How much Horsepower can a Stock S5 motor handle??
 

how much Horsepower can a S5 TII handle before engine flex becomes an issue
i know it depends on mainly the fuel and turbo set up, but if you had say a turbo and fuel mods that could run a 1000hp (not mine just to rule out any fuel or boost issues in this thread ) what is a safe limit of hp the stock internals can handle
I think i read somewhere a while ago that around 450Crank HP you need to get the engine dowelled to prevent the engine from flexing but i would like a definitive answer

the only internal things i can really think that would need to be upgraded (not including fuel and boost)for a 500+hp 13B is
Stonger Apex seals,
Engine dowelled
and a big port job
a good rebuild kit

is that all there is???

does anyone have any experience with the mazda trix stock diameter strengthend dowels , they are stock diameter but it says there no need to get the engine doweled

i know theres alot work that goes into making those kind of numbers , i'm just tryin to figure out the limitations of my current motor, and i have some plans for this fall for another motor

i think this is matter of opinion. (all internals mazda OE) id say anything over 500 you will have longevity issues.
it could take 1000 hp but for how long?

500hp


-Ted

this fall i plan on buyin another jdm S5 motor buildin it with a bridgeport and the biggest exhaust i can run on the street, atkins rebuild minus the apex seals, and i'm still undecided on the apex seals either RA super seals or rx7world apex seals, or i may just use stock, i'll research more later for those, and maybe some mazdaspeed rotor and main bearings, mazdatrix strengthened dowels
gt35r or gt40, dual fuel pump sending unit, and i have an OS giken Twin disk
i'lll modify my current fuel set up for that motor it has stock injectors with 2 550cc injectors added to the dynamic chamber and 2 550's in the IC piping, the extra injector will help lower the IAT and with better fuel atomization add a richer air fuel mixture, if i add 720 primaries and secondaries and the 4 550's running them at 70% should be good for around 512 flywheel hp 585 at 80%, according to the 2nd gen fuel calculator lol (i know its not 100% but its a rough estimate)


This is just my reasearch phase , its goin to be a year or so long project hahaha just something to keep me busy
I just want to join the 500hp club!!!!! hahahaha

In my experience 350-380 rwhp was the ideal for the car, the engine ran and started excellently and lasted the longest. I had my car up to 450rwhp and had things break fairly often on it. The engine itself though took all the power I put into it with Stock Apex seals and a LARGE Street port.

i've read alot of good feed back about the stock apex seals
jreynish what size turbo did you have?

500whp sounds like a good number to me assuming you don't detonate. This assumes you have an s5 engine with the stronger rear iron.

how do you tell if its the stronger reaer iron,

If it's the S5 motor.

http://www.rotaryresurrection.com/2n...ron_break.html


"The 89-91 castings are supposed to be larger and/or reinforced, however this is NOT always the case. IN fact, I’ve taken apart dozens of US spec and jspec 89-91 13bt blocks and only about half of them have the reinforcements pictured below. There seems to be no real pattern to which engines did and did not get the reinforced back iron."

look at it?

I think my current motor has the beefed up version of the s5 rear housing....theres the extra support but theres 7mm lip atleast where it extends pastwhere it joins the housing

Another problem with high horsepower operations is the eccentric shaft likes to flex and in turn the apex seals are crushed against the housing and blow. My boss said he used to race with a guy who had a custom centre support bearing for his eccentric shaft which was custom fabbed, and custom fitted into his 13B. That motor made over 1000hp.

I had a TD07-25 Turbocharger.
The S5 Rear housing is held next to an S4 is fairly visible in difference in the areas where dowel pins go. I understand high horsepower cars are nice to have dyno sheets for but have you Driven a 350 hp 2500lb car?
It is pretty wild and super fun.
450 hp is scary so I can only imagine that a 500hp car is scary as hell to drive on the street.

i come from a family of car guy/ mechanic's , my dad has a couple old vega's the 73 gt has a 327 outta 64 stingray bored to 331 4" stroke 4" bore clean revvin to 7 grand its 430+hp 2800lb car with a detroit locker, he lets me take it out every little bit, his other vega is all tubbed out 19" slicks in the rear and a 355 with a huge ass 850 blower, i haven't got to drive that one yet, i'm the black sheep of the family lol i'm into those "nip cars" gotta show my dad and ucles up lol

the motor and set up i have in there should get me over 350whp
i just want to build up a motor on the side

i dont mean to jack your thread. but is there anything you can do to reinforce the rear iron?

I have taken appart several Original 13BT S5 engines and they all had beaffier rear Irons as pictured in that thread. Not certain if there is a difference or not but all of the s5's I have taken appart including two 20b's have the Beaffier rear Iron Casting. Go figure same thing I guess as the pulleys seems to be no rime or reason as to which pulley you get.