speedracer2235

This weekend I finally finished my FULL non-sequential set up with newer set of turbos. The project started off just trying to figure out why my 7 was having some smoke and power issues along with the fact that the clutch was fried. I ended up doing a N/S because everything under the manifold was just basically brittle and trashed. I also needed to clean up the engine bay, it was pretty nasty from the previous owner. The writeup from "arex7" was good enough to get me started.

So this project took way longer than I wanted it to. ..

Ok here we go. I am so impressed with this new set up. Unless you just have to do idleing burnouts, you wont miss anything. My mods include a Mugen down and midpipe (yes e-bay, it's what you do when your broke), N1 duall cat-back, 9.5lb flywheel,255lph walbro pump, all block off plates. That's it. She still even has the stock air box for about another 2weeks or so.

I start boosting at about 2500rpm and hit full boost (12psi) by 32-3500rpm. 3rd gear 30mph push foot to floor results in the tires breaking free around 70mph. Shift to 4th and the boost is already there I'd say less than 2 sec later I'm over 100mph.

And BTW it does get louder!!

All I can say is WOW!!! It's worth it!

xstacy7

That's awesome man, I bet it feels good! I was contemplating doing NS a while back. I have the 99Spec Turbo's and I haven't heard of anyone who has done NS with them so I guess I was kindof waiting for some information before I did it. Your post makes me want to do it though....good work

birdy01

damn is it really that good? hmm...i'm taking off my turbos to port my wastegate maybe i should think twice, j/k glad u love it, maybe i'll try it one day

jimlab

I've been saying this for years and no one seems to believe me. In fact, they've even argued that non-sequential is no louder than sequential.

Mahjik

iTrader: (1)

Well, I know two people who were full non-seq (both dyno'd over 350 rwhp) and never had that much boost at that level (one them with BNR Stage 3's, the other stock twins). Both ended up going back to sequential.

Montego

iTrader: (1)

I would assume that the car is overall faster since the area under the curve has dramatically increased. I mean 10 psi is not 10 psi. If anyone wants to argue this just remember what happens at 4500 RPMs when running sequential .


interesting...
at what RPM where they obtaining full boost and what were their mods? Just curious as why some people experience lag and others don't.

jimlab

The question is, what other components did they have that caused the boost lag?

I've ridden in and driven FOUR fully converted non-sequential FDs (mine, Jim Dagley's, Justin Everly's, and Brian Goble's), and they all behaved the same way, probably because we did the conversions the same and they all had similar or identical components and no cats.

I don't know what causes the boost delay for other people (short of doing the half-assed "poor man's" conversion and/or still having one or more catalytic converters). Maybe Washington's air is just more conducive to providing nice boost response with full non-sequential. Minnesota air must work as well, since Kevin Wyum seemed to like his boost response also, and now we know that the air is just fine in South Carolina too.

Mahjik

iTrader: (1)

Both:

FMIC (Apexi on one, custom Spearco on the other)
Open Air intakes (K&N filters)
Ported engines (one Race Ported by Pettit, the other Streetported by Pineapple)
Downpipes
Midpipes (one with Borla welded in)
ECU upgraded (one Pettit Unlimited, other PFC tuned by Steve)

One stock fuel system with upgraded fuel pump
Other 1600 secondaries, SX FPR, fuel pump

Both using boost controllers (Greddy on one, Apexi on the other).

Both using ignition amps; HKS one one, MSD on the other

Catbacks: Racing Beat dual on one, Apexi dual on the other

jimlab

There's part of it, I'm sure.

All four of the cars I have experience with had ASP ICs. 3 large, one medium.

Mahjik

iTrader: (1)

Ok, so the new rule is "non-seq is great with SMIC's".

jimlab

FMICs will add some boost lag for stock twins, BNRs or otherwise. The pressure drop will be higher than an SMIC, and you've got more area to pressurize (and keep pressurized) in the added piping (with multiple bends).

Mahjik

iTrader: (1)

Thanks, I already understand the concept.

However, I had ridden in both cars in sequential form (only one of them in non-seq form) and noticed no lag differences from my SMIC. Granted, both cars were using ported engines with midpipes while my car was stock ports with a high-flo cat. While it may be an exponential problem (they had more flow so it was exaggerated more), it wasn't apprarent while in the sequential setup.

jimlab

Just checking.

It's a problem that feeds upon itself. It's going to take longer to spool both turbos than it will to spool only one, because you're splitting the available exhaust energy between two turbos instead of one. Having exhaust restriction, intake restriction, or an automatic transmission just makes it worse, because it slows acceleration further and keeps the engine in the lower rpm range longer. Adding a FMIC certainly doesn't help.

Engine porting probably hurts spool time as well, because port velocity is reduced at lower rpm. The larger the ports, the less low-end power you'll make, and that means less exhaust energy and slower acceleration. Back to square one.

Of all five cars (including Wyum's), only one had porting.

Mahjik

iTrader: (1)

Exaclty. So people should understand that not everyone is going to get 12lbs of boost by 3500 rpms when running non-seq (i.e. it's not the holy grail of performance modifications). While there are setups which will provide that performance around that level, they are not always typical. So, people shouldn't be surprise if/when they don't see decent boost until higher in the rpm band than mid-3000's with non-seq.

jimlab

I don't remember anyone saying that it was a performance modification. It's a reliability and drivability modification more than anything else.

I don't remember anyone saying that you'd get perfect boost response with the wrong combination of parts, either...

Mahjik

iTrader: (1)

It's more of a "mis-conception" of the public....

And the forum is filled with more it.

Maybe not, but you have made claims that people "should" see boost full boost much sooner than what people are actually seeing (in some of the older threads). Granted, you didn't specificially say "everyone", but you also didn't say "with the proper components".

Montego

iTrader: (1)

hey! hey!

please explain why it would not be a greater area under the curve?

At 4500 RPMs when the second turbo kicks in I can certainly feel a kick in the pants as both turbos spool (as it should). How is that any different when running non-seq? Both turbos are spooling but now at a lower RPM.

jimlab

Taken as a whole, "the public" is stupid. What do you expect?

Actually, he's right. Over part of the rpm range, non-sequential does accelerate faster because it has "more area under the curve" than sequential.

I think you should re-read some of my posts on non-sequential, then. "Properly converted" sort of implies "proper components". I didn't just change my story today.

11-19-04
"I didn't have to change my driving style AT ALL converting to non-sequential. I think the people whining either haven't driven a properly converted car (evidenced by the fact that they can go back to sequential afterward) and/or have catalytic converter(s)."

9-20-04
"There may be a small increase in lag when compared to sequential, but it's nothing that would greatly impact drivability and it's barely noticeable when the conversion is done right. I've driven both sequential and non-sequential back to back on the same day, and I've driven three different non-sequential cars converted properly, and if you can find something to complain about, you shouldn't be driving an RX-7. Period.

There are three factors which must be met...

1. Manual transmission only
2. Internal gates should be removed and wastegate enlarged
3. No catalytic converters"

9-19-04
"The lag horror stories can be blamed on people who were cheap and wired gates open, or went non-sequential while still having catalytic converters, or both. Properly converted, there is no noticeable lag."

7-15-04
"Properly converted (gates removed, plugged, exhaust manifold ported) without cats, non-sequential will make full boost (15+ psi) by or before 3,200 rpm in 1st gear. 1st gear goes by so quickly anyway with full mods that I don't know why anyone complains about lag or lack of low end power unless they've done the poor man's conversion and/or still have their cats."

7-7-04
"With a properly converted non-sequential system (no gates, exhaust manifold ported, no cats) you can hit full boost (15+ psi) by about 3,200 rpm. I don't know of any sequential car that makes that much boost until the second turbo comes online, so yes, a non-sequential car can reach full boost more quickly than a sequential car. That's why they're stronger in the midrange than a sequential car with equivalent mods."

3-16-04
"Maybe you don't have the history to know that there have been multiple "disatisfied" non-sequential owners badmouthing the conversion who, when questioned, turned out to have done only the "poor man's" conversion and still have at least part of their emissions equipment on the car. One or two might even have had automatic transmissions. Your comments, especially about testing back-to-back on the same day, sounded very similar.

It would be extremely difficult to convert a car to non-sequential properly and test back-to-back in one day unless you had an extra exhaust manifold, set of turbos, block off plates, and an upper inake manifold just standing by, already converted."

I could go on, but I'm sure you get the point.

Bottom line, four out of four cars converted properly all behaving the same is a pretty compelling argument for repeatability, not to mention Wyum's car, Kevin Tan's car, and several others (including Todd Serrota's R1 which Trev Dagley bought) that were modified to similar levels and had similar components.

Carlos Iglesias

iTrader: (6)

Yeah... what Jim said!

jimlab

Sorry Carlos, I forgot about your car.

TurboLumpy

i have the 99 spec turbos setup non-seq... love it

and yes they are louder than stock seq... its really noticable with the Apexi N1 exhaust

dubulup

FD3BOOST ran them NS

Mahjik

iTrader: (1)

Jim,

As far as the phrase properly converted, that really doesn't mean "proper components". The full non-seq modificaton can be done properly and the result can be less than stellar (as many people have observed). The the phrase properly converted doesn't really convey that there are other variables outside of just having the mod done right which will effect performance.

Keep in mind this is the internet so people can't read minds if you are "implying" something other than what you are typing. If I read your statement:

"The lag horror stories can be blamed on people who were cheap and wired gates open, or went non-sequential while still having catalytic converters, or both. Properly converted, there is no noticeable lag.

then simply doing the "full non-seq mod properly" should yield the correct results no matter the configuration of the car (minus cats that is). So, in that since, your statement is very misleading.



PM "RTS3GEN".

He has done that exact back-to-back test and is staying sequential. While the FMIC and porting may be causing the extra lag he is seeing in full non-seq, it's more the norm than the exception (as to people using stock ports and FMIC's). Yes he does have 2 manifolds (as well as the other person I was referring to in this thread).


I have yet to see the exact same car dyno'd with the two configurations to give a real apples to apples comparison. All I've seen is that there is more power during the transition area than the seq setup, but a lot less down lower. For what little torque the rotary has, not an outstanding mod IMO. However, from the people that I know who have done back to back driving with a perfectly working seq setup, non-seq was not all that at all.

jimlab

Yeah, it does... Did you see my checklist?

1. Manual transmission only
2. Internal gates should be removed and wastegate enlarged
3. No catalytic converters

Maybe I should add aftermarket intercooler and aftermarket intake, or do you think that most people believe you'd get stellar performance by leaving them stock?

The key is doing the conversion right in the first place, which means the poor man's "conversion" is out. Then all you need are a free flowing intake and exhaust. I don't understand what's so difficult to figure out here. I spent more time worrying about limiting boost than worrying about how soon it arrived, because that was never a problem.

I guess that depends on what you consider "a lot less" as, and whether or not you know how to downshift.

From the people I know, none would go back, so there you are.

Keep pushing. I've got a little patience left.

Mahjik

iTrader: (1)

Ok, but the 2 cars above meet your criteria and do not have boost building as fast as claimed. So, by your definition, they have done the conversion properly; yet the results are not the same.

Jim, there is nothing to figure out. The fact is, non-seq does not yield as much boost at the lower rpms as claimed by some people, for everyone. It's like saying since JD made over 400rwhp on stock twins, everyone should be able to do it in which case we know that doesn't happen.