My Next Mods, Comments please

[lukits01]

i'm only talking of my experiences here, but ..

a. you dont need a fuel reg

You don't need a fuel regulator probably because you've got bigger injectors

He said he doesnt have the funds for them so he's going to need the FPR to bump up the fuel pressure to make 250rwKw.

Im also going down this route very soon with a 2535, standard injectors and HKS 256 EX cam

Probably would have been better with the inlet cam as well but hey, this is as far as I can go right now...

[BBQ]

Not really interested in the injectors at the moment guys, I know you can get 240-250 out of the stock ones and i dont have a spare $700 to spend on something I dont really need.

 

So far it sound like i should go for:

 Z32 AFM, Fuel Reg & hi-flow tuned by Dave...

 

Is there anything that I have left out that I may need (excluding injectors )

That’s the biggest understatement of the century... Theirs no point trying to up fuel pressure if your injectors can only flow stock amount.

No matter how much you change it via a FPR, It’s still only going to pump 380cc into the motor, and if you think you can get 240 - 250kw out of stock injectors go for it.

Because for the cost of $700 for an upgrade set, or for the cost of a re-build which you will be doing if you don't upgrade your injectors. I sure know which option I would go.

Theirs no cheap way when you get to that point. You can't expect to bolt on a bigger turbo, and not upgrade your fuel system. Because it just doesn't work like that.

[DAN00H]

GunmetalR33, I'd suggest something from the Jap tuners in the way of a turbo. I looked into Hiflow GCG's for my GTR and it wasn't much more to get a set of HKS turbos...

I see you needing Turbo + injectors.

[Jay95R33]

No matter how much you change it via a FPR, It’s still only going to pump 380cc into the motor, and if you think you can get 240 - 250kw out of stock injectors go for it.

You can increase the flow of the injectors by increasing the preasure, although I wouldn't go more than 10-15% more than stock preasure. This amount might just give you what your after without having to go to 550cc's.

[GunMetalR33]

Hey BBQ : There are lots of people on this site running standard injects and making 240-250 at the wheels. In fact I think SK has tuned three of them, and by my understanding he kinda knows what he is talking about...

[pinoi_boi_r33]

and by my understanding he kinda knows what he is talking about...

now thats the understatement...

[Wazz]

lol bbq melted piston 6 (ages ago)

as long as people dont do wat he did.. (run mass boost for to long) in a hot climate with almost stock everything cept avcr fmic n zorst

[BBQ]

lol bbq melted piston 6 (ages ago)

as long as people don’t do wat he did.. (run mass boost for to long) in a hot climate with almost stock everything cept avcr fmic n zorst

If you call 10psi Mass boost, when then I think you’re in trouble running 14psi. As that’s the biggest contradiction, Considering your running a stock Cooler, stock fuel system, stock computer, with a rb25turbo, (On a rb20) Running 14psi....... Ohh yer did I mention the Heat that your running it in !!!

Your setting a good example, just like your comment.

With a stock internal motor you can't expect to bolt on a bigger turbo, run more boost and keep the fuel system stock, it just not reliable. Bigger turbo = More Air, More Air, Needs more Fuel.

If you keep your injectors stock gunmetal 33, and you do the turbo upgrade.

I would like to see how long your car lasts until you are up for a re-build.

[Sydneykid]

Hi guys, I need to clarify a few things here;

GCG ball bearing hi flow, no problems for 250 rwkw, best I have seen is 265 rwkw at 1.5 bar.

Upping the fuel pressure at the rail increases the fuel flow through the injector, but is isn't one for one. For a 10% increase in flow you need around a 25% increase in pressure. That's a lot more pressure (48 psi compared to 38 psi) so you need to make sure your fuel fittings, hoses, filter and clamps are capable.

Personally I would never aim for more than a 10% increase in flow, so 410 cc's is about the limit. Using the rule of thumb for a 6 cylinder, that's 410 bhp (306 kw) or ~ 240 rwkw. Best I have seen was 235 rwkw. That's using cleaned injectors with the highest flowing one in #6, the next in #5 etc. In a GTST this is due to #6 being at the rear, furthest from the radiator, not much air flow, radiated heat etc. Nothing to do with differential flow in the inlet system (like a GTR).

So you need to do the numbers, 1.5 bar = 22 psi + rail pressure 48 psi = 70 psi. Minimum you need a fuel pump that can supply 410 cc X 6 X 60 = 148 litres per hour at 70 psi. An R32 GTR fuel pump (used for the 265 rwkw) will do 190 litres per hour easily, as will a Z32, at that pressure. With reference to the attached tests on the Supra pump (make sure the part number actually agrees with yours) you can see that they are extremely voltage sensitive.......

At 12 volts they are below what I would consider a safe margin (155 litres per hour at 70 psi rail pressure). So if you haven't already done it, I would strongly suggest you run a dedicated supply to the pump from the battery via a relay. Use the standard wiring to switch the relay. That will get the voltage at the pump up to 13.8 volts (alternator output) and give you around 210 litres per hour, which should be more than enough.

OK on the Z32 AFM, although you might just get away with the standard R33 GTST AFM at ~240 rwkw. The Nismo "bolt on to the fuel rail" style of fuel pressure regulator will do the job for 70 psi ($149 from Nengun).

Bottom line GunMetalR33, the injectors will be the limiting factor in your plan, with around 240 rwkw being the most likely limit.

Hope that was of some help:cheers:

[Bass Junky]

All Hail to SK

[Abo Bob]

So does that mean that you need to run 22 psi to get those kind of power figures?

I was curious because I expect that would generate more heat than say a GT-RS or GT2835ProS at lower boost but same power.

[GunMetalR33]

AAHHHGGMMM knowledge flexing....

Na just jokes, thanks for the great info. What happened to the attachment???

Hi guys, I need to clarify a few things here;

GCG ball bearing hi flow, no problems for 250 rwkw, best I have seen is 265 rwkw at 1.5 bar.

Upping the fuel pressure at the rail increases the fuel flow through the injector, but is isn't one for one. For a 10% increase in flow you need around a 25% increase in pressure. That's a lot more pressure (48 psi compared to 38 psi) so you need to make sure your fuel fittings, hoses, filter and clamps are capable.

Personally I would never aim for more than a 10% increase in flow, so 410 cc's is about the limit. Using the rule of thumb for a 6 cylinder, that's 410 bhp (306 kw) or ~ 240 rwkw. Best I have seen was 235 rwkw. That's using cleaned injectors with the highest flowing one in #6, the next in #5 etc. In a GTST this is due to #6 being at the rear, furthest from the radiator, not much air flow, radiated heat etc. Nothing to do with differential flow in the inlet system (like a GTR).

So you need to do the numbers, 1.5 bar = 22 psi + rail pressure 48 psi = 70 psi. Minimum you need a fuel pump that can supply 410 cc X 6 X 60 = 148 litres per hour at 70 psi. An R32 GTR fuel pump (used for the 265 rwkw) will do 190 litres per hour easily, as will a Z32, at that pressure. With reference to the attached tests on the Supra pump (make sure the part number actually agrees with yours) you can see that they are extremely voltage sensitive.......

At 12 volts they are below what I would consider a safe margin (155 litres per hour at 70 psi rail pressure). So if you haven't already done it, I would strongly suggest you run a dedicated supply to the pump from the battery via a relay. Use the standard wiring to switch the relay. That will get the voltage at the pump up to 13.8 volts (alternator output) and give you around 210 litres per hour, which should be more than enough.

OK on the Z32 AFM, although you might just get away with the standard R33 GTST AFM at ~240 rwkw. The Nismo "bolt on to the fuel rail" style of fuel pressure regulator will do the job for 70 psi ($149 from Nengun).

Bottom line GunMetalR33, the injectors will be the limiting factor in your plan, with around 240 rwkw being the most likely limit.

Hope that was of some help:cheers:

[GunMetalR33]

aarr Sh8t there it is...

[GunMetalR33]

What sort of PSI are we talking to get the GCG hiFlow to produce the 240 mark you mentioned SK?

[croat]

I personally would not bother with the highflow. go a jap brand, when it comes to it the price difference is not that much. I bought a gt-rs for $2800 from nengun, and sold my standard turbo for $450. which ends up costing me $2350 for my new turbo. GCG have them for like $2000 and its your standard one re-done so u save few humdred $$ for what? a highflow? i just personally dont think they are as good as a jap unit, but oppinions differ.

[DAN00H]

I personally would not bother with the highflow. go a jap brand, when it comes to it the price difference is not that much. I bought a gt-rs for $2800 from nengun, and sold my standard turbo for $450. which ends up costing me $2350 for my new turbo. GCG have them for like $2000 and its your standard one re-done so u save few humdred $$ for what? a highflow? i just personally dont think they are as good as a jap unit, but oppinions differ.

I'd agree that for the few extra $$$ it is worth going the Jap brand. in the case above $350 is very little!

[Sydneykid]

I personally would not bother with the highflow. go a jap brand, when it comes to it the price difference is not that much. I bought a gt-rs for $2800 from nengun, and sold my standard turbo for $450. which ends up costing me $2350 for my new turbo. GCG have them for like $2000 and its your standard one re-done so u save few humdred $$ for what? a highflow? i just personally dont think they are as good as a jap unit, but oppinions differ.

I'd agree that for the few extra $$$ it is worth going the Jap brand. in the case above $350 is very little!

So you guys just bolted the GTRS straight on, you didn't have to modify anything, buy anything extra or fabricate stuff? The GTRS fitted up exactly the same as the standard turbo? And it took you half a day to remove and replace, no special knowledge or tools required?

Then it made more power EVERYWHERE than when the engine was standard?

Then you took it out ot the drags in a full weight R34 GTT and it did an 11.9 at 120 mph?

There is more to a turbo than how much it costs on its own and the maximum power it makes at one RPM point. Personally, I take it all into consideration, look at what I expect from the car and then make a choice.

What sort of PSI are we talking to get the GCG hiFlow to produce the 240 mark you mentioned SK?

I have seen 240 rwkw at 1.2 bar, but remember boost is irrelevant, it is simply a measure of resistance to airflow. An example, the R34 GTT has cams and headwork. It makes 15 rwkw more at similar boost because the cams and headwork have removed the restriction, so it flows more air (to make more power) but the resistance (boost) is lower. I am sure the GCG ball bearing hi flow would make more than 1.5 bar if you stuck it on a restrictive/choked engine.

Guys, don't get me wrong, I am not picking on anybody or saying you have done it badly. There are more ways than one to skin this cat, I simply post up my way. That way readers can make their own choices.

PS; I don't place any importance in having a certain "name" brand product on my cars, I only care about how nice they drive and how fast they go. I can understand that some people want to have a "name" brand to impress people, but it's just not my thing.

[cameron]

lol bbq melted piston 6 (ages ago)

as long as people dont do wat he did.. (run mass boost for to long) in a hot climate with almost stock everything cept avcr fmic n zorst

You don't even know what boost he was running and how can you call,

Frontmount, full exhaust, pod all the usual stuff... STOCK ?

GunmetalR33,

I'd personally go bigger injector's for reliability, although you can push them to 250rwkw's as SK mentioned you have to change fuel lines and fittings etc to run that sort of pressure. You don't want a fire to break out in you'r engine bay!

I know what i'd do but its you'r decision , all i can say is you will notice the car will run, rev smoother with bigger injectors, same with bigger fuel pump.

Jun