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Xxx_Ruff_Ryda_xxX

Contemplating 300+rwkw Unopened SR...

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Ok, I've been thinking of taking a dive and attempting to break (hopefully not the motor) 300 rwkw+ on a street and occasional track E85 unopened S15 Spec R SR20DET.

 

First of all I understand:

  • Increased risk of blowing the stock head gasket being 17+ years old
  • Piston rings will get hot, hoping E85 will help and street dirven yet spirited style keeps it somewhat cool
  • The S15 6 speed isn't strong, keep in mind I have had the circlip mod done and I will stick with the dual mass flywheel for cushioning with no clutch kicks. Oil will be Lightweight Shockproof. Clutch is an NPC 10" organic handling 320+ rwkw.
  • Hope the stock rocker arms don't shatter
  • The big-ends doesn't soddomise me with it's big-end
  • Yes, I know a forged motor would be a better idea but read on further down

Current mods are all the usual bolt-ons and safely reaches 256+ rwkw on E85 currrently on a hot day.

 

What I need to do before attempting the build:

  • Confirm fitment with the low mount 6boost manifold then purchase a GT3071R T25 56t 0.63 A/R turbo
  • Turbosmart external wastegate plumbed before cat
  • Quality Fuel Rail with Bosch 1150cc injectors
  • Turbosmart 1200 FPR (stock FPR won't flow enough)
  • E85 will require larger fuel lines (3/8" I believe),, to be installed.
  • Install Tomei Poncam 256 11.5mm IN / Procam 260 12mm EX
  • Supertech 75lb Valvesprings

Aim will be reaching 300+ rwkw @ 18 - 18.5 PSI on E85.

 

Anything else I need to consider or that I've missed, please fill me in.

 

Why? - I love to get more power as always but also to prove reliability for a street driven SR20, obviously if I was on a track I would drop the boost down to say 15 PSI as it would just be a risk in my opinion at such high temps.

 

This will be before going down the VET path, I'm still a couple of years off from that.

 

I still want it to be responsive as I'm currently running the GTX2863R 0.63 A/R turbo with GReddy Easy step 1 cams (256, 10.5mm IN EX), yet full boost is still at 4000 RPM...I think the 3071R will still feel as powerful down low as well but much more fun at mid and top range.

 

Let me know any concerns or factors which I need to consider please, I'm not attempting to become another "Red Dragon" example but I would like to know what I need to do before having to change pistons, rings, etc as E85 can keep the engine temps down and provide more power at the same time.

 

Cheers.

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GT3071 is a gay turbo, better off with a GTX2867R or even a GTX2871

 

Also put in ARP 2000 studs, your head will lift with the OEM studs. You're going to need about 1.6bar of boost or more for the car to boogie.

 

Cam wise is ok, but if you're keen a little longer duration would definitely put you over club 300.

 

Gearbox will grenade itself with the torque, so get ready for a Z32 conversion or be the first and do a 370z box conversion!!!

 

 

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GT3071 is a gay turbo, better off with a GTX2867R or even a GTX2871

 

Also put in ARP 2000 studs, your head will lift with the OEM studs. You're going to need about 1.6bar of boost or more for the car to boogie.

 

Cam wise is ok, but if you're keen a little longer duration would definitely put you over club 300.

 

Gearbox will grenade itself with the torque, so get ready for a Z32 conversion or be the first and do a 370z box conversion!!!

 

Thanks for the input, I know how much you love the 3071 John :P but the reason for the 3071 is being that on the compressor map it flows better at lower boost levels so I can make more power and minimise heat and stress on the engine. Hopefully this means I won't need a head gasket replacement anytime soon.

 

EDIT: Just looked at the maps again and the GTX2867R map looks identical to the 3071R map, so that's looking quite good so far. My next question is the turbine and how efficient it is versus the 3071? I've read the NS111 turbine doesn't flow and tends to choke beofre max power is reached...

 

If I need to remove the headstuds, I may as well replace the gasket (unless I'm mistaken and the gasket isn't affected?).

 

The cams I like because it's responsive yet stretching for a little bit more power. I think if I was to go larger then porting the head would be the best option to get the most from the cams but I will definitely lose response also which I want to avoid.

.

The gearbox I think will at least last a year or 2 haha. I like the idea of the 350z box conversion though (assuming you meant 350z, not 370z). Juggernaut on here has 290rwkw on his circlip modded Nismo 6 speed box. As far as I know the only difference between the boxes is the gear ratios and the word "reinforced". They don't even address the circlip issue, he had to organise the circlip mod himself.

 

oh yeah, put a RAS kit into it.. before its snap city with the rocker arms.

 

I've got a Tomei RAS installed from day one of modding the 15. I've already snapped one of the rocker arms a couple of years ago on the dyno so RAS did nothing for me... :S

Edited by Xxx_Ruff_Ryda_xxX

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Should do it fine. The secret to making the box last is that clutch you're running. I don't think you're missing anything, but, I think you'll be just as unhappy with the lag at 300kW as you are now.

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Yeah cant see you making 300kw+ very lsong with stock head bolts and gasket. Pistons and rods have been proven to handle it by powertune but that had studs and gasket. Problem will be at that kinda power you'll have high cylinder pressures and the stock headbolts will stretch.

 

Also RAS can do more harm than good. While they stop the rockers from jumping off, if the backfire is big enough to make the rockers move, the rockers will hit the RAS and snap them into pieces.

Edited by Protius
  • Upvote 1

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Also RAS can do more harm than good. While they stop the rockers from jumping off, if the backfire is big enough to make the rockers move, the rockers will hit the RAS and snap them into pieces.

 

Yep.

 

If you want to do anything to the rockers, run dual guides. Get your machinist to modify the rocker arm to accept the guide on the other side of the rocker.

You will see what I mean when you look at one. Running both guides stops the sideways movement and will help prevent rockers from flying off.

 

Been running this setup for a while to 8200rpm no probs. Keep your rev limiter span at a decent RPM range as well ( at least 500rpm).

 

Pic for reference.

 

a409feb56b.jpg

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A GT3071 real world in a T2 equates to gay... on a non-VCT SR20DET it doesn't come onto noise well over 4500rpm, somewhere in the 4700rpm range... on a VCT equipped motor (making an educated guess here) probably will come on song 4300rpm which is still gay.

 

It's 1999 technology, I am not sure why people bother with GT turbos, they're gay.. too many fanboys out there.. same goes with the likes of GT2871 or T518z.. horrible turbos. I tuned a S15 with a GT2871 and poncams and the freaking thing didn't come on till like 3900rpm, not to mention I loaded up the car at 3k rpm before I started the run.

 

GTX is the way forward, also if you're going 6 tits manifold I would get a T3 flange on it and see if you're able to fit a GTX3071 with a .63 rear on it.. with that combo you'lll make over 300kW easily.

 

 

Also your gearbox, power won't smash it.. it's the torque.. E85 will make bucket loads of torque, probably enough (with that turbo setup) to smash your 6 speed on the dyno.

Edited by Johnnilicte

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I made 321.5kw@w on a stock 15 motor with my t67 on pump with 19psi and 7000rpm cut . No mods to the head or the block at all. Ran it for 3 years and abused it like a $2 mole pulled it out to make way for the stroker. Still ran still worked still functioned. Was i just lucky? Possible, can srs cop a heap of shit? Well yes they can... Just my 2c's

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If you're tracking the car, better to drop in new studs.. the head will lift with the constant changes in temperature... street use, probably won't do it, but constant pulls on the track will do it.

 

 

You can easily do studs without needing to pull off the head, just do 1x stud at a time and torque it down to like 1/2 the torque setting, then once you're doing, go and nip them all up to spec.

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Just to give you an idea, this is the same 15 motor with a td06 make just under 260.. Copped this straight out abuse for 2 years then 3 years with the 67.. There tuff little fukas.

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^ pretty solid stuff, however track work puts more stress on the motor than frying tyres.

 

A set of headstuds cost next to nothing in the scheme of things so I don't see why someone wanting 300kW+ to skimp on it.

I'm currently about to start a basic build on the other trak-life.com car, the S15.

 

Going to try 300kW+ with the stock bottom end, however the head is coming off for some maintenance such as springs, seals, slight deck, new HG, ARP2000 studs.

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My stock box loved gtx3071 and 30psi on e85. NPC clutch didn't slip, box didn't break and I made 345rwkw.

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My stock box loved gtx3071 and 30psi on e85. NPC clutch didn't slip, box didn't break and I made 345rwkw.

 

how much torque in the mid range? many tuners pull out timing around 4k to 5.5k to preserve gearboxes.

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Not sure. To be honest, federal 595s are fairly responsible for my preserved gearbox haha

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Also RAS can do more harm than good. While they stop the rockers from jumping off, if the backfire is big enough to make the rockers move, the rockers will hit the RAS and snap them into pieces.

 

Yep.

 

If you want to do anything to the rockers, run dual guides. Get your machinist to modify the rocker arm to accept the guide on the other side of the rocker.

You will see what I mean when you look at one. Running both guides stops the sideways movement and will help prevent rockers from flying off.

 

Been running this setup for a while to 8200rpm no probs. Keep your rev limiter span at a decent RPM range as well ( at least 500rpm).

 

Pic for reference.

 

a409feb56b.jpg

 

a smidge off topic, that seams like a great idea and cheap cost effective way to keep things sturdier.

 

would one think that with rev limit set to 7500 in 3rd + cog when limit is hit the knock sensor goes off its tits, wouldnt be rockers hitting the RAS would it??

 

also, this mod, your suggesting with say even Procams 260/12 this would work sufficiently till 8000rpm ? even with a bit of rev limiter hiting?

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Thanks everyone for heir input, I'm still playing with ideas. I think I may still struggle even with a GTX2871R to push 300 rwkw just because of the turbine wheel chokes off after 6000 RPM. Because the compressor is rated for 560 hp, I doubt it would actually flow at that unless you had 264 or 272 cams and an 0.86 A/R on high boost. To see that the GTX2867R only makes 10-15 more rwkw than my 2863 uninspires me.

 

That dual valve guide option looks great, is that on a VCT lash setup also?

 

I'll be running a 0.64 A/R as I want progressive and low down power. If I need to increase boost much over 18 PSI I can drop the idea. The stock gasket will die fast. I don't like the idea of messing with ARP bolts one by one, indeed I may as well change the the headgasket if I was taking that path.. I might just hold out for my next VET project instead. I need to save some cash and see where it takes me...besides being robbed.

 

I love the idea of a VET head but it's a costly project. I'm happy to wait until have $15k spare eventually. It will just be a gradual project until I have all the bits ready to go (hopefully). If I don't do the bottom-end I feel I wouldn't be doing the NEO VVL proper justice but I could still try it. In fact I was tihnking of just keeping the stock bottom-end and fully machining / balancing it with ACL Race bearings. I think the lower stroke and higher bore would net a better result.

 

I'll be tossing up between a repsonsive high powered ported / polished head or just saving for a VET. I like the 2nd idea better...just hearing the Neo VVL kick in makes me f3king fizz through my pants hah.

 

That note after 26 seconds... :o

Edited by Xxx_Ruff_Ryda_xxX

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or even go LS path with Silky Conversion Kit

 

As much as a VE sounds good on paper, it's not that responsive - considering you lose VCT.. those motors need to be reved out to 8k~9k rpm to boogie... and the cost (if you're not doing it yourself) is phenomenal!

 

RB25DET NEO, RB25DET gearbox, 1150cc injectors, GTX3576 or even EFR 7670, manifold, ECU, custom tailshaft, custom dump/down pipe would set you back about $10k

 

$5k left over for hookers and cocaine..

 

Torque would be flat, all in at 4k rpm and run rings around a SR20VET.

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Lightweight shockproof oil is f**king garbage. get anything else. I switched to nulon and my box went from noisy and notchy to silent and smooth.

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As Johnny mentioned we'll also be aiming for 300kW on e85 in our unopened S15.

Difference is we're bolting on a GTX2867 with a Turbosmart twin port actuator, Tomei Type A valve springs, Tomei Metal head gasket and ARP 2000 head studs.

Will be a fun summer :)

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or even go LS path with Silky Conversion Kit

 

As much as a VE sounds good on paper, it's not that responsive - considering you lose VCT.. those motors need to be reved out to 8k~9k rpm to boogie... and the cost (if you're not doing it yourself) is phenomenal!

 

$5k left over for hookers and cocaine..

 

Torque would be flat, all in at 4k rpm and run rings around a SR20VET.

 

Haha what.... My VE makes the same sorta power down low as a stock cammed t28 vct motor on e85 and mine makes 350kw on a low reading dyno (more like 370kw on most) and has a powerband of around 4k RPM.

 

I can't see a vct det doing that

Edited by nicknack

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or even go LS path with Silky Conversion Kit

 

As much as a VE sounds good on paper, it's not that responsive - considering you lose VCT.. those motors need to be reved out to 8k~9k rpm to boogie... and the cost (if you're not doing it yourself) is phenomenal!

 

$5k left over for hookers and cocaine..

 

Torque would be flat, all in at 4k rpm and run rings around a SR20VET.

 

Haha what.... My VE makes the same sorta power down low as a stock cammed t28 vct motor on e85 and mine makes 350kw on a low reading dyno (more like 370kw on most) and has a powerband of around 4k RPM.

 

I can't see a vct det doing that

 

haha you see, I wasn't comparing a standard SR to your SRXXVET setup :)

 

I was pointing out the financial savings of he were to do a RB25DET NEO swap and comparing the performance of that to the likes of a SRXXVET setup.

 

OP said he wanted to fry 15k, I was suggesting better ways of frying that cash (assuming he doesn't have the same technical skill set as yourself, Chinese whispers has it you built most of it yourself)

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Fair enough. Yeah itd take a fair bit of work to get a DET close. Oversize valves/porting and solid setup. Haven't really looked at rb25 swaps but it seems like a fair bit of work still. Definitely seems like it could be cheaper to drop a stock one in.

 

 

Jeezus, rumours? Haha. Yeah built it all myself except for some weldy bits

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My vtc det is making 360kw. But yes it is lacking low down and onky has about 3000rpm power band.

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My vtc det is making 360kw. But yes it is lacking low down and onky has about 3000rpm power band.

 

if you get bored, go twin scroll and a modern twin scroll turbo.. you'll get more response :)

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Need to run a Gtx3071. A Gt just doesn't like to spin at high boost. Also a 260poncam with tomei or hls valve springs to retain vtc. Head studs. And obviously the other supporting mods. Tom tucker built an unreal Sr and so did kdog, both breaking 300wkw with a gtx3071. What mod did you get done to the box? And who did it? The box will hold that power if it hasn't started to chip teeth off the reverse gear. Only way to tell its healthy is to pull it down. If you aren't slamming/chirping in to 3rd n 4th it'll be fine. The damage is only done shifting in to those gears. Other than that 1/2 5/6 is all good just like the 5speed Sr box

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My vtc det is making 360kw. But yes it is lacking low down and onky has about 3000rpm power band.

 

if you get bored, go twin scroll and a modern twin scroll turbo.. you'll get more response smile.png

The car is exactly the way I want it :)

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