Hi guys,

In about a month or so, my car will be getting a tune by Steve Kan. I daily drive this with the occasional track days now and then. So I would like to get around 300whp safely. My question is, how much psi can the Knightsport twin withstand conservatively? Would it be possible to reach this whp number with the stock fuel system?

I also have to deal with smog test, so with this in mind, my mods and performance goals are constraint by it.

Here's my mod list related to power output:
Mild Streetport
Knightsport RF420 Sequential Twin
PFC
Blitz SBC i-color i-meter
Intake
SMIC
DP
Hiflow cat
Titanium back

All the reliability stuffs are done. (ie. all new solenoids, vacuum hoses, rad etc.)

Thanks for your time and excuse my poor english.

 

those twins will be able to handle 300whp. the stock fuel system will be able to support 300hp. the fuel system and turbos are both good to about 350whp. how do you like the SBC id3?

 

how do u like the KS turbos? i'm looking to upgrade my stocks to bigger turbos while keeping the sequential setup. I like the kick when the 2nd turbo kicks in. I was looking into the KS pair and the BNR. Which one produces more HP? Do u feel a dramatic difference after u swaped them? thx

 

they're called KS 420 twins. Guess what the 420 stands for.

 

is it that time of day already??
i guess it is haha

 

The BNRs have the largest compressors that will fit in the stock housings. What are the specs on the KS twins?

Also, ask Steve what he thinks.....he knows a thing or two about turbos

 

can someone post a link to the knightsport were i can take a look at these twins??thanks

 

i have a question if the bnr stage 3 arent rebuilt why do they need a core when u purchase a set

 

for the housings...those things don't grow on trees

 

here's the site for Knightsports turbo (in japanese)
http://www2.ocn.ne.jp/%7Eknight78/catalog_index.htm


BNR stage 3
http://www.rx7store.net/product_p/bn...e%203%20fd.htm

 

Are these the turbos you got from my buddy (NeedFD)? If so, how is it?

 

here's the english mirror site of the "functional parts" http://www2.ocn.ne.jp/%7Eknight78/OV...TS_OVERSEA.htm

yea i bought these off of NeedFD (great to deal with btw) a few months back. i didn't really drive the car much after installing cuz i am getting my engine rebuild atm. the turbo is in pretty good shape when it arrived, but i had it cleaned and rebalanced anyways. so i cant give any feedback on them until everything is put back together and after the tune in late march.

if the stock fuel system can easily support 300whp, then for now, I'll refrain from pushing to its limit. i know the turbo is said to be able to put out 420hp, but i am not sure if its to the wheel or flywheel nor with what PSI/bar.

i tried using the search function but it seems like no one have any experience with the KS twin. so for now, i can only rely on the BNR stage3 as a fair compraision to guesstimate KS' potential.

if anyone have the dimension or link to the BNR stage 3, please post them up so I can match it with the KS.

Thanks again!

edit: the SBC id control boost very well at stock level. however there seem to be two ways of installing it. I followed the instruction book's way of installing, which is hooking it up only onto the precontrol actuator. in some japanese rx7 specialized magazines, sometimes they install it like the Apexi AVC-R where you T both of the actuators and the nipple from the housing (kinda hard to explain in words). can anyone chime in on this?

 

It would be PS not HP in Japan. Change your secondary's to 1300's and pump to Walbro. You can get some new ones bored out allready from rotaryextreme or buy some from takakaira and send them out yourself. RC Eng' recomends boring out new injectors. Oh yeah, you should have had your wastegate bored out as well.

 

the japanese power rating, almost every time, is flywheel.

I think they were doing that @ 1bar (about 13psi).

Garage Alex also have a set of rebuilt twins - and, iirc, they got about 430ps (or so) using 1.1 or 1.2 bar (if I can find the magazine, I'll post up the exact details). The alex twins are considerably cheaper, also.

PS->HP at lower levels it's an almost interchangeable rating - at 420ps it = 414hp

 

just for trivia's sake: http://www2.spacelan.ne.jp/~alex/
US$1677

 

so the turbo housing is reused? that means the turbos r rebuilt am i wrong? btw good luck with ur set-up. my opinion is, if ur not going to upgrade ur injectors and fuel system just play it safe. after all the car will still be a blast im sure

 

So that made 414 motor hp at 17.4 psi (1.2 bar)? Taking into account 15% driveline loss, that is 352 rwhp......

 

I'm guessing 352RWHP is seq. set up? If so, thats not much better than stock twins..

 

make what you will of that. There has to be, I would assume, a discrepancy somewhere - whether it's in fact a wheel figure, or a dyno issue

 

I found one of the articles I was thinking of. Garage Alex rebuilds made 440ps@1bar (13psi or thereabouts).

 

...I also believe there has to be a reason why all the japanese workshops are running 0.9-1bar boost levels on twins (almost as a rule of thumb) - whereas foreign workshops are often running well over that mark. They've got access to more cars, do more tuning, etc - I can't help feeling there is something missing. Reliability @ level?

 

Not a big deal, but wanted to point out that 1 bar is 14.5 psi.

Re: reliability, I firmly believe that stock twins and 'minor' upgraded twins that are similar to stock should *not* be run on the street for an extended period of time at much more than 1 bar, 15 psi range. Drag cars are an exception, but generally speaking after that level you are making lots of heat and not in the turbo's efficiency range.

I run my BNRs set at 16 psi (94 octane) and am happy with them. Once I get my water injection problems sorted out and the system installed I plan to run 18ish regularly. The car is a weekend warrior only now, so it doesnt see the road too often.

Rich

 

440 motor hp is around 430 ps i believe, so 430 motor hp, with 15% driveline loss is 366 rwhp at 1 bar, 14.5 psi. Not too bad at all. For comparison sake, I made 366 rwhp at 13 psi on a dynapack.

 

yes, you are wrong.

CHRA, wheels, and housings make up a turbo. Housings play a part of the characteristics. Housings are what make it a bolt up operation...or as close to bolt up as possible.

 

yeah. I knew that, lol. I have the .9bar = 13psi mantra stuck in my head. If I talk in psi around here, nobody has any idea what I'm on about :p