Gt30

[CustomS14A]

Would this be the best turbo out of the t series turbo becuase im thinking of getting for my ka but im haveing my doudts it will fit...

[orion::S14]

We need more details...

HP goal, boost range, stock KA or built, cams, and which manifold?

Let us know, then maybe we can help.

- Brian

[CustomS14A]

boost around 20 built from head to toe, with 275 .405 lift cams and a ssautocrome bottom mount manifold greddy f mount custom pistons 7.5:1 with -60cc dish i have only payed for the pistons and fm the rest of everthing else i have to wait about a mounth...so i can save the rest of the money

[orion::S14]

7.5:1 compression...ouch. No need to go so low with modern turbo technology...but if you've alrerady got the pistons, then...OK. I'd do no less than 8.5, though...

So, look at the compressor map here (http://www.atpturbo.com/root/maps/gt30r.htm):

PR = 2.36

Assume spool by 4000, and 7000rpm redline.

You'll need to look at the range from 24lbs/min to 44lbs/min.

Doesn't look like it will surge during spool, and the efficiency is OK, starting in the ~68% range and ending there...but spending a significant amount of time in the 72% range, with a quick trip across the 78% island.

Seems like a decent choice.

- Brian

[kidinthehall]

damn.....why so low on the compression? havent seen crap that low since my friends 280Z 7.4:1 no IC, 1981 turbo technology

[CustomS14A]

The lower compression makes more lag sounds weird but im not really going to drive this car on the street im going to but another 98 shouldn't take to long for my to get another one...I did some research and longer stroke engine need low compression when high boosting...

I want do mabye hit aroung 30psi with 500hp

[CustomS14A]

Dodge Viper cw 3410, [email protected] [email protected] power to weight .14
1993 240sx 2790 add 50 pound for turbo+ mabye [email protected] power to weight .17

[orion::S14]

Plenty of KA/s have done big numbers with 8.5...7.5:1 is not needed due to long stroke.

If you can change the static CR, do 8.5:1.

Only advantage to 7.5 is a bigger margin of error in your tuning...but as advanced as the modern EFI systems and standalones are, you can do 8.5 easily.

Old Porsches and the Datsun ZX turbos did really low compression...and they are PIGS off boost.

Just trying to save you a headache later when you realize 8.5 is the way to go. I'd do 9:1 if I were building a block, but...

- Brian

[wootwoot]

i've heard the garrett gt3071r is one bad bitch. i have yet to see a compressor map though.click me damnit (http://optionimports.com/garrettgt3071r.html)