tjeter

I've never really been into the S5 turbo's but were going to have to take the engine out next weekend, and the hybrid turbo i got a hold of turned out to be bad, so i want to throw a S5 Turbo on there, I'm curious as to what the REAL advantages are, besides the wastegate, (i.e.: What type of power they put out, also do they spool quicker than the S4 or hold power to the redline better, sorry if its a newb question i've searched through and can't really find the answers to my question. Also i know i am going to need a S5 manifold which i'm going to get a hold of soon.

88IntegraLS

Given the "dual scroll" feature (or whatever it was called) that the S5 units had, some kind of changing exhaust gas vector toward the impeller with rpm changes in the engine, it would be a reasonable expectation for the S5 unit to spool quicker and / or at a lower rpm.

But turbo is turbo, take off ur cats on an S4 tII and you'll spool a lot quicker than either of them in stock form.

For a car that is already missing its cats, the difference would not be large enough to justify the changeover IMO. It would be more beneficial to drop a V8 in there anyways. Then you can have big power and an engine that will not pop on the first bad tank of $3.49 91 octane.

slpin

iTrader: (9)

why does everyone think... if its s5, it must be better?

cpubugs

Because why would Mazda make the S5 less than the S4. lol Makes sense. Not to mention the HP difference between the S4 and S5 7's.

tjeter

I didn't say the S5 was a better car, i heard the S5 turbochargers were better, so i'm still wondering which will create more power..

87RX27

Why would you want to put in a simple boring v8 anyway, especailly american made? Rotary power!!! Isnt that what RX's are all about? On the topic. I was told(by majestic turbo) that the S5 spools slower because of the larger hot side. But it has larger wastegate(s). And I thought it was the S4 that used the twin scroll design, isnt that what that extra actuator on the exhaust manifold is for?

88IntegraLS

Ladies, ladies, let's try to think with our more elevated heads here, the S5 came with higher stock boost than the S4. That was the main difference in source of extra power with the series change.

Don't discriminate against Real American Cubic Inches..... there is plenty of room in the FC's chest for some real muscle. The frame is very strong, the heart is weak.

cpubugs

Ok so you get coil overs, what makes them better then? I think they both have things that people want. But I think over all there were reasons Mazda's well versed engineers had a few reasons to make a new series. Generally this is done to make beneficial changes. But hey what do those crazy people at mazda know?

RenofHeavens

Infini IV FTW...S5 tehehe

tjeter

Yeah i really just want to know the advantages and differences and the max whp each will produce... please

SayNoToPistons

you have MUCH to learn...

classicauto

iTrader: (3)

One of the larger reasons for the power change between series on the turbo models is the motor internals. Lighter, higher compression rotors on the S5 are where most of the ground was made.

Other than the wastegate I haven't personally noticed much of a difference in performance - turbo wise - on these cars between series.



As far as which series is better, each obviously has its ups and downs but many of the changes made to the S5 model were to reduce costs, not necessairily make it a better car. I don't think they intentionally made it a worse performer either, its simply that some of things that were changed turned out overtime to be more lax on the S5, such as the pastic "dog bone" stabilizer links.

jacobcartmill

iTrader: (6)

the s5 car ran slightly more boost from the factory and had higher compression rotors.

the s5 turbo is better, it has a divided manifold, no twin scroll crap, the s5 AFM is better, the s5 ECU actually has a useful CEL.

NZConvertible

The S5's fully divided manifold means the strong pulses generated in the exhaust ports travel all the way to the turbine wheel and hit the blades with greater force. In the S4's common manifold some of the effect of these pulses was lost. The result is quicker spooling and less lag. The dual wastegate wasn't really about more flow (the S4's small wastegate port works fine on a stock car), but about keeping the front and rear exhaust pulses completely separated.

The compressor housing, compressor wheel and CRHA are the same, so peak power won't be improved by swapping on the S5 turbo, but a more responsive turbo means engine will receive boost sooner when you put your foot down and hence the car will accelerate faster.

(Edit...Remove reference to deleted post)

fstrnyou

hmm, i'm hitting stock 5.5psi by 2100. how much sooner do i need it?

RotaryEvolution

iTrader: (30)

most hybrids omit the twin scroll and port the runners larger than stock S5 runners anyways. there is no benefit to either turbo aside from possibly the wastegate, of which is modified much larger anyways.

NZConvertible

Who compares stock to modified? If you can port the S4 runners then you can port the S5 runners. The S5 has greater width across the outside of the runners, so it can be ported wider than the S4.

So are you saying that a divided manifold isn't a benefit?

jacobcartmill

iTrader: (6)

i totally agree with jason.

whats been the deal with people being totally dumbfounded with the turbos on their cars on here lately?

eriksseven

iTrader: (6)

topics come in waves, lol...

Boost_Creep

No one mentioned this yet, so I guess I will.

The dual-scroll feature was only featured on the S4 TurboII's and removed on the S5 Turbo. Just look at the bottom of the S5 Turbos and you will find no actuator for the twin scroll.

87RX27

Forget a turbo just throw in a big heavy american v8. Its the only way us stupid americans can make power. Personally I would run the s5 because of the wastegate. Its safer(stock) to control the boost levels at anything above stock. I replaced my s4 unit with an s5 and it spools a little slower but not much.

swanton187

finally someone speaks the truth...

but I would say s5 because of the bigger wastegate that should be ported.

88rxn/a

iTrader: (6)

thats just crazy talk!! buy a muscle car if ya want a V8 !!!
lol...

bigj50

most american V8's weigh about the same as a 13b..... especially with all the turbo crap.....


spaeak for urself buddy....... i'm an american and i'm not stupid ... you sound like the only stupid person here . Try to be a lil more open minded

SayNoToPistons

^ please just GTFO troll...