And we all know that means **** for torque. A lot of people, from what I see complain about this as if it were a "problem". I say otherwise, it keeps you and your speeds in check when you're dawdling in traffic.

HOWEVER, when you get past the boost threshold (if you're running a full exhaust you'll probably make full boost around 3.5 grand or so) hold on because you're haulin'! When you're racing, if you're driving properly, the motor should always be in the powerband--so a sequential car would offer no benefit, unless revs go below the transition point for the turbochargers. You can still run very respectable 1/4 times this way. If you're looking for a stoplight screecher, this is not the setup for you. It's for people who like to rev and run, and that's what a rotary is meant for IMHO.

That's my 2 cents. I love my car, wouldn't trade it for anything. It runs like a champ and doesn't complain.

BTW: my AFRs are 11.0:1 or less at ~12.5-13 psi on 91 octane. Timing will make a huge difference in torque, I made 20 ft-lb from reducing split from 14 degrees to 12 degrees. A lot of guys run 10 split... and they make more power than me

Dudemaaanownsanrx7

iTrader: (23)

you have something else going on if you're only making 290 on 14 psi with the sequential setup.

But yes a non sequential setup can make a bit more power because you can port things out and remove some of the flow restrictions on the stock sequential setup.

Poor mans non sequential will have the same peak power as a sequential car, with much more lag then both full non sequential and definitely the stock sequential system. Though it will simplify things and get rid of alot of vacuum hoses and solenoids.

It will shorten the length of the second turbo only because its being run all the time now, but its hardly even worth mentioning. if you have to pull one turbo to get rebuilt or replaced you might as well do both anyways.
Engine life will be the same as sequential. More wear will take place with additional power regardless of what method is used to increase the power.

bigger injectors won't in themselves give you more power. And you probably arent maxing the stock ones out at the HP level you're at. You will need an upgraded pump before you max out your injectors. If you dont already have one. And if you're running the stock intercooler that could also be part of why you arent making more power. The stock one is very undersized for even stock boost levels, and even more so for 14 psi.

janrx7

my mods are
amemiya intake
catback exhaust
custom 2.5 inch midpipe
walbro pump
v-mount intercooler (
apexi power fc

i am taking my car to the shop this weekend to confirm if i have a downpipe or not. i also was dissapointed with only 290hp. Thats why i asking peope at this forum for help. I want at least 315-320. I have not rebuild my engine but compression is good. could this be a factor? could tuning be a factor?

ptrhahn

iTrader: (9)

I think there are very few applications (the biggest being the ability to quote numbers on internet forums) where 20 peak horsepower is going to be worth the sacrifice in torque, drivability, and broad powerband.

Prophet7000

Going non-sequential is not a sacrifice, it's a trade off. Yes my boost comes on a whole 600 rpms later than the seq guys. But it has plenty of pros too. For instance: 6 vac hoses, no boost issues to troubleshoot, maintenance is a snap, instant boost from 3600 rpms on with no transition, no possibility of boost spike.

While non-seq isn't worth the 20 hp, it is in my opinion worth it and I wouldn't have it any other way. This coming from a guy who had a fully functioning seq system prior to going non seq.

Dudemaaanownsanrx7

iTrader: (23)

yeah it really depends on the person, and the application.

In this case 290 hp is still low for a sequential system and he should be able to get more without going non sequential, unless he just wants to simplify the whole engine.

OP Does your v mount have good ducting to direct air to it? and im guessing the tuner had a fan for the car when it was on the dyno?

If your compression is fine then no that wouldnt be why your power is down.
Did the boost stay solid through the run? And was the car smooth, it didnt have any breakup or anything did it?

NissanConvert

iTrader: (1)

poor man's non-sequential sucks, the previous owner of my car did it. do it right or don't do it at all.

janrx7

we had a fan, boost remain solid and car ran smooth. My v mount doesn't have a good air duct to it. should i get a vented hood? i really don't like how that hood looks. i still have to check my downpipe and pre cat...........hope there is room for improvement in that area

G's 3rd Gen

iTrader: (11)

I have owned the Fd for 10 years. 5.5 sequential and now almost 5 non-sequential. I prefer non-sequential for the above stated reasons. Dont miss the low rpm spool a bit. More keen to the onset of boost equally as oppose to the snappy pre-spooling of old. Still see 15 psi by 3600-3700 rpms. Just do it right the 1st time.

Prophet7000

Yeah, I think poor man's non-seq should only be used for diagnostic purposes.