Silvia Club of NSW

Hey guys,

I've had a look around the forums and there's not much recent info about this sort of stuff, so i figured i'd just ask!

Well here is a brief overview of my setup:
GT30 Turbo
550CC Injectors
Walbro fuel pump
Rising Rate fuel pressure reg
z32 AFM
Blitz frontmount
external wastegate with screamer pipe
3" twin turbo back exhaust
Apexi PFC

With this setup, i did a run of 243kw atw's, i am looking to increase this.
Here come the questions...

What are the optimal cams i should run? degrees of lift, ramp rate, overlap, brand etc.
What would be power figures be like? and how will it affect my power curve?

Also im thinking of getting Tomei Rocker Arm Stoppers, no harm with getting them right?

Thanks!

A few things to consider:

Are you keeping VCT? It changes what you may consider.
You need some bigger injectors to reach the turbo's potential
Definitely get rocker stoppers, though i'd use (and do use) GKTech ones which are only $60 from memory.
What size GT30? 3071, 3076, 3082?
Do you have a stock bottom end or built engine? How high you can rev it will effect what size cams will work well.

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meh

i forgot to add i've got an s14 series 1

but anyway, in reply to your questions:
this first one is silly, but how do i know if i have VCT and what changes could there be?

and for rocker stoppers, im guessing there's not much difference between brands, i've got my eye on this trust one, it's $85

i think i've got a GT3040 (i think) it's been a while, i've forgotten...

stock bottom end

If it's an s14 you have VCT unless it's been removed. Also stock bottom end means stockish rev limit.

I would get some jap valve springs as they are a bit softer then the BC stuff commonly available now. Greddys, Tomei type A's, HKS are all much the same. This should prolong VCT life

I would get a higher lift cam with short duration because you can't rev it high enough to make use of a longer duration cam. Somewhere around 256-260 inlet and max 264 exhaust with 11.5-12mm lift.

In terms of brands
HKS step 2's maybe 256in/264ex 11.5mm lift (i think)
Tomei procams 260/260 12mm lift
Unigroup Camtechs. Talk to Yavuz about his recommendations but probably 255 11.5 in and 260 12 ex. He may have something new available now.

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meh

cool info man!
thanks for all that

but i dont really understand what it all means in details
like i know that 256-260 is degrees and such and 11.5-12mm is the opening length

but how do i put that into rev and power terms =/

i guess its easier if you tell us how you want your power delivery (ie early, midrange, or top end?) and we will tell you what cams would suit.

basically lower duration = torque lower in the rev range
high duration = top end nearing redline

that turbo will need at least 11.5mm lift to allow it to breathe

another option is BC stage 2 cams
264/264 duration (in/ex) with 12.06mm lift

Bear in mind that you'll have to pay for aftermarket springs and retainers for pretty much all these options.
You can change them all without removing the head but it's fiddly to do, probably best to take the head off and do it all off the car.
You're probably already aware of this, but just so you budget in for all that on top of the cams themselves and the tuning you'll need after changing them

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1996 180sx
1990 Silvia

well right now im full boosting at round 4k rpm
maybe just a lil bit under

but what im sort of looking for is for something to help me boost earlier but also harder and for the rest of the rev range..
is that even possible? haha

here are some things i am looking at right now:

740cc injectors:
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=370290174690&ssPageName=STRK:MEWAX:IT

Rocker Arm Stoppers:
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=370362013824&ssPageName=STRK:MEWAX:IT

Valve Springs:
http://cgi.ebay.com.au/Tomei-Valve-Springs-set-Nissian-sr20-s13-s14-s15-/350020199871?cmd=ViewItem&pt=AU_Car_Parts_Accessories&hash=item517ed465bf

http://cgi.ebay.com.au/HKS-Valve-Spring-Kit-Step-2-Nssan-sr20-s13-s14-s15-/350345332078?cmd=ViewItem&pt=AU_Car_Parts_Accessories&hash=item519235856e

http://cgi.ebay.com/ebaymotors/Nissan-SR20-Valve-Springs-_W0QQcmdZViewItemQQhashZitem255ab55d7eQQitemZ160435625342QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

And as for camshafts themselves, im having quite a bit of trouble looking for them
as there are heaps of varieties, but the popular ones seems to be the Tomei Poncams and the HKS ones with different steps
i think this is where i need the most help, as cams aren't the cheapest of things to trial and error with.

either the tomei or hks ones. dunno anything about the last set so they could be anything.

yeah the poncams and hks step ones are the entry level cams. Not enough lift for a bigger turbo.

to keep the response you want to keep duration as short as possible, I would talk to yavuz about their camtechs as i had the same goal and he spec'd mine well.

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meh

just having another look around
and saw these, adjustable cam gears

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320307508783

is it the right thing to do to when you get cams?
or is this getting really serious?

doesn't hurt, but you only need one for the exhaust side if you still have vct.

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meh

this stuff is all pretty puzzling stuff..

well, first of all, i've ordered the rocker stoppers
and im about to order the injectors now
i've also enquired about a set of tomei adjustable cam gears

next thing i need to do is get the valve springs and retainers (cos apparently they are needed for the camshaft i am looking for)

the only thing i have left is the camshaft itself, i've looked around on ebay and such and there's all these different types.. i was thinking should i take it to a pro and get a custom one forged?

if i do go down this track, any recommendations on sr20det professionals?
with lots of experience with cams and such work

hey guys

is it a good idea if i get upgraded valve springs but keep the factory retainers?

yavuz at unigroup for sr cams.

Some springs need new retainers, most don't.

You could argue that the BC titanium retainers reduce weight but it's 3/5 of fuck all imho, maybe worth considering if you are reving the thing extremely high.

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meh