Jump to content
SAU Community

Recommended Posts

I tried explaining that, unfortunately the cooler was blamed for the IAT too which is pretty funny. :P

I think he realised it was the compressor that was causing the heat, hence the new turbo that was trialled.

It's way too scientific for anyone to bother but you could calculate intercooler efficiency if you measure MAP and temperature on both sides of the cooler. You can easily calculate what the temperature should be on the cold side purely based on pressure drop. The difference between that figure and the actual temperature on the cold side is due to frictional losses. You have to be sure you're measuring steady state condition and that you equalise the airflow cooling the cooler (ie dyno fan) in a fair manner.

Example, if you drop 22psi to 19psi through a cooler and your hot side is at 60 degrees, a 100% efficient intercooler would drop the temperature to 33 degrees. If you only drop the temperature to 40 degrees then your intercooler is 73% efficient. The efficiency loss is friction causing pressure drop. I knocked up a quick excel sheet to fiddle around (you need absolute MAP and absolute temperature, for a start...). It's possible I've overlooked something, my maths is a bit rusty :P

Of course, it's easier for most people to slap another cooler on and do another dyno run. Or if you run a turbo workshop you throw a different turbo in there :)

Actually, on the late run the IT stayed at about 45 degrees which wasn't too bad. But the pressure drop was still there. I think they've packed way too much fins inside their coolers. But if you are stuck with this cooler and prefer not to have it changed, all you have to do is drill a 1inch whole on both sides of the cooler pippings and bridge them together. That way it should carry 30% of extra flow, except its not been cooled of course.

The ATR45 AKA ATR43G4 SAT turbocharger is now released on our site for both Rb25det and Rb26det single turbo setups. They are $900 each to build.

front.JPG

rear.JPG

I'm working on the internal gate version of that currently. Reaching 350rwkws on pump as a bolt on turbo will be awsome

It's way too scientific for anyone to bother but you could calculate intercooler efficiency if you measure MAP and temperature on both sides of the cooler. You can easily calculate what the temperature should be on the cold side purely based on pressure drop. The difference between that figure and the actual temperature on the cold side is due to frictional losses. You have to be sure you're measuring steady state condition and that you equalise the airflow cooling the cooler (ie dyno fan) in a fair manner.

Example, if you drop 22psi to 19psi through a cooler and your hot side is at 60 degrees, a 100% efficient intercooler would drop the temperature to 33 degrees. If you only drop the temperature to 40 degrees then your intercooler is 73% efficient. The efficiency loss is friction causing pressure drop. I knocked up a quick excel sheet to fiddle around (you need absolute MAP and absolute temperature, for a start...). It's possible I've overlooked something, my maths is a bit rusty :P

Um, saywhatnow? I bolded the bit I'm most interested/worried about here. Are you saying that the ~27°C temperature drop you predict there is due to the 4psi pressure decrease? Because if you are, then I would disagree.

If you're saying something about the efficiency of the intercooler, with no mention of the temperature or velocity of the air flowing across the outside, then how can you even start to calculate the temperature drop of the air inside? I'm just not sure I follow your statement at all.

Edited by GTSBoy

There's no way the blitz cooler puts a hard limit of 250rwkw, no matter what the calculations say though. Designing turbos around intercooler efficiency seems a little weird when surely it can't be the problem.

No, my setup isn't the same as Stao's, but the setup from the turbine outlet to the throttle body IS the same (stock piping, too).

And if I can get 400rwkw at 21psi on a GTX3076.... the intercooler cannot be the issue man.

Wasn't there a change in the long side pipe diameter with the later version of the Blitz return flow kit ?

I'm not sure if it makes any difference but there does seem to be inconstant results with these IC kits .

Also that above mentioned Hypergear turbo looks interesting , are we allowed to know how its wheel diametres differe from a GT3076R ?

Cheers A .

Air temperature / velocity / pressure are all linked together in neat proportional formulas.

Just by looking at pressure drop without having the density (temperature) wont get you very far.

That's why MAP sensors always need the air temperature to calculate actual air mass.

I'm not saying the Blitz Return Flow Cooler is ideal, but it looks pretty well engineered,

The new turbo is a little bit different. It is using the steam peddle turbine system that we've been working on since the start of the year. In comparison of earlier models, the approach method of engine's dynamic discharge is more direct. This turns the negative effects of the restrictive factory engineered log manifolds with bottle necks effect positive. Since the swirl is reduced, hot air moves in and out of the turbine side at a faster rate, this makes the use of over sized compressor wheel less likely to chock an engine, this also makes turbo response less sensitive to compressor change as earlier results indicated.

This turbo can provide performance of a larger turbo while retain response of a smaller turbo, it does not necessarily relay on externally gated system to make power, and the most important of all, it is simple and cost effective to build.

That is the perfect name for that sort of a turbine system. Sure PM for details.

Dummy up the bolton version this weekend. I'm had some new actuator brackets locally made, that will mount the actuators above the comp housing instead of on side. That will not only keep the actuation angle straight, but will also making life much easier on installation:

front.JPG

rear.JPG

I have 64mm comp billet wheels, Those are from ATR28SS15. It peeked 281rwkws, and averaging about 275rwkws pump 98 fuel, on my SR. On dyno it is slightly more responsive then a 2871 while made more power.

ATR28SS15

Does the ATR28SS15 have the same turbine as the ART28SS-2 ?

If so then that sounds like what i want with 64mm comp wheel

Is it a 9 blade rear wheel or 11 ?

And can the GTR housing be made to fit to it ?

Um, saywhatnow? I bolded the bit I'm most interested/worried about here. Are you saying that the ~27°C temperature drop you predict there is due to the 4psi pressure decrease? Because if you are, then I would disagree.

If you're saying something about the efficiency of the intercooler, with no mention of the temperature or velocity of the air flowing across the outside, then how can you even start to calculate the temperature drop of the air inside? I'm just not sure I follow your statement at all.

Yeah I feel like I'm missing something as well. I'm not sure if it's fair to compare pressures and temperatures like that in a dynamic system using gas laws that are derived using a constant volume of gas. I initially thought that since the volume flow was the same on both sides that you could simply compare pressures and temperatures. But volume flow isn't the same thing as volume. In saying that though, what we really care about is the delta-T, and pressure drop. The most efficient cooler will have the biggest delta-T and smallest pressure drop, all other factors being unchanged. So your metric could simply be delta-T divided by delta-P, the higher the number the better.

The air flow across the outside is absolutely important, and changes will show up as a difference in cooled charge temperature. No flow means no cooling and 0% efficiency, you will reach an upper bound of diminishing returns depending on the design of the cooler so the main thing is to be consistent with cooling air when comparing cores.

OK, Stao, I will be making a purchase from you late this week. However I'm still not 100% which turbo. I was going to go the SS2 however I'm going to shoot higher. The car is only a toy so I don't care if driveability suffers. I'm thinking the G3. That would net a comfortable 300+rwkw on pump and 350 on e85, correct? I've just picked up some ID1000s to go into it along with a walbro460. Will be sourcing a new clutch this week after which I'll be ready to go.

I get so confused about which turbo does what!

I will be dynoing the ATR43G4-SAT model on Thursday. Thats is a very good turbo if you are looking for a high powered bolton unit. One thing is you might have to run about 23psi, which is no problem for a Neo motor.

anyone run any of the hiflows with 3" metal intake to stock airbox? if so what are your results?

i would like to avoid running pod filter if possible due to noise and wanting to keep engine bay standard looking.

anyone run any of the hiflows with 3" metal intake to stock airbox? if so what are your results?

i would like to avoid running pod filter if possible due to noise and wanting to keep engine bay standard looking.

You will not have a problem as long as metal intake its fine airbox will do 300 plus no prob

anyone run any of the hiflows with 3" metal intake to stock airbox? if so what are your results?

i would like to avoid running pod filter if possible due to noise and wanting to keep engine bay standard looking.

No problem with my 80mm intakes up to 400kw on e85. A stock looking bay is a priority these days.

  • Like 1

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

    • Back again. I returned to Japan in Jul/Aug to spend time with the car on my birthday and remind myself what all the sacrifice and compromise is for. It happened to line up with the monthly morning meet in Okutama, which I have been wanting to go to for a long time. It's a unique event at a unique spot with really rare, interesting, and quirky cars. It's where all the oldheads and OGs gather. The nighttime scene at DKF certainly has its place and should be experienced if you're into cars, but there's too much bad attention and negativity around it now. IMO the better time is Sunday morning at DKF or Okutama; it's more chill and relaxed. I'm glad I was finally able to go, but not sure it's worth the drive from all the way from Nagoya immediately the day before, unless I was already staying in Tokyo for the days right before the meet, because you have to wake up quite early to make it in time. Funnily enough though I didn't drive the car all that much this trip because it was just too damn hot. While there were zero issues and running temps were nominal and the A/C was strong, RBs already run crazy hot as it is. Sure, it took it all like a champ but something about driving these cars in the ridiculous heat/humidity bothers me and makes me feel like I'm asking too much of it. I'm just me being weird and treating the car like a living thing with feelings; I'm mechanically sympathetic to a fault. Instead I was mainly driving something else around - a KX4(silver) 2001 X-Trail GT, that I acquired in May. There's a few different flavors to choose from with Xs, but visually it's the Nissan version of the Honda CR-V. Mechanically it's a whole different story as this, being the top-trim GT, has an SR20VET mated to a four speed auto and full-time AWD! It was a very affordable buy in exceptional condition inside and out, with very low mileage...only 48k kms. Most likely it was owned by an older person who kept it garaged and well-maintained, so I'm really happy with how it all worked out. It literally needs zero attention at the moment, albeit except for some minor visual touch-ups. I wanted something quirky, interesting, and practical and for sure it handily delivers on all three of those aspects. I was immediately able to utilize the cargo and passenger capacity to it's full extent. It's a lot of fun to drive and is quite punchy through 1st and 2nd. It's very unassuming -in the twisty bits it's a lot more composed than one would think at a glance- and it'll be even better once I get better tires on it(yes, it's an SUV but still a little boat-y for my liking). So...now I have two golden-era Nissans in silver. One sports car and one that does everything else; the perfect two-car solution I think👍 The rest of the trip...I was able to turn my stressed brain off and enjoy it, although I didn't quite get to do as much as I thought. I did some interesting things, met some interesting people, and happened into some interesting situations however, that's all for another post though only if people really want to know. Project-wise, I went back to Mine's again to discuss more plans and am hoping to wrap that up real soon; keep watching this space if that interests you. Additionally, while working in the tormenting sweatbox that is the warehouse, I was able to organize most of the myriad of parts that my friend is storing for me along with the cars, and the 34 has a nice little spot carved out for it: And since it can get so damn hot in there, that made it all the more easy to remove all the damn gauges that have mostly been an eyesore all this time. Huzzah. I was standing there looking at the car and said 'f**k it'. The heat basically makes the adhesive backing on the gauge mounts more pliable to work with, so it was far less stressful getting this done. I didn't fully clean it up or chase the wiring though; that will happen once I have the car in closer possession. Another major reason to remove all that stuff is to give people less reasons to get in my car and steal s**t while it's being exported/imported when/if the time comes, which leads us to my next point... ...and that is even though it's time in Japan is technically almost up since it's a November car and the X would be coming in March, I'm still not entirely sure where my life and career is headed; I don't really know what the future looks like and where I'm going to end up. I feel there's a great deal of uncertainty with me and as a result of that, it feels like I'm at a crossroads moreso now than any point in my life thus far and there are some choices I need to make. Yes, I've had some years to consider things and prepare myself, however too much has happened in that time to maintain confidence and everything feels so up in the air; tenuous one might say. Simply put, there's just too much nonsense going on right now from multiple vectors. Admittedly, I'm struggling to stay in the game and keep my eyes on the prize. So much so in fact, that very recently I came the closest I ever have before to calling it quits outright; selling everything and moving on and not looking back. The astute among you will pick up on key subtext within this paragraph. In the meantime I've still managed to slowly acquire some final bits for the car, but it feels nice knowing there's not much left to get and I'm almost across that finish line; I have almost everything I'll ever want for my interpretation and expression on what it is I think an R34 should be. 'til later.
    • Thanks for that, hadn’t used my brain enough to think about that. 
    • Also playing with fire if they start to flow more air down low than what the stock twins can. It's not even up top you need to worry, it can be at 3000rpm and part throttle and it's getting way more flow than it should.
    • Any G40/1000 or G40/1250 results out there?  
    • You still want a proper tune on the stock ECU though. Stock tune + stock ECU with GT-SS/-9s is probably playing with fire if you're running more than stock airflow/power.
×
×
  • Create New...