Could you describe your single set-up in detail?

 

Not single, non-sequential (parallel) twins. The key is opening up the stock manifold so the turbos can breathe. David Garfinkle welds alot of metal to stock manifold, then ports it and the wastegate aggressively - this, combined with a full open (no cats) exhaust and lightweight flywheel make for a very quick revving and responsive set-up where the stock sequential system, with its akward transition, is not missed - and, unlike the stock set-up, it also pulls hard all the way to redline, where the stock manifold starts to choke off flow at high rpm. Finally, non-sequential greatly streamlines the engine bay and makes everything easier to work on, cast iron manifolds also seal better than stainless.

Thos who are quick to knock non-sequential have never driven a car where it's done right.

 

My boost in first and second is 10-8-14. If done in higher gear I might 12-10-14. I have 99' specs your mods plus a mid-pipe. The PFC handles the boost and I don't think it's ever spiked the way you have described. To that end I mean even if I set for 12 on the high side it holds it. Now do have boost creep at 14. It creates an osculation effect in power and exhaust note as struggles with controlling the boost at it's limit. But it doesn't happen in any meaningful way at 12 though.

Also there is a way to experience a seamless transition. Set the boost to 8-8-8 on my car you can't even feel it. It was my valet mode for awhile.

 

I really like the sounds of that set-up, and the fact that you can retain the original twins is even more appealing. If you don't mind me asking, how much does David Garfinkle charge for this set-up? Does he run a shop, or is he an acquaintance of yours?

Thanks for chiming in, it's great to hear from someone with a similar set-up. From what you're saying, it sounds like the boost should be fairly easy to control, so I'm looking forward to resolving my spikes. Interesting bit about the valet mode btw.

 

So Mark are you ever going to post a video of your boost response?

I'm serious and not trying to start **** btw. I really want to see proof of non-sequential lagless twins with a boost threshold of 3400 rpms.

 

I would also be interested in seeing a video, not for the sake of proving anything, but purely to see how it differs from my FD's set-up.

 

I don't turn the wrench, so I'm not going to say it's easy. I will say that it should be able to control it in your car at 12lbs, which is why I provided the feedback. I saw that we had similar setups and mine appears to be functioning "more" correctly.

Sorry, but anyone saying you didn't loss some driveability down low is just not accurate. What you are really saying is, is that you don't mind the trade off. The discussion becomes meaningless in term of performance once revving into the power-band. It's a very narrow range between 2500-3500 that most of my daily driver lives. I'm going to give that up next week for much more power via a single.

Maybe one day we'll have a nice VVT turbo that handle a rotary. Until then we must all make comprimises, lag, power, reliablity.

 

You should take a look at BorgWarner EFR turbos. They've been working on some pretty groundbreaking stuff, and are also the company behind Porsche's zero lag turbo.

http://www.full-race.com/articles/bo...fr-turbos.html

 

I’d take what YZF (Mark aka no_more_rice aka countless other forum names that he has) says as grain of salt. He is a controversial figure here in the forums and will argue just about any topic to death, in fact he stirs up countless debates for what seems to be just for the fun of it. No matter how many people are against him he is relentless and yet when given the opportunity to actually prove something that he is arguing about and thus put and end to it, he refuses. I’d badgered him in the past about posting a vid of his boost response and he either dodges my request or belittles it. As you can see here he hasn’t returned. The funny thing that I cought him on another thread requesting a vid from a person a proof to their debate Hypocritical to say the least…

Honestly I’d love to see a sequential set up with the response that Mark claims. Only here in the forum I’ve heard people claim that and all they do is claim. It be real nice to finally see some hard evidence. I’ve yet to meet an owner or a shop that has that kind of response out of non seq twins. Keep in mind that I have owned this car since 1998 and I live in (southern) ca where the majority of FD’s are at and rotary shops are plentiful. And yet nope never ever met one… Now I’m not saying it can’t be done, but what I’m saying is that it’s obviously not as simple as people make it out to be. It’s obvious, otherwise everyone would have that kind of spool.

I actually had a perfectly working sequential system. About three years after doing the silicon vacuum hose upgrade, one out of the 72 hoses would go bad just about once every three months. After a couple of years of this I decided to go non seq. Given the forum’s praise of boost threshold in the low 3k range (as long as you had the right mods) and only 6 hoses to deal with. So I had all the right mods DP, MP, CB, lightened flywheel, SMIC (short piping), and a true CAI as well… Well what was my boost threshold? 10 psi at 3800 RPMs and really laggy in comparison the instant boost that nonsequential twins provide. Interestingly enough everyone I’ve met and talked to says 3800 RPMs. I have even spoken to Brian at BNR’s (the guy that makes YZF’s turbos) and guess what he said? Yep 10 psi by 3800… Go figure.

Now nonseq does have its advantages. Given that I only had 6 hoses I didn’t once suffer from a vacuum leak, the power was linear, and the boost was much easier to control. But if you want to pass someone on the freeway, you better downshift if you are at 3K as it’s gonna be a while till you build boost. I already mentioned the lag but I hated that so much that I’ll mention it twice . Yep that lag sucked ha ha. 4500 RPMS drop the hammer… wait, wait, ok! To be fair I obviously didn’t hate it that much because I never converted back to non seq but my point is that it certainly is not the eutopia people make it out to be when comparing it to seq twins. So if you go non seq and get a threshold of 3800 don’t be surprised nor disapointed, but if you get 3400 and non laggy to boot then be stoked! And post a write up so you can benefit the forum.


Now I’m single turbo with the right mods for quick spool. GT35R (BB), T3 with 1.06, short manifold, DP, MP, CB, lightened flywheel, SMIC (short piping). And I get 10 psi by 3200, 15 at 3500. With this turbo I begin to build boost in the high 2K RPMs. Given that I push a lot more air than the twins no need to downshift when normal driving in the freeway. As soon as the car sees some boost it begins to move. I will say this though Even though I see 15 psi by 3500 the car is laggy at anything below 3700. Above 3700 my boost comes on super quick not as quick as a sequential setup but pretty darn quick.

I took a vid to show you what I’m talking about. It’s a really bad vid because it’s at nightime and I was using my cell phone cam so I apologize for that. BTW The reason you don't see a boost gauge is because I monitor my boost via my boost controller and it doesn't transfer well in video. Anyway I'm driving in Mexico and I’m at low boost (12 psi) and the vid starts with me in third gear at 4K RPMs, I drop the hammer at 0:02 and you hear my vented wastegate open at 0:03. So it took one second to hit full boost. I go through most of the gear and (relatively slowly) shift to fourth and again you can hear how quickly I hit 12 psi. No difference at the 15 psi setting but I wasn’t too keen on doing it with one and half hands (phone) on the steering wheel lol.


http://www.youtube.com/watch?v=WtGrKLKDbak

See Mark how hard is that? Post a vid already…

 

^Wow, that was an incredible response! Loads of information and a video to verify, I couldn't have asked for more.

I've been doing some research after hearing what YZF had to say, but I couldn't find proof of a non-sequential set-up with boost characteristics similar to his. It really would be great if he could post a vid.

 

I would read this thread as far as FD suspension goes..... This man definitely knows his stuff...

https://www.rx7club.com/suspension-wheels-tires-brakes-20/howard-colemans-fd-chassis-setup-723617/

 

I'm not going to beat up on anyone but, if it's was so efficient why would his numbers across the board be so low. That dyno chart that was posted was low for stock twins at the same boost level.

 

I've read through that thread a couple of times, but it doesn't go into what I'm interested in.

 

I must have missed something, what dyno chart are you referring to?