SpooledupRacing

I am curious what ACTUALLY is the "gain" in the s5 intake swap on a n/a s4? I want to keep my 6 ports, and was wondering if I could just kep my s4 lim in order to keep the exhaust pulse 6th actuation and bolt on the S5 uim and t/b or hell use the stock s4 tb so I dont have to mess with the tps etc.

anywho just trying to get some inside ideas....

Dave

Icemark

covered before.

Its is recommended on a S4 to keep the S4 LIM and put the S5 Mid and upper sections on, however you would need to port match (the S4 LIM has larger runners than the S5) and one of the bolt holes needs to be re-drilled.

Sideways7

iTrader: (7)

I believe you also have to grind down something on the TB as well, and bend the omp rod. Here is a link on the specifics: http://howto.globalvicinity.com/gv_w...i=63&co=1&vi=1
I'm in the middle of doing this myself, but all I've gotten to is taking of the s4 UIM, etc. due to a severe lack of time from a new job and shitty weather.

SpooledupRacing

I am sure it is covered However somtimes reading that FAQ etc is like reading the bible, it can be fun and full of information HOWEVER if u are not in the mood to sit down and dig in it will be boring quite quick.

My other question is why change to the s5 stuff if it needs to be ported, I dont see where there would be any gain?

I know in doing so u have to grind down something on the engien to if I remember right, and I'm just trying to find out if this is a worth wild thing to do or more cosmetic then anything?

as far as the omp rod goes thats fine I think I may pre-mix next season anyways

Icemark

The S5 runners are smaller. If you don't port match to the S4 LIM you will have about a 1/2 Dia smaller runner feeding into a larger one.

And the reason to use the S4 LIM is to avoid having to fill and tweek the S5 LIM, which has openings that do not match up to the S4 block.

I guess you could just half *** it with not bending the MOP rod and port matching, but then why bother doing the mod in the first place as you would only gain a little power between 6000 and 7000 RPM if you don't want to do it right?

SpooledupRacing

look if u cant answer the questioins I ask just dont answer.. there is no need to be a smart ***.. I KNOW u would have to port match but my questions was not why to port match but why to use the s5 intake setup AT ALL... how much of a gain are u actually getting from swapping from a s4 to a s5 setup?

again my last questions was as stated above

" And the reason to use the S4 LIM is to avoid having to fill and tweek the S5 LIM, which has openings that do not match up to the S4 block."

to translate that it means IF the s5 is a smaller dia system why even change over and port it out if the s4 is larger to begin with??? what is the ACTUAL gain after port matching from using the s4 complete setup to using the s5 upper intake and plenum?

Dave

J-Rat

iTrader: (2)

Some of the gains from the S5 intake are in the VDI. The S4 ECU cant run the VDI, so the gains would be negligable.

Rat

KompressorLOgic

iTrader: (6)

well ive seen previous threads with dynos, and people who have switched over to using s5 upper intake and stuff,
AND have the VDI working properly.

have seen a top end gain of up to 8 hp on a dyno. no clue where the thead went but it was a while ago

rotarygod

iTrader: (1)

The S5 manifolds slightly smaller runners won't matter when it comes to matching with the lower manifold. A little bit of a step is a good thing to prevent reversion. One of the worst mods that people like to do is gasket match so for the sake of your airflow please don't do it! I'd have to draw a picture to fully explain why. I should really just do this to some spares and strap them to my flowbench to just give the final results but that's not worth my time. Anyways, the advantage of the S5 manifold isn't with it's ability to flow more air than an S4. It actually doesn't and that's OK. It doesn't matter. It's all about tuning and nothing more. There is a definite power gain with an S5 manifold over an S4. Keep the VDI working. With it working and in the closed position the intake runner effective length is longer than the S4. With VDI open the effective length of them is shorter. This gives you a wider powerband as well as more higher rpm breathing. It's a good thing.

It doesn't matter what the ecu does. It's not hard to make VDI work and get a gain from it. I have an S5 manifold on a 1st gen GSL-SE. I do have a Megasquirt now but VDI and the 6 port system are both working off of air pump pressure. It works perfectly. The ecu doesn't need to do anything and neither would an S4 ecu. Go search for the how to's on this topic. It's easy.

Unless you premix you will need to modify the OMP rod to the throttlebody. You could bend it to work or you can just do what I did and use a bicycle brake cable. Problem solved. Simple and effective.

Yes you can make an S5 upper and middle manifold work with an S4 lower. Don't worry about port matching. It won't get you anything. The rearmost mounting bolt is the different one. The S5 spaces it farther out. You may have to get a little bit creative here but it can be made to work.

J-Rat

iTrader: (2)

8 horsepower to me is negligable for the work involved, but thats just me. If they did get the VDI working, they probably used an RPM switch or something to that effect. A stock S4 ECU is not provisioned to open a valve at 5000 RPM.

Icemark

Cool, then I will just delete the thread since it has been covered so many times already.

I got 15 peak more on mine when I did it, but I also had the S4 LIM and S5 VDI and Top sections all extrude honed together, so that I had perfect flow through the whole thing.

But it is a progressive change in power. Stock set up with 10-15 HP gain, might change to a 20 hp gain with the right exhaust. The extra power you get from better intake flow, always is dependent on the whole picture, rather than just the intake.

SpooledupRacing

ok so I am wondering ir u could gain the 8-15hp just from porting and extrude honing the stock S4 intake?

Icemark

You can't nor did I say you could.

Ah, I take that back, I guess if you had the entire S4 intake assembled and extrude honed you may get an extra 10 peak HP, but it wouldn't solve the problem that the S4 intake runs out of power around 6000 rpm, while the VDI allows a high RPM run out of the power

SpooledupRacing

OK so the main upgrade is not the intake itself but the use of VDI..

so if I did the swap and did not use the vdi then it would be pointless?

btw I was asking IF you could gain the 8-15hp form just boring and extrude honing the stock s4 intake.. thats all

J-Rat

iTrader: (2)

Good god Mark, how much did that cost? I checked into extrude honing and its not cheap!

Icemark

On the last two NA motors I did the S5/S4 hybrid intake, extrude honing them cost me $550, but the last S4 Turbo intake I had done cost $650 with shipping (seems cost keeps going up). Of course on the NA motor I was hitting 175 at the wheels at 6500, with 144 ft/lbs at 3800 and meeting CA emissions (well at least the sniffer- visually I was missing the EGR and first two cats. But power wise it put out considerably more than even a stock S4 T2 puts out at the wheels.

I need to send another S4 Turbo intake, but just haven't decided if I am sticking with a S4 motor or tweaking a RE, by running S4 front cover and pan and redrilling/tapping the mounts. Maybe I'll get a group buy going... it would probably save everyone $100 if we could get 10 or more people.

Extude honing in my opinion is one of the best mods, as it keeps on giving, the more other things you do to the motor, the more power you get from the extude honed intake. And it keeps the bolt on pozers away because it is not cheap ebay bolt on filter HP.

Sideways7

iTrader: (7)

Yes, and kinda. The main advantage to the swap is the VDI. If you wire it open you will get more peak power (above 5k) and less elsewhere.
The link I posted details everything involved in doing the swap, including how to operate the VDI.
I'd really like to see what my old motor would have done with an s5 intake. It was completely s4 and made good power to 7500....

As for extrude honing, I would rather spend a couple hundred more and just get ITB's. I realize that this involves a standalone, etc, but I would already have done this before I attempted anything that drastic on the intake anyway. I also realize that this would affect the low end torque, but if I'm spending this much on an NA I want the absolute most power I can get because its going to see track time and not be a daily driver.

J-Rat

iTrader: (2)

I couldnt agree more, but the cost is a bit prohibitive. I can afford it, but I cant honestly understand why its so pricey.

Sideways7

iTrader: (7)

I forgot, there is actually a before and after dyno of the s5 intake swap on the link I posted.

Icemark

see, the cost is not anymore than a partial rebuild kit, or a decent exhaust, so I guess it doesn't seem that much to me.

staticguitar313

iTrader: (2)

Random question, do S4 intake manifolds match up right to an S5 n/a block? need to know . . . im keeping emissions.

NZConvertible

The first thing you should do to a modded S4 NA is ditch the exhaust pressure operation of the 6PI system. It works perfectly stock, but as soon as you reduce the exhaust backpressure with an open exhaust you move the auxiliary valve opening point higher in the rev range, meaning you loose potential mid-range power compared to opening it at the ideal time. Change it to air pump and rpm switch operation. Personally I'd do that before the VDI swap.

Actually all of the gains from the S5 intake are from the VDI system, and all you need to control it is an rpm switch.

Ugh, the obsession with peak power... The whole point of variable length manifolds is to give the engine two different states of tune. If you've ever seen the two torque curves produced by the two different positions of the VDI valve you'll see they are totally different, and being able to switch from one state of tune to another at exactly the right point gives you a much broader torque curve than with a fixed length manifold. Even though the S5's peak torque wasn't much higher that the S4's, the increases on either side of the peak were considerable.

J-Rat

iTrader: (2)

Yeah, if you read further down the thread I had already figured out it was an RPM switch affair.

YEP! And I got plenty of it!

McHack

I've been looking for this, but its taken me a couple of days to find it. Can we get this Archived, plz?

McHack

Actually, I found a couple of good threads regarding this swap... maybe compile all of the valid data & then archive that?