What do I need to safely run 15psi & 300hp+?

[m_melen]

yeah, that's cheaper than half the other mods on my list. way to go nistune!

[Paradis]

if you're happy with staying at 300 then you don't need to rebuild. You can run a safe 16-17psi and do 300rwhp on stock internals with good EMS

[Skym]

Most ECU's have similar gains in hp when tuned correctly. The more expensive MAP based ECU would achieve more hp, due to removing restrictive MAF (gauze screens) infront of turbo.

For roughly 15-30hp gain in hp after retune, Nistune is worth every cent. Similar hp gains to fitting a exhaust.

I saw a dyno graph with roughly 22.5 kw (31.17hp) gain from a retune with stock ECU on RB20DET.

Here's the dynograph -

http://www.trademe.co.nz/Trade-Me-Motors/Car-parts-accessories/Nissan/Other/photos/a-219693772/p-87754459.htm

242rwhp with stock RB20 turbo at 9.1psi. From what I have noticed, common rwhp for stock turbo with intercooler, exhaust, etc mods.

[m_melen]

i've decided it wouldn't be so bad to shoot above 300hp, so I think I'm going to go all out on this one. If I weren't going to change anything I wouldn't bother getting NIStune but with the upgraded MAF, injectors, turbo, etc I think it's necessary for my computer to know what I've done.

[m_melen]

alright, i've put up a shopping list on my original post. now's my next big decision: TURBO.
I've seen alot of people with rb20's swap in the rb25 turbo, but is it really powerful enough? Should i just forget that and go find myself a greddy or hks for a reasonable price?

[love_boost]

i dont think you can push a RB25 turbo that far.

if your looking for something cheaper look into a TDO6 20G that will give you simular numbers.

also a GT3076R turbos are relativly cheap and should give you the power you are looking for.

[Paradis]

alright, i've put up a shopping list on my original post. now's my next big decision: TURBO.
I've seen alot of people with rb20's swap in the rb25 turbo, but is it really powerful enough? Should i just forget that and go find myself a greddy or hks for a reasonable price?

You sound like me a couple years ago, thats not a slam. I'd recommend not jumping head first into the kind of build you're talking about. If you're still at the stage of learning about power of an rb25 turbo, then maybe it's a bit early to be tackling major engine builds and such. Drive your car an enjoy it first. Start picking up parts and add them as you go. Just buy stuff that you'll be able to use down the road on a bigger projects. fuel pump/injectors, E-boost controller, EMS, suspension, FMIC etc.

[m_melen]

i think you've got a good point paradis. since my engine needed to be taken apart (bad gaskets, bad pistons, warped cylinders, etc) i don't think i'll want to have to tear down the entire engine again in the near future for mods. so i think i'd like to do the things that are best done with the engine in pieces while it's still like this. i think the following mods would be a really strong platform for next year's upgrades. i've still got lots of time to think about whether i want to go ahead with the other mods or wait for them.

Nismo engine mounts
ARP head studs
Re-bored cylinders (actually necessary)
Forged pistons (need new pistons, rather do it now and have super strong pistons that will handle future upgrades)
Tomei metal head gasket (can't hurt to have a better gasket)
Gizzmo intake gasket (not too expensive, pain in the butt to install down the road if the engine's already in the car)
RB25 turbo (it's bolt in, I'll worry about going big and fancy later on)
Z32 MAF (no reason I can't give my computer a little extra info about what's coming in)

The optional mods will be
550cc injectors from deatschwerks
GTR fuel pump
NIStune
Bigger turbo, probably a top mount if so

[Paradis]

my bad, i missed the part about your engine being in pieces.. ops:


If thats the case, then by all means go for it. may as well while its pulled apart!!

[m_melen]

yeah, compression was awful, i had a boost leak, i had fluid leaks all over my engine bay. i was going to do the rebuild next year if not now, and id rather learn sooner. thanks for all your input guys, i'm sure i'll have technical questions later but i've got my list!

[rak123]

i think you've got a good point paradis. since my engine needed to be taken apart (bad gaskets, bad pistons, warped cylinders, etc) i don't think i'll want to have to tear down the entire engine again in the near future for mods. so i think i'd like to do the things that are best done with the engine in pieces while it's still like this. i think the following mods would be a really strong platform for next year's upgrades. i've still got lots of time to think about whether i want to go ahead with the other mods or wait for them.

Nismo engine mounts
ARP head studs
Re-bored cylinders (actually necessary)
Forged pistons (need new pistons, rather do it now and have super strong pistons that will handle future upgrades)
Tomei metal head gasket (can't hurt to have a better gasket)
Gizzmo intake gasket (not too expensive, pain in the butt to install down the road if the engine's already in the car)
RB25 turbo (it's bolt in, I'll worry about going big and fancy later on)
Z32 MAF (no reason I can't give my computer a little extra info about what's coming in)

The optional mods will be
550cc injectors from deatschwerks
GTR fuel pump
NIStune
Bigger turbo, probably a top mount if so

if your engine if blown why not just go all out and get the 650 or 750cc injectors... that way if u ever decide you want to go for REALLY big power you wont have to swap them again and spend the money again... just a thought its your build though do as you please

[m_melen]

i'd consider 600cc, but 750 seems a bit over the top for a rb20 doesn't it? how much are the 600cc good for, 450hp? i'll probably throw new coil packs into that list too though.

[Skym]

From what I understand bigger injectors allow injectors to run at a lower duty cycle, which is like ticking over instead of being pushed to the limits where injector could overheat and fail. Most aim for 85% duty or lower for race use.

You'll need Nistune or aftermaket ECU to adjust MAF table for upgraded MAF.

[m_melen]

the 650cc injectors are an extra 60 bucks, i could go for those. i'm definitely planning on nistune, but only when i'm ready to throw in the big injectors and new MAF. would it be a good idea to skip the big injectors, maf, and nistune while i'm breaking in the rebuilt engine, and throw them in once i'm sure the rebuilt worked out?

[Skym]

Nistune should have the stock maps installed, so everything runs as it does now.

But I suggest you buy Nistune software, cable, and download the tune from your cars stock ECU using "Consult download" (it's easy to do if you follow the supplied instructions). Then send tune to creator or a local dealer of Nistune like Ztune (or pay Ztune to download maps and sort out the ECU side of it). Then they can copy the tune onto Nistune for you. Then with creator you pay for Nistune and he sends to you and you or whoever is going to install Nistune inside ECU installs Nistune. That way you have the same tune as what your cars ECU has now. Don't need to retune ECU until your ready to.

Why I say this, as it seems every car has a ECU tune that suits the motor it was tuned for. So best to use the maps on your cars ECU and not another cars ECU.

From what I understand, the maps for factory engine was made up via tune on a engine dyno, then fine tuned on a chassis dyno. Then road tuned where it has the cars weight. So tune should be accurate and safe for run in. Factory wants car to last the 100,000km warrenty period.

Nismo has a "sports resetting" upgrade for GTR ECU that involves making the factory tune better for throttle response, etc. That's with stock exhaust, etc. Some retunes with stock exhaust, etc can be up to 27hp. I guess it shows how mild the factory tune on a Skyline is for longevity.