RX7Club.com - Mazda RX7 Forum - Sequential vs. Non Sequential

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Check DJ's comment on post #25 about non-seq gain up top.

You are right about running just the primary at 12psi, that guy probably won't last very long too.

Quote:

Originally Posted by ZE Power MX6 (Post 12509498)

Check DJ's comment on post #25 about non-seq gain up top. You are right about running just the primary at 12psi, that guy probably won't last very long too.

Thanks. I don't know how I missed that post. Makes sense and is pretty cool to see 10hp from a few flow mods.

Quote:

Originally Posted by cr-rex (Post 12509414)

tldr: nothing will change my mind :lol:

That's ok. It was just a synopsis of the data provided by your videos. Which is: A non-sequential setup is super laggy, just like we told you in that other thread. Thank you for proving our point and finally putting this debate to rest.

I'm going to document my non-sequential setup now, and then compare it to the 8374iwg. I'm at 1.25bar on the twins, I think that's perfectly achievable with the 8374 on E20, same as now. Let's see the trade-off of non-sequential vs proper single.

Quote:

Originally Posted by cr-rex (Post 12509414)

and for @djseven, of the 100+ cars youve converted how many came back and said they were unhappy with the conversion? and if its so bad, why did you do it so many times? did you not inform all these people that it would turn the car into a turd?

My main reason was because I was buying, repairing and selling these cars when they were at their lowest price point. It was not cost effective to keep the cars sequential with all new solenoids as resale price was rarely effected by Sequential vs. Non-Sequential. I explained to every customer whose car I converted or anyone I sold to that Non-Sequential was a more reliable way to get consistent boost and less headache. I also always explained it was very laggy and not near as fun to drive.

Now with EFR turbos and newer ECU's it just doesnt make sense to go non-sequential. Its a cheap alternative that just lessens the driving experience. I took some videos this morning of me in 4th gear on flat ground starting at 2200 rpms with my street ported REW to see what rpm my EFR 7670 on base map PFC would hit 10psi. It was right at 3000rpms. Since you say on paper things can look different than reality I challenge you to do the same test with your Non-Seq car. I love that you did this test but it went against everything you still believe. I have had a ton of fun in Non-Sequential FDs and hurt a lot of buddies feelings in other cars with that setup. I dont hate it, it is just a step backwards from seq twins or an EFR single setup.a

Ill attempt to upload the video but with my computer skills we shall see.

EFR 7670 4th gear pull from 2200 Rpms on a mediumish street ported REW 3” exhaust with Hi-Flow Cat.

3rd gear pull from 4000-6000 Rpms. Keep in mind this engine has around 100-130 miles on it right now so I’ve kept boost at 10psi and its trailing off on the top end down to 8psi just above gate pressure.

Quote:

Originally Posted by Testrun (Post 12509496)

I am sorry to keep this going, but it brings up a question that I've had a hard time getting an answer I can understand. Awhile ago I was running on just the primary as I was having an issue with the sequential system (I had the damn pre controller plug reversed). I guess that would technically be a problem with myself and nothing to do with the system... anyway, the car made a solid 12 psi. It was holding it's own on the track, but I was wondering how much power I had lost without the secondary online. I had a couple "knowledgeable people" tell me not much power is lost as it is at 12psi. 12 psi is 12psi. I am guessing these people don't take into the account efficiency? Like the charge temp itself? 12psi with both turbos kicking should result in a much cooler charge resulting in a more cfm correct? Am I looking at this wrong? If I have that right then why would the non sequential make more power on the top end vs mid range? Is there more flow through the manifold the way it is modded? What am I missing? I would think maybe the non would pick up some mid then taper back off to equal the sequential. I need to go review cfm vs psi again I guess.

was it holding 12psi on the primary? That’s strange. It typically drops to 5-6psi after transition without the secondary turbo. With the second turbo offline you were really probably giving up 50-70rwhp. It’s substantial.

That's kind of what I was thinking on the power. These are the sp so not sure if that makes any difference. so that brings up another question since at the same time I was having a slow leaning condition while holding WOT for long duration. Would it be possible the EGT started climbing since it was on a single turbo? Heating up slowly? Possibly causing the very slow leaning condition?