Dyno Run - Interesting Results !!

[R31Nismoid]

I've never seen a flat spot THAT bad on an R33 with stock ECU.

I've seen many small dips before, but nothing that severe!

Maybe your ECU was just really having a bad day!

[Jay95R33]

I've never seen a flat spot THAT bad on an R33 with stock ECU.

I've seen many small dips before, but nothing that severe!

Maybe your ECU was just really having a bad day!

Having a total shocker of a day !!

But now it's mega smooth.

For a stock ECU I'm really happy at how smooth it is now.

There's a bit of a dip right up top where the wastegate is having a hard time, but apart from that it's all good.

If I'm real keen I could squeeze another 1-1.5 psi out of it, then run it again on a cold day and maybe break 175rwkw on the stock ECU.... Or run it in shootout mode and it'll read higher.....If I'm really keen that is, which I'm not...

Just as a comparison on the dyno - A R32 GTR ran up straight after I did, this GTR did 240rwkw on a dyno down in Melb, and only pulled 225rwkw on this dyno. This same car has managed a 4.1 sec 0-100 time !!!

Just goes to show that you can't compare different dynos etc...

J

[SLY33]

mat, i thought 7krpm in 4th was 180?

[EnricoPalazzo]

Nah i can definately get over 180 in 4th. So can matt. So yeh..

[nitemare5]

u sure the speedo isnt out of whack? the speedos are known to be out of whack alittle at those speeds, because my speedos seems to reading like 190km, but im in 5th gear and at 5k rpm, and hit the 180km/h speed cut.

[EnricoPalazzo]

Those speed cut things are wierd. They dont all cut in at 180. Put ur car on a dyno to check its accuracy.

[benm]

I got a feeling mine could be out of whack too. 190km/h is speecut for me which is flat in 4th gear (7,000rpm). I hit both speed limiter and rev limiter at the same time.

[whatsisname]

Al,

I used a car speed estimator table that uses g'box ratio, diff ratio, & wheel/tyre circumference. It spat out 204.12km/h @ 7000rpm in 4th. This is using a 255/40/17 tyre size.

nightmare5,

According to the same car speed estimator I mentioned above, the speed in 5th at 5,000rpm will be 193.88km/h. The limiter (usually ~180-190km/h) would be pretty much at those rev's!

6,500rpm in 5th is 252km/h

7,000rpm in 5th (if you have enough power & tarmac to get close to those rev's) is ~271km/h

[Jay95R33]

I'll have to check mine, but I think it does around 3000rpm at 80km/h in 4th.. I could be wrong though, so I'll check on the way home tonight.

I've got the stock size of 225/50/16's.

J

[whatsisname]

J,

So you can confirm how accurate my Car Speed Calulator vs. your actual reading is I'll give you the CSC reading for 3,000rpm 4th gear - The CSC suggests that on 225/50/16's you "should" be doing 86.87km/h in 4th @ 3,000rpm.

Let me know what you get mate.

[Jay95R33]

Yepp, no problems Matt. I'll make a metal note of it later on and let you know.

3000rpm is just a guesstimate, years of late nights and days down the pub are taking their toll on the memory

[drifto]

G'day JAY

I might wind the boost up a little cause it's dropping off at the top (see attached) due to the wastegate creeping open at high RPM's.....

More boost will probulary induce more wastegate creep and give same result.

Invest in a HKS electronic boost controller and wastegate actuator, it's one of the best mods to a stock turbo system to improve boost response and will help hold boost higher in the rev range. The only llimiting factor will be the turbo but it should be able to produce 13psi all day safley till redline.

I also agree there's more power to be had with a leaner setting in the top end but this way she'll be safe from detonation.

Cheers

Nick

[drifto]

The CSC suggests that on 225/50/16's you "should" be doing 86.87km/h in 4th @ 3,000rpm, before taking drag into account

Matt, what drugs r u on?

Explain to me how drag effect the speed vs rpm.

[whatsisname]

Yeah good call mate I have lost the plot haven't I Doh! I have drag on the brain. Of course aerodynamic drag will not change the result of diff, g'box & tyre size speed calculation. I dunno' what I was thinking about there?

Drag will however make it harder for a car to reach it potential maximum top speed.

[EnricoPalazzo]

Matt i worked out that exact top speed in 5th by measuring speed at 1,000rpm, 1,500, 2000, 2,500, 3,000. Then i worked out what the intervals were and got a top speed of 270 @ 7,000RPM.

[whatsisname]

Yep sounds spot on to me Dean.

[Jay95R33]

More boost will probulary induce more wastegate creep and give same result.

Invest in a HKS electronic boost controller and wastegate actuator,

Yeah, I think your right there.

I was thinking about upgrading the wastegate to a 13psi one (if they come in that rating), but I think you have to pull the turbo out to replace the actualtor A bit of a pain in the butt for a small improvement

Do you think a EBC (without using a upgraded actuator) would help reduce the boost drop off ?

J

[Jay95R33]

Matt - At 80km/h mine sits about half a needle off of 3000rpm. So it's probably about 2950rpm or pretty damn close to it

[Cecam]

I wouldn't rely on your rev counter too much, like the speedo they're not that accurate.

[Busky2k]

Yeah thats very true. The tach is about 5% too high compared to the reading on the SAFC.