Supercharged VEC2 testing results...
- Thread starter Sean Roe
- Start date
You realize that you're trying to compare the Viper engine to two factory engines that were designed with Superchargers to begin with (the appropriate cam design, head design, intake and exhaust size), right?
Sean
Sean
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>You realize that you're trying to compare the Viper engine to two factory engines that were designed with Superchargers to begin with (the appropriate cam design, head design, intake and exhaust size), right?<HR></BLOCKQUOTE>
Yes and no. Yes of course I know the two examples came with a supercharger from the factory and that the engines were modified somewhat for use with the blower. However, my understanding of what was done (which I can't claim is complete) is that most of the modifications were for the purpose of making the engine more durable by using forged pistons & rods, lowering compression, etc. My understanding of the Cobra and Lightning heads is that flow was not dramatically improved, and I don't know how or if the cams in either vehicle vary from the n/a versions. I think it's well established that heads and a cam can be optimized for use with a blower, thereby producing more power (total and over an operating range). But I don't see how that distinguishes the two examples, or provides an answer to my basic question.
If in fact this blower can't be used at higher boost levels (say at least 10 psi) with stock heads and cam, even with charge cooling, I can think of only two possible answers: 1) The blower isn't large or efficient enough to supply that much air; or 2) there is something unusual about the Viper V10 that doesn't seem to be a problem with most other engines that people put blowers on. But I'm certainly no expert, which is why I started asking these questions.
Yes and no. Yes of course I know the two examples came with a supercharger from the factory and that the engines were modified somewhat for use with the blower. However, my understanding of what was done (which I can't claim is complete) is that most of the modifications were for the purpose of making the engine more durable by using forged pistons & rods, lowering compression, etc. My understanding of the Cobra and Lightning heads is that flow was not dramatically improved, and I don't know how or if the cams in either vehicle vary from the n/a versions. I think it's well established that heads and a cam can be optimized for use with a blower, thereby producing more power (total and over an operating range). But I don't see how that distinguishes the two examples, or provides an answer to my basic question.
If in fact this blower can't be used at higher boost levels (say at least 10 psi) with stock heads and cam, even with charge cooling, I can think of only two possible answers: 1) The blower isn't large or efficient enough to supply that much air; or 2) there is something unusual about the Viper V10 that doesn't seem to be a problem with most other engines that people put blowers on. But I'm certainly no expert, which is why I started asking these questions.
GTS-R 001
Enthusiast
Hey Ronnie,
No dyno run since the blower install, I am expecting some big numbers as the car did 614 rwhp and 644 rwtq before the blower ( .98 corr. factor applied ). I am expecting a good 725 - 740 rwhp this spring and maybe more now that Sean has given us a tool ( Vec2 ) for fine tuning.( thanks Sean )
Further to the discussions on this thread I believe that as the boost levels increase the horsepower will as well but the gain per psi of boost will decrease as the efficiency of the stock engine to move air decreases, and the cars that attempt this will require way more fuel ( new pump and regulator ). We must all be cautious when attempting higher boost as Sean's system while probably capable of producing some incredible Hp numbers was designed to be bullit proof at his recommended levels.
I think that if you want more power the safest way is to do so is to open the airways in the engine with a cam and heads. Yes, you can push the envelope and try to get more power with just a pulley, and yes, a pulley is much cheaper than a cam and heads package, but keep in mind that for every psi of boost the intake temp increases by 10 degrees. So with an 8 psi pulley add 30 degrees with a 10psi add 50 degrees and so on. There will be a point when you will not be able to control the heat and unfortunately the viper hoodline is way too low for an intercooler, even whipple's 1 inch intercooler will not fit under the stock viper hood.
Steve
No dyno run since the blower install, I am expecting some big numbers as the car did 614 rwhp and 644 rwtq before the blower ( .98 corr. factor applied ). I am expecting a good 725 - 740 rwhp this spring and maybe more now that Sean has given us a tool ( Vec2 ) for fine tuning.( thanks Sean )
Further to the discussions on this thread I believe that as the boost levels increase the horsepower will as well but the gain per psi of boost will decrease as the efficiency of the stock engine to move air decreases, and the cars that attempt this will require way more fuel ( new pump and regulator ). We must all be cautious when attempting higher boost as Sean's system while probably capable of producing some incredible Hp numbers was designed to be bullit proof at his recommended levels.
I think that if you want more power the safest way is to do so is to open the airways in the engine with a cam and heads. Yes, you can push the envelope and try to get more power with just a pulley, and yes, a pulley is much cheaper than a cam and heads package, but keep in mind that for every psi of boost the intake temp increases by 10 degrees. So with an 8 psi pulley add 30 degrees with a 10psi add 50 degrees and so on. There will be a point when you will not be able to control the heat and unfortunately the viper hoodline is way too low for an intercooler, even whipple's 1 inch intercooler will not fit under the stock viper hood.
Steve
varanus
Enthusiast
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by 1TONY1:
I wonder if the atomization is still going to be there after it travels all the way thru the intake tubes then thru the blower. In most cars such as turbos and centrifical s/c it goes in after the air maker....meaning lots more turbulence/airflow etc. Is the flow of air in the intake tubes going to hold the water in the air???I don't know. Also most run alcohol/water or methanol even straight methanol is becoming popular......there is a corrosion problem unless its straight water. I'm not sure if I would want that in my blower. I think a 2 or 4 nozzle system in each end of the intake would be the best. The Buick guys are the experts and this is what I have come up with from them. ta
That's what i was wondering. It seems a long way to go but i guess it depends on the velocity of intake to see if it stays in suspension. On the other hand doesn't the blower itself kind of chop things up all over again? I was planning on water only since alcohol makes tunig more difficult. What do you think?
<HR></BLOCKQUOTE>
I wonder if the atomization is still going to be there after it travels all the way thru the intake tubes then thru the blower. In most cars such as turbos and centrifical s/c it goes in after the air maker....meaning lots more turbulence/airflow etc. Is the flow of air in the intake tubes going to hold the water in the air???I don't know. Also most run alcohol/water or methanol even straight methanol is becoming popular......there is a corrosion problem unless its straight water. I'm not sure if I would want that in my blower. I think a 2 or 4 nozzle system in each end of the intake would be the best. The Buick guys are the experts and this is what I have come up with from them. ta
That's what i was wondering. It seems a long way to go but i guess it depends on the velocity of intake to see if it stays in suspension. On the other hand doesn't the blower itself kind of chop things up all over again? I was planning on water only since alcohol makes tunig more difficult. What do you think?
<HR></BLOCKQUOTE>
BTW, if you look at KB's different applications (all of which use Autorotor blowers), they have systems for numerous engines that were not designed to be used with a supercharger, including the standard 5.4 2 valve in Ford's F150 and Expedition, the 6.8 liter V10 in the Excursion, and GM's 8.1 and 6.0 liter V8's. They don't list boost levels, but the dyno graphs all show a 50% or more increase in power and torque, so they're obviously not running 4 psi. My guess is 8-10 psi. With no charge cooling (they do have an optional water injection system for some setups). And no exhaust mods. So I'm back to the question of why an Autorotor equipped [name your favorite Ford, GM, or Dodge truck or SUV] can produce a 50% gain with no charge cooling or flow enhancing mods, and can be pulleyed down in most cases to produce far more without modifying the heads or cam, but Vipers are stuck around 28-30% unless the heads or cam are modified to increase flow THROUGH THE ENGINE (as opposed to into or out of the engine).
On the subject of water injection, I did a fair bit of work on this a few years ago and even went as far as to patent my own system to work with blown intercooled engines. My test vehicle was a Renault 5 GT turbo and the water injection was very successful allowing the boost to be raised about 4psi over the non injected state. I ended up using a 50/50 methanol water mix and injected after the blower and obviously the intercooler. The optimum position is to inject water into the manifold and use the latent heat of evaporation to "absorb heat" from the intake charge. There is a danger on a turbo of blade damage if injected before the turbo and obviously in the presence of an intercooler, this would not be suitable, (probably recondense in the cooler). Injected into the right place in the manifold, it is even possible to see a boost rise due to the pressure rise by water changing to vapour or even steam ! I did, but then I was running that basically standard street motor at 20psi. The water was injected at only slightly higher pressure than the boost pressure and as such was pretty much injected as a low volume stream of water just before the throttle butterfly, but despite the crudeness of the system it worked a treat. Other experience was on a 2 litre 16 valve turbo GM motor. The difference with water inj or without was clutch slip or no clutch slip.
I'd recommend giving the water a try, the UK company Aquamist make some excellent systems.
I'd recommend giving the water a try, the UK company Aquamist make some excellent systems.
varanus
Enthusiast
Joel, did you try water only rather than the mix? I heard tuning was more difficult with alcohol. Plus possible corrosion on the sc parts. water itself on the compnents should evaporate quickly from heat and motion of the screws.
Where would you inject with nozzles on the roe kit?
Where would you inject with nozzles on the roe kit?
Yes, I did try water on its own but it used to freeze around the throttle flap in cool weather and stick the throttle open, methanol fixed that. Pure water probably fine in the SR supercharger application and yes, methanol is corrosive to steel, and some other metals, but in two years use it was never a major problem, the nozzle was stainless, so it was ok. No ill effects in the motor at all.
I can see distribution being a problem in the manifold of the Roe supercharger, its base is quite flat and the ports are widely spread(due to the size of the motor, it isn't exactly a prissy little 1400cc 4 cyl !) It might be worth trying injecting into the supercharger inlet, dont think it could damage the rotors and it might evaporate nicely and distribute better, I'm sure Sean has his own ideas there.
BTW, don't think the methanol if used would act as a fuel, or at least not much, the quantities injected are relatively low in comparison with the main fuel(gas/petrol), but probably best to steer clear of methanol in this instance unless injecting before the throttle flaps which I think in this case wouldn't be a good place...
I can see distribution being a problem in the manifold of the Roe supercharger, its base is quite flat and the ports are widely spread(due to the size of the motor, it isn't exactly a prissy little 1400cc 4 cyl !) It might be worth trying injecting into the supercharger inlet, dont think it could damage the rotors and it might evaporate nicely and distribute better, I'm sure Sean has his own ideas there.
BTW, don't think the methanol if used would act as a fuel, or at least not much, the quantities injected are relatively low in comparison with the main fuel(gas/petrol), but probably best to steer clear of methanol in this instance unless injecting before the throttle flaps which I think in this case wouldn't be a good place...
varanus
Enthusiast
Thanks Joel, I had planned to inject before the throttle bodies. My concern is that the water mist must travel down the long runners, make a u turn, then go thru the sc.
Options would be to inject water somewhere along the length of the intake tube closer to the u turn. Sean reccomended before the throttle bodies too.
What do you think?
BTW where I'm at in California freezing won't be a problem. warm days might be though.
Options would be to inject water somewhere along the length of the intake tube closer to the u turn. Sean reccomended before the throttle bodies too.
What do you think?
BTW where I'm at in California freezing won't be a problem. warm days might be though.
Injecting in the smooth tubes would be worth a try (depends on the nozzle style), but is not something I tested.
We sprayed a 0.030" stream directly at the rotors. The engineers at Autorotor said the same as Joel when we had inquired about it (the rotors will atomize the water since there's only 0.002" clearance between the rotors).
The only thing I didn't like about the water is, it runs out
I may test it again when we start pushing the limits more. I had run it just to see what it did (cleans the plugs and combustion chambers up real nice). Our R&D car never had any ping, so we didn't see any change there.
Sean
We sprayed a 0.030" stream directly at the rotors. The engineers at Autorotor said the same as Joel when we had inquired about it (the rotors will atomize the water since there's only 0.002" clearance between the rotors).
The only thing I didn't like about the water is, it runs out
I may test it again when we start pushing the limits more. I had run it just to see what it did (cleans the plugs and combustion chambers up real nice). Our R&D car never had any ping, so we didn't see any change there.
Sean
Yup, we're agreed, directly into the supercharger inlet sounds good, won't need methanol, and may be able to simply use the boost pressure to push the water in, 5 psi wouldn't produce much of a spray, but that may not be important here, since as Sean says the rotors will do the "chopping". However, unless there is detonation actually occuring, there probably isn't a benefit to using the water, apart from keeping everything nicely steam cleaned.
BTW, ethanol would be much better than methanol with no associated corrosion problems, but it is much more expensive, however I believe it is quite drinkable (unlike methanol)
BTW, ethanol would be much better than methanol with no associated corrosion problems, but it is much more expensive, however I believe it is quite drinkable (unlike methanol)
