Jump to content
SAU Community

Recommended Posts

Did dyno run a few weeks ago and now wondering what it means and how much more can be gained. Setup is fairly stock, 3" turbo back, 12psi, superspark coils.

My limited knowledge of AFR's tells me this gets fairly rich, and by getting the WOT AFR closer to 12.5-13.2 I could squeeze more power from it? Can anyone estimate how much? And what would be the best method, haltech, safc, pfc (nothing wrong with future proofing :(

Only have the boost/afr part pic of the sheet with me at work, if the whole sheet is required then I'll upload once home. Also, what causes the 10. flat spot at the end of the run, injectors maxed/ecu?

post-63773-1257477377_thumb.jpg

Thanks!

Link to comment
https://www.sau.com.au/forums/topic/295126-yet-another-dyno-sheet-thread/
Share on other sites

I wouldn't really go leaner than 12:1 personally, the high 12/low 13 AFRs are ratios suited to NA cars... turbo cars like a fatter mixture but yes, the air fuel ratios you have are terrible. I'd consider checking to make sure you don't have an air leak somewhere.

here in nz we get 220-240kw on 12psi out of stock rb25det with front mount and 3" exhuast and a link ecu on dynapack hub dynos

standard injectors are maxed about 230kw although we have got 237kw on stock injectors.

safe and ideal af ratio for turbo car is between 11.6 and 12. 11.8 is the aim

getting an ecu that runs with out an afm is always good. depends on what your tuners in your area are familar with.

220-240rwkw out of a stock turbo is stupidly innacurate. your dyno is just plain wrong if its spitting out figures like that with a stock turbo, especially with a stock ecu

as said 12:1 is ideal under full load for a turbo car

220-240rwkw out of a stock turbo is stupidly innacurate. your dyno is just plain wrong if its spitting out figures like that with a stock turbo, especially with a stock ecu

as said 12:1 is ideal under full load for a turbo car

+1

From all what I have read, 200rwkw is about the max you can make with just 'basic mods' for the RB25DET. Moving beyond 200rwkw most likely need a aftermarket turbo or high flowed stock one & run more boost & also require the supporting mods.

For reference, my auto 33 made ~180rwkw with basic mods (3" turbo back exhuast, R34GTT SMIC, bleed valve +10psi setting & SAFC II)

220-240rwkw out of a stock turbo is stupidly innacurate. your dyno is just plain wrong if its spitting out figures like that with a stock turbo, especially with a stock ecu

as said 12:1 is ideal under full load for a turbo car

A hub dyno will always read higher KW figures over a roller dyno.

Their figures are quite accurate for the dynos they're being measured on. You can't compare, and this is why dynos are BULLSHIT.

if you read my post i had said Link ecu(i think its called vipec over there)

dynapack hub dynos are the most repeatable dynos out there, hence why nascars etc are tuned on them, as there is no crap like tyre slip etc

only thing they lack is a shootout mode for comparing against other dynos.

ie if you do 2 runs in a row. with out changing anything the runs will be within .2% of each other.

most people don't push stock turbos above 220kw.

here is the 2 that im talking about on this page. the first one is r34 neo rb25det(VVT isnt working), the 2nd is r33 rb25det. both with links, front mount and exhuast

http://www.skylinesdownunder.com/forums/sh...8244&page=2

my r33 with stock turbo, front mount, 3" exhuast made 220kw on 10psi on a basic road tune with a LINK ecu.

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

    • Because people who want that are buying euros. The people with the money to buy the aftermarket heads and blocks aren’t interested in efficiency or making -7 power, they’re making well over 1,000hp and pretty much only drive them at full throttle  best way to way make money is know your customer base and what they want and don’t spend money making things they don’t want. 
    • It's not, but it does feel like a bit of a missed opportunity regardless. For example, what if the cylinder head was redesigned to fit a GDI fuel system? It's worth like two full points of compression ratio when looking at modern GDI turbo vs PFI turbo. I'm pretty reliably surprised at how much less turbo it takes to make similar power out of a modern engine vs something like an RB26. Something with roughly the same dimensions as a -7 on an S55 is making absolutely silly power numbers compared to an RB26. I know there's a ton of power loss from things like high tension rings, high viscosity oil, clutch fan, AWD standby loss, etc but it's something like 700 whp in an F80 M3 vs 400 whp in an R33 GTR. The stock TF035HL4W turbos in an F80 M3 are really rather dinky little things and that's enough to get 400 whp at 18 psi. This just seems unwise no? I thought the general approach is if you aren't knock limited the MFB50 should be held constant through the RPM range. So more timing with RPM, but less timing with more cylinder filling. A VE-based table should accordingly inverse the VE curve of the engine.
    • I've seen tunes from big name workshops with cars making in excess of 700kW and one thing that stood out to me, is that noone is bothering with torque management. Everyone is throwing in as much timing as the motor can take for a pull. Sure that yields pretty numbers on a dyno, but it's not keeping these motors together for more than a few squirts down the straight without blowing coolant or head gaskets. If tuners, paid a bit more attention and took timing out in the mid range, managed boost a bit better, you'll probably see less motors grenading. Not to name names, or anything like that, but I've seen a tune, from a pretty wild GT-R from a big name tuner and I was but perplexed on the amount of timing jammed into it. You would have expected a quite a bit less timing at peak torque versus near the limiter, but there was literally 3 degrees of difference. Sure you want to make as much as possible throughout the RPM range, but why? At the expense of blowing motors? Anyhow I think we've gone off topic enough once again lol.
    • Because that’s not what any of them are building these heads or blocks for. It’s to hold over over 1000hp at the wheels without breaking and none of that stuff is required to make power 
    • Dort sounds above 3k rpm are dorty 🤣 I might krinkle black the alloy 🤔
×
×
  • Create New...