Boost questions

[Logo]

Since I'm very serious about making a 240sx my project car I need to ask a few more questions. <img src="#/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

How much boost can the blacktop sr motors handle? &nbsp;What about the s14 ka's? &nbsp;Has anyone gone to forged internals on their ka and if so, how much cash was spent? &nbsp;One last question: how much boost can the stock turbo on the blacktop sr20det make? &nbsp;Thanks for taking time to read through this. <img src="#/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

[ScottC]

People around here seem to put to much stock into psi of boost. Psi alone doesn't really tell you anything about what you are doing to the engine. I.E. different turbos will all make different amounts of power at the same boost. Also you can blow an engine up at 5psi with a bad tune (or lean condition) or have it run fine at 20 psi (with a good tune)

My $.02

[West]

With the STOCK SR turbo I would only run max of 14-15psi, this of course would be with every other supporting mod. I would imagine the stock turbo would be good for 320rwhp.

S13 SR20DET: T-25, 60 trim 56mm BCI-1 compressor, 53.8mm 62 trim
T-25 turbine, .64 A/R turbine housing. Journal
bearings.

S14 SR20DET: T-28, 60 trim 60 mm BCI-1 compressor in T-04B housing,
62 trim 53.8mm T-25 turbine. .64 A/R turbine housing.
Ball bearing center section.

S15 SR20DET: Same as S14, but with Inco turbine wheel (instead of
GMR), cast divider wall between turbine discharge and
wastegate.

The s14 KA engine can handle about 10-11psi. So on estimate you should have about 240-300rwhp depending on mods. I plan to build my KA motor but not for some time as my car needs other things <img src="#/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

[Logo]

Thanks for the info WeST. Where can I find detailed information about the sr20det? I need to know such things as stock boost etc. Has anyone built up a ka or sr motor yet? How much would an entire rebuild cost? What internal componant is the weak link in both motors? I'm assuming that only the pistons up until a point. Also what turbo kit for the ka produces the most bang for the buck? Regardless of cost, what turbo's currently on the market would produce nice power at lower boost, and experience minimal lag? If there are any good faqs out there that would help me to answer these questions as well as learn more about both motors please let me know. Thanks <img src="#/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

[ScottC]

Check out heavythrottle.com

[PSI240SX]

I have spent about $4700 on my KA so far in total. The pistons were Arias, $800 The rods were Carillo, $1000 The reason they were so expensive is cause I didnt want to wait for them. I got them from Jim Wolf and they were in stock, plus the rods are longer and the pistons shorter to give a better rod ratio. I could have gotten the rods from crower $667 and waited 12 weeks and the pistons JE from Enjuku Racing for $450 and waited 10 weeks. Well I dont know about ya'll but I cant wait 3 months for my motor to be done so I coughed up the big $$$ and got em quickly.