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non sequential turbo questions

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Old 04-06-05, 04:09 AM
  #76  
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I converted to poor mans because I was pissed with the failure of trying to solve my secondary boost problem. I removed my y-pipe also, and when I put it back on, the charge control valve was faulty -_-. Unless you're upgrading to single turbo or want to SEE what its like if you go single, then stay non-seq. You eliminate that lag that single turbo gives off and when you're on the street.... as I'm assuming majority of FD's usually see, it's great. you THINK you're getting more power because you don't feel the transition anymore... but you're really just making the same... you're just feeling all the power after 3900-4200.

Jeremy
Old 05-26-05, 09:28 AM
  #77  
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Heres I guess a good way of knowing whether to go NON SEQUENTIAL over SEQUENTIAL. If you have every driven a street bike such as a gsxr 1000 or fzr 1000 and like that ripp you feel when you twist the throttle and it just pulls you out in one long shot, then go NON. Its sort of like saying when the FD is set up NS you feel almost like your driving a street bike. Thats just my view on it. Ive had two m3's, one m5, and plenty of race bikes. I personally like the NS just because of the way it feels. Try both and see what feels better for you and your driving environment. Peace out.
Old 05-26-05, 06:29 PM
  #78  
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Heres a modified cliche for you: "Arguing over whether Non-Seq is better than Seq or vice-versa is like the Special Olympics; even if you win you're still retarded."

Instead of saying one is better than the other, state the characteristics of each, and leave it at that. Each person has their own preference and driving style, so neither is the "best".
Old 07-28-05, 08:54 PM
  #79  
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Hey guys, don't joke me too hard, this is only my second post. I have a '93 and only a few things done to it. After reading all of your posts, I am pretty cerytain that I want to go nonsequential. My main question is, how did you guys figure out the poor man's nonsequential method. I went to the post on this forum but a few of the pictures will not pull up. I realy want to do this so can you guys help a brother out? I also have a Greddy profec B spec II still in the box. Should I go ahead and install it now or wait until I make it nonsequential?
Old 07-28-05, 09:31 PM
  #80  
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Originally Posted by quid
I also have a Greddy profec B spec II still in the box. Should I go ahead and install it now or wait until I make it nonsequential?
Go ahead and install it...going non-seq won't change anything to do with the Profec install.
Old 07-29-05, 03:48 PM
  #81  
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Originally Posted by rynberg
THEY ARE BOTH EXACTLY THE SAME AFTER 4500 RPM. I think it's very poor logic to make up your mind on something when you haven't even driven it, especially when you still don't understand how it works.

After 4500 rpm, both turbos are fully online in either setup, there is zero difference in power output or character. On true full non-sequential cars, you will pick up a FEW ponies at the high end due to removing airflow restrictions. With seq, you make full boost by 2800 rpm or and essentially hold that until just before 4500 rpm, when there's typically a slight dip in the torque curve and then a small rise before slowly tapering off. With seq, you will make more power from 0 to at least 3500 rpm (usually closer to 4k rpm). With non-seq, you will make more power from 3800-4000 rpm to 4500 rpm. After 4500 rpm, both setups will make exactly the same power (with the few hp exception noted above).

Now you tell me which setup makes more sense for street driving? Like I said earlier and have said many times. In hard driving except for auto-x, the car is essentially running non-seq, no matter whether the car is seq or non-seq. So, I see ZERO reason to convert to non-sequential other than boost reliablity concerns.

What would you recommend for autox use ? I like to stay in the 4500-6000 RPM range, but I have definitely felt the "no love" driving like this in autox.

Neil
Old 07-29-05, 03:53 PM
  #82  
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Originally Posted by M104-AMG
What would you recommend for autox use ? I like to stay in the 4500-6000 RPM range, but I have definitely felt the "no love" driving like this in autox.

Neil
Seq for auto-x. On many auto-x courses, there are hairpins or tight 180s and you can't afford to shift to 1st, so you are pulling from low rpm in 2nd. That would not be pretty with non-seq....
Old 07-29-05, 04:06 PM
  #83  
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Is it normal when just feathering the throttle at 4800 RPM in 2nd gear (in a hair-pin turn), to not get any boost for about 2-seconds after you nail the throttle (WOT) ) ?

That's what I'm experiencing . . .

Also happens under the same conditions on the highway (also when light on the throttle at 6000 RPM).

:-( neil
Old 07-29-05, 05:38 PM
  #84  
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rynberg, thanks brother. I will go ahead and install it this weekend, probably. I was afraid that the profec might learn the current boost map and then it might be confused when I change the turbos over to nonsequential. Speaking of which, do you know where I can find a good thread, post, or page on the conversion? I saw there was one on this forum but the pictures did not come through. So, it is a little hard to follow. I want to do the poor man's conversion. Any advice?
Old 07-29-05, 05:46 PM
  #85  
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Originally Posted by M104-AMG
Is it normal when just feathering the throttle at 4800 RPM in 2nd gear (in a hair-pin turn), to not get any boost for about 2-seconds after you nail the throttle (WOT) ) ?
That's what I'm experiencing . . .
Also happens under the same conditions on the highway (also when light on the throttle at 6000 RPM).

:-( neil
Not normal, you have a problem with your control system....if you jump off the throttle and then get back on it, do you get boost? If so, vacuum chamber leak....

Originally Posted by quid
rynberg, thanks brother. I will go ahead and install it this weekend, probably. I was afraid that the profec might learn the current boost map and then it might be confused when I change the turbos over to nonsequential. Speaking of which, do you know where I can find a good thread, post, or page on the conversion? I saw there was one on this forum but the pictures did not come through. So, it is a little hard to follow. I want to do the poor man's conversion. Any advice?
I am not familiar with the "learning" process, if there is one, with the Profec B SPEC II. Yes, you will likely have to change all the settings slightly on the control box, but the physical connections will remain the same.

Since my advice is to stay sequential, I'm not a good source as to how to do the poor man's non-seq, sorry.
Old 07-29-05, 09:37 PM
  #86  
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So, you don't agree with the other fellas that tell me I will eventually get a rediculous boost spike with the sequential set up? Either way, I would like to clean the engine bay up.
Old 07-29-05, 10:38 PM
  #87  
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Originally Posted by rynberg
Not normal, you have a problem with your control system....if you jump off the throttle and then get back on it, do you get boost? If so, vacuum chamber leak....
Yes, boost returns, but after a 2-second delay. I should check the black vacuum chambers, correct ?

:-) neil

Last edited by M104-AMG; 07-29-05 at 10:58 PM.
Old 07-30-05, 08:13 AM
  #88  
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Originally Posted by rynberg
Not normal, you have a problem with your control system....if you jump off the throttle and then get back on it, do you get boost? If so, vacuum chamber leak....

Originally Posted by M104-AMG
Yes, boost returns, but after a 2-second delay. I should check the black vacuum chambers, correct ?

:-) neil
It actually is normal if you are above 4,500 RPM because both turbos are online.

Unless, it is as Rynberg described with the throttle (i.e. instant boost response after getting off the throttle and back on). If boost builds slowly, then that is normal. Just let the idle drop below 3k to unlock the turbos
Old 07-30-05, 01:27 PM
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Originally Posted by quicksilver_rx7
It actually is normal if you are above 4,500 RPM because both turbos are online.

Unless, it is as Rynberg described with the throttle (i.e. instant boost response after getting off the throttle and back on). If boost builds slowly, then that is normal. Just let the idle drop below 3k to unlock the turbos
I completely disagree. If you are above 4500 rpm, boost should be coming up with very little lag, even with the stock cat. Now, if you are stuck down at 3200 rpm in 4th or 5th gear, I definitely agree.

I'm sure he's having a control system problem.
Old 07-30-05, 06:18 PM
  #90  
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Today I boost 12-8-10, if I start at about 3000 RPM, in all gears.

Here's how I normally drive autox:

Hit first and second hard at 12-8-10.

Back off the throttle while in second, and modulate around 6000 RPM (not 4800 RPM like I first posted) through the corners; then WOT out. Here is where I have poor boost, more like 5-6 lbs then 2-3 seconds later, I'm up to 10lbs, but too late for that section, so back to modulating the throttle around 6000 RPM.

I just replaced BOTH the charge control solenoid and the turbo control solenoid. Both solenoids were tested with 12VDC and a pressure test to 15-lbs so there is no sticktion/slow response in them.

I also just tested both vacuum chambers, and each holds 15-lbs of pressure and vaccuum.

New Viton hoses done in January 2005.

Maybe this is just normal for a stock non-sequential when feathering at 6000 RPMs ?

neil

PS: I have a M2 Stage III ECU, DP, Cat-back (stock cats and air intake box)
Old 07-31-05, 12:14 AM
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Originally Posted by M104-AMG
Maybe this is just normal for a stock non-sequential when feathering at 6000 RPMs ?

neil
I'm confused as well. I thought that you were running sequential?
Old 07-31-05, 12:23 AM
  #92  
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Originally Posted by quicksilver_rx7
I'm confused as well. I thought that you were running sequential?
Whoops, you're correct, I'm running sequential (stock turbo system).

Brain fart!

neil
Old 07-31-05, 12:59 PM
  #93  
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Originally Posted by M104-AMG
Here's how I normally drive autox:

Hit first and second hard at 12-8-10.

Back off the throttle while in second, and modulate around 6000 RPM (not 4800 RPM like I first posted) through the corners; then WOT out. Here is where I have poor boost, more like 5-6 lbs then 2-3 seconds later, I'm up to 10lbs, but too late for that section, so back to modulating the throttle around 6000 RPM.
Here's your problem. As soon as you let off the throttle, even if you are at high RPM, you loose boost (i.e. the manifold pressure drops to vacuum). And you're still above 3K RPM, so both turbos are still "online" You have to drop below 3K in order to unlock the turbos, even if it's only for a second. Some of the more experienced auto-xers can probably tell you the best way to do this, but I would say just dump the clutch long enough to let the RPM's fall below 3K while you're in the turn, and then get back on it. But be careful not to push it too hard comming out of the turn because if you hit above 4,500 RPM in the turn you're gonna go into a tail-spin when that second turbo comes back online.
Old 08-01-05, 10:11 AM
  #94  
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Thanks, and thanks to all for letting me "hi-jack" this thread.

:-) neil
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