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

[RB2600]

So something that I've recently been questioning is why many results of the 7's in "RB26 turbo upgrade, all dyno results" thread are the way they are.

I'm lead to believe that these are the most responsive turbos of the bunch when comparing against the -9, -5 and -10. Quite certain that most people who

have these turbos are reaching full boost quite a bit earlier than 4,000rpm; if anything, probably closer to the 3,500rpm mark?

Which makes me wonder, why are the below dyno sheets showing full boost at such high rpm? Some are as late as the 5,000rpm mark, wtf?

I understand that dyno graphs and real world may differ, is that what's responsible for my misinterpretation?

Would be great if the owners of the cars below could have a say in this as they would most likely know whether or not the dyno graph is a reflection of the real

world boost curve. Anybody with a similar setup is also most welcome to provide some feedback.

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300wKw at 20psi on 98RON

R34 GT-R V-Spec II

* -7 Turbos

* 700cc Denso Inj

* Power FC D-Jetro

* Blitz front pipe

* K & N Panel filter

* Greddy DSBC

* Tomei Poncams 260/10.25

* Tomei Cam Gears

* Bosch 044 fuel pump

* Nismo 3" Exhaust

* Hi Flo Cat

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Unopened RB26DETT

Stock cams

HKS Cam gears (inlet at 0 Exhaust retarded 2 degrees)

-7 turbos

TOMEI s/s dump pipes

3.5" do luck exhaust

Trust 100mm fmic

walbro fuel pump

stock fuel reg

Sard 700cc injectors

Power-FC D'jetro

398.3hp at all 4 hubs @ 1.2bar

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99 R34 GTR non-vspec

Unopened engine. Done approx 70K.

100K service done with all OEM parts, including water pump, timing belt, bearings and seals.

Adjust Cam gears

Garrett -7s

Stock injector

Stock fuel pump

Stock air box with high flow air filter

Stock intercooler with full HKS hard piping

Nismo fuel regulator

Spitfire Coilpacks

Iridium spark plugs

EVC 5 boost control

Power FC

Stock dumps and manifolds

Full NISMO WELDINA NE-1 Exhaust De-Cat

Koyo Radiator

EXEDY hyper multi twin plate clutch

Tuned @ Racepace

Pulled 288.7 RWKW @ 18.2 psi, on BP 98.

Bought Sard 700cc and Bosch 044, but told no need to install them as I had -7 only. Stock injectors cycle duty @ 98.8%. Knocking rarely exceeds 25 under the sun. Feels hell a lot better to drive.

http://www.skylinesaustralia.com/forums/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=322462

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Updated in BOLD

1995 R33 GTR

Performance list:

garrett 2860 -7 running 20psi drops to 19psi

tomei dump pipes

trust front pipe

ballistic cat

nismo catback

1000cc injectors

splitfire coilpacks

bosch 044 fuel pump

haltech platinum pro (mafless tune)

bp ultimate 98

115 Greddy front mount intercooler and piping kit

Greddy air intake kit

280awkw at 19psi

Now 310awkw

[GTR_JOEY]

There are many factors that will influence what your talking about

-health of engine

-how the dyno is set up

- restrictions in exhaust

- aggressiveness of the tune

These are to name just a few

[SiR_RB]

my old gtr had -7's with all the fruit made about 300rwkw and the dyno sheet shows it making full boost at 4800rpm, on the street it definetly feels much sooner then that !

[RB2600]

GTR_JOEY:

I agree on all accounts, however the specific graphs I've chosen mainly consist of quite well known workshops which have (I assume - probably shouldn't) relatively honestly setup dyno's. Correction factor will take into account ambient temp and altitude? These setups seemed to have relatively decent exhausts.

SiR_RB:

How much sooner are we talking? 4,000rpm? Below 4,000rpm? Have you ever loaded it up in 4th gear and had a look? I'm quite happy with the idea of 300kw-330kw.

My friend's r34 gtr was already quite quick at 318rwkw tuned by racepace. Mine being 5 speed 4.11FD in an R33 GTR may not feel quite the same, but I'm hoping some weight reduction and mild increase in displacement (86.5mm built motor) would negate the difference of the 6 speed

[GTR_JOEY]

I wouldnt be so sure mate, I know that UNIGROUP have a very conservative dyno..

Cannot speak for the others though...

We need a dyno day to set some records straight

[R31Nismoid]

There are many factors that will influence what your talking about

-health of engine

-how the dyno is set up

- restrictions in exhaust

- aggressiveness of the tune

These are to name just a few

Exactly. I was driving a mates GTR with -7s not 7 days ago.

I can tell you now by 3300rpm it was well and truly game on where my -5s were ~4000-4200rpm. -9s are about 3400-3500rpm.

Yet when you dyno the cars, the graphs come on & look very similar (nowhere near 800rpm), due to ramp rates and other factors.

[cobrAA]

^^ Make sens! Great reseach by the way.

[RB2600]

Why is it that they have set the ramp rates to make full boost look like its coming on later than it is?

You say that they are well and truly on by around 3300rpm. I take that as the perfect world situation on

a stock motor with all the correct supporting parts.

In the event that you run these turbos with a mild built motor for example with:

86.5mm cp 9.0:1

Light h beams

0.9-1.1mm Thin metal head gasket to keep comp high

Light head work to clean ports and improve entry and exit velocity

A GOOD TUNE

would it be reasonable enough to say that these turbos are likely

to come on even earlier, say around the 3000rpm mark?

-7s coming on by around 3000rpm mark (probably e85 or well sort out

motor) making power to 8000rpm would really be something impressive

I think. Sure it might be short of 350kw atw but a solid powerband of 5000rpm

is not something to be laughed at

[GTR_JOEY]

-7s will nose over well before 8000 rpm

At the end of the day -7s aren't going to flow much more then 300rwkw and these days that isn't alot of power anyway

Would still be a reasonably quick street car no denying that..

I would find it boring though

[R31Nismoid]

Why is it that they have set the ramp rates to make full boost look like its coming on later than it is?

You say that they are well and truly on by around 3300rpm. I take that as the perfect world situation on

a stock motor with all the correct supporting parts.

In the event that you run these turbos with a mild built motor for example with:

86.5mm cp 9.0:1

Light h beams

0.9-1.1mm Thin metal head gasket to keep comp high

Light head work to clean ports and improve entry and exit velocity

A GOOD TUNE

would it be reasonable enough to say that these turbos are likely

to come on even earlier, say around the 3000rpm mark?

-7s coming on by around 3000rpm mark (probably e85 or well sort out

motor) making power to 8000rpm would really be something impressive

I think. Sure it might be short of 350kw atw but a solid powerband of 5000rpm

is not something to be laughed at

When I say "on", you aren't making "full boost" - given such a term is silly. Is "full boost" 5psi or 50?

By 3300rpm the torque is coming on and boost is really driving so at a stab maybe 10psi which is 10psi more than a set of -5s would at the same RPM.

Every setup varies but i think 3000rpm for them to be really moving is a bit of an impossibility.

[RB2600]

Despite small increase in displacement, e85 and some headwork?

I understand that stands true for an unopened motor on with 98 but with the above changes?

Edited September 16, 2012 by RB2600

[R31Nismoid]

The car i was driving the other week had a built motor. You'd probably expect it to be a bit lazier on the stock engine.

[RB2600]

Fair enough, I was having a look at the build of the old Advan R32 GTR and have just accepted that I won't get it to that type of response.

According to Russ, 3500rpm and the power was already over 300kw with a peak of 380kw-400kw depending on temps. Although it quite an extensive build,

I still wonder..really?

Starting to lean towards the -9 if they're only 100-200rpm behind..

[GTR_JOEY]

You would need to spend big cash to get that sorta power and response

Ie

Big compression

Stroker

E85

380-400rwkw on -7s is pretty out there

Edited September 16, 2012 by GTR_JOEY

[RB2600]

hi Roy

i will try and tell you what we have found really important and our mods.

power is approx 380 to 400 kw's @all four depending on weather and temp.

so yep, still 2.6 bore size, 270 cams tomei, adj cam gears, cleaned up cylinder head ports, n1 valve springs,cp pistons, tomei rods, n1 oil pump with reinmax gears(also use tomei oil pump previously), hi octane racing large sump (will be going to a hi octane racing 4 stage dry sump in a month or so) standard exhaust and intake manifolds, are intercooler, n1 garret equivelant turbo's, greddy intake boost pipes, apexi airfilters, autronic ecu and cdi ignition,gonzo exhaust, vp109 fuel( good for 30kw's and much safer than pump fuel), tilton brake pedal box, australian spec tein suspension, bosch fuel pumps, advan suge tank, npc clutch ( i swear by it!!), carbon tailshaft. block and crankshaft are standard, acl race bearings, 25 row oil cooler, standard blow off valves. we also run a water sprayer for the radiator and oil cooler for longer circuit runs.

we have tried hard to make the power come on hard down low in the rev range , which makes it easier to drive, we tried aftermarket extractors and the car made more power but we lost over 500 rpm before boost would come on so we went back to standard manifolds, adjust cams to get power as early as possible, car has over 300 kw's at 3500 all the way to rev cut, rev cut we have lowered to 7800 till we get a dry sump.

the other thing we have spent a lot of time on is the 4wd system and wheel alignment setup, nearly all r32 gtr 4wd drive systems we have looked at including our car when we got it, do not function as they should. wheel alignments also have been a real issue. we have had a lot of trouble get alinment shops to align to the spec you ask for and ahen checked they are way out!! we now do all our wheel alignments by string line and have had far better results.

the car will be coming off the road in two months(after nsw dutton and maryborough sprints) for a full rebuild, dry sump if not before) , side exit exhuast for events that allow it, chromoly strut to strut cage, try to lighten it some, total repaint, stack dash , hopefully carbon doors, bigger swaybars & a few other changes.

hope this helps if you want to anything specific just ask

cheers russ

Not a stroker, but a damn good motor lol

[R31Nismoid]

Also note the fact it's not running PULP - you are talking 109, thats the biggest difference and lets you get away with a lot more

[Shoota_77]

HAS he ruled out a stroker??

Not trying to argue with you but he just says "standard bore size" which obviously leaves the door open for a longer stroke size??

It's pretty amazing power if it is all standard but seems to be pretty solid power with fairly standard upgrades and -7's.

[RB2600]

HAS he ruled out a stroker??

Not trying to argue with you but he just says "standard bore size" which obviously leaves the door open for a longer stroke size??

It's pretty amazing power if it is all standard but seems to be pretty solid power with fairly standard upgrades and -7's.

I was assuming it was not stroked considering he mentions "standard bore size, standard crank" but now that I look at it, he does mention Tomei rods, so they're possibly the 119.5mm centre to centre model?

Which would effectively increase stroke to 77.7mm?

[RB2600]

Bleh...slightly off topic, but I found a lovely crack in the block...guess I won't be thinking about turbos anytime soon...

the crack is actually worse than it looks in this photo

[SiR_RB]

May aswell go 2.8 stroker and -7's if response is ur aim