Any one miss the twins?
08-03-12, 01:09 PM
#26
Interesting point. People talk about making full boost at whatever rpm but I think it's more important to see how much power at what rpm you are making (also how it comes on obviously). A single turbo car may not make the same boost as the twins would at a certain rpm but it may make the same power.
08-03-12, 01:27 PM
#27
Going single will simplify the super complicated crowded (relatively speaking) engine bay.
If and when my engine goes a street ported engine with a gt35r is going in. OR an LS
. Depending on whether I decide to tackle the swap myself. Because if I go ls I'm doing it myself. If I decide to stay rotary, I'm going to a shop to have it done.
08-03-12, 01:46 PM
#28
Yeah, its all about the setup not all singles are laggy. I see 5psi by 2500 and 10psi at 2800, never paid attention to when i get to full boost of 16-17psi but its not much past 3200-3400 I would guess. I don't have tire spinning low end torque but if i want to make it thru a yellow light or pass someone I don't feel like i HAVE to down shift and on canyons im never chasing a super narrow powerband just to enjoy the car.
08-04-12, 09:43 AM
#29
Huh?! (In honor or what used to be below your avatar.) 
10psi at 3200 is impressive. I hit 10psi at about 3000.
How's the ramp up to 10psi from a stop light? Does is happen all of a sudden from 3000 rpm on? I just looked over a log from this morning's tuning run in to work. If I floor the car in 2nd gear at 1500 rpm, my boost starts at 2100 and peaks at 3100. The ramp up is a fairly linear slope on my PFC chart.
Put another way, if I would like to accelerate briskly (not race) from a light I rev the engine to about 2000 and let the clutch out. The turbos are spinning enough at this point that response is nearly instant.
What's does your intake / exhaust look like? The limit in my setup is the stock cat.
10psi at 3200 is impressive. I hit 10psi at about 3000.
How's the ramp up to 10psi from a stop light? Does is happen all of a sudden from 3000 rpm on? I just looked over a log from this morning's tuning run in to work. If I floor the car in 2nd gear at 1500 rpm, my boost starts at 2100 and peaks at 3100. The ramp up is a fairly linear slope on my PFC chart.
Put another way, if I would like to accelerate briskly (not race) from a light I rev the engine to about 2000 and let the clutch out. The turbos are spinning enough at this point that response is nearly instant.
What's does your intake / exhaust look like? The limit in my setup is the stock cat.
Im not ignoring you I'll come back and respond.
08-04-12, 10:33 AM
#30
Yeah, its all about the setup not all singles are laggy. I see 5psi by 2500 and 10psi at 2800, never paid attention to when i get to full boost of 16-17psi but its not much past 3200-3400 I would guess. I don't have tire spinning low end torque but if i want to make it thru a yellow light or pass someone I don't feel like i HAVE to down shift and on canyons im never chasing a super narrow powerband just to enjoy the car.
Damn full boost by 3500? Thats great.
While I have the stock twins, it's non seq. Its LAGGY. I know its mainly because I have the stock cat but reason why I never converted back to seq because I don't want those problems.
I have NEVER had a turbo/boost issue except the time a hose was knocked off my wastegate which was user error causing me to get boost spikes like crazy.
I suppose a hf cat will lessen the lagginess and maybe I'll reach full boost by 4k instead of 4500, is it really worth it?
08-04-12, 11:05 AM
#31
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I've had stock twins, bnr twins, gt35r, and now an aspec 500r. I liked the bnr, and the 500r setups. BNR was tuned to 16-17 and they came on lightning fast. Power was instant, and predictable, but I got bored and wanted more oomph in the top end. By third gear it didn't have enough for me.
The single turbos are tuned to the same boost, and power is less linear compared to the twins, and with less response. If you down shift then that certainly makes a huge difference, and is likely what anyone would do. With the bnr I didn't need to. The 500r has enough power to keep me focused on the road, where with the twins I wasn't thrilled. The 500r obviously moves much more air than the twins could but I can't help wonder what more power would be like.....
Summary
Twins are ok, BNR with higher boost is good but a single makes up for the response difference with more top end smiles.
The single turbos are tuned to the same boost, and power is less linear compared to the twins, and with less response. If you down shift then that certainly makes a huge difference, and is likely what anyone would do. With the bnr I didn't need to. The 500r has enough power to keep me focused on the road, where with the twins I wasn't thrilled. The 500r obviously moves much more air than the twins could but I can't help wonder what more power would be like.....
Summary
Twins are ok, BNR with higher boost is good but a single makes up for the response difference with more top end smiles.
08-14-12, 08:35 AM
#32
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I love my sequential twins! Over 400 HP, smooth transition, quick spool, and great low end power(Thanks to Banzai racing). For my kind of driving, weekend touring and track days sequential is the way to go. I think single is more for straight line drag racing, extreme high power and for shops that don't know how to get twins to work properly. I've driven single turbo FD and FC with more power and less power than my car. I'm very happy with my set up.
The main thing is to decide how you plan on using your car, driver, weekend touring, weekend street racer, drag strip, road course, autocross. One set up will not do them all.
Just my two cents,
Joe
The main thing is to decide how you plan on using your car, driver, weekend touring, weekend street racer, drag strip, road course, autocross. One set up will not do them all.
Just my two cents,
Joe
08-14-12, 08:40 AM
#33
I love my sequential twins! Over 400 HP, smooth transition, quick spool, and great low end power(Thanks to Banzai racing). For my kind of driving, weekend touring and track days sequential is the way to go. I think single is more for straight line drag racing, extreme high power and for shops that don't know how to get twins to work properly. I've driven single turbo FD and FC with more power and less power than my car. I'm very happy with my set up.
The main thing is to decide how you plan on using your car, driver, weekend touring, weekend street racer, drag strip, road course, autocross. One set up will not do them all.
Just my two cents,
Joe
The main thing is to decide how you plan on using your car, driver, weekend touring, weekend street racer, drag strip, road course, autocross. One set up will not do them all.
Just my two cents,
Joe
08-14-12, 09:34 AM
#35
Here is Joe's previous dyno sheet from 3/10 402whp/341tq, this is before we ditched the AEM tru-boost and installed a Greddy Profec. Once I was able to keep the boost from dropping off and do a few mods so that there would not be a huge dip at transition we achieved the above posted power. The initial goal was to get the car over 400whp with 99 twins, then the next goal was to make the boost consistent to extend the torque curve and make transition less of a power/torque drop. I am sure he has other charts from the 4/11 tuning session which show even higher low rpm hp/tq since we managed to get the primary boost more consistent as well.
08-14-12, 10:17 AM
#36
Yeah, its all about the setup not all singles are laggy. I see 5psi by 2500 and 10psi at 2800, never paid attention to when i get to full boost of 16-17psi but its not much past 3200-3400 I would guess. I don't have tire spinning low end torque but if i want to make it thru a yellow light or pass someone I don't feel like i HAVE to down shift and on canyons im never chasing a super narrow powerband just to enjoy the car.
Always kills me when people talk about turbo response but we never know all the details. Of course single turbo guys want to justify their decision so some guys want to make response look better than it really is. What turbo are you running, and on a typical 3rd gear pull when is 10psi or 16-17psi reached?
08-14-12, 10:19 AM
#37
Here is Joe's previous dyno sheet from 3/10 402whp/341tq, this is before we ditched the AEM tru-boost and installed a Greddy Profec. Once I was able to keep the boost from dropping off and do a few mods so that there would not be a huge dip at transition we achieved the above posted power. The initial goal was to get the car over 400whp with 99 twins, then the next goal was to make the boost consistent to extend the torque curve and make transition less of a power/torque drop. I am sure he has other charts from the 4/11 tuning session which show even higher low rpm hp/tq since we managed to get the primary boost more consistent as well.
08-14-12, 02:34 PM
#42
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Thanks Chris for answering everyones questions, I'm at work and can get online much.
I would like to add, I can run my car with boost controller "off" giving my car low 300HP or on "low" giving mid 300HP or on "high" giving my car over 400HP. It's like having three cars in one. Touring, track and strip. FD, the greats car ever!
I would like to add, I can run my car with boost controller "off" giving my car low 300HP or on "low" giving mid 300HP or on "high" giving my car over 400HP. It's like having three cars in one. Touring, track and strip. FD, the greats car ever!
08-14-12, 06:46 PM
#43
What gear and situation was this pic taken in? I can make factory non-seq twins hit 10psi by 3000rpms if Im in 5th gear going up a hill. Always kills me when people talk about turbo response but we never know all the details. Of course single turbo guys want to justify their decision so some guys want to make response look better than it really is.
What turbo are you running, and on a typical 3rd gear pull when is 10psi or 16-17psi reached?
Always kills me when people talk about turbo response but we never know all the details. Of course single turbo guys want to justify their decision so some guys want to make response look better than it really is. What turbo are you running, and on a typical 3rd gear pull when is 10psi or 16-17psi reached?
I plan to do some logging to contribute to the thread when I make it back home.
08-15-12, 10:56 AM
#45
Rotary Enthusiast
I'm glad that I have a tuned twin setup. The sequential boost kick is more fun when you drop the hammer.
08-15-12, 12:16 PM
#47
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I don't think going single is going to lower your temps, you be better off with a FMIC. I also had high IAT at the track but didn't want to change the look of my engine bay. Chris from Banzai recommended water/meth injection and its one of the best things I've done to my car. IAT in check always even on the hottest days.
08-15-12, 01:23 PM
#48
Rotary Enthusiast
The previous owner of my car won road races in SCCA Solo (CASC) with a sequential setup on a modified base model. My car has a Pettit Racing intercooler and a Mazdaspeed radiator, but I think it is missing the R1's oil coolers. Otherwise, the car ran on Mobil 1 5W30 and it didn't seem to develop any overheating problems.
