what is the max amount of boost the motor can take even im talking about the actualy motor i mean if you have the upgrades like the fuel injectors etc whats the max boost it cant handle thats all i really need to know

im intrested in this car NOONE BUY IT! lol but im really intrested in this car and was wonderign how much boost it can take....


http://cgi.ebay.com/ebaymotors/ws/eB...472669466&rd=1


TwEaK

 

erm.... it depends on what you are doing.
i would think it could at least handle 400-450 to the wheels, if we are talking about JUST the block. Might have to upgrade the oil jets in the ec shaft(not sure on this one, maybe this is a high rpm thing and not a high boost thing? I know it has a lot to do with cooling the rotors...)

 

i do want a decently fast FC check out the link and tell me what you think and what you would do..
TwEaK

 

Just remember that the amount of boost and the life of the engine are inversly related.

 

well the guy says the car is rebuilt new engine from atkins rotary with 0 miles on it and was going to put different injectors on it so and then i would need to bolt on the upper intake and crap like that...
TwEaK

 

you should of just posted the question and not mention the car on ebay IMO. People have drilled out new spots for extra dowel pins on the S4 block to reinforceit. I dont remember how many dowel pins were on the s4, any one??? -alex

 

o well hopefully i can trust the people here and let them give me the chance to finally get my TII

TwEaK

 

you should be thinking about breaking the car in properly first. Then doing ALL supporting mods before you try to just turn the boost up.

 

it was actually just a question out of curiosity i know the i need to get the car down here first and check out what it needs i would need to email him and see if the fuel rail and stock injectors are included and if he has all the bolts and throttle body upper intake and intercooler and etc..... but i just wanted to know to see
TwEaK

 

oh ok. I thought you were planning on gettin it and cranking the boost up first thing.

 

well my brother told me that the stock block can handle up to 14psi he said by the time the car is 100% done to put it at 13 so if it creeps it goes to 14
TwEaK

 

bumparu
TwEaK

 

bumparu
TwEaK

 

bumparu
TwEaK

 

Stock s4 block will start to crack around 400rwhp. Irons are not reinforced. You can't really squeeze more than 400rwhp out of stock ported motor. Psi does not equal hp fyi. That motor can take anything you personally can throw at it.

 

yah, but 400hp can be reached with a huge turbo flowing a lot of air at low pressure or a small turbo pushing 40psi.

So the question isn't really how much power can be made, but how much pressure can the stock internals withstand?

 

ok thats my question then how much pressure can the internal take?

TwEaK

 

haha nobody really ansewered your question. If you want to know how much boost the car "effectively take" then I would say around 14psi without mods or 16psi with mods until the efficiency of the turbo dies off, creates more heat and starts making things worse possibly. I dont know through expierience. Just 16 is the number I have heard on the stock turbos for a long time. I would say 1 bar or 14.5 is safe for a tuned car but you can do whatever you want and find out otherwise. 1 bar with mods is alot of power.
mabey around 300rwp with a standalone. Ofcourse you can get more if you boost more with supporting mods but ideally I dont hear anybody going over 16 and when they do the turbo doesent last as long. My friend in his 3rd gen had 280rwp with a standalone and 12.5psi on the dyno here in SD...FDs can generally go to 16psi as well.

 

on the stock turbo or aftermarket?

 

Stock turbo you don't want to push past 9psi. It starts to choke on the turbine side of the turbo past that. Past 12psi and you are going to fry the bearings pretty fast.
I've seen dynos of stock seals holding up to 35psi.