xzyras

212rwhp if i remember correctly

What law of physics are you applying here? 85-90psi? You mean on a piston tester then. Thats kind low compression isn't it? I dunno what your getting at with compression, but my motor was tested last month at 8.1 on each seal.(on the mazda tester) And this is way after those mods, years later, im at 272rwhp now. You can take your car up to 10K in 1st and 2nd gear? If not how do you know? Im not sure what that means.

I have to? Its not possible? I dunno what to tell you, other than I certainly never got boost creep in 5th gear. Although in all fairness it isn't often I WOT in 5th gear past 5K, even on the track. So I might have gotten creep in 5th at WOT, but the 1 or 2 times i did that, no creep.

No worries, we're just talking. That turbo is not ported, because when it came off my buddy borrowed it so that he wouldn't have any down time while his turbo was upgraded. At the track when I rode with him on his session, he crept to 14psi a few times on my old turbo. I already said this.


?

What happen to "you cannot change the fuel ratio to compensate" Acoording to you, doing the second one would be very bad. And people who added any kind of mod without addressing there fuel are in big trouble, according to you. (i.e. intake, dp, catback) And why would he need a MBC, I thought we were trying to keep from boosting more, not help it? Porting helps, but does not eliminate the creep problem. I dunno whats going on here either...

What if I get thirsty from all the work? Whats going on here?

Yeah but you need more sun block and it takes a while to put on, then you gotta wait before you go in the sun Ok, so your saying the car goes faster in the summer but needs more gas? Winter? Summer? Cloths, water, thirsty, easy to move? All this is the same as a motor?

Now there's some good advise! Excpet for the gatorade part.

Impossible to not to boost creep? A lot of us on the neverending quest for more power can't get those damn turbo's to hold boost till redline. Mine died to 8psi sometimes creeping down to 7psi after 5.5k. That's why we go hybrid. Is this new info?

Ok holloween time guys. No more car talk for today. I posted to much already too.

NZConvertible

No they aren't really. A healthy 13BT with a healthy turbo and a full exhaust will completely outflow the stock wastegate port. My engine (plenty of miles, never rebuilt) made 8psi with with a very restrictive stock DP in place and hit fuel cut in 2nd gear with ease once that was upgraded. Either something was wrong with your car or the wastegate was not stock. To claim you can run a full exhaust on a stock wastegate and not worry about boost creep is simply spreading misinformation.

WTF? Are you serious? Of course 75% throttle will limit boost! Most people would not considered feathering the throttle the preferred method of controlling boost.

That's the stinkiest load of BS I've ever heard.

That's good advice. You should follow it...

While you're learning about turbos, learn about EFI too. The ECU does not have a "set fuel ratio". Increased airflow from mods is measured by the AFM and up to a certain point the ECU can compensate for that as long as the fuel hardware can provide enough fuel.

xzyras

They aren't really? Come on, they either are or they aren't. Im not claiming you can run a full exhaust and not worry about creep.

Someone, well a few people told the thread starter it's "imopossible" to not and that there were no ifs and's or but's about it. So I said " MY <----- car didnt creep. Thats it. Then you told me that it had to. I asked you to tell he how and why, if you like you can go back and read my question,quote it and answer me on my "broken" car. But you conveniently over looked it. Ted was curtious enough to take a stad at it. And if you can explain to me why more power to you. I never told anyone not to worry about boost creep if you get a full exhaust. When and where is that said? I said all cars are different. My car is not the only one not to boost creep. Although 90% of the TII's I have been around do creep, and they should address there problem, the other 10% including me don't. So what do I say to people when asked about this? I tell them it most likley will. I never had that problem but its very common in the TII becuase of the WG. If you understand that as me caliming something like that and informing people not to worry about creep, I don't know what to tell you.

And your boost pattern is not the topic here because he has a S4 and you are running more boost to begin with, a different fuel cut setting and a different turbo. That said, I understand why you may be skeptical about what my set up did, I would be to had I not seen it a handfull of times, but I don't know what to tell you. I asked you a few questions to see if maybe we could figure out why, then us 10% could finally join the ranks, but...Lets just agree to disagree that every single TII ever made will creep. Cause I need your help on a heating issue, haha.

RETed

You're asking about the difference in engines?

http://fc3spro.com/TECH/FAQ/ZVK/zvk.html


-Ted

RETed

Ah...you have a fuel computer installed?
That kinda makes a difference.


Yes, it sure does.
In mild rich instances, it suppresses boost.
In extremely rich instances, it'll prevent the engine from running cause all the fuel fouls the spark plugs, and this keeps the spark plugs from firing.
No spark...engine cannot run.


It's not unheard of, but it's surely not common.
As NZConvertible has already mentioned, something is "wrong".
I think we're overlooking something that you didn't mention or forgot to mention.
There are a lot of things that can affect boost, and I'm sure we missed something somewhere.

I think for now, be glad you don't have to worry about it.
Just enjoy the car!


-Ted

NZConvertible

The basic design of all S4's is the same. In stock form they all have the same engine, the same turbo, the same tiny wastegate and the same restrictive intake and exhaust that let Mazda get away with that.

Not, you are the one that didn't realise you had a problem to address (or didn't know your wastegate was already ported). Boost creep is caused by only one thing; insufficient wastegate flow. All S4's have exactly the same wastegate port which when stock is too small to cope with the increased exhaust flow you get from significantly reducing exhaust restriction. If there was nothing wrong with your engine or turbo, how come your wastegate was able to flow so much better than everyone elses? Are you sure it wasn't ported before you got it?

Actually I have an S4 with the same fuel cut and the same turbo. But my point was to show you that my engine had a more restrictive exhaust than yours and yet had the same boost.

If I slapped a big exhaust on my stock-turbo S4 and only got 8psi I'd worry...

xzyras

Oh, I thought he ment just rich where only a wide-band would catch it or a strong smell. A mild rich instance, like you said, how does that affect boost? I guess it wouldn't flow as much exhaust gas and all that unburned fuel would slow the turbine down. My guess. Close?

Rich, rich, with bogging and so rich the car won't run I understand.
Im with you on that one. All I been saying

Absolutely, Im glad the car ran great. Now Brian at BNR ported and clipped my S5 stage 1 hybrid, so I won't have creep ever, ever!

RETed

Sorta, it still has to do with spark plugs and combustion.
With the mild rich condition, the spark plugs don't fire as consistently and the combustion is incomplete - i.e. if the mixture is rich with too much fuel, the burn is "lazy".

At 14.7:1 stoic, you get a big BANG.
If you light a "pool of gas", it doesn't go BANG.


-Ted

xzyras

Not? Haha, ok. I dunno what that means. We disagree I get it. A few rex's don't creep and you loose it, hehe, sorry I had to much candy.

I believe you when you say you would worry, but im not worried. We do after all have a few nice rotary machines here in California, we must be doing something right.

xzyras

But the cause is the unburned fuel exiting in "lazy" form causes the turbine to spin slower instead of a full clean burn exiting faster. That's what I said, isn't it? I guess I did know that. Thanks!

RETed

Yeah, that's one half of it.
The other half is that is kills the spark from the spark plugs somewhat.
A richer mixture makes it harder to ignite the spark plug.


-Ted

nubian

xzyras, your a pain in the ***! :P

Peyman

iTrader: (2)

no, i know the difference in power, i want to know how to identify the difference....my car feels very strong and fast, so i've been thinking maybe he did a s5 swap into my s4 vert.....so i was just asking if there is an easy way to tell if it has a s5 swap or s4.....

RETed

Guess you didn't read the entire page...


-Ted