Brettus turbo 11
01-18-2013, 01:06 PM
#126
Back to the thread ...
Tweaked it up to 10PSI last night and have to say I'm disappointed in how the car is performing .
Sure - it's quick . But my old setup was spooling up quicker which really made the car feel like a rocket ship . Seems it's taking a good 600 rpm longer to reach full boost now . This could be from the port mod or the larger compressor wheel or a combination of the two.
Top end is ok but not really seeing anything exciting there yet . Still a ways to go there .
On the log below you can see it reaching full boost (10psi - ish) where the blue line is at 4200 . Old setup would do that at 3600 .
Tweaked it up to 10PSI last night and have to say I'm disappointed in how the car is performing .
Sure - it's quick . But my old setup was spooling up quicker which really made the car feel like a rocket ship . Seems it's taking a good 600 rpm longer to reach full boost now . This could be from the port mod or the larger compressor wheel or a combination of the two.
Top end is ok but not really seeing anything exciting there yet . Still a ways to go there .
On the log below you can see it reaching full boost (10psi - ish) where the blue line is at 4200 . Old setup would do that at 3600 .
01-18-2013, 01:17 PM
#129
Remember discussing/arguing over this with MM a while back . He was saying that if the turbine is the same size but you increase the compressor wheel size , spoolup wont change . Not sure what is going on here - if there were an exhaust leak I'm sure i would hear it .
01-19-2013, 01:54 AM
#131
edit: never mind, the turbine was clipped, of course it is coming up later now
.
Last edited by TeamRX8; 01-19-2013 at 01:57 AM.
01-19-2013, 02:18 AM
#133
except that now you combined it with a larger compressor wheel so the dynamics are all different i.e the specifics matter
comparing boost without temperature = pointless exercise, the flow could be the same or more if the discharge temp is lower, boost pressure without reference is a meaningless number
you need to be comparing vehicle speed vs time in 6spd-5th vs 5spd-4th to have an accurate performance comparison, with the trans change you jacked the gearing around so the "feel" between now vs then is not valid
comparing boost without temperature = pointless exercise, the flow could be the same or more if the discharge temp is lower, boost pressure without reference is a meaningless number
you need to be comparing vehicle speed vs time in 6spd-5th vs 5spd-4th to have an accurate performance comparison, with the trans change you jacked the gearing around so the "feel" between now vs then is not valid
01-19-2013, 01:09 PM
#134
Yes - I am fully aware that changing the ratios will change the feel . I don't have logs from 5th gear on the 6spd (cuz that would be suicidal) but can fairly accurately compare load at various rpms - which is what I was doing.
01-19-2013, 02:18 PM
#135
it's easier to say that you're a genius and walk away than spend several weeks arguing about why comparisons that lack a common reference point are invalid
the usual suspects will be happy to enthusiastically lap it up and ask for moar just the same
the usual suspects will be happy to enthusiastically lap it up and ask for moar just the same
01-19-2013, 02:27 PM
#136
I don't know what you are trying to achieve here . I stated i was "disappointed" yet you seem to be coming from the angle that I'm saying " ZOMG it's fantastic !" and wanting to shoot me down ? Que Pasa ?
I knew that doing too many things at once was a bad way to get a good comparison . But I wasn't going to do one thing at a time just to please the likes of you . It is what it is - if the result is good - i'll talk about it . If that upsets you - tough . BTW - I've been driving and tuning turboed RX8s for 4 + years now and have a pretty good feel for how things interact - how about you ?
I knew that doing too many things at once was a bad way to get a good comparison . But I wasn't going to do one thing at a time just to please the likes of you . It is what it is - if the result is good - i'll talk about it . If that upsets you - tough . BTW - I've been driving and tuning turboed RX8s for 4 + years now and have a pretty good feel for how things interact - how about you ?
Last edited by Brettus; 01-19-2013 at 02:38 PM.
01-19-2013, 04:49 PM
#138
*Seat of the pants - from years of driving one of the best performing turbo 8s on the forum.
*Load charts
*maf charts
*Virtual dyno
And all i'm saying is ................. i'm dissaointed at what i am seeing so far (in regards to spoolup )
Spoolup is really the only thing I've made a definitive comment on so far .
Last edited by Brettus; 01-19-2013 at 04:58 PM.
01-19-2013, 04:52 PM
#139
brettus, when are you going to get some video up?
01-19-2013, 05:19 PM
#141
edit: sorry, thought the what would you like to see comment was directed at me
based on the conversation you don't really collect it, 3rd gear between the two transmissions is close but still enough to skew it in the 6spds favor, but even then the tests have to be run over a level road and preferably under similar weather conditions or you'll be trying to factor that in too. That might be a best case option.
I've been doing this a long time to which is why I don't trust my own butt dyno let alone yours, so it's not personal. I've got maps and logs out the @ss WRT testing, it's not fun or easy, just necessary if you want anything close to a reasonable assessment on real performance. In the end it's all about assessing velocity change vs time change. Everything else is noise.
based on the conversation you don't really collect it, 3rd gear between the two transmissions is close but still enough to skew it in the 6spds favor, but even then the tests have to be run over a level road and preferably under similar weather conditions or you'll be trying to factor that in too. That might be a best case option.
I've been doing this a long time to which is why I don't trust my own butt dyno let alone yours, so it's not personal. I've got maps and logs out the @ss WRT testing, it's not fun or easy, just necessary if you want anything close to a reasonable assessment on real performance. In the end it's all about assessing velocity change vs time change. Everything else is noise.
01-19-2013, 05:41 PM
#142
I think he does get it Team. I think he saying that it simply isn't performing how he expected.
I would like to see anything really. WOT runs mostly. REally, whatever you have time to video.
I would like to see anything really. WOT runs mostly. REally, whatever you have time to video.
01-19-2013, 06:33 PM
#144
edit: sorry, thought the what would you like to see comment was directed at me
based on the conversation you don't really collect it, 3rd gear between the two transmissions is close but still enough to skew it in the 6spds favor, but even then the tests have to be run over a level road and preferably under similar weather conditions or you'll be trying to factor that in too. That might be a best case option.
I've been doing this a long time to which is why I don't trust my own butt dyno let alone yours, so it's not personal. I've got maps and logs out the @ss WRT testing, it's not fun or easy, just necessary if you want anything close to a reasonable assessment on real performance. In the end it's all about assessing velocity change vs time change. Everything else is noise.
based on the conversation you don't really collect it, 3rd gear between the two transmissions is close but still enough to skew it in the 6spds favor, but even then the tests have to be run over a level road and preferably under similar weather conditions or you'll be trying to factor that in too. That might be a best case option.
I've been doing this a long time to which is why I don't trust my own butt dyno let alone yours, so it's not personal. I've got maps and logs out the @ss WRT testing, it's not fun or easy, just necessary if you want anything close to a reasonable assessment on real performance. In the end it's all about assessing velocity change vs time change. Everything else is noise.
No ? ..............oh well guess we'll never know then . LOL
BTW - I'll be putting it on the dyno when i know it's better than it was before - I'm certainly not there yet .
Last edited by Brettus; 01-19-2013 at 06:36 PM.
01-23-2013, 02:00 AM
#146
Fixed a boost leak - red line is run I did tonight - blue from a few days ago .
gained 20 g/s and 50 hp on virtual dyno
Note how much quicker the rate of rpm climb is .
Top end is feeling ........................ very quick ! At least equal to anything previous and 15 g/s more than I ever did on the old setup.
Edit : fixed red vs blue
gained 20 g/s and 50 hp on virtual dyno
Note how much quicker the rate of rpm climb is .Top end is feeling ........................ very quick ! At least equal to anything previous and 15 g/s more than I ever did on the old setup.
Edit : fixed red vs blue
Last edited by Brettus; 01-23-2013 at 11:55 AM.
01-23-2013, 07:43 AM
#148
Registered
Virtual Dyno calculates the hp based on logged acceleration and some known facts about a car. If used on the same stretch of road, it should be fairly accurate for comparison runs.
thewird
thewird
