I agree. The thing I didn't care much about drag racing is a lot of sitting around waiting. Same thing with Autocross.
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Aerochargers TT more testing
- Thread starter DDozier
- Start date
I agree. The thing I didn't care much about drag racing is a lot of sitting around waiting. Same thing with Autocross.
Well finally got my pictures in the mail from the trip to Road Atlanta so I wanted to give an update on the car and my first time at this track.
All I can say is if you have not run Road Atlanta then you need to, I can say this now after running there for my first time. I did a two day event in November and on day one I was more than a little respectful of this course. I had seen many videos on YouTube as I studied up for this track that made me more than nervous about running my baby on this particular track. If you get a chance search YouTube for "Road Atlanta" and a good number of the videos that pop up are of crashed at Road Atlanta, and if you watch any of the videos pay very close attention to the skid marks on the track and the impact marks on all the tire walls and guard rails. They are everywhere. This is one scary track, until you learn it, then it is a thrilling high speed course with a nice rhythm. Did I mention it is high speed? I was hitting 147.3 mph in 5th gear on the back straight and that was even getting out of it way before the crest of the hill and before the braking zone going into 10A. Car has no aero mods and the front end gets a little fuzzy at 140mph.
On my last track day at Autobahn Country Club I had all kinds of issues with cooking my brakes, this time I added some large brake cooling ducts to the front and changed the fluid to ProjectMu from ATE Super Blue. That did the trick and the brakes were flawless all weekend long. The NT01's had about three track days on them before I got to Atlanta and by the end of the first day they were coming in nicely, not quite Hoosier levels of grip but I could run turn 1 flat after the turn in and they stuck with zero drama. They seem to be holding up well, as after the weekend the tires still have lots of life left on them. I think as long as they do not fall off too bad I feel like I can get at least three maybe four more weekends out of this set. We will see.
The Aerocharger Turbos running 6lbs of boost and 400whp were perfect the entire weekend with no issues. I would go out run the car, bring it back into the pits let her idle while I checked the tire pressures and temps then shut her down, that was it. No brake issues, no tire issues, just add fuel and wait for the next run. Exactly how every track weekend should be. On the track the car performed flawlessly, I did have to adjust a little for Road Atlanta. I found myself running out 3rd gear in a lot of places on the track and even though the car felt faster in 3rd my track times were quicker in forth and letting the torque of the turbos pull the higher gear. Oh at Road Atlanta on Sunday morning I had a little issue, they have noise limits until noon on Sundays. I got a black flag on my second session of the morning for the car being too loud. I have been on many tracks and have heard many cars, most of the cars in my run group were much louder than my car but I got the drive through and the warning for excessive noise. Anyway it was a good thing as it forced me to short shift and work on a perfect line instead of ringing out every bit of power in every gear. I actually was able to improve on my times and my line around the track. Then in the afternoon the noise issue was gone and the track was getting a little less crowded as some guys had headed home early. We were all gaining confidence in the track and were pushing harder, driving the lap times down. By days end I had pulled off a three pack of 1:41's and a golden lap of 1:40.06, not a bad time considering it was my first time there and on Saturday I was running 1:45's and slower. The big HP cars like the Z06's and the Viper ACR-x were running in the 1:39's and 1:38's. I still have great respect for turn 12 and never pushed it any harder than 90% down the hill and through the turn just too much concrete for me to let loose and push hard through that baby. There were guys in Spec Miata's pulling a car length on me in turn 12 but I did not care that turn defines "Pucker Factor". I know in my head I can go through that corner faster but I could not tell my foot to go any faster.
I had plans to retire the car from track use after the end of this track season but I may have a problem, I have already committed to the COTA's in Feb. and will most likely run the rest of the MVP Track Times calendar for 2013. I replaced my last NSX because it was a track rat and was way to hard for street use, so I will have to continue on with great restraint and leave this car much more street then track or I will end up back were I was before. What sucks is the guys I run with all have serious track weapons and even though I am down on power I know I could spank them if the car was setup like my old NSX for serious track duty, but I also know I will hate the car if I do that. The car is competitive in its current state but with the softer suspension I have now it just moves around a lot more under me than I am use too. Predictable but softer than my last setup. What I am giving up in the corner entry I am gaining back on the straights and corner exit, with the added torque of the turbos in the top of the rev range. The turbo does not drop off in power like the CTSC did as it heat soaked. With the CTSC you had two laps to get the tires up and you had two golden laps to run hard then you could feel the power loss on the next two laps if you tried to run hard. Now with the turbos and the WTA inter-cooler, IATs were rock solid at 118* after two warm up laps and you get full power till the checkers. The car was well matched to the Z06-CE that my buddy runs in the corners but while I could hang on too his bumper for a few laps the fact that he could pull me by three to four car lengths on the long back straight means all I can do is hang on, Road Atlanta has very few places to pass and they all require HP to get it done. The Z06 and the Vipers were all hitting 150-155mph on the long straight.
Just to give you an idea of the amount of elevation change in this track.
Chasing the Z06-CE
Some other pics of the car at speed
All I can say is if you have not run Road Atlanta then you need to, I can say this now after running there for my first time. I did a two day event in November and on day one I was more than a little respectful of this course. I had seen many videos on YouTube as I studied up for this track that made me more than nervous about running my baby on this particular track. If you get a chance search YouTube for "Road Atlanta" and a good number of the videos that pop up are of crashed at Road Atlanta, and if you watch any of the videos pay very close attention to the skid marks on the track and the impact marks on all the tire walls and guard rails. They are everywhere. This is one scary track, until you learn it, then it is a thrilling high speed course with a nice rhythm. Did I mention it is high speed? I was hitting 147.3 mph in 5th gear on the back straight and that was even getting out of it way before the crest of the hill and before the braking zone going into 10A. Car has no aero mods and the front end gets a little fuzzy at 140mph.
On my last track day at Autobahn Country Club I had all kinds of issues with cooking my brakes, this time I added some large brake cooling ducts to the front and changed the fluid to ProjectMu from ATE Super Blue. That did the trick and the brakes were flawless all weekend long. The NT01's had about three track days on them before I got to Atlanta and by the end of the first day they were coming in nicely, not quite Hoosier levels of grip but I could run turn 1 flat after the turn in and they stuck with zero drama. They seem to be holding up well, as after the weekend the tires still have lots of life left on them. I think as long as they do not fall off too bad I feel like I can get at least three maybe four more weekends out of this set. We will see.
The Aerocharger Turbos running 6lbs of boost and 400whp were perfect the entire weekend with no issues. I would go out run the car, bring it back into the pits let her idle while I checked the tire pressures and temps then shut her down, that was it. No brake issues, no tire issues, just add fuel and wait for the next run. Exactly how every track weekend should be. On the track the car performed flawlessly, I did have to adjust a little for Road Atlanta. I found myself running out 3rd gear in a lot of places on the track and even though the car felt faster in 3rd my track times were quicker in forth and letting the torque of the turbos pull the higher gear. Oh at Road Atlanta on Sunday morning I had a little issue, they have noise limits until noon on Sundays. I got a black flag on my second session of the morning for the car being too loud. I have been on many tracks and have heard many cars, most of the cars in my run group were much louder than my car but I got the drive through and the warning for excessive noise. Anyway it was a good thing as it forced me to short shift and work on a perfect line instead of ringing out every bit of power in every gear. I actually was able to improve on my times and my line around the track. Then in the afternoon the noise issue was gone and the track was getting a little less crowded as some guys had headed home early. We were all gaining confidence in the track and were pushing harder, driving the lap times down. By days end I had pulled off a three pack of 1:41's and a golden lap of 1:40.06, not a bad time considering it was my first time there and on Saturday I was running 1:45's and slower. The big HP cars like the Z06's and the Viper ACR-x were running in the 1:39's and 1:38's. I still have great respect for turn 12 and never pushed it any harder than 90% down the hill and through the turn just too much concrete for me to let loose and push hard through that baby. There were guys in Spec Miata's pulling a car length on me in turn 12 but I did not care that turn defines "Pucker Factor". I know in my head I can go through that corner faster but I could not tell my foot to go any faster.
I had plans to retire the car from track use after the end of this track season but I may have a problem, I have already committed to the COTA's in Feb. and will most likely run the rest of the MVP Track Times calendar for 2013. I replaced my last NSX because it was a track rat and was way to hard for street use, so I will have to continue on with great restraint and leave this car much more street then track or I will end up back were I was before. What sucks is the guys I run with all have serious track weapons and even though I am down on power I know I could spank them if the car was setup like my old NSX for serious track duty, but I also know I will hate the car if I do that. The car is competitive in its current state but with the softer suspension I have now it just moves around a lot more under me than I am use too. Predictable but softer than my last setup. What I am giving up in the corner entry I am gaining back on the straights and corner exit, with the added torque of the turbos in the top of the rev range. The turbo does not drop off in power like the CTSC did as it heat soaked. With the CTSC you had two laps to get the tires up and you had two golden laps to run hard then you could feel the power loss on the next two laps if you tried to run hard. Now with the turbos and the WTA inter-cooler, IATs were rock solid at 118* after two warm up laps and you get full power till the checkers. The car was well matched to the Z06-CE that my buddy runs in the corners but while I could hang on too his bumper for a few laps the fact that he could pull me by three to four car lengths on the long back straight means all I can do is hang on, Road Atlanta has very few places to pass and they all require HP to get it done. The Z06 and the Vipers were all hitting 150-155mph on the long straight.
Just to give you an idea of the amount of elevation change in this track.
Chasing the Z06-CE
Some other pics of the car at speed
Dave what's a CE? You said z06Ce. Also what spring rates are you running and what are your wheels and tires? What are you running front and rear camber and toe?
Those elevation changes look nuts...
I'm surprised you are saying the Z06 was still pulling on you. You are at 450 or so WHP, not that far down with a slight weight advantage. I'm pretty close to Z06's with a CTSC but I'm not even getting close to 147. More like 130-135 max at WGI and 118 on my small local NHMS track.
Last question, do the aerochargers need extra cooling time because there is no water cooling?
Those elevation changes look nuts...
I'm surprised you are saying the Z06 was still pulling on you. You are at 450 or so WHP, not that far down with a slight weight advantage. I'm pretty close to Z06's with a CTSC but I'm not even getting close to 147. More like 130-135 max at WGI and 118 on my small local NHMS track.
Last question, do the aerochargers need extra cooling time because there is no water cooling?
A Z06-CE is sometimes called a Z07, Chevy made a special edition Z06 in 2011 that had the ZR1 brakes and body kit but the Z06 engine, they are the lightest Z06 you can buy from the factory and they have the ZR1's carbon brakes. So you get a lighter car with much better brakes than a standard Z06. If he had not let me do all the other performance mods to the car they would be really close, we did long tube headers, exhaust, cold air, and a custom tune taking the car to 525 whp, a Z06 is only rated at 505 hp at the crank so he has a lot more power to play with. Also I only run 6lbs and 400whp in track trim, so even though his car weighs about 130lbs more than mine he has 125 whp over me and about 170 wtq more than me. That is giving up a lot on the long straightaway at Atlanta. The other really big limitation the NSX has is tire size, his front tires are 30mm wider than my rear tires. This makes his overall braking potential much higher than I can with my little 205's up front.
My suspension setup is quite modest, I have bilsteins with stock 04 springs on the lowest spring perch and a more aggressive track alignment. Camber F/R = -1.5/-2.2 both maxed out but even side to side. Toe F/R = 2mm out/1mm in. I run the Dali street/race in the front full stiff and the street bar in the rear on full soft. Brakes are Tar-ox 10 piston fronts and 6 piston rear. Wheels are SSR Integrals 17" F&R. Believe me I am working my ass off to make this car work but I have been down the road of a fully track prepped NSX and I hated it on the street. This car has to be a street car first and will someday, when I have time to build a track rat again, be a street only car.
All turbos should be allowed to cool after spirited driving. During normal street use the Aerocharger require no additional cool down time as there is no oil in the bearing to coke from the heat. It is a matter of habbit for me to cool the car down on the last lap and to let it idle while I check all the tire presures and temps with the rear glass and cover open.
Dave
Any turbo that can reach full boost by 4k - 5k RPM will be relatively equal on the track, as you spend very little if any time under 4k RPM if you are running hard. An argument can be made that the on/off throttle transistions in the Aerocharger will be faster as all the exhaust moves accross the turbine and as a result the turbine can react quicker whereas a traditional wastegate controlled turbo has to open/close the wastgate and divert the exhaust away from the turbine. My guess is that you would be talking about fractions of a second in real world use. In my mind the Aerochargers advantage is low to mid level RPM's and the Aerocharger and a traditional turbo even out above say 5k RPM. Keep in mind I am only using the Aerocharger to supply 6lbs of boost if you were able to run a higher boost pressure say 12-15+ psi the Aerocharger advantage would be even bigger. Quicker spool rate means higher torque at lower RPMs.
Dave
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Here is a real world track test of the Z07 and a ZR1. The Z07 really addresses most of the Z06's weak links except the crappy seats.
http://www.corvette-mag.com/issues/63/articles/sibling-rivalry?page=1
Dave
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Just seen this thread after Tysama gave me a kind heads up.
Very very cool project.
Very interesting inter cooler setup, just like a 2L Wing Turbo Legend (ca. 1988-1989)
I'm wondering how the volume of the manifold would be effected when in v-tec.
Very very cool project.
Very interesting inter cooler setup, just like a 2L Wing Turbo Legend (ca. 1988-1989)
I'm wondering how the volume of the manifold would be effected when in v-tec.
I am the one that gave the heads up to Tysama. LOL... I've continued to preach, this is the best FI system for the NSX once you want to go beyond the CTSC which is a very basic bolt-on. As soon as you decide to go to tuning, aftermarket management, intercooling, etc.... this is the most well designed system there is. And a big bravo to Dave for developing it. It's on my to-do list.
I'm not so sure that I agree. My only issue here would be the limitations of the intra? :tongue: cooler due to it being confined to such restrictive dimensions, and how that may limit higher build/boost applications. Also, there is complexity of tuning the variable Aerochargers, but I can see overcoming this obstacle with time and $$$. If keeping internals stock, I can see this being a great strait forward bolt on option given that tuning would already be sorted out and pre-programmed into the EMS.
Yes, I agree and I left that part out. This is the most well designed system without doing a full internal build. It is the best at its power range. For someone that wants to build their motor and go very high output these turbos are not it.
What's your basis for that statement? It's not true at all, their offerings will support a 600WHP NSX. I know from personally sizing these for my setup on a built engine.
Dave
Well if they can move that much CFM, great. I am all for this system. Obviously if someone wants 800 HP they have to look elsewhere.
The Legend "Wing" Turbo
There where prototype NSX's with this engine (2.0L variable turbo)
There where prototype NSX's with this engine (2.0L variable turbo)
Very interesting concept. What was you temp drops before and after the intercooler ?
Some time ago I took over Ken Sampson's project, worked with it awhile and ran into restrictive air flow problems and gave up on that concept.
This was for a 2.3 Whipple.
But it looks like you've solved that problem.
This is what I was working with.
Some time ago I took over Ken Sampson's project, worked with it awhile and ran into restrictive air flow problems and gave up on that concept.
This was for a 2.3 Whipple.
But it looks like you've solved that problem.
This is what I was working with.
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I had a CTSC car before I decided to build this setup, I came up with this intake design after trying everything I could think of to make a proper water to air setup for the CTSC. The biggest problem is not the size of the core it is the outlet size of the blower and the lack of space to allow for the air to cross the entire core. This small discharge port on the blower heats the part of the core closest to the blower discharge and it heat soaks very quickly, the core can recover quickly if the water supply is sufficient and the blower is not held in continuous boost. As a result the CTSC cars with water to air coolers have big swings in the IAT's when driven hard with lots of time in and out of the boost. This big swings cause the car to loose power in long pulls or extended time on the track.
I have logs of 20 min runs at high speed tracks and with this setup the IAT's hit a wall at about ambient plus 30*, but more importantly the IAT's are very consistent. They slowly creap up to the peak temp and they stay there until you get off track. As a result I can tune the car for a consistent track condition and IAT's are one less variable in the equation.
Right now I am not logging the IAT prior to the core just the OEM IAT sensor, I had to use the IAT sensor input on my logger for testing on another idea I had. When I was logging it the IAT's pre-cooler would hit peaks of 190* and would average closer to 155-160*. On those runs it was 78* ambient and the IAT's on the OEM sensor after the core were 118*, these were with me running 6.4lbs boost.
Dave
Thats exactly what I was experience as well. The lack of air across the core and the bottle up of air at the discharge outlet because of the small discharge port actually became restrictive and counter productive for a SC'd set up.
With your system, a 60-70 degree drop is very good for low boost, lower HP with what you developed. Its very clean, very simple in complexity and very efficient. Nice work Dave !
However, I could be wrong, but what I see as the limitation to this design is that with more boost and more HP, (not that your 440 is a slouch by any means) being that there would be more heat being generated, would require a bigger core, and therein lies the problem of placing it in the manifold. At least for us that run higher boost and more HP cars in the 550 rwhp range..Your thoughts on this ?
Thats not meant to take away from what you've done, please don't take it that way. I think what you've done is a great piece of work for the general masses in regards to finding a inter-cooler solution that's very clean.
Very well thought out and applied. I'm always looking for new and better ways to bring my IAT's down
Its a pity something can't be done for SC'd cars along the same lines as your development for turbo'd cars.
Very nice job Dave on your work and development !
Here's outlet on the set up I had that you brought up.
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Bell Intercoolers did the calculations and the core work, they estimated with the proper sized heat exchanger and volume of coolant the core would be good for 600HP, that puts it is the 520-540whp range. For most guys that is enough. Keep in mind this intercooler was a solution for my twin turbo setup and the goal was to produce the most HP on a stock bottom end with the least amount of boost. My turbos are going to be CFM limited to about 600HP anyway so for my application the core size was perfect with a little room to grow. I have a few more pieces in development and testing that will make the heat exchanger and coolant volume better suited to the track guys needs. I hope to have these built and tested before the end of this track season.
For those looking to run higher HP you could always run meth just after the throttle body and the meth/water would drop IAT and core temp very fast and set it up to spray when in a higher boost range. This would only be needed for a 550whp and higher setup.
Dave
Your running twin turbo's, do you think the numbers would be the same for a single turbo platform ?
Its a solid piece Dave. Looking forward to seeing your further development and the testing data at the end of the season.
Optimized design. The lack of overkill and overbuilding. Efficiency as the goal.
I. LOVE. THIS.
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Now I need to figure out how to do the same for the CTSC. Uphill battle indeed.
(Damn you CARB!!!)
I. LOVE. THIS.
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Now I need to figure out how to do the same for the CTSC. Uphill battle indeed.
(Damn you CARB!!!)
Coz - I don't see why not. If Dave's inter-cooler can handle the smaller Aerodyne's then why wouldn't it handle the CFM's of much larger single turbo? If his system is rated up to 600 HP with a boosted system, it wouldn't make a difference if there was one or three turbos. CFM's are CFM's.
Awesome setup and I can't wait to get my hands on one for my system.
Awesome setup and I can't wait to get my hands on one for my system.
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What he said.^
While I have no reason to doubt the boys at Bell, untill I see it, log it, and prove it I can not say my system is rated to 600HP. They were spot on in their calaculations thus far but since I do not have a built bottom end to throw 12lbs of boost at I do not have anyting other than the math to prove anything. So for now I know the core will support 500HP at 20+ min lapping sessions on track without issue or elevated IAT's above 130*.
I have the cores in production, I am making 10 units, the frames are built and ready to have the cores welded in, I have to figure out how to market these things and then decide if I want to sell parts or kits. I really had hoped to have the other pieces ready to package with the core but I am still testing. The other pieces are not a must have thing to make this part work but when used with the system you will not have to worry about system heat soak or large volume of coolant stored in the system. I can say no more as I have already said to much.
Dave
