Opinions Wanted

[ggs]

Hello i am currently starting a engine rebuild and wanting opinions from the more experienced than me, which is probably most on this site, i am putting Nitto stroker 2.8 kit into my Gtr r33 2.6 ,also tomei procams duration 270, high , lift 10.8, tomei 1mm oversized valves, my question is would you keep the twin turbos which are garrett 2860-5 which are 6 months old or would you change to a single turbo and if so which one. thank you

[HarrisRacing]

I debated this as well.

Questions you will get:

Pumpgas, racegas, or E85?

Power goal?

Use for the car? Drag, street, road course?

I found that the proven best singles for use on rowdy streetcar builds for nice response have been:

Precision 6262 or 6266

Borg Warner EFR 8374

No doubt these will both out-respond and out-perform your -5's across the board, but on pumpgas the -5's will still make nice powerband while bolting up like factory.

Edited April 24, 2015 by HarrisRacing

[breaker1845]

You need to provide more information regarding power levels you want to achieve and what you plan to do with the car and other variables which all can factor the decision. You've asked a very broad question and no one can give you a straight up answer or suggestions until you provide us with some more details.

[GTSBoy]

I think it's very simple. If you want more than the -5s can give, and you are happy to drop more money, then change to a single. If not to either of those, then keep 'em.

[Blackkers]

You should also know that there are single turbo options that will give a similar top end HP figure but will come on boost much earlier than the -5's will.

Edited April 25, 2015 by Blackkers

[XKLABA]

There is alot of people talking about response v HP of twins over single, the issue i have with this is people going from a twin setup that hasn't had the support mods done to help the twins work properly to a single that gets all the needed support mods then turn around and tell tails of how much better the single is

So my point, if the twins aren't afforded the same level of supporting mods as the single then saying the single is better is misinformation

Now i'm not saying singles are better or worse, i'm saying compair apples with apples and not oranges

-5s on a 2.8 with the right supporting mods is a good match when setup correctly are a force to be reckoned with

So my opinon is this, get the breathing support mods done and change the 270s back to 260s then dial in for response and enjoy

[HarrisRacing]

There is alot of people talking about response v HP of twins over single, the issue i have with this is people going from a twin setup that hasn't had the support mods done to help the twins work properly to a single that gets all the needed support mods then turn around and tell tails of how much better the single is

So my point, if the twins aren't afforded the same level of supporting mods as the single then saying the single is better is misinformation

Now i'm not saying singles are better or worse, i'm saying compair apples with apples and not oranges

-5s on a 2.8 with the right supporting mods is a good match when setup correctly are a force to be reckoned with

So my opinon is this, get the breathing support mods done and change the 270s back to 260s then dial in for response and enjoy

I agree with this until a point...

I see no reason to go single if the goals are 450-500 whp total. I would suggest -7 to nearly anyone wanting a nice powerful stock feel...it's an inexpensive and reliable bolt-on solution and they just flat work. OR -9 for those who may need a little more HP (500 whp?), but I wouldn't suggest -5 (550-600 whp) to very many and the supporting mods part is actually the big issue for me. I recently had this debate and sold my twins to install a single on my build.

Big power on twins (just turbos - not listing fuel, ecu, etc as this is the same in both cases listed below - prices in US):

Tomei manifolds: $700

Tomei dumps = $550

Turbos (-5) = $2200

downpipe = $300

$3750 Total

Big power on single:

BW 8374 internal Gate turbo = $2300

RAW Brokerage manifold + DP = $2550

$4850 Total

So this setup could cost $1k more, but I would almost guarantee these things:

1) As good, if not better response from the single

2) More Overall HP capability from the single

3) Easier service on the single

4) No "shuffle" from the single

This being said, a divided, TWIN WASTEGATE single is still about as expensive as above, but starts to cramp the engine bay.

I feel like the new BW EFR line carries the most merit in simplicity, cost, technology, included WG, and ease of ownership over ther twins personally.

Again, not saying the twins can't make good HP, but I think Geoff with full-race proved alot with the 8374 EFR on his 2.6 bottom end with his car. (704 whp through a cat with a decent boost threshold on HUGE cams).

Edited April 27, 2015 by HarrisRacing

[r32-25t]

You can get rid of the tomei manifolds in your twin pricing, they crack and we have managed to see cars with in excess of 600whp with the standard manifolds

You also forgot to factor in the custom intake pipe, intercooler pipe and oil/water feed lines required for the single turbo set up

[HarrisRacing]

You can get rid of the tomei manifolds in your twin pricing, they crack and we have managed to see cars with in excess of 600whp with the standard manifolds

You also forgot to factor in the custom intake pipe, intercooler pipe and oil/water feed lines required for the single turbo set up

You could be correct.

but we'd also have to add the intakes to the twins for maxxing them out. Do you know of any proven hardpipe / suction solutions and costs for the twins? Also I would DEF be going braided lines for twins after messing with the hard lines!!

Single piping is dirt cheap after ditching MAFS (which you would in both cases for fairness).

[r32-25t]

Personally I'd the only thing is be doing to the intake is modifying the twin turbo pipe which can be done for under $200aud, I've changed plenty of turbos in GTRs and all of them still have the original hard oil and water feed lines in them cause they do the job perfectly

[XKLABA]

Brett has already said what i was going to but i will add

Going off the dudes pic he already has hard pipes and he mentioned he has near new -5s which flow alot more then -7s

So in this case factor in to the cost the fact he already has pretty much everything needed to make them work, just needs to make sure the manifolds where opened up to flow better into the bigger 0.64 housings instead of the factory 0.48s

Then good dumps front and rest in 3.5" min, shorter duration cams and time them for response and the turbs will take care of the topend

[XKLABA]

Also i have standard manifolds on my 34 that i modded to match the GT-RSs

I also have the factory airbox and intake pipes with Z32 AFM blanks and modded elbows that bolt to turbos and modded twin turbo pipe, with that i made 623hp @ all 4

Granted that is with a RB2630

[HarrisRacing]

Also i have standard manifolds on my 34 that i modded to match the GT-RSs

I also have the factory airbox and intake pipes with Z32 AFM blanks and modded elbows that bolt to turbos and modded twin turbo pipe, with that i made 623hp @ all 4

Granted that is with a RB2630

Right, I watched some of your videos...car is nasty! I LIKE IT!

I agree with you especially since he has all the hard parts (didn't notice picture at first!), I wouldn't change a thing...going stroker will only make it better.

Edited April 27, 2015 by HarrisRacing

[XKLABA]

can't wait to race it on the new wheels and tyres so can run more then 19psi

28psi is 623hp

[HarrisRacing]

What does it make at 19 psi? I'm curious. I'll likely be running straight pump gas for a while on my setup. The closest E85 station is an hour away.

[XKLABA]

About 500hp at all 4

But that is on E85

[ggs]

ok more info , i need to provide , thanks for the replies already, power 500 to 600 horses i would be happy with , pumpgas will be used 98 of course, mods shit were do i start, hpi dump pipes with blitz front to tip exhaust 80mm all the way threw , 1000cc injectors split fire coil pack ,expreme tomei manifold, hks blow off valves sequentials, apexi power fc d jetro, greddy electronic boost control, hks spark amplifier, trust greddy induction kit, genuine nismo intercooler , and im sure theres more just cant think at moment but mostly everything been replaced or upgraded except the engine internals , oh and excedy twin plate clutch , project mu brake kits front and back,tomei oversized oil pump and n1 waterpump brand new engine wire harness. engine will have nitto 2.8 stroker kit , 1mm oversized tomei valves , tomei procam camshafts 270 duration 10.8 lift, tomie adjustable pulleys, twin garrett 2860-5s walbro fuel pump

the car im hoping to show it occasional track days but not dragging it ,

Edited April 30, 2015 by ggs

[Piggaz]

You do not need Tomei manifolds unless you enjoy ripping them off later on to use as a doorstop or a paperweight. I've done a back to back myself, they do not make ANY difference.

Keep the stock BOV's.

Keep the factory airbox

[XKLABA]

Nah Piggy, that's a list of already has

So when they crack, and they will, replace with stockers and match port them to suit head and turbos

500 at the wheels will be easy with what you have, 600 will be easier with a 3.5" exhaust

Get rid of the HKS spark amplifier, it will cook your coils at some point, splitfires are ok for 600 but the Mojo LS2 coil kit with built in ignitors would be better, they have a kit that plugs in and deletes the ignitor

[Piggaz]

Oh oops.

Carry on then.