Garrett Gt2860 -9s

[usmair]

cam gears n cams are 2 different things, personally cam gears are great mod for the money, with my turbos I'm setting it for max response n powerband to start as early as possible

beerbaron has posted dyno of before n after cam gear mods with great gains, my car has similar results

what kind of difference did cam gears make in terms of response... mine seems to come on strong at around 4k which i thought was laggy for -9s

[bradsm87]

Stock cams already have FARK ALL overlap. Reducing it even more will be very hurtful for top-end power. Tomei cams with stock cam sprockets are set up to have a great balance of response and power out of the box.

You're getting a small turbo to get good response. If I had to keep stock cams, i'd either keep the stock sprockets or install cam gears to increase top-end. Stock cams are already naturally good for response due to the tiny duration.

[bradsm87]

what kind of difference did cam gears make in terms of response... mine seems to come on strong at around 4k which i thought was laggy for -9s

The front pipe and better or no cat will help response. The reduction in back pressure will help as well as the extra ignition timing it'll allow u to run.

[R31Nismoid]

^ ye gotta have cam gears, they are a winner with stock cams etc.

[bradsm87]

^ ye gotta have cam gears, they are a winner with stock cams etc.

why? what huge flaw does factory cam timing have?

[R31Nismoid]

With a minor adjustment to the gears with stock cams, most people see a reasonable increase.

BeerBaron & other uses have posted up their before/after graphs and you can clearly see the difference.

Perhaps Rich might see this thread and be kind enough to do so again

[STATUS]

6x injectors = about 900

1x fuel pressure reg = about 180

Because u only want a tiny bit more than the stock injectors will do. An increase in fuel pressure will get that easily.

I personally think cam gears are WAY overrated in the skyline community. U already have stock cams which are tiny, why further reduce top-end power from the already tiny cams? I understand tweaking cam timing on huge cams but i've never seen any evidence to show a gain in changing cam timing on stock cams. Fuel pressure reg and a set of Tomei Poncam type B cams cost about the same as injectors and camgears. I know which one would make bucketloads more all through the revs.

i reckon GTR are about the only skylines worth putting the gears on.... rb20 and rb25 generally don't respond anywhere near as well as the RB26, dialling in a 6 odd degrees (deftly setup) on a set of cam gears on the rb26 and -5's (little less on the -7 and -9's) and it can make a marked difference.

[usmair]

ok so just took the car for a drive and there is a fair bit of lag...

full boost (15 psi) is at around 4700RPM...

now the exhaust the main culprit... I only have a 3" cat back atm with a shitty compliance cat

a front pipe and a high flow cat is a must...

wondering what kind of a difference the exhaust will make in terms of response... power will def go up but I'm more concerned about the lag right now... not very fun to drive on the street as it is...

do you think another tune is a must after the exhaust is complete?

[bradsm87]

ok so just took the car for a drive and there is a fair bit of lag...

full boost (15 psi) is at around 4700RPM...

now the exhaust the main culprit... I only have a 3" cat back atm with a shitty compliance cat

a front pipe and a high flow cat is a must...

wondering what kind of a difference the exhaust will make in terms of response... power will def go up but I'm more concerned about the lag right now... not very fun to drive on the street as it is...

do you think another tune is a must after the exhaust is complete?

Absolutely if u want more response. The AFR and timing as it comes on to boost makes all the difference to response. Finish the exhaust and get a tune and that'll improve greatly.

[Raymondl]

hey all i just about to buy a r32 gtr it has Garret GT2860 -5 the person i am buying off recons it makes 350hp at all four wheels on 15psi just like to know if that's right running larger than stock injectors and in-tank sard fuel pump plus hks cams i will be getting it tunned at xspeed as soon as i get it book and will let you all know the results

:why drive a v8 it's only a cock magnet:

[usmair]

thats around 260kw... not much at all mate... especially for -5s... with 15psi running through them I would be expecting 300kw+ if all the supporting mods are there

[GTScotT]

Personally, I think there has got to be more there than the exhaust. For now, I would smash that cat out in case its blocked, but would not expect it to hold back boost delivery this much.

I feel this is tune related.

[Don Dada]

ok so just took the car for a drive and there is a fair bit of lag...

full boost (15 psi) is at around 4700RPM...

now the exhaust the main culprit... I only have a 3" cat back atm with a shitty compliance cat

a front pipe and a high flow cat is a must...

wondering what kind of a difference the exhaust will make in terms of response... power will def go up but I'm more concerned about the lag right now... not very fun to drive on the street as it is...

do you think another tune is a must after the exhaust is complete?

Whats the latest guy:?

[Beer Baron]

I know it's old but since it's been bumped I'll enter the cam gear debate. for standard turbs, -9s or even -5s cam gears on standard cams are a good way to go. they will not hurt top end power at all (at the worst you might lose 2 or 3kw at best you'll gain 2 or 3) but in the midrange you can gain as much as 20kw which is bloody huge for a couple hundred $ in parts and 1 or 2 hours of dyno time.

my old 32 GTR was running stock turbos (well I think they were stock, could have been n1s or something), HKS actuators, power FC, standard injectors, standard AFMS, standard intercooler, standard dumps, standard front pipes, 3.5inch cat back exhaust (with very high flow cat) and it make near on 270rwkw on 15psi and ran that way (still runs that way) for years.

I've just spent 10 min looking for the back to back graph but can't find it. I can find one graph of when it was finished.

here's the sheet. it's not bad for a very standard GTR. it was pretty quick too.

I have personally had cars with:

standard cams, standard turbos (adjustable cam gears)

tomei type B cams, GTSS turbos (adjustable gears)

midori cams (slightly milder than type B, 256 duration ~9mm lift) with 2530s

HKS cams (from memory they are 264 duration and about 9.5mm lift) GTSS turbos

now currently have tomei cams type B with 2530s (on a jun 2.7 stroker engine).

To be honest if I were going GTSS again I would stick to stock cams and cam gears. same goes for standard turbos. for 2530s cams are a consideration but again stock cams with gears work well on them too. don't get me wrong I love cams, love the beaty idle, love the hard edge they give the exhaust note. but considering a set of cams is nearly $1000 and in my mind I would not be fitting ANY type of cam with standard valve springs (another $500) and I also would not be fitting any cams to an old engine without checking and re-doing valve clearances (another few $100) it suddenly becomes expensive and may not give the results you want. standard cams with small=ish turbos and adjustable gears is proven to offer gains. how much of a gain varies a bit but it's quote common to see at least 15kw in midrange gained and a couple of kw up top.

[Beer Baron]

edit: found the graph.

it went from 221 to 247. I'm pretty sure this is the before and after cam gear tuning graph. basically at 220rwkw it was about normal for a stock GTR with pods, exhaust, power FC and 1 bar boost. but with the cam gears it suddenly competes with most GTSS powered GTRs running 1 bar.

you can see to get to that gain took only 5 levels of adjustment (we knew where to start and just tried a few settings either side of that point to get the optimum gain).

[GTRsean]

This is mine with standard actuators.

Had an eboost street, and it has trouble holding/controlling boost with stock actuators at 18PSI.

compliance cat, crappy droney cat back exhaust, cam gears, standard everything else.

Injector duty at 84%.

RWD dyno.

I'll have to post up a new one once it gets dynoed and tune adjusted again due to fitting a nismo cat, HKS adjustable actuators, HKS cat back. I want a flat boost line!

Planning to run 20PSI. Running at 14PSI then running at 17-18 PSI makes so much difference to mid range torque and power but still missing a little near the top end of the rev range, even though the graph shows it going back up. It's partly due to boost pressure dropping after initial peak is reached as seen on the graph.

[Nee-san]

With headwork, cams and a really good tune they would go pretty darn close.

+ non standard fuel.

[Don Dada]

edit: found the graph.

it went from 221 to 247. I'm pretty sure this is the before and after cam gear tuning graph. basically at 220rwkw it was about normal for a stock GTR with pods, exhaust, power FC and 1 bar boost. but with the cam gears it suddenly competes with most GTSS powered GTRs running 1 bar.

you can see to get to that gain took only 5 levels of adjustment (we knew where to start and just tried a few settings either side of that point to get the optimum gain).

Doesnt boost automatically raise when cam timing is changed via gears??

If so i think we're only seeing part of the picture as we cannot attribute those gains seen "just" as a change in cam timing but also an increase in boost

Would have loved to see a boost plot on this graph too

[MrStabby]

Doesnt boost automatically raise when cam timing is changed via gears??

If you mean come on earlier, yes. "raise" ie above one bar, no because its the boost controller's job to keep it at the right level.

[Don Dada]

Good point but what if youre running straight off actuators?

My point is tho...... doesnt a change in cam timing have some effect on boost???