non seq boost pattern
 

Do non seq still have the 10 8 10 boost pattern like seq? I seem to be 10psi @ 5-6k and then it drops to around 8psi but stay around 8ish till redline. Any ideas why? Honestly this seems to have happened after I put on the torque brace. Engine is new with about 3000 miles, but turbos are orginal with about 66000.

Non-seq = no boost pattern.

should be solid 10psi thru redline.

Did you do the poor man's way or the FULL mod the exhaust manifold and take all the butterfly valves out?

seems as if you have a boost leak, should get 10psi by at least 4k (depending on motor port) if you still have all emissions and stuff.

I had the non seq done by local shop and had the air pump removed in the process when i bought the reman. I will check for the leak. Other than not creating the correct boost, could having a leak cause any damage to the turbos or motor.

Maybe over boosting the twins (trying to make 10psi in the UIM), but no damage to the motor will occur.

I'd double check what the shop did...do you have a mp or Hi flo? You should be seeing 10psi before 5k.

I don't think you will attain 10 psi until about 3500 rpm with non-sequential. The boost builds progressively with the rpms.

Actually if you have the full non-seq, then the boost lag shouldn't be to bad.

I read it starts from 3000 RPM or even less.

hmm....no. Most people are lucky to be getting full boost by 3500 rpm, and that's with running a big streetport and a full exhaust.

A lot of cars won't hold 10 psi all the way to redline, especially if they still have a cat. A drop to 8 psi after 7k rpm is typical (without an electronic boost controller).

As one of the leading advocates of the "everyone should be non-seq" campaign, I feel I should speak up.

WRONG!!!

Closer to the truth. With a full exhuast, stock motor, the best spool up time I've seen is full boost by 3800 rpm. I forget who that was, but it was someone on here.

Turbos might have some issues that are causing the boost to build slowly, and taper off. When I first did the non-seq, with my old turbos, my secondary was blown and I wasn't seeing full boost till about the same time you are. I'm not saying that thats what it is, just throwing it out there.

Did the turbos work fine before they were non-seq?

I'll let you guys know how mine works when I get it back. It will be non-seq with downpipe, midpipe, cat-back, streetport, and PFC.

You should have some sick spool up time. Let me know.

Oh sorry guys i did not realize i said 5k it at full boost around 4 - 4.1 about. The only exhuast mod i have is a downpipe. It pulls strong at till 6.5 - 7 then boost lowers to 8psi.

so since it taper off , somthing could be wrong with my turbo.

I get just over 11 pounds in my setup.. I'm making a boost controller to up the psi to oh I'd say 15(that'll make those turbos sing). anyway, you have a boost leak somewhere. unless your shop did not do the work right, did you give them a write up? or are they familar with the non-seq rx-7's? I see full boost by 3700, and then it's nothing but 11 psi till red line.

hope you find your problem soon. So you can enjoy your seven.....Non-Seq RULES!!!

That's pretty much what you get with a Power FC out on the open track...

Ok, that makes much more sense. Tapering off is normal without a boost controller. I have no idea why, but seq. FD's do it too. If you're making full boost by 4k rpms with just a dp, you're doing fine. I get full boost right around there too.

With a boost controller, you should see full boost to redline. If you have the cash for an electronic one, the Greddy Profec B or profec b spec II is awesome, and simple.

Got bored about 3/4 through this thread.
I dont get a full 15psi till around 4200-4300 rpm.
Thats straight through exhaust, Street/exhaust housing port, on 99 twins.

I hate to be the guy to tell you but the shop you had make your car "non squential" doesnt know shit.
It very plainy still has a transition.
Check my site and back track their work and find out what they fucked up.


http://www.fd3boost.com/Non_sequential_HT_Page.php

http://www.nopistons.com/forums/inde...howtopic=16665

Enjoy,
-Dave

BTW, You guys running anything under 17 psi and are buying up ProfecB's etc. You are throwing your cash away. A $75 turbosmart manual controller will handle anything you can throw at them and is acurate to 1 psi.

Actually the shop is know around here for exceptional work, and mostly work on are rx7's. I am sure something started to leak or since some of you guys are saying it is normal to see it taper off without a boost controller. Thanks for the replys, I will checkout the site.

10 psi to redline????

im was peaking around 11 and tapering to about 8 by redline... thought this was normal :P oh well my single will be here shortly and i can get rid of this redicilous twin setup once and for all!

Turbo F1, do you hear any whining from spool up? Just do a quick check on the ic couplers and then move on to the next potential culprits. Use the process of eliminiation....

Exactly. I have a $29 Dawes Device that works perfectly up to 12.5 lbs of boost. (I won't go higher on stock twins).

I don't consider it throwing money away. I have an electronic controller that is easily adjustable and I can instantly switch between three boost settings (including off - 7 psi). The controller can be easily adjusted WHILE driving to set perfect boost. I also don't have to make adjustments everytime the ambient temps change 30 degrees.....

To some people, convenience and time savings are worth a few extra bucks.

Umm I would agree with you if you had said that you just wanted a ProfecB so that you won't have to buy it anyway if and when you run higher boost levels.
But I don't need to adjust my boost controller that often. I actually used a Profec B for a year or so and I honestly like the turbosmart one I have know better.
I run 15 psi and it doesn't change unlees the temperature outside drops like 20-30 degrees. In which case I take 5 sec. to lift the hood and twist the knob 1/4 turn. If that 5 seconds of your time is worth $200 then knock yourself out. And who the hell considers $200 just "a few extra bucks" anyway
I can't belive that you are actually so lazy that you would pay $200 just to adjust the boost while sitting in the seat as opposed to taking a whopping 15 seconds to get out of your seat and do it.
I mean really who even needs ot play with the boost that much anyway?
I am not saying that a Profec isnt a nice unit. It is. But its more than you need for stock twins. Thats all I am saying. Why throw cash away at shit that you really don't need.
:confused:

So, what if you forget to lower your boost and overboost past what you have it set at? 15 seconds? Hardly. Say I get on the freeway and notice the car is overboosting. So I'm supposed to pull over, pop the hood, reach and touch hot metal components and GUESS how much to lower the boost? I'm sorry but your statements sound like a justification to not spend $200 (I could say, "I can't believe you are so cheap that you won't pay $200 to have safer, more convenient, and BETTER boost control"......)

Besides, my car is a daily driver. During the winter, it's nice to be able to lower boost easily from within the car if it starts to rain or whatever. For ME, the cost is certainly worth it. I know no matter what I say, you'll disagree, but that's ok. Everyone's entitled to their own opinion. :)

I don't necessarily disagree.
I agree that if you have the car as a daily driver that it would be more convient to adjust boost from the cabin.
For instances of incliment weather. But Imo you are taking more chances of fucking up your car by driving in bad weather than any boost controller being at fault to a damaged car.

But I if all of a sudden my car starting overboosting. i would know that since my car always runs the same boost, obviously something has gone wrong. At which point my god given 2 cents worth would tell me " hey something just poped loose or broke or something" so I won't boost the car till i get it home find and fix the problem. If your car is healty it is not going to just starting inexplicably over boosting and still be ok enough to rail on it.
What I am getting at is if your car startes to over boost then you DONT FLOOR IT!

Other than that I don't see any added benifit to having a Profec B controlling stock twins.


And If I felt the need to pay an extra $200 to keep my engine from blowing up I would. But the fact of the matter remains that my boost controller is extremely reliable and I have never had any issues with it that would make me change my mind.

Cheers.
Thanks for the debate. I 'll drink one for you.

We'll just agree to disagree....:) FWIW, you do bring up good points about the manual boost controller. I think a manual boost controller probably has an easier time with a non-sequential setup though...(you're non-seq, right?).

About the foul weather though, this car actually drives decently in the rain, especially with the Profec set to off, which limits boost to 7 psi (and boost builds more slowly as well). My FD certainly handles far better in the wet than my 79 RX-7 did.... I would NEVER drive this car in the snow though.

I'll drink one for you too...:)

Yea, non sequential.
I had a Profec when I wasnt running them in tandium.
I really don't likr getting caught out in the rain in my car. But mostly becasue my AC isn't charged and the windows fog up quickly :(