poss

iTrader: (5)

I'm not sure what you mean by this? The double throttle solenoid is not needed for sequential operation. He is right on in saying that by getting rid of those 5 solenoids, you basically halve the number of vacuum lines in the system.

kcolyer27

i like twins but cant singles produce more hp

donny

Thats not what I was getting at! I was just saying that with all of those other solenoids gone it is much less confusing as to which solenoids and vacuum lines are running the seq. set-up and there for make it easier to diagnose.

donny

the right single turbo will produce WAY more HP than the stock twin set-up But there are trade-offs.
Lag for the the T88 and similiar, and an FD with 500rwhp on street tires isnt really any quicker on the street from a dead stop if you cant get it to hook up.
I think its a personal preference and if you know how to diagnose the twins there not that bad. But if you dont have the knowledge of the set-up, then single is the way to go, in that respect.

Jim Swantko

A wastegate has a HUGE impact on spool.

Don't believe me - go loosen up your WG to it's loosest setting and see how it drives. Then crank it down and see the difference.

Stiffer wastegates = better spool. The gate stays closed longer and the BC has less work to do.

Jim (19 psi spring user)

doncojones

To quote the old adage...

What do a 500 hp Supra and a 900 hp Supra have in common?

They both run 10s.
That's assuming of course, that you let the wastegate see boost all the time. Most boost controllers completely cut off the boost line to the wastegate until the pre-set boost level is reached and then allow it to see boost. That keeps the wastegate closed pretty much all the way up until peak boost is reached.

SleepR1

The Factory Shop Manual has a trouble shooting matrix for diagnosing the factory sequential turbo control system. Once you know which and where those specific solenoids are, it's not all that complex. My point is that those solenoids you referred to have nothing to do with turbo control except for the DTC. IF that goes bad, the DTC butterfly doesn't open, you get no more than 5 psi boost.

SleepR1

There are people who remove the DTC system, altogether, while not affecting turbo control to eliminate the possibility of having the DTC fail and not allow the DTC butterfly plates to open, thus limiting boost to 5 psi, even when the motor finally warms up.

SleepR1

Niether are probably very streetable.

Does one really need 500-900 hp on the public roads?

10s are extremely tough to do with a factory-based drag car...

I'm beginning to think you live in a dream world, my friend.

doncojones

It's just a common saying among drag circles...and maybe it was 11's. I'm not sure. Anyway the point of the saying is that you can add a crapload of power to the car and it still won't run much of a lower ET because of traction problems.

SNracing

if i were to upgrade my turbo setup, i think id get the bnr's, or this: http://66.216.67.51/product.asp?0=220&1=362&3=720. i prefer the constant power of having 2 smaller turbos. i dont drag race, or race at all for that matter, so a smoother power band is for me. but to each their own.

SleepR1

Oh, ok, I follow you now. Traction and driving skills are KEY!

SleepR1

I don't think these run sequentially.

SNracing

i know the twin t28's are not bnr's, just a nice twin setup. the 2 t28's may not be sequental, but wouldnt the lag be a little less than a large single.

Larz

I'd like to ride in an FD with a single. I want to switch once I get the money.

clayne

I thought the DTC was default state OFF. The only time it is ON is during cold-start and medium load / cold.

Ahhh, your point is that if the actuator or solenoid fails and results in closed plates the entire time.

Just remove it and use a blockoff plate.

clayne

I bet SleepR1 likes Lord of the Rings.

SleepR1

Many do, but I like the DTC. I don't have to worry about overloading the motor first thing in the morning LOL

SleepR1

Help me out. I don't get it...?

clayne

You like the DTC? C'mon.

But are you a LOTR fan (I am not)? It was a joke about the type of people who would have certain humour go right over their heads :P

pp13bnos

iTrader: (1)

I'm not into the bling, bling kinda thing...but there is something kinda impressive about a nice single setup sitting in a engine bay.

SleepR1

See this thread for my dyno plot of '99 Jspec twins, streetport motor, and mods https://www.rx7club.com/showthread.p...64#post2511664

MazdaRx7Racer4Life

no, running bif parallel twins has the same lag as running one turbo. My brothers 300zx has twin t28s and the lag is not huge but its noticeable. I think lag is fun, alot of cars think they can beat him, then the turbos kick in and he flies by them, really an awesome car.

MazdaRx7Racer4Life

Really a awesome car SleepR1

D1Import2nr

In the end its personal preference, theyre both great systems, it depends on what you want in a car, the seq's are great for daily driving, but if your hp crazy its usually the single set up, not saying that some twins dont have a lot of hp, just usually its the single, In the end is personal preference, what you want out of ur rx7...