need opinions please!

[Phillyb]

Next month i'm gonna start getting my rb26 rebuilt. right now it has 2 top mount twins (trust td05 18g), dual hks wastegates. they reach full boost at like 6000 rpm and its way too laggy to be practical for the street. made 460 whp on a mustang dyno at 1.2bar. I was thinking of selling the kit and doing a single turbo conversion instead...if i were to do that what do you think i could sell the turbos/wastegates/manifolds for? (very minimal shaft play on the turbos) And what turbo would you guys recommend? I was thinking maybe a precision. thanks.. heres a pic of the setup

[gtrjon]

Pte turbos are great but only the ball bearings are worth looking at. the journal bearings fail time and time again. the only downside to the pte journal bearing is the $$. ON the other hand a best of both worlds is the borg warner airwerks line. Many many people run these turbos on rb26's including atleast 5+ people who frequent this forum. The most common mid sized turbo is the 83-75. great combo of power capability and spool. As far as the price on your twin top mount set up i have no idea but you dont see too many twin top mount set ups on the market. To go single you will need a quality manifold (6boost, full race, doc, etc) $1200-2500, one or two wastegates (300-1000), a turbo (800-2500), add a downpipe in and youre good assuming you have a proper ecu to match.

[gtrte37]

+1 for borg warner, you will not be disappointed!

[r33_gtst]

Full boost at 6k rpm and it only made 460hp.... Seems off to me
You will love a single turbo, gt3076r or seething aroud that size will give you 450 at the rears and mind snapping reponse

[RABBIT]

Are your sure your tunn is 100% ? You should be putting down more i would imagine,
But if you want a cheap(er) single look at a borg warner TS360 series.
Bu first see if a re tune might get what you feel you are missing.

[Phillyb]

thanks for the replies guys.. Its tuned on a power fc, The company that did the tuning said if i upgrade to larger injectors than i could be looking at 6-700 hp? but would larger injectors reduce the lag at all? At 1.2bar the 550cc injectors are pretty much maxed out at 90% duty cycle. I will be getting it re tuned also. It has low compression pistons so im not sure if that has something to do with the lag? Bought the car this way and it spun a bearing weeks after purchase

[Dragon Humper]

D jetro? I would do the rebuild and pop in some 1000cc RCs or IDs. Get someone who knows what they are doing on a MAP based system (if that's what you have) and try it again. There is no way you should be all in at 6000 rpm with those turbos. With a good tune and bigger injectors you should be all in at 5000ish and making at least 650 whp.

Edit: never mind, I see you have a MAF there in that one pic. A retune will help but you would be better off with a Djetro at that power level. If you spend a whole wack of time on a dyno or have someone ride shotgun as you drive around for a few hours you should be able to get those bad boys to come in sooner. 5000 rpm would be about it though, you'll never get those to come in at 4000 rpm without a stroker.

Once you get the motor back together, make a note of where the cam timing was set at and zero them out. Then once the motor is broken in adjust the timing, intake last, untill you have the most compression. That should be the big torque down low setting and will get those turbos up the quickest. Compare that to what was the setting before. If it is now advanced on both with a wider separation angle then the cams were set for max power up high. If it turns out to be the same then the tune was your issue.



Jon.

[Skym]

The lag could be a few things, intercooler is too large (increasing capacity of engine helps to solve this or change size of intercooler to match hp level), camtiming is set for peak hp via adjustable cam gears (takes engine longer to really move car), have a restriction in exhaust system (not straight enough or too small diameter exhaust piping for hp level, turbo's, especially just behind turbo's), A/R of exhaust housing is too big, lower compression could play a role.

HP at engine vs intercooler size can be found here -

http://www.turbobygarrett.com/turbobygarrett/intercoolers

That's one thing you can eliminate straight away.

[r33_gtst]

Agreed with info above
Bigger injectors, 750cc or bigger, fuel pump and proper size intercooler/piping and retue you will do 600 at the wheels easily.
You'd be amazed at what injector size can do. Do these things and it will be a whole new car. The previous tuner should have tuned it correctly, 6k rpm full boost is bonkers, twins should come in strong sound 4k

[Phillyb]

also here's the dyno vid, just doesn't seem right how laggy it is.... http://s182.beta.photobucket.com/use...81378.mp4.html

[r33_gtst]

What are the dimensions of your intercooler?
What psi do you run and do you have a boost gauge?
Fuel pressure regulator?
Need bigger injectors for sure, tune may be all he could get out of it with limited fuel compared to air. Internal
What waste gates are on the manifolds. My car was night and day with a precision 60 compared to the previous eBay one that didn't seal properly. What springs are in the waste gates? You have the set up capable of big numbers, just need a re tune and tweak here and there

[kengeroo]

what sort of exhaust manifold is it ?
been looking for a top mount for bi-turbo.
may be interested in it and the piping...
thx

[Phillyb]

What are the dimensions of your intercooler?
What psi do you run and do you have a boost gauge?
Fuel pressure regulator?
Need bigger injectors for sure, tune may be all he could get out of it with limited fuel compared to air. Internal
What waste gates are on the manifolds. My car was night and day with a precision 60 compared to the previous eBay one that didn't seal properly. What springs are in the waste gates? You have the set up capable of big numbers, just need a re tune and tweak here and there

I'll be getting 1000 cc injectors, it has the nismo fuel pump also. Sard fuel pressure regulator and greddy fuel rail. yes i have a boost gauge its 1.2 bar (17 psi). The intercooler is quite thick its a trust 4 layer dual inlet intercooler but I dont think thats the problem. Dual hks wastegates and im not sure what springs are in them because it has an electronic wastegate controller. Wiseco low compression pistons with r33 rods and crank.. and the head is also built with Greddy cams 264 intake and 272 exhaust side. Isky valve springs.. Im thinking i might need to build the transmission first if im going to be seeing 700 hp? Also what are people opinions on this kit ---> http://rawbrokerage.com/CP-Pistons-M...manleyrb26.htm

[r33_gtst]

It's gotta be fuel and tune, you should be puttin down stupid power with those mods
Try a new tuner once you get your injectors

[NismoS-tune]

Keep the cool setup and go rb30. More displacement, better response, more top end.