Starting my Turbo build, need some help please!

[hotrodstu77]

good call on unpluggin the stock 02. once i'm done the adjustments do i plug it back in or just keep it diconnected? also i'm running an unrecirc BOV and i'm pretty sure i have a vacuum leak somewhere i cant find.

[Skym]

Any tuner will disable stock 02 sensor when tuning any brand of ECU. Some turn it on after tuning ECU (stock engine).

O2 sensor is there for fuel economy or basically keeping stock engine around 14.6:1-14.7:1 at idle, cruise. Some tuners reckon if you leave 02 sensor disconnected and tune for fuel economy (cost's more $$ for tuner to do this), stock 02 sensor is not needed.

I had o2 sensor disconnected on my car and engine ran smoother at idle without missing. Reconnect o2 sensor and engine missed, spluttered at idle. That's with gapped down sparkplugs to 0.8mm. I presume why some tuned engines run smooth at idle, is due to disabling o2 sensor.

Any airleaks, clogged fuelfilter can affect final A/F ratio on wideband. Make sure you solve these before making any fuel adjustments.

[hotrodstu77]

thats gonna suck. to many vacuum lines, we ran a propane tank around but couldnt find the source. all i know is its got one hell of a hunting idle. i'll try unpluggin the 02 and see what happens.

[Skym]

I was watching a TV show called "The Garage" (English mechanics in Spain), they were having the same faulty o2 sensor/missing problem with a BMW and had to replace o2 sensor, so it looks like it doesn't matter what car you have, o2 sensor always seems to be a problem.

The Garage -

http://www.youtube.com/watch?v=7wPjqKzvElw

They get the nicest looking cars into their Garage.

[hotrodstu77]

my o2 sensor is brand new. i'm gonna try unplugging it and see where the car idles and sits a/f wise and ill let you guys know how that comes out.

[hotrodstu77]

Update.

Ok so I messed around with my car and it is runnin perfectly where it should be a/f wise. So my mods list is: stock rb20, frontmount(large), cone filter, screamer style turbo elbow, 3" turbo back exhaust no cat, aem wideband, hks ssqv unricirc, 255 lph fuel pump. That's it enginewise. I have an rb25 turbo sittin here in like mint shape with ss lines. So I'd like to use it if I can. It got dyno'd at 222 whp and 214 wtq. My boost gauge could be wrong but it's saying I'm runnin peak 13.5 psi and tapers to at least 12 psi. So I'm definatly thinkin about gettin ztune to tune my car or at the very least get nistune and do it myself. So do I absolutly need the gtr injectors?

[Skym]

Another +30hp or so (depends on how aggressive the ECU tune is) for stock ECU retune with Nistune.

With that fuelpump, 550cc Deatschwerks Injectors -

http://www.deatschwerks.com/catalog/product_info.php?cPath=0_24_44&products_id=114

Select 550cc from dropdown menu (has price for set of 6 x injectors). These injectors are drop in with stock O rings and don't need a resistor pack like stock GTR injectors do.

[hotrodstu77]

Ok good to know. Also I was lookin at nistune and I'm not quite sure wat te deal is. If someone could explain it better then ztune's website it help me out. All I see is for 400 or so you get a board. Do I tell them my mods or what? I don't quite understand

[Brody_Howell]

This Thread has given me soo many ideas... i love you guys haha. I just bought a white 1990 skyline GTS-T for 3600 $ and have been curious where i should go next.. first upgrades were a boost gauge and an AEM wideband. P.S. Lordco has UEGO wideband gauges on sale right now for 198.00... crazy deal. (In the Lower-mainland B.C. at least).

[Skym]

The Nistune board replaces the EPROM chip inside ECU.

The Nistune board essentially updates the stock R32 ECU, so it acts like a modern Nissan ECU on new cars, where you can reflash the ECU (make changes to fuel, ignition maps). But with older R32 ECU the maps can be changed in realtime and engine responds to changes straight away. When finished with tuning, changes are saved to ECU. You can't do that realtime part with new Nissan ECU's. It's make the changes to maps, send to ECU with year 2000+ Nissan ECU's or called reflashing a ECU and see if the changes made a difference.

What they do is they can download the EPROM information from your cars stock R32 ECU via using Nistune software, laptop, cable that connects to diagnostic plug under dash. I did this with my car (borrowed a laptop), as it's really easy to do if you follow the instructions that come with cable, etc.

Then they write that downloaded EPROM file that you send to them to the Nistune board, which will replace the EPROM chip inside ECU and allow you to make changes to maps in realtime via plugging laptop up to diagnostic plug under dash (next to fuses) on drivers side. With Nistune board installed + stock maps from your cars stock ECU, your car will drive and react the same way it did with EPROM chip until you plug laptop up to car and make changes to suit new mods. So don't really need to tune ECU straight away, if your stock ECU maps are not causing problems.

Ztune does the above for you, including installing the Nistune board, etc inside ECU. Then if you have upgraded injectors, fuelpump, Z32 AFM, etc, they can fit, tune stock ECU to suit.

[RB25DET]

As far as I know -

Podfilter (Apexi)
3" Exhaust from turbo
GTR Front mount intercooler
ECU retune (Nistune)
98 octane fuel (can't remember what the equivalent octane rating is in Canada)

It's roughly 305hp at engine. 2x RB20DET's I know of have had the same 241rwhp result with stock turbo. But there are sometimes good engines off the production line that produce more hp than others. Engine condition (km travelled) or if it was thrashed (worn out), fuel octane (how far you can push ignition timing with high octane fuel before engine knocks), etc can affect the final hp output.

Ztune (Nistune dealer) can supply Nistune and tune Nistune -

http://www.ztune.ca/

OK I dyno'd 296 RWHP with a stock turbo producing Stock boost.

1)MAF Z32
2)Q45 Throttle body
3)FMIC Greddy
4)Intake Greddy
5)Splitfire Coils
6)3" Trust dump, down and N1 Apexi
7)Greddy Emanage w/ special cable & a good TUNE

My injectors cut out at about 18lbs. of Boost @ 386 RWHP

Next move
1)Bigger INjectors
2)Garret 35
3)External Exaust Manifold
4)Re-Tune

Expecting Realistically @ 22lbs. boost @ 450ish

[Skym]

Wow, congrats.

So with 91, 94 or E85 fuel and DynoJet dyno??

[hotrodstu77]

Rb25?

[RB25DET]

I am Running 93 Octane with no Cam-2 (100 or 110). Also it is an RB25. My Chevy HHR has E85 Thanks Skym.

[hotrodstu77]

UPDATE
ordered all my parts. should be in withing the month.

hybrid turbo airesearch t04 inlet and a z31 exhaust housing(t3)
aem WIDEBAND
HKS SSQV unrecirced
have to build my own turbo elbow
arp studs
intake gaskets
exhaust gaskets
stock intake mani
DW 550cc injectors
stock exhaust mani with turbosmart internal WG
Nistune
z32 maf
stock 240sx rad
huge FMIC
3 inch turbo back catless exhaust
oil cooler
electric boost controller

thats about it. shooting for 300-350 whp on higher boost(18psi)
that sounds pretty realistic right? (feel free to comment skym)
i know that the tranny and diff will be weak points. im going to replace my open diff with a 240VLSD because thats what i can afford and ive seen guys do 500hp to those diffs with no problems. im not going to race this or take it to track days. might go to the drag strip once or twice a year for a couple runs. and if my tranny breaks ill get an rb25 trans then. so it will mostly be my DD. and as far as DDs go i am a pretty tame driver.

hey skym how much do you know about nistune. i will be tuning my car myself on a safe tune till i can hit up a dyno. so i could use some pointers lol. i have read through the forums and the documentation on the nistune site but there is still stuff i dont quite get.

if anyone has any other pointers for my build just chime in thanks!