Twin Intank Pumps For A Gtr

[R31Nismoid]

at least now we know that 3in will flow 350rwkw but at slightly higher boost.

That's the wrong way to look at it. Put in a 3.5 or a 4" exhaust and all of a sudden you'll pick-up power, no doubt about that.

This means the 3" is not flowing enough at 350rwkw and is causing a restriction. It's only making the power because you are jamming boost into it.

Think about it, I'm making 360rwkw on 19psi/PULP with the same turbos.

Piggaz is making over 400rwkw on E85 and ~23psi

I wouldn't be surprised if you found 30-40rwkw just in an exhaust swap! That's HUGE.

[Brezza]

That's the wrong way to look at it. Put in a 3.5 or a 4" exhaust and all of a sudden you'll pick-up power, no doubt about that.

This means the 3" is not flowing enough at 350rwkw and is causing a restriction. It's only making the power because you are jamming boost into it.

Think about it, I'm making 360rwkw on 19psi/PULP with the same turbos.

Piggaz is making over 400rwkw on E85 and ~23psi

I wouldn't be surprised if you found 30-40rwkw just in an exhaust swap! That's HUGE.

i wouldnt mind picking up 30-40rwkw from just swapping exhaust.

Nismoid you're still running std cams too aren't you?

how about you Piggaz?

from what i remember the tuner said that anymore boost wouldn't net any higher results. it would just generate more heat.

[Piggaz]

i wouldnt mind picking up 30-40rwkw from just swapping exhaust.

Nismoid you're still running std cams too aren't you?

how about you Piggaz?

from what i remember the tuner said that anymore boost wouldn't net any higher results. it would just generate more heat.

Im running 270's @ 10.25 but the intake is advanced pretty hard. They are too bloody big!

On my last setup (2.8, RS's, E85) at 1.75 bar we got 402 rwkw. at 2.0 it made 414 IIRC. It turns out the Kakimoto had a 2.5 inch restrictor in it.

New setup (2.8 -5's,E85 and a twin 3inch Racepace exhaust) it made 420 at 24 psi but then tailing back to 22.5psi (1.53 BAR) top end (EBC OFF). More power, on less boost and on smaller turbo's. What would it have done with the RS's? Mind you this -5 result is with a stock airbox too!There will be more tuning to be done and see what the -5's can do at 'whenever they stop making anymore power!'

[Brezza]

Im running 270's @ 10.25 but the intake is advanced pretty hard. They are too bloody big!

On my last setup (2.8, RS's, E85) at 1.75 bar we got 402 rwkw. at 2.0 it made 414 IIRC. It turns out the Kakimoto had a 2.5 inch restrictor in it.

New setup (2.8 -5's,E85 and a twin 3inch Racepace exhaust) it made 420 at 22.5psi (1.53 BAR) top end. More power, on less boost and smaller turbo's. What would it have done with the RS's? Mind you this -5 result is with a stock airbox too!

i've only got a 2.6L so it wouldnt have as much torque as a 2.8L

the 270's would be laggier than the std cams, but flow much better top end.

with stock cams in mine and a bigger exhaust i think 380rwkw would be more realistic. 400rwkw would probably be a little bit of a stretch?

400 might be achievable with bigger exhaust and some 260 degree cams?

go the stock airbox!

i've got no intentions on changing to pods!

i love the std look under the bonnet. completely thows people when it get strapped to the dyno and is a 350rwkw car.

[Piggaz]

i've only got a 2.6L so it wouldnt have as much torque as a 2.8L

the 270's would be laggier than the std cams, but flow much better top end.

with stock cams in mine and a bigger exhaust i think 380rwkw would be more realistic. 400rwkw would probably be a little bit of a stretch?

400 might be achievable with bigger exhaust and some 260 degree cams?

go the stock airbox!

i've got no intentions on changing to pods!

i love the std look under the bonnet. completely thows people when it get strapped to the dyno and is a 350rwkw car.

Cams seem to be a very touchy subject around here. Some people swear by whacking a cam in that hardly closes.... others swear by small duration. After speaking to the guy that tunes my car about cams he had an example. A big single GTR with a 260 @ X lift. Made sometime stupid like 750 rwhp, spun it to 9800 RPM and the power was just starting to nose over. Put a 280 in and it made a bee's dick more up top but it lost a whole heap through the middle.

Daniel in VIC, he cracked 400 on a 2.6, 2530's and baby cams.... at something like 21-22 PSI IIRC.

[SS8_Gohan]

on E85??

yes, on powerplus E85, 400rwkw, 21psi - Nismo intank, ID1000's. 356rwkw on 98, 385rwkw on e-flex (tune was around E65-70) - 400rwkw on E85, same boost

Cams seem to be a very touchy subject around here. Some people swear by whacking a cam in that hardly closes.... others swear by small duration. After speaking to the guy that tunes my car about cams he had an example. A big single GTR with a 260 @ X lift. Made sometime stupid like 750 rwhp, spun it to 9800 RPM and the power was just starting to nose over. Put a 280 in and it made a bee's dick more up top but it lost a whole heap through the middle.

Daniel in VIC, he cracked 400 on a 2.6, 2530's and baby cams.... at something like 21-22 PSI IIRC.

256/9.15 i believe...

2.6 + 2530's is not the most responsive package getting around, so i wouldn't think about getting bigger cams at all. If anything with E85, something smaller might be interesting...

Should get a Racepace dyno for comparison to some of the other known GTR's on SAU

[Piggaz]

yes, on powerplus E85, 400rwkw, 21psi - Nismo intank, ID1000's. 356rwkw on 98, 385rwkw on e-flex (tune was around E65-70) - 400rwkw on E85, same boost

256/9.15 i believe...

2.6 + 2530's is not the most responsive package getting around, so i wouldn't think about getting bigger cams at all. If anything with E85, something smaller might be interesting...

Should get a Racepace dyno for comparison to some of the other known GTR's on SAU

252 @ 10.05?That's what is going in my new head. It will be interesting

[R31Nismoid]

Nismoid you're still running std cams too aren't you?

Yep, and 2.6l

[T-Rex]

What are peoples thoughts on the Walbro 39/50 in-tank fuel pump? 400lpm but requires a few mods to install (wiring and holder mods). Its the closest thing to the EL5M pump from the Bugatti Veyron and C6 ZR1 which cannot be used without an electronic controller.

[Brezza]

UPDATE:

i have the car booked in for a 4in cat back system.

i'll be dynoing the car to see if this makes any difference.

i've also got type 'b' cams going in afterwards to see if they make any further difference.

will hopefully post up comparative results

and hopefully Nismoid's theory of bigger exhaust = better is true!

[N1GTR]

So what eventuated with the fuel pumps?

[Brezza]

i've got twin walbro in tank pumps

it is a similar system to what powertune is offering.

my tuner has made up a bracket that slots into the standard cradle and holds both pumps. the fuel tank lid had to be tapped with a new fitting and a separate line was run out of the tank.

the tuner used the std return line as the second feed, and bent up a new line from some tubing to make a new return line. theory was that the return line wouldn't be under pressure like the feeder lines so it doesnt need to be as strong.

the two lines merge into one larger line in the engine bay and the tuner welded a new thicker feed into the rail.

i'm still using one entry in the rail, and std fuel reg.

all works fine now.

all the wiring for the pumps had to be redone as the old one was stuffed and caused all sorts of issues.

have done 2 track days on e85 and it's been running for quite a while now with no issues.

and the pumps aren't noisy.

apparently the bosch pumps make more noise than the walbro's.

for anyone looking at doing the same, go for the walbro's, because you will struggle to fit 2 bosch pumps in the cradle.

[GTR_JOEY]

UPDATE:

i have the car booked in for a 4in cat back system.

i'll be dynoing the car to see if this makes any difference.

i've also got type 'b' cams going in afterwards to see if they make any further difference.

will hopefully post up comparative results

and hopefully Nismoid's theory of bigger exhaust = better is true!

Very interested to see how this turns out

[XKLABA]

also at what limit have people found the std fuel lines to run out of flow? what power levels do you have to run twin lines?

Cheers,

When i pulled out the rear steering of the 32 gtr I wondered how hard it would be to use one of those lines for fuel supply and the fuel suppy line as the return line ?

[luke gtr]

I'm wondering how a returnless system would work.

Hmmmm.

Something to try one day.

Just use both stock lines as feed.

Anyone tried anything similar?

[jangles]

When i pulled out the rear steering of the 32 gtr I wondered how hard it would be to use one of those lines for fuel supply and the fuel suppy line as the return line ?

Not hard at all, it's what people have done for years

[Brezza]

OK the 4in cat back is on!

going to hopefully drop the GTR off at the tuner tonight.

it might get onto the dyno early next week!

first thoughts of the 4in exhaust is its quieter. for some reason the car feels a little off. it doesnt go as hard as i remember.

it feels like the tune is slightly off?

hopefully with some tweaks to the tune it will be much better.

[Brezza]

okay,

time for an update

the tuner ran the car up on the dyno yesterday morning.

it made the same power on the same boost, but he ran into a small problem with the boost controller.

the boost doesnt seem to want to hold, waves and varies by 3psi.

he said before the boost starts to wave the curve looks like it should be heading towards 370kw

they're going to modify the swing arm on the actuators to try and get the boost to hold a little better.

i do recall the car feeling like the power does feel like it cuts in and out. only when high in the rpm range though and its worse higher in the gears.

[Brezza]

Results are in!

I've been told that the car made 372rwkw @ 25-24psi

the boost peaked at 25psi and trailed off to 24psi

last time it was dyno'd at the same place it made 364rwkw @24psi

but on a mainline dyno it made 353rwkw @24psi

so read into it what you'd like.

obviously factors such as air temps will effect the power produced.

but this is making no changes other than going from a 3in cat back to a 4in cat back. ( and a tickle to the tune to ensure that mixtures are correct) all that was needed to the tune was a little more fuel in the top end.

i suppose its not bad considering its still a STD cam'd engine.

will have to see what happens when the Type-B poncams go in.

[Piggaz]

Results are in!

I've been told that the car made 372rwkw @ 25-24psi

the boost peaked at 25psi and trailed off to 24psi

last time it was dyno'd at the same place it made 364rwkw @24psi

but on a mainline dyno it made 353rwkw @24psi

so read into it what you'd like.

obviously factors such as air temps will effect the power produced.

but this is making no changes other than going from a 3in cat back to a 4in cat back. ( and a tickle to the tune to ensure that mixtures are correct) all that was needed to the tune was a little more fuel in the top end.

i suppose its not bad considering its still a STD cam'd engine.

will have to see what happens when the Type-B poncams go in.

Got a graph man? I'd like to see the curve.