Twin 707160-5 Powered RB26's

[Allan74]

What is the quickest, or most powerfull Twin 707160-5 Powered (GT2860-5) RB26 (preferably in a BNR32) that you are aware of ?

Please provide Links, rough Engine Specs and any other info you can.

The most baddass car I know of personally is the BNR32 from Quebec, but it's a stroker......(sr20gtr30 username on this forum). High 9's, 600+WHP.

sr20gt30r's street legal beast - GTRPWR Forums


Is this pretty much the BEST one could hope for ?

I wish we had a STOCK STROKE example RB26 and not a stroker.......

I have the 'Turbo Blues'........please help.
Allan

[mcfly]

theo whoolet ran 9.6 on federal street tires with hks gt2530's. Similar to what you are after. This was way back when his car was white and running a os giken gear set which kept dying.

I dont have the issue of hpi next to me otherwise I would scan it.

[Allan74]

I have 2 options for staying with Twins......

1) Bolt on a pair of 2860R-5's (707160-5) to my manifolds and call it a day, never able to make much more than 600 WHP, even if everything is 100% in terms of the build/tune.

2) Custom Low Mount Twin Manifolds that maintain OEM Geometry 100% and bolt up to EVERYTHING as if they were stock - with the addition of a BALANCE/EQUALIZATION TUBE that connects the front and rear manifold BEFORE each turbo.
This will allow me to mount GT2871's (707160-10) and not have as many problems with shuffle and surging.

I already emailed 6Boost tonight to see if He is up to the task and am waiting for a response.

I currently have cast Nismo/N1 oversized manifolds and I am not sure if welding in a balance tube would be a good idea, as welding on cast might casuse me more problems with cracking etc. I can howver take an off-the-shelf set of tubular Twin manifolds (Tomei, HPI) and get a custom balance tube made to tie them together.

Without running some sort of exhaust pressure equalization for the GT2871's, they will be a nightmare on the street. Chuf Chuf Chuf....all bloody day long.

I will wait and see what 6boost has to say.
Allan

[mcfly]

Why would the 2871's shuffle more then the 2860's? In your view anyways.

[Terrh]

I'm going to be running the 2871-10's on stock manifolds. I doubt there will be issues with shuffle or with making 700+ with nearly stock displacement (just overbore)

[Allan74]

The 2871's are not known as the 'Shuffle Twins' for nothing....lol

[mcfly]

I still believe no twin is better then another in regards to shuffle

[Allan74]

I still believe no twin is better then another in regards to shuffle

Well, regardless, I would rather put in the wrench-time before in a pre-emptive way, than afterwards, when trying to salvage drivability.

What are your thoughts on welding to cast manifolds ?

[mcfly]

Well they are cast steel so it's possible. Depends greatly on the carbon content in the manifolds. If I was there I would take an angle grinder to your pretty manifolds and tell you if you can weld them or not.

I wouldn't butcher a nice set of n1 manifolds. Worth more as they were made.

[Allan74]

Ya, I shouldn't butcher these.

I should find a set of Tubular Manifolds to MOD with a balance tube.

[rb-racer]

any pictures of this balance tube idea you have?

[Allan74]

Not really an idea.....HKS already made the Manifolds, but have discontinued them.

[Snow]

I saw this. Yes it is the FNF car, but it's got a mod list and a dual GT28 setup... not stroked. Has dyno sheet and the whole nine yards. Just ignore the vinyls lol

http://www.bigbirdskyline.com/BigBirdSkyLine/index.html

Here's also a single setup from turbonetics:

http://www.bigbirdskyline.com/BigBirdSkyLine/godzira.html

[mcfly]

That's interesting. Big Bird disappeared but had no engine when it left.

used to run 1.5 bar with 2530's and make 612 rwhp.
had nitrous as well i might add, direct port.

[333]

seems a little odd that he ran 612whp with 660cc injectors and the mods he was running. 575 whp give or take a few more, is about as much as I've seen on a 26 with head work , bigger injectors, no nos and 91 octane. also no meth injection. He also does not make mention of cams or what spec the engine was built to.

[Allan74]

My big problem is, I don't wanna shoot myself in the foot.

I don't wanna pickup -5's and find myself not making the most of things.

On the other hand, I don't wanna pickup -10's and find that I am limited by pump gas and can't take advantage of big power they make, by sacrificing driveability - as they will be shit on the street.

Did any of that make sense ?

[333]

Allan. Seems like you've hit that proverbial fork again. Here's what I've experienced. -10s give you a lot of power, but they also shuffle like crazy, even with fine tunning there still is quite a bit of shuffle, with the -5's, I cannot say enough about these turbos, They spool quick, they don't run out of steam, and they're good for 550- 575whp safely with the proper mods. You don't even need meth, just 91 pump. Anything 500 - 575whp on these cars is just crazy the cars are fun to drive and you have more than enough power to smoke most anything on the road, maybe just shy of a liter bike.
-5's with the proper supporting mods and a pair of goods cams will make any gtr a beast to be reckoned with. Trust me you dont need more hp than that for the street.

[Allan74]

Trust me you dont need more hp than that for the street.
Ya, I know.....but I want the bragging rights.......lol

My car will never be light and I don't think that -5's will net me a 9.....ever.

How are Arleigh's -10's on the street ? with his small Cams, when does he hit full boost ?

I don't exactly have 'Man Cams' but they are not that small either (10.25/270 ProCams). I am hoping that these will help a bit with the bigger turbos.

[333]

light throttle and low boost the car shuffles quite a bit, even after it was tuned. The cams are not too bad and the power starts coming hard at around 4k or so, maybe a little more. The -10's would be perfect if they were on a stroked engine, 2.8l. If you can get the shuffle sorted out and dont mind the higher revs that the power start coming on, the car would be quick.
However the -5 car would be quite a bit ahead and you would have some serious catching up to do.
Allan 2.8l stroker, -10's, the cams you have, some good headwork, fuel, rest of the supporting mods and you will have the fastest setup in Canada that I know of so far. ( until I go single in a couple of years ).

[Allan74]

Well, I have invested enough coin into a Twin setup with all of my accompanying pieces now, to make it too late to go Big Single. It's Twins for me all the way unfortunately.

I still have not herd back from 6boost, on a custom low mount manifold setup, but am hoping to soon.

I think that the balance tube/pressure equalizer on the front and rear manifolds along with proper attention paid to the intake piping will make all the difference with the -10's and I am willing to do so, in order to mount, as they are the largest available for this application......but as people have shown us in the past, not very friendly in terms of shuffle and streetability.

Oh well, I will continue my search for an exhaust manifold setup that will work.

Allan

[mcfly]

the balance tube could not be a solid pipe between the manifolds. I could see it expanding a bit a cracking a stud or something like that.

[Allan74]

Exactly. There needs to be a flex section as part of it...just like what HKS did on theirs. I wish I had pics to show it.

[Allan74]

Here's another option.....

How about I order the 707160-5's (GT2860R-5) but substiture the .86 A/R Exhaust instead of the normally included .64 A/R Exhaust housing ?

http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT28/GT2860R_707160_5.htm

http://www.gtrpwrgtrpwrgtrpwrgtrpwrgtrpwrgtrpwrgtrpwr.com/downloads/pics/707160-5_options.jpg


I didn't even realize that Garrett were offering this option. This would definately give those dash-5's some longer legs and possibly work a little better with the bigger cams that I have. Overall HP on the top end should increase slightly as well without the turbos running out of breath, no ?

Comments ?

[Terrh]

I still don't think that shuffle is anything but a tuning issue (or possibly bad plumbing in some cases).

[mcfly]

I still don't think that shuffle is anything but a tuning issue (or possibly bad plumbing in some cases).

we agree, setup issues