Jump to content
SAU Community

Recommended Posts

On 07/04/2021 at 9:18 AM, RB335 said:

8474 didn't deliver anything special in my application, 2.8L high comp RB26 2.8l.  WIth a 1.05 rear, compared to the 9180 it behaved very similar.  It was quite more eager to come onto power faster on full throttle in 1st and 2nd gear, but it felt so restricted as soon as you got it moving.  The 9180 didn't feel like it was choking the engine as much, overall felt much more healthy and a better match  

The 9274 was the next turbo I was going to try, but it looked like it would just be an extension of the drawbacks I had with the 8474.  74mm wheel simply too restrictive to swallow all the flow the larger compressor can give.  Wasn't impressed with the 9280 from very limited testing I done

Why are you chucking money at all these different turbos when your setup isn't optimised?

On 4/1/2021 at 1:19 PM, Robo said:

I went from a 7163 to 8374 to 8474 to 9174 and I am glad I did, it's an incredible turbo with amazing spool.

My car is not a Skyline sorry, it's an EVO X with sleeved and built 2.16cc engine (plazmaman IC, direct port meth injection, S2 cams, sequential 6 speed etc)

8474 was twinscroll  IWG and only 0.8 A/R rear

9174 was twinscroll EWG with 1.45 A/R rear

The 8474 came onto boost way too hard and made it undrivable (like between 3.5k to 4.5k was vertical on the dyno).

The 9174 we all thought being so much bigger rear housing would be lag city but surprisingly it was about the same as the 8474 (we only changed the turbo and nothing else). I see 1.5bar (22psi) by 4,300rpm. I am not done yet, I'm increasing the downpipe and going to S3 cams (Time attack car).

Rob

^ So many people just don't get this, it's a well known fact that too small a turbo while nice for a dyno sheet saying "look kuntz here is superior spool low down power" it is totally shit for applying power after apex to corner exit.

On 4/1/2021 at 1:19 PM, Robo said:

 

 

 

1 hour ago, RICE RACING said:

^ So many people just don't get this, it's a well known fact that too small a turbo while nice for a dyno sheet saying "look kuntz here is superior spool low down power" it is totally shit for applying power after apex to corner exit.

thats a very non-DBW way of thinking of things. a responsive turbo gives you more control authority.

  • Like 1
45 minutes ago, burn4005 said:

thats a very non-DBW way of thinking of things. a responsive turbo gives you more control authority.

That's how the European cars do it, it's not a pedal for the throttle, it's a pedal to request for torque.

On 4/9/2021 at 2:51 PM, burn4005 said:

thats a very non-DBW way of thinking of things. a responsive turbo gives you more control authority.

The DBW does nothing but mask the problem, it is still totally pointless restricting the engine when you actually need the power, the DBW cant magically 'add' power. And this is why its important to use the right turbo, way too many people get hung up on the modern bullshit as a panacea for bad fundamental choices, a loss is a loss, too small a turbo gives power where its useless and not enough where its needed, simple.

11 hours ago, RICE RACING said:

The DBW does nothing but mask the problem, it is still totally pointless restricting the engine when you actually need the power, the DBW cant magically 'add' power. And this is why its important to use the right turbo, way too many people get hung up on the modern bullshit as a panacea for bad fundamental choices, a loss is a loss, too small a turbo gives power where its useless and not enough where its needed, simple.

Thats a pretty "broad statement " turbo size pends on many things. Too big of a turbo is exactly the same as too small of a turbo it depends where you drive the car as to where you need the grunt.

 

2 hours ago, Mick_o said:

Thats a pretty "broad statement " turbo size pends on many things. Too big of a turbo is exactly the same as too small of a turbo it depends where you drive the car as to where you need the grunt.

 

No it is not exactly the same, you are taking me out of context, I realize its a forum and everyone thinks their opinion is worthwhile but its actually useless cause if you take note I replied to the OP who brought it up and he shared his real world track experience and I have same experience personally and through end users.

Too small a turbo is a massive mistake on a track car end of story.

It is similar to adding traction control, this does not solve issue of lack of grip, the TC cant make more grip it can only let you use closer to the limit of what your car has. Too small a turbo cant be made to have more power than it can deliver, so the DBW comment was just a pointless bit of dibble put up to make someone feel good about themselves NOT to understand the point of the OP's post....... just another reason why forums are forums in the main part.

Except a smaller turbo often has more area under the curve. Realistically if you're serious you would evaluate the RPM ranges you use most commonly and do some math to determine where you'd get the most gains.

DBW and TC can make for better lap times for better auto-management of torque so the driver can have an easier time getting the thing out of a corner. A bigger, laggier turbo making less power in this scenario (if its noticeably less than the amount that TC and DBW combined with the smaller turbo can provide) would be slower.

But yeah if you're at this point you probably have telemetry you can lean on on to see what RPM's you're actually in, when you're in them, and how much average power you're making when you want it.

I won't say bigger is better but generally if you're under 5000rpm you may be in the wrong gear.

  • Like 1

100% agree with above.

And from practical experience I am 1.5-2secs slower on a Rally Sprint over a 150sec lap when using a 8474 vs 8374.

There are times in 2nd gear I am below 4000rpm and that’s where the smaller turbo picks up time even though I have less power and top end speed.

  • Like 1
On 11/04/2021 at 1:52 PM, Kinkstaah said:

Except a smaller turbo often has more area under the curve. Realistically if you're serious you would evaluate the RPM ranges you use most commonly and do some math to determine where you'd get the most gains.

DBW and TC can make for better lap times for better auto-management of torque so the driver can have an easier time getting the thing out of a corner. A bigger, laggier turbo making less power in this scenario (if its noticeably less than the amount that TC and DBW combined with the smaller turbo can provide) would be slower.

But yeah if you're at this point you probably have telemetry you can lean on on to see what RPM's you're actually in, when you're in them, and how much average power you're making when you want it.

I won't say bigger is better but generally if you're under 5000rpm you may be in the wrong gear.

it gets more complicated than that as you also adjust what gear you are in based on the power available in rev band....  for example in my old RX8 i was always in lowest gear i could find so i was revving the thing out as much as i could as all the power is up top, now im using a few gears higher as all my torque is in the middle of the rev range. I guess theres a point that you will also adjust your driving based on the powerband...

  • Like 1
On 4/11/2021 at 11:00 AM, RICE RACING said:

No it is not exactly the same, you are taking me out of context, I realize its a forum and everyone thinks their opinion is worthwhile but its actually useless cause if you take note I replied to the OP who brought it up and he shared his real world track experience and I have same experience personally and through end users.

Too small a turbo is a massive mistake on a track car end of story.

It is similar to adding traction control, this does not solve issue of lack of grip, the TC cant make more grip it can only let you use closer to the limit of what your car has. Too small a turbo cant be made to have more power than it can deliver, so the DBW comment was just a pointless bit of dibble put up to make someone feel good about themselves NOT to understand the point of the OP's post....... just another reason why forums are forums in the main part.

ok I'll bite.

traction control gives you CONTROL to allow you closer to the limit. if it is done correctly, you will be faster.

DBW doesnt give you more power. it gives you CONTROL of available power. if it is done correctly, you will be faster. "big turbo good" isnt the answer. the post was about the 8474 coming on too hard. DBW can linearise the power developed. and compared to an 9280, sure the peak power isn't as high, but the spread of controllable power is wider. a larger turbo just gives you a smaller band you have torque demand authority. if your gearing dictates a second gear hairpin or third gear chicane complex down to 4000rpm, i garantee the smaller turbo with DBW torque demand will get you around it MUCH faster than a larger turbo with a cable throttle.

if we are talking about turbos of this size you dont need more peak power at the apex, you need more control  of midrange torque and having a large turbo so it doesn't come on as hard is a bandaid solution. sure, at QR "big turbo good". but at lakeside/morgan park its not useful.

  • Like 1

I've been doing traction control before most of you could walk lol. You missed the point actually you dont get any of it I think as you are not an engine person nor someone who drives properly on track or road? just guessing there cause I cant really work out other than you wanting to type to read back your own posts what is the point.

You have two experienced people telling you why a wrong (smaller) turbo is inferior yet you keep on about doing it the ghetto way and not addressing any points.

I get it if you want to go slower and stress the engine more, other than that don't really get what you are on about honestly.

  • Like 1
1 hour ago, burn4005 said:

I need a 700kw turbo and a cable throttle to drive my no aero no slicks car on a twisty track because more peak power is faster. got it.

You're still not getting it m8. You need to stop running that shitty e85, toss the emtron in the bin and upgrade to a syvecs and rice racing water injection kit tuned by the rice master himself. 

Then and only then will u truly understand what quick is m8.

 

  • Like 1
  • Thanks 1
  • Haha 3

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



×
×
  • Create New...