Do I want to convert to Non-sequential turbos? HELP!!!
 

I am pondering the thought of going to Non-sequential turbos.... My question is....... What are the pros and cons....What kind of changes happened when you converted/.... Loss of low end?...Gain in low end?....Happy with your decision???? help me make my mind up....

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I don't think there is much advantage in doing this if your sequential turbo control system is currently working properly. Unless you have a strong desire to simplify things under your hood.

To me a better solution would be to get a PFC or the new AEM EMS and lower the RPM at which the 2nd turbo comes on line. That should help you get about the same midrange power as a non-sequential setup without sacrificing the low end.

That is the approach I am planning to take. I agree, it does seem like 5000+ rpm is too long to wait for both turbos to come online, if you have exhaust mods that can spool them faster. Something in the neighborhood of 4400-48000 rpm might be better. I have heard XS Engineering tuned PFS do something like this, I'm just not shure about the RPM point used. Ideally it would probably be different for each car.

I have a PFC w/Commander, downpipe, Apexi FMIC Apexi Intake, Cat back but I am not sure if my turbos are getting the full 10 psi I am only reading 8psi I am sick of troubleshooting....

Isn't "enjoys troubleshooting" a prerequisite to owning a Rotary?? :)

Yeah! but Having a life of simplicity is one too!

Haha

I would convert only if your sequential is not working properly. There is a sequential simplification mod at rx7turboturbo.com which helps get rid of alot of vacuum lines and stay sequential. The more exhaust and engine mods you have it will help non-sequential turbos spool faster. My setup is streetport, dp, hi-flo cat, and N1 cb. A lightweight flywheel will also help a non-sequential system spool faster. I get full boost by 3200 rpms and it pull extremely hard until redline. If you have a midpipe you'll need to have your turbos clipped because with a midpipe it'll be a dog down low. There's a lot of criticism about non-sequential but I'd put my car up against any a sequential car with similar mods and I know I'd pull it. There's a little lag down low but if you have the right setup to help the turbos spool faster - this mod rocks. If your turbos do't get full bost until 4-4.5K with non-sequential then there is no benefit - actually sequential is much better - but full boost by 3200 rpms means BOTH turbos are pulling for a full 1.3-1.7K rpms more than with the sequential system. Also, there is no more troubleshooting. Even I can understand which lines go where and if something does go wrong I could troubleshoot it. I'd get rid of your maincat for a hi-flo cat though - helps control boost creep.

how does a hi-flow over stock cat control boost creep? Isn't it usually the other way around?

Any one else running Non- Sequential? Tell me your story....

KDR told me it was not worth the $$. For a few extra $$ I went single and got rid of all the stock problems.

Ken 57 years young,
'94 white, pep, red leather,
mods: Street port and polished stage II, upgraded coolant seals,
Hurley 3mm racing apex seals, XS T04E Turbo Kit,
GReddy SMIC, Pettit ss resonated MP, Pettit ss cat-back,
RP Racing fuel pump, Aquamist 2s water injection kit,
under pulley kit(no air pump), Pettit short shifter kit, boost gauge,
AEM EMS, 3-bar MAP Sensor, Profec B(12-2?psi), 1600cc injectors,
LaBreck bushings, Evans coolant.
<http://nopistons.com/luv94rx7.html>

The cost seem reasonable...... Just the time to do it yourself...

I decided to do it since I was getting an engine rebuild and it only cost me $75 for KDR to do it. If you have the time and knowledge you can do it yourself. Probably cost around $500 to have someone do it. It's not for everyone. If your car is close to stock I wouldn't do it since you wouldn't get boost until almost 5K rpms unless you had some exhaust mods. A little more for a single????? Where do you buy your singles at? Even on a group buy your still looking at $2500 for a T04. If you're getting your engine done and are having problems with your turbos then it's basically a free mod. It's a tradeoff of midrange power with non-seq. and low-end power with sequentials. They both have about the same highend power. When racing, I feel mine benefits more than sequential but tooling around town below 3K, the sequential was much nicer. Pros and cons to both.

Who cares about lag? When you drive around town, your mostly in Vacumn anyways except when romping on it or racing. when racing you launch at whatever RPM you want 4k and so on and you should never be at a low enough RPM during the race when both Twins are'nt making full boost. Unless you want to do somehting different then I would stay with the Sequential Twins until you go Single.