Assuming intake air temperature is not an issue, just how much power can a Turbo S4 engine take?
Also, once it reaches that power limit, what parts tend to give out?

 

Anything over 350 Hp, in my opinion, is about the time you start breaking EVERYTHING!

 

Can you be more specific? What breaks and why?

 

transmission. motor mounts. =/
i cant really answer your question (especially from any experience), but out of curiosity and to help you out, do you mean a recently rebuilt or at least properly running S4 block?
87GTR's car (sold) made 499/399tq on race gas. depends how you drive the car, of course, and how often you hit higher numbers (higher boost/rpm). i'm sure i'm not telling you anything you don't know already, of course.
but yea, everything i heard of that he broke was not engine related. i wanna say his was an S5 block with S4 rotors. i don't know the exact differences between the 2 engines, but i'm curious (just not curious enough to search right now).

 

People go over that just fine.

 

I mean a properly running S4 block.
The car doesn't get beat on. I don't drag it, but the occasional autocross or performace road racing seminar isn't out of the question .
I'm going to rebuild the engine this fall/winter and I want to build it to be reliable for that type of driving.

 

Typically, about the 450 HP range without redowelling the engine.

 

So basically, unless I plan on pushing more than 450hp, the engine should be able to handle the power?

What, exactly, is redowelling?

 

the s4 engine usually shouldn't be expected to take more than 400 rwhp stock... and for the $$$ ur gonna be puttin in it just go to a junkyard and pull a s5 motor...
What breaks after this point is the engine internals and housings and stuff.. .the motor can literally fly apart after this (never seen it, but heard about it).
Also, your tranny won't be able to take even close to this amount of power, nor the rear end, shaft, etc...

 

past 350twhp your pushin it for safty sake without doweling it. otherwise youll have little oil leaks poppign up here and there

 

Yep...then one day the plate will get a BIG crack and bye bye oil S4 rotors + S5 housings/plates is the big boost combo.

But honestly, how much faster of a car does someone need for the street than a 350rwhp FC?!!?!?

 

A seriously, the much power in a street driven FC is like driving a goddamn rocketship.

 

Need?? Outside of the relatively few on the board that use their FC for racing or some other legitemate business purpose, how many of us really NEED a 2 seater that drinks gas like a V8 Pickup but has half the luggage space of a 1975 VW Rabbit?
There're alotta words I could use to describe the FC -- practical ain't one of 'em.
But, IMO, if you're gonna be impractical and drive one of these rotary rockets, you may as well up the power if you can do it safely.

 

How much more power can an S5 engine take?

 

that much power in an fc in the streets u will come out in the news..hehe local man wa arrested today for going over 200mph on the highway, or a time bomb or death trap. honestly how many people would actually drive slow if there fc had 400hp? how many people are actually gona try to kill them selfs? oh look my car is fast i can clean the corner look at me guys< oh **** im going to fast u roll 3 times and come out and say damn i think theres oil in the road lol. im gona get flame fuc* it im bored , i been in this stupid *** class(how to use a mac) it's for a stupid as web site class lol. i own a mac do but theres chicks here(hope my chick don't read this haha

 

350RWHP isnt that fast. Low 12s, high 11s in the 1/4 mile. ABout as fast as a stock Z06 corvette. I personally would like to see 400-450 at the wheels. I think past that would be past the limit of anything you could really "use" on the street.

To answer your question of the difference between S4 and S4 engines, the S5 irons (especially the rear) have extra casting around the top dowl pin hole, to help eliminate the issue with it cracking like some S4s do under high boost pressure/detonation.

 

Wha? I've never seen anyone break the tranny in a TII with only 350 hp. That tranny is baised off the older type R transmission used since the 70's, and is almost identical internally as the third gen tranny. I know these handle 600fwhp with no problems. As for the rear end the limitied slip is a popular choice for people drag racing high output 3rd gens, running over 500-650fwhp . The half-shafts I'm not certian about, but are should be good for AT least 400fwhp. I've found that as a general rule (which may not be accurate) the S4 handles 400hp ( do a search on online, there is a good article on this, under 13bt vs. 13b-rew), S5 about 550hp, and S6 650.

 

Funny.
Maybe I should start a poll..Which would you rather be doing right now-driving a 400 rwhp FC or be stuck in Mac 101.
--i dunno, maybe this audience would be *a little* biased.

 

[QUOTE=Rxmfn7]350RWHP isnt that fast. Low 12s, high 11s in the 1/4 mile. ABout as fast as a stock Z06 corvette. I personally would like to see 400-450 at the wheels. I think past that would be past the limit of anything you could really "use" on the street.

Agreed...but a low 12 second street car is pretty damn fast! Is there anything stock that fast under $50K?

Besides, you're not 100% sane - you buy a new set of Volks every other week (I'm just playing- I'M JEALOUS hehe)

 

let me see st1 the evo rs or the new evo the mr , svt lightning. the new ones

 

eh, a little off topic, but in lowfreq sig it says "hybrid turbo". Hybrid with what? im really curious.

 

So for 400hp would you recommend the lower compression s4 rotors? (series 5 sideplates)

 

Honestly LowFrec not trying you or anything, but I think if you
took a drive in a 350 + RWHP Turbo-II you would **** your pants litterly my brotha.
A friend of mine had a Turbo-II running a Holley 650 Double Pumper carb with a Blow through box setup, running a 60-1, and all the other trimmings such as FMIC, and fuel upgrades. We would go to the hang out, and line up all the "Pony Boys" with there 5.0's
and even a Supercharged Cobra stang, and smoke the **** out of them one by one, just lining them up one after the other. His Turbo-II dynoed 375 RWHP @ 14 PSI, and at the track it ran a 11:75 quarter mile. When we ran the stangs it was on street tires. If he puts on slicks the car should run a low 11" quarter for sure. Now to answer your question, with the setup he was running, he was already cracking the rear plates, and I believe also he broke the drive shaft once. Then again for the power that his Turbo-II had, it was pretty reliable, unfortunatley the car was not meant to be a daily driver because of the bad gas mileage he would get, I believe it was like 11 miles the gallon due to the Holley Carb. The
87-88 blocks have a tendency to start twisting once you start exceding over 400 HP. Thats why some pople pin there motors to prevent the twisting, pinning the motor consists of adding extra dowel pins, this process has to be performed buy a knowledgeable person that knows what the Fu.." there doing with out a doubt. As far as breaking things like someone mentioned earlier yes I also strongly agree once you start pushing over 400 RWHP thats when things start breaking, then again it depends how hard you drive the car, eg: "taking it hard off the hole", doing burn outs, hole shots, etc. In my Turbo-II im going to run the same setup my buddy did, but im going with a Haltech, and a 60-1 or a 62-1. More than that son, and you'll probably end up wraping the car around a pole or killing yourself. Seriously though why do you need or, better yet what do you need with more than 400 RWHP in a street driven FC ?
Im sure you driving skills arent up to par to handle that kind of power sorry to tell you. Start of slow get used to the car, then when you can handle it go for more power. Good Luck.

 

None of those cars are even close to running low 12's. Bolton's would not allow those cars to run low 12's on regular street tires.

 

Just to set things straight, first off-I'm not a 17 year old kid with his first ride, secondly-neither am I some 25 year old kid with his first decent job looking to dump money into his ride so that he can smoke Mustang's on the strip Saturday night.
[climbing onto soapbox]
I was legally driving before alot of the people on this board were born. Tho I have taken performace driving courses and have done *some* road racing and autocrosses-I would say I'm FAR from a Pro driver, but I would also say I'm FAR from a novice.
Unlike yer buddy with the Holley powered 7, I don't feel the need to 'flex' and 'front' by racing Stangs or anyone else on the street. To each his own, I'm not gonna sit in judgement, but that's not my gig. Take some performance driving seminars with REAL road racers as instructors and get a respect for your life, other people's lives and not to mention the car that you've dumped so much money in, and you'll realize just how stupid racing on the street is. -- but hey, that's just my opinion.
[climbing off soapbox]
That being said, even if I could put 800hp to the wheels-if my dual-stage MBC is set to low at ~250hp the car would be perfectly streetable-then on the track, just kick it to Hi.
Now..a little background on my original post..the reason I was asking the question isn't because I PLAN on putting that much power to the wheels--it's because I ALREADY HAVE.. and, as a side note Donn Hecht, my drawers are still white. Attempting to test the limits of my WI, I've done a few runs with my MBC close to maxed out. I'm not sure how much boost I was pushing because my gauge was tilted at 20. So, I was pushing well over 20lbs and intake air peaked at 42degs C (I guess my WI passed the test). And even on high boost, the car is perfectly streetable. (Ask my wife, she drives it regularly with the kid in the carseat in the back)-- Just keep your foot off the floor. How simple is that?? That kinda power/weight ratio is fairly equal to the 04 Vettes and 911 turbos around here and I don't see them wrapping their cars around trees. Why? Well I guess 1 Because they don't feel the need to have their foot to the floor all the time. 2. They drive responsibly.
So, to sum up, contrary to popular opinion, I think it is indeed possible to drive an extremely powerful car on the street without killing yourself, your car and other people. How? 1-get a dual stage mbc or 2-I know this is somewhat of a foreign concept to some, but--DRIVE RESPONSIBLY. 3-keep your foot off the floor.
But the REAL question is--what would need to be done to keep the engine reliable.