downpipe choice ?

[cortexx]

Can someone recommend a decent downpipe for an R33 GTR please ?

already have greddy FMIC , nismo clutch , HKS air filters and a jasma cat back system.

Will be probably be using some Garrett GT2860R -5 Turbos on stock manifolds and dump pipes for now .

I want to install a wideband and dont want to waste time welding the bung into a factory downpipe if i have to remove it for that.

BTW where is the best place to situate the wideband O2 sensor ?

Cheers

Paul

[frankiman]

you could go with Trust, HKS, Nismo or MINE's
choose an equal length downpipe is a good idea,
or going with a downpipe with a flex joint is also a good idea,
i personnaly own a Nismo dp with flex joint and i am 100% satisfied


the wideband should go at the very end of the downpipe, or in a test/cat-delete pipe if you have one,
and it should always be mounted at a minimum of 10° angle from horizontal (tip of sensor points downwards) to avoid any condensation on the tip of the sensor

[cortexx]

Thanks for the info , just ordered an HKS pipe .

Also have Apexi dual solenoid boost controller on the way for a boost control , and an AEM wideband .

Now im thinking a PowerFC commander setup, but not sure which to look for , maybe even the Nistune setup.

[frankiman]

imo, i don't see the point of getting a standalone ecu if you're not going over ~500whp
i still have the stock one, and i'm rocking 450bhp and 520bhp before summer's end

[cortexx]

I guess my main justification for the standalone ECU is to tune the engine precisely . My main worry is that fact the ECU is calibrated for japanese 103 octane fuel (or whatever it is over there) , and running it on our lower octane fuel here could potentially cause long term engine damage. The fact that the car came with some decent mods makes me suspicious that the ECU would have been retuned to use them properly. (Or at least I would assume that having spent cash on expensive gear the previous owner would have optimised the ECU for them).

As far as i know the stock ECU is not really tunable unless i use the nistune mod and software , get it modded by a tuning shop or use a piggy back ( which i have always hated).

I dont mind dropping the cash on a standalone because in comparison from 10 years ago , they are relatively cheap to buy and much easier to tune. I remember buying an edelbrock standalone fuel injection setup for the 327 corvette motor that i had in my firebird , what a severe pain in the ass that was to setup!

If i'm going to mod the engine i'll always start with the long standing supporting mods that will cater to future power increases. I'm never going to invest cash to build a 1000hp monster , but 500ish in the long term would be a consideration.

On another Note - I was checking out the boost solenoid from the Greddy profec and notice there are 2 vacuum tubes going to it with 1 plugged. I would assume the plugged line would have been the line to the second turbo ? which makes me wonder how it is presently hooked up.

So if anyone has a diagram for the Vac system that would be awesome ) , cant seem to find it anywhere on the net ...


CHeers

Paul

[frankiman]

it doesn't matter what octance level the oem ecu was preset for,
and btw, japan's 103 is similar to our 94, the octane ratings differ from country

but anyway, the cheapest way to go, and still very effective, imo is what i did;
i got the oem ecu chipped to be reprogrammed and then got the ecu tuned with the car on a dyno,
basically, the tuner will tune the ignition map considering what fuel you have in your tank, principally basing is tune on a AFRs and boost curve
i got it tuned with 91 octance (cheaper and available everywhere) , so the spark advance and fuel maps are totally safe when used with 91 octane, but using 94 is even safer to prevent knock
total cost was below 400$, including the tuner installing the chip himself

but still, thats good only below 500whp, considering the limitations of the tunable parameters of the stock ecu

are you looking for the profec's vac diagram or simply the over vaccum diagram from a GTR ?

this is the oem vaccum system for the stock boost selenoid and wastegate actuators



this is how i setup my HKS EVC-S just 2 weeks ago

[cortexx]

Wow thanks for the diagram , thats invaluable for me.

I got the AVC-R because i wanted the dual solenoid setup (one for each turbo). Reasoning was that on my last project (a 3000gt TT) a single solenoid running a t-split to the 2 waste gates had a hard time trying to control spikes with fast spooling turbos. (9b turbos spool extrememly fast). Dual solenoid BLitz system totally rocked though. BLitz seem to have fallen off the face of the earth in the US and Canada though so i picked the apexi one instead. The Greddy profec that came on the car is totally inadequate the way it is installed at the moment, and after more than a few hours of friggin around still does not behave the way i want it. Probably more my fault than the boost controllers fault but still , I'm changing it !

Why did you ditch the evap cannister ?

Thanks again on the info on the ECU. I'm going to have my wideband installed in a weeks time when the downpipe arrives. Il be able to have a better idea of how the AFR is then. ANother thing i will be installing is a knock meter:-

MSD Ignition 8964 - MSD Engine Knock Alert Systems - Overview - SummitRacing.com

I have used this in the past and it is awesome for detecting undesirable detonation. We found in the 3000GT that the intercoolers were becoming heatsoaked in 3rd gear during a 1/4 mile pull because of the boost we were running, the knock went crazy, and the ECU pulled timing because of this. This would have been difficult to diagnose because the AFM did not show a particulary lean condition. We remedied it by modifying a couple of DSM 1 talon intercoolers that were twice as thick and using them instead to reduce heat buildup and it worked great.

I don't expect this to be a problem with this platform with the gigantic greddy fmic, but i consider this meter to be a cost effective solution for my own comfort level

Cheers

[frankiman]

i ditched the canister for the simple reason that its a 20 year old car, and the charcoal is totally saturated, so the canister is absolutely useless and takes up useable space
i blocked the vac lines going to it and re-routed the evap line directly to the frame rail, where the canister had it going anyway if i remember clearly

you can read about it here; http://forums.gtrcanada.com/gt-r-pro...tml#post398844

[cortexx]

Will this affect the emissions test ? If not i may remove mine too.

[frankiman]

it doesn't affect emissions in any way
its a catalyst for evaporating gazes coming from the fuel tank
but like any catalyst, i gets saturated at some point, and i've never seen anyone replace it with a new unit

[NismoS-tune]

AEM wideband is fine if your budget is limited. Innovate has a much better WB all around and a DB gauge is less than $400.

[cortexx]

Thanks for the advice Nismo , i just called the supplier and he is getting me this instead :-

Innovate Motor Sports On-Line Store

I would have bought this in the first place if i knew it existed i didnt really like the look of the AEM gauge anyways.

Got any suggestions for a oil pressure gauge ? im suspicious of the factory guage , when the engine speeds or slows down the factory gauge takes about 10 seconds to register a chnge lol..

I might also go for a decent boost gauge too , it has an old HKS one atm which is coming out. I will have the AVC-R screen so i might not need it as the AVC-R has a digital readout though.

Also - how the heck does anyone mount extra gauges in an R33 without butchering the dash or removing the center console cluster ?