Rb25det Turbo Upgrade

[MZTRBO]

Hi,

(Car- R33 rb25det s2 running gear)

I have recently acquired a VG30 BB 450hp turbo. I want to put this on my standard rb25det, mainly because of the fuel consumption, it always been on boost with the auto when im driving.

I know this turbo will bolt straight up, though my questions are

1. I want to run stock boost, what is the stock boost on this turbo, I dont know what wastegate/actuator is on it?

2. If running for eg 10psi, will I run into any problems with the ecu like fuel cut, boost cut etc.?

3. What power level can I expect with front mount intercooler, exhaust with split dump and cold air induction. ?

4. By reading posts within the forum, i think im going to run rich, which will inturn defeat the purpose of going the bigger (laggier) turbo as my fuel economy wont be good. I plan on getting a SAFC be it the 1st one or second. Will this fix these issues.?

5. Are there any high priority procautionaries I should be taking with this bigger turbo?

Overall my plan is to put this bigger turbo on, and been on a budget I am only after the necessary things to run it. I already have a front mount intercooler and exhaust. I will eventually buy a safc and get it tuned though in the mean time, what I want to know will it be safe to drive.

I thank you in advance for your replys

Cheers

[BezerkR32]

Boost pressure is not the issue, its volume. If this turbo flows more air at 10psi you may run into trouble. the more air, more fuel has to be added. i would personally wait till i could afford a ECU so the car could be tuned to suit. Cant say if the car will run alright wiyhout knowing how much that turbo flows and at what pressure it will flow at, and series 2 standard computers are very sensiteve to boost increases as the boost retart will come into play.

Hi,

(Car- R33 rb25det s2 running gear)

I have recently acquired a VG30 BB 450hp turbo. I want to put this on my standard rb25det, mainly because of the fuel consumption, it always been on boost with the auto when im driving.

I know this turbo will bolt straight up, though my questions are

1. I want to run stock boost, what is the stock boost on this turbo, I dont know what wastegate/actuator is on it?

2. If running for eg 10psi, will I run into any problems with the ecu like fuel cut, boost cut etc.?

3. What power level can I expect with front mount intercooler, exhaust with split dump and cold air induction. ?

4. By reading posts within the forum, i think im going to run rich, which will inturn defeat the purpose of going the bigger (laggier) turbo as my fuel economy wont be good. I plan on getting a SAFC be it the 1st one or second. Will this fix these issues.?

5. Are there any high priority procautionaries I should be taking with this bigger turbo?

Overall my plan is to put this bigger turbo on, and been on a budget I am only after the necessary things to run it. I already have a front mount intercooler and exhaust. I will eventually buy a safc and get it tuned though in the mean time, what I want to know will it be safe to drive.

I thank you in advance for your replys

Cheers

Edited July 10, 2006 by BezerkR32

[mad082]

4. By reading posts within the forum, i think im going to run rich, which will inturn defeat the purpose of going the bigger (laggier) turbo as my fuel economy wont be good.

the more air you put into the motor the more fuel that has to go it to make it run at the right air/fuel ratio. for example if the bigger turbo at 4000rpm flows the same amount of air the standard one does at 7000rpm, then at 4000rpm it is going to pump in the same amount of fuel as 7000rpm on the stock turbo. if you are worried about fuel economy, then don't change the turbo.

as far as rich and retard mode (boost cut)goes, if you hit it with this turbo you have a few options.

a full ecu upgrade, but your gear changes will suffer slightly,

the safc will be out of the question because if the afm is maxing out then the safc will be of no use above that point. you could go to a fuel cut defender (such as the turbosmart one that has a setup for skylines) and a fuel only computer such as a mircofueler. but that setup puts you pretty close to a full ecu.

if it stays under r&r then a safc would be fine, and if you could pick up a sitc (controls timing) that would make it a little bit nicer too.

[dangerman4]

bolt the turbo on and keep it under 13 psi and you wont hit fuel cut with the standard ecu. approx 215kw's

then buy a power fc from greddy on here for around $960 and put that on and get it tuned. approx 230 kw's

then get a larger Air flow metre and some larger injector's 550cc etc $1000 then a re tune. approx 245kws

then sell your turbo or get it converted to gt30, and the power will keep on climbing until the ringlands die.

get a full rebuild with forged bits, and lots of arp studs. $6000

then sell your highflow and stick a 35 40 on it and go have some fun. 300 - 350kws

my auto 33 is handling 280 kws ok.

this is asuming you allready have all the basic mods.

[paulr33]

bolt the turbo on and keep it under 13 psi and you wont hit fuel cut with the standard ecu. approx 215kw's

then buy a power fc from greddy on here for around $960 and put that on and get it tuned. approx 230 kw's

then get a larger Air flow metre and some larger injector's 550cc etc $1000 then a re tune. approx 245kws

then sell your turbo or get it converted to gt30, and the power will keep on climbing until the ringlands die.

get a full rebuild with forged bits, and lots of arp studs. $6000

then sell your highflow and stick a 35 40 on it and go have some fun. 300 - 350kws

my auto 33 is handling 280 kws ok.

this is asuming you allready have all the basic mods.

this information is wrong, please ignore it. the stock protection is not a fuel cut. it is not boost cut. it has nothing to do with boost. it is based on air volume and volume alone. once the protection is activated the ecu retards the timing and richens itself up to protect the engine as it believes too much air is coming into the system for the factory components. you are likely to hit the excess airflow protection when you change the turbo as it will have a larger compressor wheel and housing, which will in turn flow more air. its also likely to have a different actuator, which determines the minimum about of pressure before the internal gate opens, again dialing in more air is going to make you reach the excess airflow protection.

as you have an auto the only comprimise you have is

apexi safc + apexi sitc and just tune it the best you can.

[dangerman4]

this information is wrong, please ignore it. the stock protection is not a fuel cut. it is not boost cut. it has nothing to do with boost. it is based on air volume and volume alone. once the protection is activated the ecu retards the timing and richens itself up to protect the engine as it believes too much air is coming into the system for the factory components. you are likely to hit the excess airflow protection when you change the turbo as it will have a larger compressor wheel and housing, which will in turn flow more air. its also likely to have a different actuator, which determines the minimum about of pressure before the internal gate opens, again dialing in more air is going to make you reach the excess airflow protection.

as you have an auto the only comprimise you have is

apexi safc + apexi sitc and just tune it the best you can.

sorry god all mighty but i think he will find that you are wrong and not me.

yes correct about the ecu having a fit if the airflow gets to high, fuel cut was a simple term that i used

so he would understand what i ment.

at this point i will point out that unlike "paulr33" i actually own a 33 auto and have allready done all these mods and experienced what happens when you modify certain things.

Paul has had no experience with r33 autos at all so shouldnt be giving out missleading advice that he know's nothing about.

i bolted on a gt30 with a vg30 rear housing, which is rated to flow 500hp. with it the standard ecu worked fine as long as i stayed under 13 psi. yes the dyno showed it was running a little rich, but it still performed a lot better then the stock turbo. so with a standard vg30 turbo you wont have a drama if you stay under 13 psi as i have allready proved.

as for not getting a new ecu.

what a joke !!!!

Paul why do you persist in telling people missleading information

the 33 auto drives flawlesly with a standard ecu, or with a PFC.

no if's, but's, or maybe's. IT WORKS

there are plenty of people on here that have already done it,

and not one person that has tried it has failed.

i cant wait for you response God.

[paulr33]

i do not care. it has been coevered many many many many many times over and over and over and over. it is simply not possible for it to be the same, there is no technical way it is possible for it to be identical. something must be different. the auto box logic is in the stock ecu. the powerfc (like many ecu's) has no auto box logic so it just does what it feels is right and lets the driver and manual clutch engage/disengage.

[paulr33]

you asked the same questions back in december 2005

and got the same answers with many reasons to show why. if you still don't aceept that, then perhaps you should read over it again

http://www.skylinesaustralia.com/forums/in...98962&st=20

by all means, go ahead, by a powerfc its a fantastic ecu, or any other ecu you please but its not technically possible for the gearbox shift logic to be the same. this is assuming you are using the stock skyline auto box.

if you are using a non electronic auto box then none of this is relevant. using a vlturbo auto box is a suitable replacement box to work around this problem. you too know this fact, as its in the thread you posted up in dec 2005. so if you have a jatco auto box, carry on and worry not. if you have the stock box then proceed, but you have been given caution (by lots of poeple, not just me)

[paulr33]

oh and whilst we are on a the topic of stock ecu vs others and so on, as i feel this is relevant. a different ecu type doesnt instantly mean you are going to make more power. many people (including myself a few years ago) believed that certain ecu types made more power, or give you access to more power. ie: moving to a powerfc is likely to yeild at least 20rwkw. moving to a greddy piggyback should give you 15rwkw. a lot of people have these expectations based on assumptions and what they feel is right. it has nothing to do with the ecu type or format of it, brand, model etc.

its all the state of the tune and how well it has been tuned accordingly. its certainly possible for a stock ecu to make more than a stock tuned powerfc. its certainly possible for a stock ecu to make more than a stock tuned motec, and so on. the state of the tune makes the power, not the ecu itself.

so saying i make $xyz rwkw with a stock ecu is pointless and means nothing. what it does mean is that you are making a given power level and AFR is coming out, but you have little or no control over it. you can piggyback away and influcence its descision but you simply can't set IGN timing for a particular spot at X and Y on the load map. you can dial in XYZ AFR at 4500rpm on medium load. you can only influence other factors to get these results, which is a comprimise.

so in summary, there is no special bonus for keeping the stock ecu. you don't get super cool status if you make 274rkw on the stock ecu. what you do get is a comprimised, or best case scenario piggyback style tune. the same car with the same mods and a stand alone (or even fully remapped stock ecu) is going to preform better, be more fun to drive, repsond better and overall be a much better car to drive

[dangerman4]

oh and whilst we are on a the topic of stock ecu vs others and so on, as i feel this is relevant. a different ecu type doesnt instantly mean you are going to make more power. many people (including myself a few years ago) believed that certain ecu types made more power, or give you access to more power. ie: moving to a powerfc is likely to yeild at least 20rwkw. moving to a greddy piggyback should give you 15rwkw. a lot of people have these expectations based on assumptions and what they feel is right. it has nothing to do with the ecu type or format of it, brand, model etc.

its all the state of the tune and how well it has been tuned accordingly. its certainly possible for a stock ecu to make more than a stock tuned powerfc. its certainly possible for a stock ecu to make more than a stock tuned motec, and so on. the state of the tune makes the power, not the ecu itself.

so saying i make $xyz rwkw with a stock ecu is pointless and means nothing. what it does mean is that you are making a given power level and AFR is coming out, but you have little or no control over it. you can piggyback away and influcence its descision but you simply can't set IGN timing for a particular spot at X and Y on the load map. you can dial in XYZ AFR at 4500rpm on medium load. you can only influence other factors to get these results, which is a comprimise.

so in summary, there is no special bonus for keeping the stock ecu. you don't get super cool status if you make 274rkw on the stock ecu. what you do get is a comprimised, or best case scenario piggyback style tune. the same car with the same mods and a stand alone (or even fully remapped stock ecu) is going to preform better, be more fun to drive, repsond better and overall be a much better car to drive

well said but your getting a little off topic..

the thread is about getting results and what they would be so i have passed on my experience with the same set up. he can use it if he wishes i am only giving proven advice not hearsay, or guess work

[paulr33]

well said but your getting a little off topic..

the thread is about getting results and what they would be so i have passed on my experience with the same set up. he can use it if he wishes i am only giving proven advice not hearsay, or guess work

its not guess work or hearsay. all you have done is your changed your ecu and used the hit and hope method. you hope'd it was going to be ok and now the result is (if you have infact moved to a powerfc or other ecu) that you feel its the same and therefore it must be ok.

there is proven evidence that it cannot physcially be possible for it to be the same.

the gear shift logic is in the stock ecu. is it not in the powerfc and many other ecu's.

this is how i suspect it works (my theory)

stock ecu

- right before gearchange auto box notifies ECU its about to change gear

- stock ecu goes sure and makes ignition timing changes and possibly other fuel related changes

- autobox performs phyiscal gear change

- autobox notifies ecu gear change complete

- stock ecu goes back to normal settings

powerfc (and others)

- right before gearchange auto box notifies ECU is about to change gear

- powerfc (or other ecu) ignore communication - runs as normal

- autobox performs phyiscal gear change

- autobox notifies ecu gear change complete

- powerfc runs as normal

so, there will be no changes during gearchange. this will put extra stress on the autobox. other likely side affects are jerky changes, holding onto gears during changes and other nasties or side affects associated with braindead ecu's, well ecu's designed for manual gearboxes only

[MZTRBO]

fantastic info, thanx all for replying.

- Has anyone had any experience in running into rich and retard issues.

What was the set-up and what power level did this rich and retard occur.

-If an safc and an sitc will fix the richness and any airflow changes id be happpy to do this. What is a apexi sitc and what is its core function.?

- Does a jacto bolt straight up to existing tailshaft etc...?

Thanx keep'em coming

[BezerkR32]

correct me if i am wrong but i thought this thread was about conserving some kind of fuel economy. now it is just a free for all performance upgrade thread. suggest everybody reads first post again to see what the guy is trying to achieve. as far as i understood he was upping exhaust housing as to increase lag so turbo was not always on boost to conserve fuel. Mate if i were you i would be spending my money on a auto to manual conversion. will work out cheaper and give you excellent economy results. have done a few now and customers have told me they gained 80-100km a tank.

fantastic info, thanx all for replying.

- Has anyone had any experience in running into rich and retard issues.

What was the set-up and what power level did this rich and retard occur.

-If an safc and an sitc will fix the richness and any airflow changes id be happpy to do this. What is a apexi sitc and what is its core function.?

- Does a jacto bolt straight up to existing tailshaft etc...?

Thanx keep'em coming

[NickR33]

fantastic info, thanx all for replying.

- Has anyone had any experience in running into rich and retard issues.

What was the set-up and what power level did this rich and retard occur.

-If an safc and an sitc will fix the richness and any airflow changes id be happpy to do this. What is a apexi sitc and what is its core function.?

- Does a jacto bolt straight up to existing tailshaft etc...?

Thanx keep'em coming

I have SAFC and EBC set to 10psi... on really cold nights (middle of winter) when WOT the ecu will occasionally go into R&R... that's with approx 200rwkw in a 95 GTSt... no stress tho, I just turn the ebc down a couple of psi and all is good again

If you are worried about fuel consumption you should grab a SAFC at least, as with your exhaust and cooler you will be running rich already... an SITC controls ignition timing if I'm not mistaken and the SAFC controls fueling

[paulr33]

correct, a good tune will likely get rid of any bad fuel ecomony. adding a larger housing is not the correct way to get some good economy. boost doesnt give you bad fuel economy.

state of tune + driver habits + 02 sensor = fuel economy

so make sure you have a good working 02 sensor.

make sure you have a suitable tune, including cruise and low load.

if you floor it, its going to come on load and take in lots more air, which means more fuel.

if you drive in peak hour traffic its going to be less efficient

[mad082]

and if you sit in drive thru at maccas waiting for the uselss pricks to take 5 mins to make a burger that only takes 90 seonds to make, that doesn't help either.

[R31Nismoid]

1) Easy, just use the RB25 actuator

2 & 3 & 4) Possibly. Each car is different. I suggest you invest in an S-AFC as you plan too and have it tuned.

You then will avoid the issues that you are already aware of. But i would save the $$ and do it all in one hit, easier and cheaper.

Power, well it all depends on how much boost you decide to run after you chat to your tuner, you should tip into the low 200's

5) Exhaust, I/C... and S-AFC... you pretty much have covered everything off. If you dont already get a small boost gauge so you know whats going on. The stock item is far from accurate in many cases.

So yeah, overall, do the turbo and tune all at once and you should have a car that makes good power, and is economical aswell

sorry god all mighty but i think he will find that you are wrong and not me.

Its not fuel cut. Sorry dude, your incorrect. i CBF'd quoting your half page of inaccurate information. But you get the idea.

Because your car run 13psi before entering the R&R mapping of the ECU, does not mean for one second that the next person along can do the same.

To assume this is quite silly as no two cars are the same, no two parts after 10 years function the same either.

[MZTRBO]

Bezerkr32, your are difinately right in this regard as it is documented very well that manuals are better on fuel then autos, though my budget does not alow this at the moment. I think im going to stick with the auto. Before I am asked why I bought turbo before manual conver. is that as stated I acquired the turbo (given 4 free/was lent) and the intercooler was a gift. the only items to purchase are the safc, sitc and dump pipe/front pipe. Im guessing this will be under $1000 then get a tune $250. So i still think this is cheaper then a manual conversion, $2500+ for box,clutch, install etc. So im pretty happy if i get good fuel economy + good power.

The engine seems fresh with what previous mechanics say are genuine klms for a jap car (65,000kms), so Im pretty happy with the current performance.

Cheers

"quote"Mate if i were you i would be spending my money on a auto to manual conversion. will work out cheaper and give you excellent economy results. have done a few now and customers have told me they gained 80-100km a tank."quote"

[MZTRBO]

R31nismoid, thats exactly my plan and what I also thought to be a good idea was to get it all done at once,

My plan is to install the vg30bb turbo, install intercooler, purchase safc and sitc + a turbotech boost controller + boost gauge, install rb25det wastegate, try and run a constant 9-10psi and hope that I dont run into R&R and then get it all tuned. I will be going to Race Solutions/Hitman a penrith.

I think im getting under 300klms to a tank, so in doing these mods I think/know im going to make a good investment.

I had forgot that my turbo and the vg30 are almost identical as in actuators etc..

thanx 4 the reply

1) Easy, just use the RB25 actuator

2 & 3 & 4) Possibly. Each car is different. I suggest you invest in an S-AFC as you plan too and have it tuned.

You then will avoid the issues that you are already aware of. But i would save the $$ and do it all in one hit, easier and cheaper.

Power, well it all depends on how much boost you decide to run after you chat to your tuner, you should tip into the low 200's

5) Exhaust, I/C... and S-AFC... you pretty much have covered everything off. If you dont already get a small boost gauge so you know whats going on. The stock item is far from accurate in many cases.

So yeah, overall, do the turbo and tune all at once and you should have a car that makes good power, and is economical aswell

Edited July 13, 2006 by MZTRBO

[MZTRBO]

correct, a good tune will likely get rid of any bad fuel ecomony. adding a larger housing is not the correct way to get some good economy. boost doesnt give you bad fuel economy.

state of tune + driver habits + 02 sensor = fuel economy

so make sure you have a good working 02 sensor.

make sure you have a suitable tune, including cruise and low load.

if you floor it, its going to come on load and take in lots more air, which means more fuel.

if you drive in peak hour traffic its going to be less efficient

paulr33, I have thought about your comment and your are totally right in most cases, though I still think with all of these issues state of tune/driver habits/02 sensor that the small turbo would still be on constant boost.

I have feathered the throttle and it stills climbs boost to easy as the auto is draining so much power/torque. If i push the throttle any lighter I go nowhere.

I think I will purchase an 02 sensor anyway, hopefully it helps. I tought about the process of elimination strategy going through one by one, though i dont think it main issue is caused by these certain things, but is caused by the actual combination of small turbo vs's auto.

Cheers