Mongo

Since acquiring this car back in 2001, I have always wondered if there is any easy way to achieving 400HP at the crank. With all the upgrades out there involving EFI such as the Sharktuner and chips, along with the X-pipe, what else is there really without doing anything internal to get to the number? Clearly the only solution would be to get a GTS of course as the power output is closer to 400 than the S4, but what is the alternative to that?

I'm not trying to be facetious here, but what is a realistic way to achieving that number as clearly bolt-ons do get you close, but no cigar?

Koenig-Specials 928

Nitrous baby! for when you need it.

mark kibort

i did it.... and didnt change that much of anything. equal length headers, remove the maf screens, KN, and pump up the fuel pressure . it got me to about 335rwhp for a few years and then never went lower than 320rwhp. Oh... forgot one mod.... put in the GT cams or make some out of a set of 85 cams
im sure if i wanted to do some intake mods on the plennums, there would be 10hp lurking in there too.
do the cams and a trick exhaust and that will get you very close to what you want..

Mongo

Do the MAF screens really cause that much of a blockage? That's a little dangerous in my book to remove those.

Rob Edwards

30,000 posts over 15 years and you're still looking for 80 hp without any internal modifications? If that power was there for the taking easily, you'd already have it.

Maybe an e-RAM?

Speedtoys

Why...is the filter missing smoething it shouldnt?

wpgshark

Neat question, is it even possible given the present max RPM? You're looking to boost volumeric efficiency by 25%, with out forced induction or raising RPMs I doubt that it is possible.

But I hope that it is.

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mark kibort

i think the filter does that job.. however, if you are worried, you can always seal the air box as i did. that way, nothing can get through. MAFs are used all over the world without screens. screens are havok on air flow .. when the harrier jet had screens, it couldnt even take off! removing them will provide some decent gains. dont know how much, but they have not been on my car since the day i pulled them off in 2002.

It is easy.. and the eram only did 4hp, but nothing on the stroker.
dont take my word for it... an equally prepp'ed GT has the exact same HP... why is that? because it can be done... headers, free flow exhaust, optimizing flow though the air box, and more fuel pressure.

yep, been there done that. i got the car without cats and it made 290rwhp. most all S4s are around 275 to 280rwhp stock. take off the cats, mount some nice equal length headers and adjust the fuel a bit... remove the screens off the MAF and that should get you close.... Oh yeah,, bolt on the 85 cams (after minor mods) thats where most of the gains are found.

Rob Edwards

Would you be willing to define a cam swap as an internal modification, Mark? They do live in the oily bits.

Mongo

It just dawned on me that Dennis K's screamer engine achieved this with regrinds from Elgin. Cams seem to be the quickest route. I'm curious to know what the specs of the grinds are. Searching has not led me to the exact numbers. All I know is they were derived from S3 cams, but I wonder if I could have S4 cams modified to the same profiles once I know what they are.

mark kibort

oh, again... my reading comprehension has not been up to snuff lately. yes, i guess that is an internal mod... i think of internal as INTERNAL, not bolt on stuff like a cam. but, without it, no chance at 400hp.

yes, his cams were 1mm lift more than mine.. bace circle grind would do that with the 85s. that would be the quick and easy route. 85 cams, maybe lap off .5mm and that might get you to 330rwhp with a nice set of headers and a cat delete .

Mongo

We are in CA and this is a street car. Factory manifolds stay on unfortunately. I have an X-pipe with high flow cats in the garage hanging on the wall. I am going to lop those cats off and just clamp two straight pipes in place and merge them with the Y-pipe I have on there now (single exhaust post-cats). My factory cats on there now are just for smogging.

davek9

You already have kens chips and 24# injectors, yes?

mark kibort

so , the removable stuff is a good idea to swap out at smog time, or get some high flow cats. i would get the headers and the nice merge collector, a big high flow cat and a 3.5" exhaust to the rear . but , you might be ok with your plan.... nice equal length headers do make a diff, even though the stock manifolds are not that bad. I think the cams are the best choice for the power bump and a rising rate fuel regulator.

Mongo

Yes. I just have not installed them yet.