Jump to content
SAU Community

Recommended Posts

Ye that's pretty much where the upper limits are going to be.

E85 would see you around the 350rwkw marker. Maybe a tad more, maybe a tad less, always subjective.

I was making 270rwkw @ 17psi with a bad 3" exhaust, factory cams, GTS-R manifold.

Held to 8000rpm no problems (GT3040/600hp).

I wish I'd had a chance to test it with a proper 3.5" exhaust that flowed nicely, would have seen over 300rwkw without much of a fuss was the general consensus and this was what… 4 years ago now.

Ended up making 370rwkw on 104 octane/24psi. Guilty-Toy made ~350rwkw factory head with a GT35 in a 3ltr not that long after.

45ULT - most setups (RB25/30s) have all run out around the 300rwkw marker factory exhaust manifold… a few have tried to go further and not really seen much gain. I believe some of those were using GT35's are well.

Change the manifold as well and then I think there was around a 20-30rwkw gain, and nicer midrange once everything was flowing inline with requirements so perhaps have a dig in the RB30 section of the forum.

I'm all for taking stock parts to untested waters, many said for ages you couldn’t make 300rwkw on factory cams (RB25 & 26)… and now there is a good number of cars over that. Some RB26’s making 380rwkw – factory cams!

It would just seem however the RB25 exhaust manifold just don’t have much to offer. That’s not to say there is anything wrong with it. Just don’t hope for much more than 300rwkw, and if you make more then count yourself lucky (but remember a manifold change, could well offer some decent $$ vs gain improvements)

This business of welding external gate mounts to the std RB exhaust manifold raises one more possibility , welding on two mounts and keeping the divided nature of these manifolds intact .

ATP are advertising twin entry "T3" flanged turbine housings for GT30 and GT35 BB turbos so that would solve the what to hang it off issue .

I'm not sure what the worst flowing section of say an RB25s exhaust manifold is but possibly the most significant choke points could be where each set of three runners merge into the turbos twin exit mounting flange . If each of the gates could communicate with the front or rear three runners you may coax a bit more than 30 out of a 25 with a GT3076R .

Not as good as a purpose built manifold but food for thought .

Cheers A .

  • Replies 97
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images

Well one day the plan is to buy a ETM or 6boost manifold and tial wastegate and run that as my setup.

im starting to wonder if im losing power/torque due to running the greddy copy plenum? maybe go back to stock inlet?

on the road the car pulls nice. 2nd gear is a waste of time it comes on hard bout 4200 and spins straight to limiter 3rd has a nice pull aswell, havent been into 4th yet.

overall happy with the feel/power so far. but i know ill get use to it real quick.

be nice to get some mt street slicks and run it at the track

Edited by l0WRB
  • 4 weeks later...

yeh i got mine all tuned and finished and came out with the same results as justin..

i find the car to be laggy for street use..

but have a track day this monday and will c how she goes there...

but i still love it..

yeah after last 3-4 weeks driving

290kw feels like 180kw now haha no matter what your always gonna want more.

my mates rb25 with gt3082 .63 got tuned other day and made 286kw on 17psi and it feels stronger then mine, he is still running factory inlet manifold but a highmount setup, feels so strong, yet mine makes more torque and power onyl by like 4kw lol

once colder weather comes in, im going to take it to test n tune and try beat my old 114mph trap speed.. hopefully 118-120 would be nice but i doubt it haha

Edited by l0WRB

mines laggier then the 3082 might be because he is running .63 rear and im running .82.. he is seeing 17-18psi by around 3800-4000rpm

im seeing 19-20psi around 4100rpm

yeh on the street its not a bad setup still responsive but it doesnt give u that WOW factor like a 400rwhp aggressive turbo would. although i really need decent tread (just run stock 16" rims with 225 federals) because 1st/2nd gears its just wheel spins therefor i cant even feel the torque, but my mates has 255 on 9" wide nismo rims and it just grips in 1st and 2nd and pulls like a train

might just be me, every car i go in always feels better then what you drive. id love 2 ditch the stock manifold i really would.

Edited by l0WRB

Very good result. I got a internally gated 3076r .82. Running standard manifold and standard inlet manifold. Still got the cat in there too. Making 280rwkw @ 17 psi. Will get a new exhaust manifold and a de-cat so should see close to 300kw soon. See how it goes

mines laggier then the 3082 might be because he is running .63 rear and im running .82.. he is seeing 17-18psi by around 3800-4000rpm

im seeing 19-20psi around 4100rpm

yeh on the street its not a bad setup still responsive but it doesnt give u that WOW factor like a 400rwhp aggressive turbo would. although i really need decent tread (just run stock 16" rims with 225 federals) because 1st/2nd gears its just wheel spins therefor i cant even feel the torque, but my mates has 255 on 9" wide nismo rims and it just grips in 1st and 2nd and pulls like a train

might just be me, every car i go in always feels better then what you drive. id love 2 ditch the stock manifold i really would.

if you can get a copy of his dyno sheet post it up.

by the WOW factor do you mean the sudden hit of boost by a larger turbo?

not really sure what your after, it spins the tyres in 2nd from 4200rpm to redline lol thats what i want :D

it sounds to me like 300rwkw is never going to make you happy. go buy a new LS3 V8 and turbo that :D

Edited by Harey

hahaha.

but i am correct 300kw now days is like 200kw 5yrs ago, it felt fast but u get over it real quick

i went for a drive in mates 32 with rb25/3582r made 471rwhp and that feels quick alot quicker then 390rwhp haha 3/4th gears just rev out instantly where as with mine u gotta watch it rev :D

mate it aint even fast lol trust me. you will keep up.

think all us boys heading up towards winter to race every car of ours will have over 300kw one will have 500kw haha should be fun :D

Edited by l0WRB
hahaha.

but i am correct 300kw now days is like 200kw 5yrs ago, it felt fast but u get over it real quick

i went for a drive in mates 32 with rb25/3582r made 471rwhp and that feels quick alot quicker then 390rwhp haha 3/4th gears just rev out instantly where as with mine u gotta watch it rev :cool:

Its all about power to weight. Thats another reason why the R32 would have felt faster, not to mention the extra 80rwhp :ermm:.

I think its also about expectations, I wonder if you would be happy with 350rwkw or still want more haha.

mate id love to have the setup you do.

Honestly tho running that power through stock rims? get some wider rims an put some 255s or wider on it.

An yeah by the sounds of it you need just a lil more power an you may be happy lol.

Either that or your a power broad minded person thats never satisfied lol.

mate id love to have the setup you do.

Honestly tho running that power through stock rims? get some wider rims an put some 255s or wider on it.

An yeah by the sounds of it you need just a lil more power an you may be happy lol.

Either that or your a power broad minded person thats never satisfied lol.

Lol ok i guess you cant say that word i wanted to call you on here haha.

broad minded person indeed lol :cool:

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • For once a good news  It needed to be adjusted by that one nut and it is ok  At least something was easy But thank you very much for help. But a small issue is now(gearbox) that when the car is stationary you can hear "clinking" from gearbox so some of the bearing is 100% not that happy... It goes away once you push clutch so it is 100% gearbox. Just if you know...what that bearing could be? It sounding like "spun bearing" but it is louder.
    • Yeah, that's fine**. But the numbers you came up with are just wrong. Try it for yourself. Put in any voltage from the possible range and see what result you get. You get nonsense. ** When I say "fine", I mean, it's still shit. The very simple linear formula (slope & intercept) is shit for a sensor with a non-linear response. This is the curve, from your data above. Look at the CURVE! It's only really linear between about 30 and 90 °C. And if you used only that range to define a curve, it would be great. But you would go more and more wrong as you went to higher temps. And that is why the slope & intercept found when you use 50 and 150 as the end points is so bad halfway between those points. The real curve is a long way below the linear curve which just zips straight between the end points, like this one. You could probably use the same slope and a lower intercept, to move that straight line down, and spread the error out. But you would 5-10°C off in a lot of places. You'd need to say what temperature range you really wanted to be most right - say, 100 to 130, and plop the line closest to teh real curve in that region, which would make it quite wrong down at the lower temperatures. Let me just say that HPTuners are not being realistic in only allowing for a simple linear curve. 
    • I feel I should re-iterate. The above picture is the only option available in the software and the blurb from HP Tuners I quoted earlier is the only way to add data to it and that's the description they offer as to how to figure it out. The only fields available is the blank box after (Input/ ) and the box right before = Output. Those are the only numbers that can be entered.
    • No, your formula is arse backwards. Mine is totally different to yours, and is the one I said was bang on at 50 and 150. I'll put your data into Excel (actually it already is, chart it and fit a linear fit to it, aiming to make it evenly wrong across the whole span. But not now. Other things to do first.
    • God damnit. The only option I actually have in the software is the one that is screenshotted. I am glad that I at least got it right... for those two points. Would it actually change anything if I chose/used 80C and 120C as the two points instead? My brain wants to imagine the formula put into HPtuners would be the same equation, otherwise none of this makes sense to me, unless: 1) The formula you put into VCM Scanner/HPTuners is always linear 2) The two points/input pairs are only arbitrary to choose (as the documentation implies) IF the actual scaling of the sensor is linear. then 3) If the scaling is not linear, the two points you choose matter a great deal, because the formula will draw a line between those two points only.
×
×
  • Create New...