hey im just wondering what i should do, i want to make my na turbo, i have some money around to get the turbo and all. Plans will be to run 6-10psi on a stock s4 turbo.

how much hp should i get @ the wheels with my engine stock? or should i get the engine ported (someeone told me this is a bad idea and will want to overboost)...

i want to make about 220-240 rwhp , stock port is this possible or streetport needed, if not i would just get the exhaust ports ported

 

Well if you think about it, the big changes from the TII to the NA turbo are

1)Higher compression ratio
2)6 Ports

So if the TII is 200hp stock, and the NA is around like 170 (s5), I'd assume, well take a guess, that you'd be making like 220fwhp or so?

 

It's more that. Higher compression makes more power with boost, the overall port area is slightly larger with the N/A than TII, if you add an exhaust (necessary when doing turbo'd n/a anyways) that is larger and flows better it'll show a bunch of improvement, you might as well do a cone intake at the same time since you have to convert it anyways which mean more power, etc. Basically, you SHOULD be seeing more than 20hp increase at the flywheel with all of those factors.

Just think of it this way. If the stock TII has 200 at the flywheel, you'll at LEAST have that. With all the other factors invovled 20hp at the flywheel would be a pretty big disappointment.

 

beat me to it

 

And also, I know you had something leading to this in your original post RexRyder. But Blackpleague was talking about s5 TII and s5 N/A when he was quoting numbers. He was incorrect with the N/A, though. For those interested.

S4 TII = 182 bhp (net) @6500 RPM and 183 lb-ft @3500 RPM
S4 N/A = 146 bhp (net) @6500 RPM and 138 lb-ft @3500 RPM
S5 TII = 200 bhp (net) @6500 RPM and 196 lb-ft @3500 RPM
S5 N/A = 160 bhp (net) @7000 RPM and 140 lb-ft @4000 RPM


So since he has an s4 according to his profile, obviously you'll have to take some of those numbers and factors into account with power guesses. What was stated before by me was comparing s5's, not s4's. Obviously the s4 will make less power.

 

A guess isn't wrong, its a guess, my guess. I said 'around' 170 as I wasn't sure of the exact number. Please don't make it sound like im spreading misinformation, I gave him a ballpark figure, this is evident with the words like 'guess' and 'around' in my post. I knew someone would come in with some real fact, but in case they didn't, im just trying to help out.

 

Yah we understand, but sometimes guesses don't really help

Truly, the only people that should be giving him real "guesses" or estimates are only people that have actually done turbo'd n/a's. I have not, so anything I said was also an uneducated guess. I can say, though, that it is pretty likely that he'll see better gains than like 20hp at the flywheel, but again it's only my uneducated guess I suppose.

 

I would really like to know the answer to this as well. I'm soon going to be rebuilding my gsl-se motor and am going to be turboing. If i don't neeed new housings i would rather not get them. If i do need new housing i will probably get turbo ones though. Anyhow if i can make more power with the 6port block then that would be awesome.
Dom

 

I have turbo my s4 na with s5 turbo front mount intercooler and ran mid 13 easily. Not sure what hp number were like

 

howd u kno

 

i want like 220-240 rwhp, so that is about 280 hp @ the flywheel or so... what would i max at with 8psi on stock ports (ported exhaust ports), or what would i be maxing at if i steetport it (though i heard an s4 turbo wont be able to handle boosting a streetported motor)

my goal is at least 220 hp at the wheels with the turbo and leaving the engine stocks ports, possible ? or am i looking at more like 220 on the flywheel? i thought id get more with turbo, i was lookingat getting 170 @ the wheels with no turbo

 

i want to make at least 220 to the wheels minimum

 

would i be able to run turbo on my car reliably with a safc , turbo injectors, and turbo fuel pump ?


s4 turbo on s4 na

could see on one site that the wastegate gets in the wway of the frame using the spacer to clear the intake manifold... is it possible for me to get an external wastegate so i can clear the frame , and will there be enough space for the engine to move without the turbo/compressor wheel hitting the frame ?

 

Because I read your post before you edited it

 

It really all depends on other mods/tuning to go along with it I guess. We need some of the actual people with turbo'd n/a's to step in and give their experiences, though.

 

yeah that would be nice, im trying to search on it but my computer is being gay and the search isnt working for some reason lately ....

but yeah i want to be able to run 8-10psi safely on my system

 

220 HP to the wheels is easy. Stock turbo, stock intercooler and 550CC injectors (with S-AFC and fuel pump) will do it without breaking a sweat.

Very easy to get power out of a 6 port turbo setup due to the long duration of the aux ports. Sort of like a streetported TII.

Most of this info is in the FAQ, as well as direct links to various turbo-NA projects (including mine).