Jump to content
SAU Community

Recommended Posts

Hello all, I noticed i have a missing exhaust stud, which would throw out the ecu to rich mode (too much oxygen present)

butttt.... Does the ECU also stay on full rich mode if your open looped with no thermostat installed, or is that only for the Holden Commonwh*res VN onwards ??

I put in bp ultimate 98 full tank, and have barely got 340 km city driving and its just above the line, and i hardly thrashed it .... like i should have.

Any thoughts would be appreciated from knowledged individuals. thanks again!!

Link to comment
https://www.sau.com.au/forums/topic/440229-r33-rb25det-thermostat-question/
Share on other sites

Exhaust would leak out of the manifold father than air being sucked in.

All efi cars run richer when cold. If your car doesn't get up to temp cos it has no thermostat it will run rich.

Talk liters per hundred k's to get a more meaningful consumption figure.

Replace your O2 sensor if you haven't yet.

If you have no thermostat then you are wasting fuel and causing excess damage to your engine from it running too cold all the time. This goes for any car with an ecu.

And as superben said, an exhaust leak will let exhaust gases out, not oxygen in. It will however cause a slight loss of power.

And also as superben said, without knowing your actual economy in L/100kms then it's hard to say whether you are getting poor economy, average economy or just have a dicky fuel gauge.

thanks guys, well i guess the skyline is 60 litres, i filled up what was it, 53 litres, so 53 litres, 340 km

6.4 km to a litre, doesnt sound right does it?

15.625 litres per 100 km , had to rack the brain for a good 30mins to get the equation down pat , LOLLLLLL, i used to be top of the class in algebra too LOOOOOLLLLL!!

Edited by REEMER_31

on another note, i know its not covered here, any-how , i noticed the 5 speed manual and whatever stock diff gears are on the back are not going to cut it, given that i have a 300kph dash read out, and with the current gears it will be near impossible to reach that without 8000 rpm in 5th,

even after the mods im going to do with it, top feed rail + top feed 750 cc injectors, power fc computer, ATR hyper flow turbo,bosch z32 A.F.M / 250 litres per hour fuel pump, adjustable fuel pressure reg with read out gauge and new racing timing belt + water pump tensioner / idler . I want to pull at least 200 in 3rd at max rpm and 300 in 5th at max rpm. what ratio do i need? cheers

Edited by REEMER_31

Different gears aren't going to get you to 300.

Part of a 100k service won't get you there either (you left off cam seals) seems kinda odd you even mentioned it ;)

And whatever turbo that is won't get you to 300 , so you probably should reassess your goal to avoid disappointment.

And cos I'm feeling helpful, you don't need the adjustable regulator.

Your O2 sensor would be screwed, they go bad overtime so just replace it and good luck noticing the difference in economy with a synthetic oil.

on another note, i know its not covered here, any-how , i noticed the 5 speed manual and whatever stock diff gears are on the back are not going to cut it, given that i have a 300kph dash read out, and with the current gears it will be near impossible to reach that without 8000 rpm in 5th,

even after the mods im going to do with it, top feed rail + top feed 750 cc injectors, power fc computer, ATR hyper flow turbo,bosch z32 A.F.M / 250 litres per hour fuel pump, adjustable fuel pressure reg with read out gauge and new racing timing belt + water pump tensioner / idler . I want to pull at least 200 in 3rd at max rpm and 300 in 5th at max rpm. what ratio do i need? cheers

What do you need to pull those speeds in those gears? A 6L Chev motor would be a good start. Unless you like getting beaten of the line by a hyundai excel.

Look at this way, 4th gear won't get to 200kmh on the stock ratios and you want 3rd gear to go faster than 4th. So imaging taking off from a stop in 2nd gear with a big laggy turbo that doesn't make boost until 70kmh. By the time you get to 60kmh the grandma in her corolla that was stopped next to you will be a pair of tail lights in the distance.

And rev limit is the least of your problems when it comes to hitting 300kmh. Aerodynamics plays a major part.

And if you are planning on building your motor with big injectors, turbo, etc then I wouldn't bother about fuel economy because it's only going to get worse with those mods

ahaha , ok back to the original problem at hand, fair enough i wont see those figures of speed with the setup im looking at,

Now i finally realize somehow the ATR HYPERGEAR turbo is not such a "DIRECT BOLT ON " mod after all, somewhere along the lines of external waste gate, * * * F F S inserted here...

Yes i realise another financial downfall is in store to

a> mod the external hypergear turbo to an internal gate,

or b> buy a hi mount manifold with individual hi flow runners etc plus whateever else is needed for the external gate.

the question is, I am not familiar with turbocharged vehicles especially gating systems.

if i buy the 350 dollar stainless high mount manifold, what other expenses am i looking at incurring to change the factory stock setup , baring in mind i have a 250 cigweld welder at my disposal, what is the external gate BS, does is simply mean another bolt on mod to the himount manifold and then hole saw the stock exhaust a lil and weld another pipe in to it, ,

can you break it down for me? thanks guys

on a stock r33 how can i get this new turbo and keep it and buy another manifold and mod the whole car to take this 380kw rated external gate turbo.??? help much appreciated, its obviously going to be a long term project, as i`m sick of the car not being on the road blasting posers as it is.

I would (option C) purchase a hypergear turbo that is a direct bolt on and not f**k about with changing wastegates and manifolds.

I see, the bloke from hypergear is proposing me to re send the external gate to him, and he will fit an internal gate and re ship it for 370 bucks, so it directly bolts on, is this the option C i should take?, because he wont accept item return , not sure if thats legal or not, most people have a return policy ,maybe i overlooked something. When asking why no refund, " such an old model, the *EXTERNAL (EDITED) gated turbos , be worthless to me ", as he built it customly for me ( not sure if thats mentioned in the ebay ad , will build once you pay, but f**k here i am )

Edited by REEMER_31

on a more simpler note, another problem i was facing before fixing the broken exhaust studs and attempting a major performance upgrade was intermittent fuel cut-out or so it seems

you'd plant it or try to plant it (throttle) and hit or miss the engine likes the idea or else it kinda stuttered / missed the mark all together and totally loses power,, I put injector cleaner in it, perhaps i need metho and a miracle also?

is this a

A) blocked fuel filter ?,

B)screwed regulator / and or 's (i notice theres 2 diaphragm units on the r33, one coming up near the fire wall and one on the fuel rail itself,) ?

or

C) fuel lines gunked up from a car that sat around too long before being re-purchased( this one ) ?

Any advice would be good , thanks!

What ecu are you using?

You realise you will need a tuneable ecu, bigger fuel pump and injectors, new clutch etc to get the power you are after?

It's never as easy as bolting on a turbo.

I got the power fc,

750 cc bosch injectors top feed that is

top feed big bore fuel rail

, z32 genuine AFM, ,

, adjustable fuel pressure reg with gauge readout,

new gates water pump +racing timing belt + cam seals, crank seal, tensioner , idler,

the new shit turbo i cant use LOL, ATR HYPERGEAR

255 lph indwelling fuel pump, aftermarket, cost 100 + didnt see the need to buy a bosch, rather take a chance ROFL

guess i need a HD 3 button clutch to live up to the power demand, but heh, im going to bolt the old shit on and just wait around until i can get a clue at the labour / parts i`m looking at here, been a head f**k so far, can only be even more of a head f**k later on LOL !!!

what about the fuel starvation issues, whats the first thing i should change you think?, i re-gapped the spark plugs to 0.8 mm they were over 1.0 gapped causing it to miss on one cylinder, guessing the most gapped cylinder, even at idle, i cured the missing problem re gapping them, but theres a starvation of fuel/air at certain times, doesnt matter what rpm, usually starts when you plant it then it comes good after you settle down, definately seems like it rev limits at 6000 no matter what, and spluttering at those rpms, what am i looking at, bad ecu ? coil pack or simple fuel delivery problems?

all i can say is that its annoying as f**k, i was guessing its the air leak on two of the studs that f**ked the air / fuel ratios on the ecu , but time will tell once i bolt up the stock parts tomorrow

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • For once a good news  It needed to be adjusted by that one nut and it is ok  At least something was easy But thank you very much for help. But a small issue is now(gearbox) that when the car is stationary you can hear "clinking" from gearbox so some of the bearing is 100% not that happy... It goes away once you push clutch so it is 100% gearbox. Just if you know...what that bearing could be? It sounding like "spun bearing" but it is louder.
    • Yeah, that's fine**. But the numbers you came up with are just wrong. Try it for yourself. Put in any voltage from the possible range and see what result you get. You get nonsense. ** When I say "fine", I mean, it's still shit. The very simple linear formula (slope & intercept) is shit for a sensor with a non-linear response. This is the curve, from your data above. Look at the CURVE! It's only really linear between about 30 and 90 °C. And if you used only that range to define a curve, it would be great. But you would go more and more wrong as you went to higher temps. And that is why the slope & intercept found when you use 50 and 150 as the end points is so bad halfway between those points. The real curve is a long way below the linear curve which just zips straight between the end points, like this one. You could probably use the same slope and a lower intercept, to move that straight line down, and spread the error out. But you would 5-10°C off in a lot of places. You'd need to say what temperature range you really wanted to be most right - say, 100 to 130, and plop the line closest to teh real curve in that region, which would make it quite wrong down at the lower temperatures. Let me just say that HPTuners are not being realistic in only allowing for a simple linear curve. 
    • I feel I should re-iterate. The above picture is the only option available in the software and the blurb from HP Tuners I quoted earlier is the only way to add data to it and that's the description they offer as to how to figure it out. The only fields available is the blank box after (Input/ ) and the box right before = Output. Those are the only numbers that can be entered.
    • No, your formula is arse backwards. Mine is totally different to yours, and is the one I said was bang on at 50 and 150. I'll put your data into Excel (actually it already is, chart it and fit a linear fit to it, aiming to make it evenly wrong across the whole span. But not now. Other things to do first.
    • God damnit. The only option I actually have in the software is the one that is screenshotted. I am glad that I at least got it right... for those two points. Would it actually change anything if I chose/used 80C and 120C as the two points instead? My brain wants to imagine the formula put into HPtuners would be the same equation, otherwise none of this makes sense to me, unless: 1) The formula you put into VCM Scanner/HPTuners is always linear 2) The two points/input pairs are only arbitrary to choose (as the documentation implies) IF the actual scaling of the sensor is linear. then 3) If the scaling is not linear, the two points you choose matter a great deal, because the formula will draw a line between those two points only.
×
×
  • Create New...