I want out of my SMIC so i can actually run fun boost.
On a budget, I found Hybrid on zilvia selling complete fmic setups for under $600. which is pretty nice.
But, their intercooler and coldpipe is 3". Cars running 400whp don't even run 3". The throttle body isnt even 3".
Will the massive core and cold pipe contribute to much turbo lag?
Is any lag a result of the turbo having to spin faster to produce the desired PSI all the way at the throttle body? If so, are the extra RPMs harmful to my sleeve bearing T-25?
Is compressor efficiency based on how much air the turbo can compress? Or does it rather have something to do with being Able to compress air past a certain shaft speed per compressor design?
i.e. i know its bad to run a t25 past 15psi, but is that because at 16psi it cant push past the literal wall of air, or is it because the turbine is spinning so fast the compressor can't "process" the air?
i dont know if im being clear enough... but i dont really know how else to explain my concern. Im assuming its not that big of a deal but I just dont want to prematurely ruin my turbo by making it do 16psi worth of work to get 12psi at the throttle body.
Intercooler piping size?
Re: (BaliLover)
i was mistaken... The intercooler piping is 3" out of the intercooler and transitions to 2.75 to the throttle body.
anyway I was concerned about the compressor having to do abnormal work to pressurize a larger volume, but its just as simple as taking longer for pressure to build up > hence turbo lag. It wouldnt have to be spinning any faster to pressurize it, it would just take longer to do so.
and 15psi is the hairy edge of a T-25 before it cant do any more work... 13/14psi is about all you can safely use out of it per cfm/charge temp
anyway I was concerned about the compressor having to do abnormal work to pressurize a larger volume, but its just as simple as taking longer for pressure to build up > hence turbo lag. It wouldnt have to be spinning any faster to pressurize it, it would just take longer to do so.
and 15psi is the hairy edge of a T-25 before it cant do any more work... 13/14psi is about all you can safely use out of it per cfm/charge temp
Re: (Neil)
you can use a 3" cold and hot pipe. no it wont induce turbo lag its cause by not enough exaust flow to make the turbine spin to its potential
Re: (Neil)
Increased i/c pipe diameter and longer piping will increase "turbo lag". The proper term for this scenerio would be boost threshold.
No, your compressor will not be doing "abnormal work" to pressurize the larger piping.
No, your compressor will not be doing "abnormal work" to pressurize the larger piping.
Re: (ibekinq)
ibekinq wrote:you can use a 3" cold and hot pipe. no it wont induce turbo lag its cause by not enough exaust flow to make the turbine spin to its potential
Remember, the right amount of exhaust flow isn't just Given to you.
The turbo shaft is (obviously) solid, Therefore boost threshold with enormous piping produces sort of a catch 22 scenario. With 3" piping The compressor wont spin up quickly enough to pressurize the system, because there is not enough intake to produce the combustion gasses required to spin the turbine in order to do so. I mean, it'll happen eventually, but at the cost of drivability... which completely negates the reason behind owning a T-25.
I figure Nissan's pretty smart. Using a 2" hot pipe with a T25 probably had a foundation of reason.
All I want is a FMIC setup that'll efficiently cool off 16psi (when the time comes) and not be the cause of significant turbo lag. The more research I do the more I come to realize it's intercooler design that has the most effect regarding safe power output. I used to think intercoolers were "air to air radiators, nothing special here" but tried and true.. you get what you pay for.
Re: (Neil)
No, it has nothing to do with "how quickly" the tubro "spins up". It has to do with the amount of time it takes for the piping to be pressurized. You're overthinking this and no offense (really, don't be offended) but you don't understand the basics behind turbocharging so it's pretty much pointless for you to try to figure this out in your head using logic. Why do people run i/c cores behind the core support or v mounts (amongst other reasons)...the shorter piping means less time for compressed air to reach the trottle body. That means better throttle response! Stop thinking this is about the compressors ability (from an efficiency standpoint) to pressurize the piping. That's wrong.
Intercoolers are heat exchangers just like a radiator. Calling an intercooler an air-to-air radiator is like saying an oil cooler is an air-to-oil intercooler. It doesn't make sense. They are all heat exchangers. Same basic rules apply to all heat exchangers so really, there is nothing special to it.
Modified by Dori Dori at 2:21 AM 2/28/2006
Intercoolers are heat exchangers just like a radiator. Calling an intercooler an air-to-air radiator is like saying an oil cooler is an air-to-oil intercooler. It doesn't make sense. They are all heat exchangers. Same basic rules apply to all heat exchangers so really, there is nothing special to it.
Modified by Dori Dori at 2:21 AM 2/28/2006
Re: (Dori Dori)
youre right... i do tend to overcomplicate when i try to figure certain things out.
thanks for helping me to understand
Modified by Neil at 8:39 PM 2/28/2006
thanks for helping me to understand
Modified by Neil at 8:39 PM 2/28/2006
Re: (Neil)
i'm trying to do a simple 7lb setup and i have 2 intercoolers a 1st gen dsm then a front mount 6" by 2' i think,dunno haven't gotten it yet!trying to do an inexpensive setup but i want maximum response but i don't wanna overheat! can i get away with the dsm and 2.5 piping throught, ive seen the 'silvia' kits on ebay for 100.