Last summer the magazine guys were testing my 08 at Englishtown when team SRT was there using the roadcaorse to intro a new model.As soon as they saw my 08 they talked with me for quite some time.A key component to the development of the GEN 4 was the endurance test that Dodge mandatated the new GEN had to pass .(ENGINE MUST BE ABLE TO RUN FOT AT LEAST 3 DAYS STRAIGHT ON THE DYNO AT NEAR REDLINE )No Superchargeed application whatsoever could come anywhere near the above mandate infact none made it more than a few hours without serious mech failure.
Gen 3 S/C'ed vs. Gen 4 NA
- Thread starter TexasSnake
- Start date
Chrysler produced a supercharged engine that passed all the tests also. Turbocharged also. Durability on engine dynamometer tests is a given for any OEM application. And the number of test hours at peak torque and peak power are more in the 500 to 800 hour range (depending on the test procedure). A mere 72 hr test would be an easy test indeed.
Basically what iam tryin to say is if SUPERCHARGING was the true answer the Gen 4 would have simply been a Gen 3 with a supercharger adopted to it (this would have costed a fraction of the amount of developing a totally new NA motor ).As we all know though SRT decided against this and inturn went NA
So you're saying that SRT did test a supercharger on the GenIV/III and it didn't last more than few hours?
What ERIC had said to me was that they experimentated with the bolt on Paxton application (Gen 3 )and it was no where near where they needed to be .
They tested the stock bolt on Paxton kit on a Gen 3 motor and it lasted a few hours at near redline.
Ps how it came about was i asked him specifically why they did not simply bolt on Paxton to the Gen 3 instead of doing all the R&D on a NA Gen 4 .He replied that SRT knew all about the bolt on Paxton Kit (Gen 3 )and it could in no way pass their durability tests(thats when he got into the specifics of hours at near redline bolt on Paxton Kits heatsoak ect )
Actually I witnessed that engine running on the dyno. It ran a lot more than that. Lots of tests. Note also it was not running the Paxton inlet air cooling system. And it was done well after the Gen IV engine was under development. Not sure if Dave checks in here anymore (he retired) but since he did the tests I believe he may know a bit more than most.
Dont get me wrong iam sure that if SRT did the same thing Chevy did with the ZR-1 (R&D GROUND UP SUPERCHARGER IN MIND )it could easily pass their tests but thats not the case here with a bolt on blower application on a Gen 3 motor.
Ah, but here is a twist. They never set it up with the same inlet cooling and control system to try to understand the reliability as Paxton provided for. They dialed in fuel and spark on their own and ran the aftercooler with city water temperature. In effect it tells little about how a Paxton install would fare in a normal application.
But on the other side, as the engine was designed for the BMEP and combustion characteristics it had, any increase in output would reduce life. No question. However, the peak power test you refer to indicates more of an infant type failure rather than a durability failure, which frequently points to calibration which was not standard Paxton. As such I do not think any conclusion can be drawn. And it wasn't by the person running the test. You see my interest was a bit more than yours because I had a Paxton installed prior to that and was more than just an observer. And I doubt Eric H. (I assume that is who you were talking to) was as close to the test as Dave.
But on the other side, as the engine was designed for the BMEP and combustion characteristics it had, any increase in output would reduce life. No question. However, the peak power test you refer to indicates more of an infant type failure rather than a durability failure, which frequently points to calibration which was not standard Paxton. As such I do not think any conclusion can be drawn. And it wasn't by the person running the test. You see my interest was a bit more than yours because I had a Paxton installed prior to that and was more than just an observer. And I doubt Eric H. (I assume that is who you were talking to) was as close to the test as Dave.
Another aspect he mentioned was the heatsoak issue since team SRT knows many Vipers are roadraced..It was some day.Evan Smith had the latest Saleen Mustang on the road coarse and set the record for the fastest time ever around the track in it.The SRT guys were hanging out waiting to use the track(NEW CHALLANGER ) when they started to get into it with the Saleen engineers who were bragging about their new 125 grand Stang.Eric H told them flat out if he got out there in my Gen 4 the Saleen record would be very short lived.On one hand i wanted him to take my car to show them up but it really would have made for an ackward senerio this going on in the middle of a Muscle Mustang and Fast Ford test of the latest and greatest from Saleen.(The 125 grand Stang DID great BUT a bone stock Viper kicked its ass )
Yes it was Eric H also an English guy was there (Colin I BELIEVE HIS NAME WAS )
I grant you that. Absolutely the Paxton kit can not get rid of the heat and loses power dramatically. I would estimate an easy 100+ hp loss after just 3 or 4 hot laps. But not necessarily a durability issue as the fuel increase and spark pull back are extreme (note the Paxton does use post aftercooler inlet air temps). Correctible with more capable intercoolers of course. That is the bane of water to water intercooler systems as they build up over time. An air to air system would avoid that entirely.
ps on the drag strip that Saleen was no match for the Gen 4
The entire conversation was interesting what truely got me was the attitude of the SRT Engineers -they we not going to let ANYONE show up any of their products (they were not even there for Viper)esp when they were sure the Gen 4 would have beat that stang no problem.Eric H pointed right out to the Saleen Engineer that the Viper has just as much power ,less weight and ALOT more tire.
Malu59RT
Enthusiast
Several 08's have dyno'd 530-560+whp. Mine dyno'd 560whp on a dynojet (stock). The 08 ACR stock dyno'd over 560whp as well at DC Performance, but that was on a dynapack.
ShadowLight
Viper Owner
- Joined
- Sep 20, 2008
- Posts
- 385
- Reaction score
- 0
The heat is a very good point, if anyone has done any road course driving, you'd know the forced induction guys typically have a lot more issues with heat than NA. Here in Texas, even having NA builds a ton of heat!
Steve 00RT/10
Enthusiast
I only go once a year, but my 5 pound Roe has never had a heat problem during the 15-20 minute sessions. I get about 90 miles per event. Of course, we don't have Texas temperatures. I think the warmest track day I remember was 75-80F.
Even if I did get some heat soak, the track makes up less than 1% of my yearly miles. It wouldn't be an issue at all.
Steve
EXACTLY it comes down to this everyones defination of running a car hard is different.In years gone by my cars were used as test mules for the mag guys at McMullen Argus (Super Chevy, Muscle Mustang-Fast Ford )Last Year(before i bought my Gen 4 )i was thinking about putting a Paxton on my Gen 3 but my engine builder (Nick at Modern )talked me out of it.He told me flat out there was no way in the world i could turn a Gen 3 with a Paxton over to Evan Smith on a 95 degree day and expect it to live.(Alot of times during a test Smith will hot lap 3-4 times in a row sometimes completely going thru all the gears ect-NO COOLDOWNS)
Steve 00RT/10
Enthusiast
I have nothing against NA cars, but the thread started with the 1st quote above. The answer is: A Gen III S/C ed car should smoke a Gen IV car in most every situation.
As far as the heat thing goes, I'm guessing it's a moot point for the majority of those who S/C ed their cars. Evan Smith type guys apply to a fraction of 1% of all Vipers, much less S/C ones....hardly a valid reason to base your mods on. If your car's mission is to only run a track in hot conditions, then a SC is likely not the way to go. If a track happens a time or two a year...who cares if you get a little heat soak. You'll still have made your eyes big and had a fun day.
....I do run the advance group in our track days and have held my own. I consider that fairly hard running....considering I'm driving it 500 miles to get there and need to drive it home again. There is a GEN III Paxton car who gets ahead of me...part of it car / part of it a better driver
Steve
Well slapping a S/C on a GEN 3 motor was never going to work for 08/09 cars. They would never pass the new cold start requirements by the FEDs, hence the new cam-in-cam, Venom controller and total change approach for 08/09. Let's not say it was because they could not blow it because the old configuration was DOA for new emmissions requirements anyway. I am sure there are other reasons, but it was NEVER an option for 08/09 cars, so let's not confuse the issue.
One is majority of guys never run a car at near WOT for long periods of time, hence the fact the car can handle WOT for days on end, means nothing to most. Most guys who S/C are looking for that one or two fast jaunts up to redline at a time but to hold it there forever, who would? I sure as hell would not. Not all Vipers are track ******. Mine sure isn't.
It has also been my experience that positive displacement and screw blowers don't have the same extreme heating problems as opposed to Centifugals (Paxton). Yes they still have heat, but they are a lot more linear in the way the heat/fuel/ignition is dealt with and easier to handle programming wise. THAT is why you almost never see a factory centrifugal supercharged motor. They are almost always a Roots or Screw blower. Saleen S351Rs had factory centrifugals and almost all blew up when pushed real hard but that was bad design and no forging of internals.
The test while interesting, proves nothing. If it was not properly set up to deal with the heat with aftercoolers, etc. and the proper programming for fuel/ignition/heat, (which is crucial on a Centrifugal Blower) then it was doomed from the start and an improper test. Vegas would not even take the odds of blown motor or not. The motor was going to blow.
The Saleen Extreme is NOT a $125K car. It is $85K and of course the Viper is going to beat it. I mean the Viper is purpose built race car. The Saleen is a car built to look good and perform as well as it can on the street with the factory mustang platform as base. It is the best that Mustang base is ever going to do. It is an apples to oranges comparison.
One is majority of guys never run a car at near WOT for long periods of time, hence the fact the car can handle WOT for days on end, means nothing to most. Most guys who S/C are looking for that one or two fast jaunts up to redline at a time but to hold it there forever, who would? I sure as hell would not. Not all Vipers are track ******. Mine sure isn't.
It has also been my experience that positive displacement and screw blowers don't have the same extreme heating problems as opposed to Centifugals (Paxton). Yes they still have heat, but they are a lot more linear in the way the heat/fuel/ignition is dealt with and easier to handle programming wise. THAT is why you almost never see a factory centrifugal supercharged motor. They are almost always a Roots or Screw blower. Saleen S351Rs had factory centrifugals and almost all blew up when pushed real hard but that was bad design and no forging of internals.
The test while interesting, proves nothing. If it was not properly set up to deal with the heat with aftercoolers, etc. and the proper programming for fuel/ignition/heat, (which is crucial on a Centrifugal Blower) then it was doomed from the start and an improper test. Vegas would not even take the odds of blown motor or not. The motor was going to blow.
The Saleen Extreme is NOT a $125K car. It is $85K and of course the Viper is going to beat it. I mean the Viper is purpose built race car. The Saleen is a car built to look good and perform as well as it can on the street with the factory mustang platform as base. It is the best that Mustang base is ever going to do. It is an apples to oranges comparison.
I have a stock Paxton kit with the stock kit intercooler. I also have the DC blower tune, 170 degree thermostat and colder plugs. The engine is otherwisae stock. I run Corsa cat backs. I have run 25 minute segments at H.O.D. events at Homestead. Heat soak was of no consequence. I pulled away from a stock ( except for exhaust and filters), track prepped Gen III like it was parked and easily kept up with a Gen IV ACR. On the straights I pulled away from everything that happened to be in back of me. Is this determinative proof? No. It's just anecdotal since the only real proof is the same driver under the same conditions on the same track with both cars.
Once again Bob everyones defination of running a car hard is different.Over the years i have seen alot of TUNERS or OWNERS show up at Englishtown with a car for Smith to test that leave with major problems brought about by HEAT almost all of them are supercharged.(Alot of them big name players in the auto game )Interestingly enough if a tuner or owner knows of a preexisting condition he will INSIST ON NO HOTTLAPPING.
ShadowLight
Viper Owner
- Joined
- Sep 20, 2008
- Posts
- 385
- Reaction score
- 0
People with blowers that don't have heat issues (or perhaps you have a higher threshold) are the exception, not the rule. You cannot get all that extra horsepower without some consequence and one of them is heat.
C.Thomson
Viper Owner
When I purchased my 06 coupe, the 08's were not even a rumor. I was upgrading from a 98 and wanted more power. A blower was the only way to go at the time and I now have the perfect car for me. The car feels like it was made for 650+-RWHP.
I just turned 19,000 miles and have had no issues whatsoever with the Paxton. There is heat soak in the summer, but winters are the BEST! Outside air temps of 40 are nothing but pure excitement. Given todays prices, I would probably go for the 08, but there is no reason to get one with the car I have now.
I just turned 19,000 miles and have had no issues whatsoever with the Paxton. There is heat soak in the summer, but winters are the BEST! Outside air temps of 40 are nothing but pure excitement. Given todays prices, I would probably go for the 08, but there is no reason to get one with the car I have now.
C.Thomson
Viper Owner
Opps...I forgot. I would love to have an ACR!
Steve 00RT/10
Enthusiast
You're kind of missing the point. Especially the question that started the thread. I would bet that most Vipers with a SC very seldom see heat soak as a show stopper for the mod. Heck a stock Viper doesn't run as good when it's hot because the OEM fuel mapping sends a richer mixture to help cool. I won't argue that the higher SC -- HP you go...the more heat is created. ...but it sends the wrong signal to say that because you have a SC (base Paxton or Roe) you're automatically going to have troubling heat issues. Myself, I like the low end grunt of the twin screw blower. You can't beat it for tooling around the 10K miles we try to get every summer. Our car has never left the garage without the SC being fully engaged before it returns to the nest.
All mods have consequences. None are perfect. I have 3.45 gears. That puts me at a disadvantage from 125 or so to 150 MPH. Has it ever happened in the 50,000 miles since I switched the rear end. No. It also means I run out of 3rd gear on the track I run forcing a shift to 4th.....or just leaving it in 4th. With the 5 pound Roe blower and Fidanza flywheel, I have enough grunt to break loose on any corner exit in 4th gear....and out pull GEN III stock Vipers running in 3rd on the straights. RPMS run between 2000 and 5000....saving lots of wear and tear on the engine.
Steve
I think you guys are missing my point from a reliability standpoint you can take an 08 out on the hottest of summer days BEAT THE HOLLY HELL out of it(hand the guys to a professionsl test driver ect )and not have an issue ( in the ultra rare event you do who cares its covered )you simply can not do that with a bolt on Paxton (sooner or later there will be an issue esp if you start hot lapping the thing without cooldowns )and that issue can easily be very costly.
Steve honestly i understand what your saying but once again everyones defination of running a car hard is different.For instance during a test on a hot day they will run a quarter mile come back around (no cooldown )go thru the starting lights at say 50 mph to try to see what it will trap out out in 5th at near redline (hell of it ).Very few people if any are doing this on the street (How many times have you had your car over 180 plus on a very hot day )Also during a test a driver may run 25 plus quarter mile runs in a day.(i have seen them go thru a clutch in a new Ford GT in an afternoon.)You're kind of missing the point. Especially the question that started the thread. I would bet that most Vipers with a SC very seldom see heat soak as a show stopper for the mod. Heck a stock Viper doesn't run as good when it's hot because the OEM fuel mapping sends a richer mixture to help cool. I won't argue that the higher SC -- HP you go...the more heat is created. ...but it sends the wrong signal to say that because you have a SC (base Paxton or Roe) you're automatically going to have troubling heat issues. Myself, I like the low end grunt of the twin screw blower. You can't beat it for tooling around the 10K miles we try to get every summer. Our car has never left the garage without the SC being fully engaged before it returns to the nest.
All mods have consequences. None are perfect. I have 3.45 gears. That puts me at a disadvantage from 125 or so to 150 MPH. Has it ever happened in the 50,000 miles since I switched the rear end. No. It also means I run out of 3rd gear on the track I run forcing a shift to 4th.....or just leaving it in 4th. With the 5 pound Roe blower and Fidanza flywheel, I have enough grunt to break loose on any corner exit in 4th gear....and out pull GEN III stock Vipers running in 3rd on the straights. RPMS run between 2000 and 5000....saving lots of wear and tear on the engine.
Steve
