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Hock87 04-16-17 10:21 PM

New to me FD
 
Well after going from an RX8 that was pretty much just an engine swap away from perfection, I came across a deal on a Montego Blue 1993 Rx7 with 72k original miles on it. The paint is pretty rough and right now it runs pretty rough so I'm guessing a rebuild is close to being in order, a new set of turbos, and an overall paint job to take it back to its original Montego Blue beauty. Paint Job will be done by me with hopefully a 99 front, and rolled fenders and quarter panels. Hoping to run non sequential 99 spec twins as well, and the rebuild will comprise of just a street port. No need to get to insane with it. I'd like to keep it fun to rip around the mountains. I'll get pictures eventually.

evo_koa 04-17-17 02:28 PM

stay with the sequential system. there is no need to go non sequential.

alexdimen 04-17-17 03:00 PM

Yep, get the sequential system working. It's awesome when it runs right.

And I wouldn't assume it needs a rebuild or turbos right off the bat. Turbos normally have shaft play, so you can't even tell from that. I made the mistake of replacing perfectly fine turbos on my car when i got it. Do a compression test to see how healthy the engine is.

Most importantly: if it's your first... read and ask what this community has to say before messing with anything!

cr-rex 04-17-17 03:14 PM

Go non sequential. If you're even considering it.... DO IT! It's the single greatest mod you can do. The simplification of the engine bay, the shedding of so many vacuum lines and solenoids, the smooth and linear power on tap from 3000rpm to redline, the sequential set up just doesn't compare. I have a dyno graph I will post later and I challenge anyone to post and sequential graph and make the argument that its better. Linear and predictable power with a simplified turbo system vs however you want to describe the sequential system to be.

Narfle 04-18-17 03:20 AM


Originally Posted by cr-rex (Post 12175111)
Go non sequential. If you're even considering it.... DO IT! It's the single greatest mod you can do. The simplification of the engine bay, the shedding of so many vacuum lines and solenoids, the smooth and linear power on tap from 3000rpm to redline, the sequential set up just doesn't compare. I have a dyno graph I will post later and I challenge anyone to post and sequential graph and make the argument that its better. Linear and predictable power with a simplified turbo system vs however you want to describe the sequential system to be.

Nonsense. A correctly functioning sequential system is ages better than non-sequential.

cr-rex 04-18-17 09:43 AM

In what way? How is the complex sequential system with its vtec like PowerBand superior to the simplicity of a linear powet non sequential set up of the same turbos?

Narfle 04-18-17 06:20 PM

Sequential makes more power down low and the same power up top. There's no drawback to sequential, unless you're incapable of maintaining a correctly working system.

300+ on stock twins and bolt ons...
https://www.rx7club.com/3rd-generati...1104322/page2/
https://cimg8.ibsrv.net/gimg/www.rx7...5aa7bfc765.jpg

Looks pretty smooth to me.

And, here's someone making 400+ sequential:
https://www.rx7club.com/time-slips-d...sight-1108026/

Not hard to find similar results....near 500...
https://www.youtube.com/watch?v=lpoI...ature=youtu.be
https://www.rx7club.com/3rd-generati...ecord-1108155/

RotorA 04-18-17 06:40 PM

Truth is your both right and wrong...LOL
The twins can be ok in a perfect working sequential setup but those are few and very far between. The twins nonessential is usually better feeling because most people who do it did not have a perfect working sequential setup...... I dislike the sequential setup because the transition is so inconsistent between the first and second turbo even with good check valves and vacuum hoses. It was a bit better when simplified but I still didn't like the momentary drop in psi. I then went non sequential and liked it the most as it was more linear feeling because a hiccup is not linear. LOL. The lag was barely noticeable and the smoothness and midrange drivability made up for any lag I could have noticed.

Now why your both wrong.....LOL.. A street ported single turbo setup is so much better then any twin setup, My best friend just drove my fd with a street port and ball bearing single turbo (which gets full boost by 3500) and he can't stop talking shit about his 99 spec efinis and the 4500 rpm transition.

To each there own, but you can't make a honest choice without trying the best of each option.

Just my 2 cents

Aloha
Alex

Narfle 04-18-17 06:47 PM

I'll take a well done single over non-sequential any day. But, if you get a big hiccup at sequential transition it's because something is broke or you've done something wrong. Banzai's dyno chart is proof of that.

RotorA 04-18-17 09:38 PM

Sorry I really don't mean to argue but bonsai's dyno is perfect proof of the sequential transition hiccup and yes I understand its not actually a hiccup, but at 4396 the power dips and IMHO that feels like crap even in the best setup. Truth is the stock turbos are just old tech and can be out performed in every way with new turbos and tuning.

Narfle 04-18-17 10:03 PM

Whatever you gotta tell yourself to get to sleep at night, I guess.

That's a dip of 10hp for 200rpm and it's literally imperceptible on the butt-dyno. The 7670 is the only turbo that compares to sequential spool, the BNRs are posting better peak numbers than all the 7670 builds I've seen so far.

Banzai-Racing 04-19-17 05:25 AM

The turbo transition is more evident on cars that retain the cat, with a midpipe and non restrictive catback (read not RB) I can tune the transition to not drop in most cases.


https://cimg4.ibsrv.net/gimg/www.rx7...e43488c273.jpg

misterstyx69 04-19-17 02:14 PM

Woah.

You can Talk tech in the TECHNICAL SECTION.

This INTRO is now Closed.


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