New supercharged GTV6

[75evo]

Hi Greg,

I think you should look into a dual mode exhaust. There is this muffler from Flowtech called the Warlock. What you can do is choose between a boost activated butterfly valve or a electronic (operated by the driver) butterfly valve. The Warlock muffler has 2 paths. You should attach the butterfly valve to the straight through path. When the butterfly valve is opened, it allows the exhaust to go straight through the muffler. When it's closed, the exhaust gas will have to go through 3 chambers. Make the pipe from the chambered path of the muffler be small when you are in quiet mode. That added with the regular GTV6 S-bend tail pipe and you will have a really quiet exhaust.

[Greg Gordon]

Hi ToonRboy,

The intercooler has a cap because that's the fill point for the system. On a Syclone the pump doesn't turn on until the coolant is pretty hot so in that application it does become pressurized to an extent. That's the reason it uses a pressure cap. On my application I seriously doubt any significant pressure would build up. Having done this before, I am 100% certain that the front heat exchanger needs to be a radiator style (very similar to your FMIC suggestion). The current heat exchanger is a B&M oil cooler, exactly what Corky Bell says to use in his book. It's a very poor heat exchanger and I have the numbers to prove it.

I never have to use water injection because I am conservative with the boost vs compression ratio issue. However I always use it. It provides a huge margin of safety against what I consider to be inevitable human errors with forced induction. They are:
1. Knock caused by fuel errors while tuning.
2. Knock caused by timing errors while tuning.
3. Use of incorrect fuel (i.e. the wife puts in 88 octane and you don't know about it!)
4. Failure to foresee some sort of worst case convergence of conditions that would cause knock (i.e. intercooler pump fails on a really hot day while lapping at the track with a slightly clogged fuel injector)

I get a lot of piece of mind from water injection so I will always use it. I will put up a chart to show how effective it is.

Hi Zamani: I never heard of that product but I will look into it.

Greg

[Greg Gordon]

Ok, the data isn't mine, although the chart is. As you can see even a low water/fuel ratio of .2:1 allowed an increase in knock-limited boost from 3.2psi up to 8.9psi with a 12.5:1 AFR. Now that's water alone, NOT water/methanol which is even more effective. Water is cheap, and that's the ultimate in cheap protection.

With a richer mixture and a lot more water, knock-limited boost went up to 20.3psi, although that's sort of misleading because you could never raise the boost that much and maintain the same low air temperature at the intake valve.

The chart has been removed.

Greg

[ToonRboy]

That makes a lot of sense - especially in light of the fact that knock sensors are ineffective on the 12v engines.

BTW - I personally like the sound on that U-Tube clip. Could maybe just use a little resonance. I see the air temp gauge went to 86* on that run. If Celsius, that would be approximately engine coolant temp. Do you remember what the ambient outside temp was? If Farenheit, that would actually be pretty darn good.

I suppose an aluminum heat exchanger installed in an FMIC position might help a little, but would be more expensive than the B&M Oil cooler. What do you think?

[Greg Gordon]

That's a good point about the knock sensors. Although SDS supports knock sensors, I seriously doubt anyone could get it to work on a 12V Alfa V6. I don't plan to try it.

I am glad you like the sound. The owner wants some changes in that area, so when it comes back for it's initial 500 mile check up I will quiet it down a little.

That temp gauge reads in Fahrenheit. The outside air temp was probably about 65F. The air doesn't really heat up much under boost, the issue is the temperature at which the intercooler stabilizes at when off boost. In that video it was about ambient +20F, which is where it should stay when off boost. However it eventually rises to ambient +40F or a little more in normal off boost driving. That's because the heat exchanger just doesn't keep up. I know a better heat exchanger will help because I have used them before and kept everything down to ambient +20.

When under boost the temp rise is almost insignificant because the Syclone intercooler is so effective. The problem is it's starting from ambient +40 because of the heat exchanger. Clear as mud???

To further complicate matters, the air temp gauge shows temperature in the plenum, and of course that's downstream from the water nozzle. So....once the water injection starts, the sensor gets a little wet and reads about 10-20F too low. That's actually the way I designed it so it provides back up information about the intercooler and water injection status. It also provides heat soak information after the car is parked.

The fuel injection's temp sensor is located before the water nozzle to avoid false readings. You can see all these in the picture. The sensor and then water nozzle are just after the intercooler on the black transition pipe. The Nordskog sensor is on the side of the plenum near the middle.

Greg

[Gabor K.]

Dear Greg,
I think it might interest you that both 164 V6 12V 2L turbo and 166 V6 2L 12V turbo(same engine with factory turbo) have knock sensors in their system, so its been done, and off the shelf system
Wiseness of the system has been discussed however, as it can confuse unrelevant noise and thereby reducing the pre-ignition sometimes unnecessarily.

[Greg Gordon]

Thanks Gabor,

I was totally unaware of that.

The last time I messed with knock sensors it was on a solid lifter Chrysler Hemi, it constantly retarded the spark because it really couldn't tell the difference between the solid lifter noise, and knock. The Alfa V6 sounds a lot like 3/4 of a Chrysler Hemi so I would expect similar issues. I understand Jim Steck messed with knock sensors without success, although I may be wrong there.

I don't doubt the factory was able to do it, but we never had those engines over here so I can't really look at them, let alone evaluate them. The factory has the resources to blow holes in dozens of pistons in order to get that knock sensor working correctly, I don't.

It seems to me water injection is a more reliable solution. I know for sure when it's working, and it stops knock before it starts.

Greg

[ToonRboy]

Yeah, my experience growing up with American Muscle cars with solid lifters make clatter, but the Alfa 12v make some serious clatter - probably because of the all alloy block-n-heads - and open block design acts like a friggin' sea shell!

I wonder what the fellas at Glenwood used in their turbo-charged engines? Like Gabor says "why re-invent the wheel?"

The water/meth is proven to work, you just have to make sure you don't run out of water while out on the road...

Also, there may be some subtle differences in the 2L V6 we don't know about.

[75evo]

Greg,

Actually you can user any muffler with the Quicktime Performance Valve and Y pipe. But the Flow Tech Warlock muffler has a pretty nice concept too. You can use the Warlock muffler with the Quicktime Performance valve without the Y-pipe.

Here is a QTP valve photo taken from their website. This is electrically operated. But I've seen some valves which are boost or vacuum activated.

[Greg Gordon]

ToonRboy: Running out of water really isn't an issue. The 1.5 gallon tank lasts about 2 tanks of gasoline. Water is cheap and available everywhere. I would worry more about running out of gas.

Zamani, I am going to look into that a little more, although I worry that space issues would be the problem. I plan to do some exhaust work in the near future.

Greg

[oldschooleuros]

WOW, nice video. Sounds insane. Have a speedo shot in a vid?
NICE!

[Greg Gordon]

I don't have any other videos, but here is chart from a 3rd gear dyno pull. Notice the torque curve is really flat giving the car a huge usable range in all gears. As you can see third is very strong from 38mph to 93mph.