Definitive Guide To Building 300-330awkw Gt-r

[N1GTR]

No dramas.

A built engine isnt a requirement for that power level, but if you've got it done already there's no point not using it. Yes the -7's are bolt on factory position, while you're at it though with the turbos off it is a good chance to upgrade your dump pipes (std 32 suck) and also so you know, that result was on the stock exhaust manifolds

[R31Nismoid]

-7s are basically the R34 N1 equivalent.

The -9 are a little bigger. So yes the -7s will be responsive, about as responsive as you can get really.

I did a comparo a while back you should have a bit of a read over etc.

http://www.skylinesaustralia.com/forums/topic/350440-dyno-comparo-various-twins-rb26/

[piranha]

Thanks for the reply with graphs.

Nismoid, I notice in the comparo that a couple of the cars went from -5s to -7s.

Was this from a drivability point of view or something else?

Final question

Car is a daily so between -5s and -7s what do you think?

I should mention that I work fairly close to home so not huge amounts of ks.

Will -5s be a response improvement from early nismos?

Sorry for all the questions. Trying to gather as much info before making decision

Cheers

Luke

[Rolls]

-7s are basically the R34 N1 equivalent.

The -9 are a little bigger. So yes the -7s will be responsive, about as responsive as you can get really.

I did a comparo a while back you should have a bit of a read over etc.

They come on about 4-4.5k surely there are more responsive setups out there. Something only slightly bigger spec than the stock turbos would be fantastic for a 95% street car, make ~280kw and come on at 3-3.5k instead.

[R31Nismoid]

Thanks for the reply with graphs.

Nismoid, I notice in the comparo that a couple of the cars went from -5s to -7s.

Was this from a drivability point of view or something else?

Final question

Car is a daily so between -5s and -7s what do you think?

I should mention that I work fairly close to home so not huge amounts of ks.

Will -5s be a response improvement from early nismos?

Sorry for all the questions. Trying to gather as much info before making decision

Cheers

Luke

They were all different cars mostly, the ones that went to smaller (-9/-7) from larger ones -5 was mainly from a rule situation given Targa ruling and other motorsport etc.

I've had -9s, -5s.

Currently have -5s and for the street IMO they are too laggy on a 2.6ltr. You really have to ring the neck and peg back gears where with the -9s in the hills you had power everywhere

Whilst it only seems like a "few" hundred RPM on the graphs/dyno loaded in 4th - i can tell you on the street it is much more noticeable in 2nd/3rd and to anyone that asks i will always say -9s for a street GTR.

-7s being a tad more responsive again (over -9) would be an excellent choice if response is your #1 goal.

[piranha]

Thanks again for the info nismoid.

Looks like -7s it will be then.

I will let you know how I get on

Cheers for the help everyone

Luke

[R31Nismoid]

They come on about 4-4.5k surely there are more responsive setups out there. Something only slightly bigger spec than the stock turbos would be fantastic for a 95% street car, make ~280kw and come on at 3-3.5k instead.

4500rpm?

Are you trippin?

[Rolls]

4500rpm?

Are you trippin?

Looking at that graph full boost looks about 4500rpm, I've never been in a car with them though, what is it like on the street to drive?

Edited September 15, 2011 by Rolls

[N1GTR]

I've never been in a car with them though

Without being rude, this is the issue.

Please dont forget this isnt an RB25 thread, it's built GTR owners talking from their own experience with other GTR owners

[Rolls]

Without being rude, this is the issue.

Well with other cars when the dyno comes on at 4.5k they usually seem very laggy, I'm just going on my own experience, at what rpm do they seem to come on when you are driving them on the street?

Also prefacing something with 'without sounding rude' doesn't mean it doesn't come across as rude.

Edited September 15, 2011 by Rolls

[N1GTR]

Well with other cars when the dyno comes on at 4.5k they usually seem very laggy, I'm just going on my own experience, at what rpm do they seem to come on when you are driving them on the street?

Also prefacing something with 'without sounding rude' doesn't mean it doesn't come across as rude.

Ok well tell me another preface to use and I'll happily use it.

There is positive pressure pretty much all the time. Between gears there is zero drop off compared to some of the popular large direct fit turbos like GTRS's/Tomei's new turbos and to a lesser extent -5's which Ash has already mentioned.

In an R32GTR that has these, std cams, PFC, larger front pipes and exhaust and R34GTR dumps to give you an idea from a set of lights in first gear by 2500rpm it's moving along "swiftly" (i guess thats a decent word) add another 1000rpm and it's making as much as a late model commodore does (when it's going flat out). Add one more thousand and you've pulled so far away from normal traffic that you really should back off and change gear, if you dont, the needle will flick up very quickly to 8000rpm and then you grab second, as soon as the gear is engaged and you open the throttle the rear of the car squats down again and the needle will be heading sharply towards the limiter. You're now over 100kmh, about to grab 3rd where it will pull just as hard (but take longer to reach 8000 than in the lower gears of course) and if at any point you're seen by a policeman you're in trouble.

In an R34 (the one above in the graph) with the same basic upgraded parts but 260IN&EX 9.15mm cams, it's much the same, pulls from 2000rpm, moving quite well by 3000rpm and by 4000rpm if you're still flat stick make sure there's no one infront of you for a bit.

Something else worth noting, both of them have perfect street manners just like Ash's car did on 9's (and all the ones listed on his dyno graph thread with the exception of the -5 powered ones), no police issue's (engine bay looks totally stock) other than the exhaust, you dont need to flog its brains out to make it move along with traffic etc. That should give you a bit of an idea what they're like

[R31Nismoid]

Well with other cars when the dyno comes on at 4.5k they usually seem very laggy, I'm just going on my own experience, at what rpm do they seem to come on when you are driving them on the street?

Also prefacing something with 'without sounding rude' doesn't mean it doesn't come across as rude.

With -9s its well and truly all on by 4000rpm.

You then have 4000rpm then to play with, in my case im using 4300rpm. This isn't a RB25 thread where the show ends at 7000rpm - this is a GTR/RB26 thread.

[Rolls]

Thanks for that.

Out of curiosity what lets them keep on flowing to 8k where in a 25 etc it will fall over after 7k, is it the better head etc? Or ITBs and a combination of things.

[N1GTR]

The whole setup is what gets the result. They dont stop at 8000rpm, they can go past, most stop at 8000rpm though to not wreck an expensive-to-rebuild engine.

[Moodles2]

Thanks for that.

Out of curiosity what lets them keep on flowing to 8k where in a 25 etc it will fall over after 7k, is it the better head etc? Or ITBs and a combination of things.

rb25det stock cams have 7.8mm of lift on both in and ex, rb26dett stock cams have 8.58mm in, 8.28mm ex of lift. It's why rb25det's make peak power at 6400rpm and rb26dett's at 6800rpm

[Rolls]

Just found this really interesting link.

http://www.tomei-p.co.jp/_2003web-catalogue/e090_camshaft-specs.html

Looks like the neo rb25 has even more lift than the rb26s on the exhaust cam, curious to see if this follows through on dyno sheets with neo rb25dets, do they seem to hold top end power better than r33 rb25s?

neo in 8.4 ex 8.7

rb26 in 8.6 ex 8.28

though the 26 ex has more duration and different LCA

The whole setup is what gets the result. They dont stop at 8000rpm, they can go past, most stop at 8000rpm though to not wreck an expensive-to-rebuild engine.

What are the parts of the 'whole setup' that allow it? all that is different is ITBs and cams/valves yes?

[R31Nismoid]

This is really not on topic dude - this is about GTRs and a responsive package with a specific target.

Not musings about RB25s

[Rolls]

This is really not on topic dude - this is about GTRs and a responsive package with a specific target.

Not musings about RB25s

Stop being a party pooper, it'll be like 5 posts, who cares?

[Count Grantleyish]

Rolls, you start new thread about it.

People come to this thread to learn about building 300-330kw GT-R, thus this thread is to provide info on the requirements of building one, simple as.

[Rolls]

http://www.skylinesaustralia.com/forums/topic/377362-neo-cam-specs-vs-r33-rb25-do-neos-hold-power-longer/

done