Response Of -7's With Reference To Rb26 Dyno Results Thread

[XKLABA]

need a new block, want better response, got a R33 GTR, RB30 FTW, would nearly spinup -7s at ideal

unless the tuner puts in the ratios and rolling diameter of tyres for every car that goes on dyno then the chances are the revs are not going to be correct, I know with the dyno sheets I have with my cars are about 1400rpm off

I have HKS EVCs on both cars, I clear the peak hold select the 1:1 ratio in the box ( 4th for 32 and 5th for 34 ) sit it on 2000rpm and WOT till 3000rpm then shut it off, the 32 stock turbos has 1.3bar ( max boost set for both cars ) and the 34 gets 1.1, so then I repeat with different RPMs the 32 gets 1.3bar at 2800 and the 34 with -7s and type R poncams use to get 1.3bar at 3200rpm

[SiR_RB]

Won't get more responsive then that ! That's crazy

[RB2600]

1.3 bar on stock turbos? Surely that's only one side of the story? What tricks do you have up your sleeve to keep the things alive ?

[Hadouken]

Luck and low revs

[XKLABA]

Luck and low revs

lol, more luck then low revs, it's in the setup, particularly cams and there timing to make as much use from any given amount of air so they don't have to work as hard to make power, dump pipes to keep temps down and let back pressure escape

plus driving style and choice of when to use it, drags and 2-3 power runs on the dyno at a time only, I've had this car over 10 years now with this being the second set of turbos, on the first set the bearings wore out

response is in the setup, the choice of parts make a big difference, cams, cam timing, dump pipes, exhaust, spark plugs etc, the right choice and combination of parts and how they are setup then tuned is difference between good and great, 11.13@123mph with only 292.7rwkw on stock turbos

unfortunately I didn't get to drag the 34 after I got it where I wanted it, it spun a bigend at EC 4 days after being tuned, 11.8@118mph was the best I got out it the day after I brought it which is the only time it was dragged

[R31Nismoid]

And car loaded up for 5-10 seconds (2000rpm to 3000rpm) with cams will bring on boost harder.

Do it in 2nd/3rd or on/off & between gear changes and the story is not the same as being full loaded/primed. I could get -5s coming on under 4000rpm when fully loaded from 2000rpm (probably 10 seconds to get there in 4th). Is that realistic for what you can expect 99% of the time you drive it? No.

Depends on the use and how you drive it.

[XKLABA]

And car loaded up for 5-10 seconds (2000rpm to 3000rpm) with cams will bring on boost harder.

Do it in 2nd/3rd or on/off & between gear changes and the story is not the same as being full loaded/primed. I could get -5s coming on under 4000rpm when fully loaded from 2000rpm (probably 10 seconds to get there in 4th). Is that realistic for what you can expect 99% of the time you drive it? No.

Depends on the use and how you drive it.

I don't under stand what your getting at with this post, the OP used dyno sheets to give examples of boost response by a certain rpm and correct me if i'm wrong, but don't they make the dyno lock at a certain rpm then load the car up for a few seconds before releasing it for a run and almost always in a 1:1 ratio gear, now I don't sit on the brake for 5-10 seconds while "loading" it up then let it go I get it to 2000rpm then just hit the throttle and wait for a certain rpm then check the peak hold

now I sure I've seen you post about variables with dyno runs now you are questioning me when I use the same gear and method ( except actually "loading" the car up before testing ) everyone uses for said dyno runs

In the 32 If I tried it from 3000rpm or more it gives instant boost or try it in lower gears it starts to spin tyres so tell me when someone asks how low in the rev range the boost comes how do you give a correct/constant answer cause if you try from say 4000 rpm and the turbos will boost from 3000 then the answer you give is wrong

anything above 3000 rpm in the 32 is instant boost, 3500rpm for the 34 with -7s, doesn't matter 2nd/3rd on/off/on throttle, it's instant and angry but then the OP didn't ask about that he asked when in the rev range do -7s come in using said dyno sheets as examples

I drive the 32 between 2500 and 3500 rpm daily driving as it give usable boost from under 2000rpm so this is what I expect 100% of time and if I don't get it there is some thing wrong

but then I build my cars for response to pull the cars out of corners not to make a big figure on a dyno, even with only 292rwkw for the 32 and 311rwkw for the 34 the cars are alot of fun to drive with loads of torque

[R31Nismoid]

now I sure I've seen you post about variables with dyno runs now you are questioning me when I use the same gear and method ( except actually "loading" the car up before testing ) everyone uses for said dyno runs

What I'm saying is what i said:

Is that realistic for what you can expect 99% of the time you drive it? No.

I wouldn't sit there from 2000-3000rpm for boost to build (over X seconds), i'd just change gear, like anyone else would - and get on with it!

I didn't question you, it was rhetorical :

I do find it impressive you have 18psi on @ 3200rpm with -7s, never seen a single result here (before that) that gets that much boost in that early

[XKLABA]

I wouldn't sit there from 2000-3000rpm for boost to build (over X seconds), i'd just change gear, like anyone else would - and get on with it!

I didn't question you, it was rhetorical :

I do find it impressive you have 18psi on @ 3200rpm with -7s, never seen a single result here (before that) that gets that much boost in that early

I don't usually either I just do it when I have changed something to see if there was an improvement and as well as that I find cruising up a empty freeway in a 110km zone at 2am is boring so I find it a good way to stay alert and pass time as I drive home

I'm not doing it over x time my aim is to see at what point/how early in the rev range the car gets full boost and as I have said there i no point accelerating from 4000rpm to find that out if it will get "full boost" ( in my case 1.3bar) much lower then that

I tend to not post alot of my results as I find there are alot of people on here that believe cause they can't do it can't be done and as well as that there is so much info on here already I figure my results aren't going to do much either way, as I have said aswell it's also in the setup and choice of parts and as I aim for response that's what I get, most people use the type B poncams I use the type R which have the same lift but 10deg less duration P/C so less overlap, I went from the type Bs to the type Rs and this change alone gave me about 700rpm better response with the same peak power then retuning the camgears allowing for the overlap gave me even more response

[Piggaz]

But don't big cams bring turbos on earlier?

[XKLABA]

big lift yes, big duration not so much

is that motor in yet? less keyboard punching and spanner swinging

seriously though, if you want a hand any time shot me a PM or txt

[GTR_JOEY]

Duration just moves your power band left or right in the rev range...

You know this Paul, have you been drinking?

Get that engine bolted in!!

[Piggaz]

Sarcasm boys. Geez

[XKLABA]

Duration just moves your power band left or right in the rev range... +1 on this

You know this Paul, have you been drinking? you've got jokes, of cause hes been drinking

Get that engine bolted in!! again, this

then you can come do some skids around a bunch of cones in a car park

[zebra]

Here for the lulz about rod length changing capacity

[linkems]

Last time i was on a track i did a few runs in third gear timing 80-120km with a 10hz gps reciever. I wanted to log some numbers so i can compare my times before and after mods. I thought that spooling up from 60km would give it plenty of time to build boost, it recorded pretty consistent times of 2.74 and 2.75. I then tried one run from lower rpm about 40km, the time then dropped to 2.69. So how long you load the car up makes a huge difference.