DOB Install

[BruceH]

Yes. It had been put in place temporarily without being fastened. The belt also put a small ding in my hood. Might be time for a working hood scoop, lol.

What was the cause of the shredded belt exactly? The PS bracket?

 

[Dubstep Shep]

Yes. It had been put in place temporarily without being fastened. The belt also put a small ding in my hood. Might be time for a working hood scoop, lol.

Yea I have a similar dent from my initial DOB install and shredding a belt.

I was just curious as you had mentioned putting a smaller pulley on.

 

[Department Of Boost]

Update:

I had been seeing iats of 40 or so degrees over ambient during normal cruise conditions. I realized that the coolant ratio might be a little rich. Took about a quart and a half of coolant out and replaced with water wetter and distilled water.

The initial results are that cruising iats are now about 25 over ambient. I was also doing pulls so that figure might be a little off. During wot pulls the max was 40 over ambient which was 102 with an ambient of 62.

Wow! That is a MASSIVE swing! Do you know what the ratio was? What it is now?

How well would 10psi and 12:1 go together with 92 octane fuel?

I would like to know this as well. That 11:1 motor you have is still an option for my neighbor. He wants to make 550-575 on 93. The only thing I am a little worried about is he could be blowing it up and not even know it.

 

[DiMora]

Isn't the tvs still a roots type?

Sent from my Nexus 5 using Tapatalk

Yes, it is a roots, but it uses 4 lobes instead of 3, and has 160 degrees of twist vs 60.

Basically those (VMP) are old TVS blower cases that they modify and charge out the ass for (well, price is fair for the work and r&d but still not cheap). Problem is they (VMP) do not run much better than the 2013 tvs. Cost of HP per Dollar is pretty steep..

VMP claim to fame with that blower is they machine the snout etc.. to accept an even smaller pulley. Well... that means shit if you use a overdrive crank pulley instead. The rotors will max out eventually no matter how small the blower pulley. If you can achieve that with speed with a crank pulley, I prefer the benefits of that over a smaller blower pulley.

On the DOB setup you will only get a 2.4" pulley on it either way so I would save a TON of money and buy a 2013 TVS imo.

The 2.3 liter TVS is rated up to 18,000 RPM

Oh I absolutely agree it's fantastic for a street car. No one needs 600+ whp for the street.

It'll just never make as much power as the same size twin screw. It's simply inferior by design.

That's untrue. At the same displacement (2.3 liters) the 2.3 TVS is more efficient (runs cooler) vs. a twin-screw of equal displacement - it makes more power.

Google the Lysholm 2.3 blower maps and overlay them on the TVS maps and the TVS is superior.

When you read a head-to-head article on a TVS vs. a twin-screw, and the twin-screw defeats a TVS, it is always because the twin-screw is bigger (2.8 liters or bigger).

Back on thread track - Bruce - I like your build. If the E85 is not a direction you are headed, then I definitely think that either a TVS or some meth injection would be a great way to go to minimize IAT's and preserve the power you seek. Have you run meth before? I have a Snow Performance Stage 3 setup I'll be installing on my car later this week. I'm excited to see the results.

 

[BruceH]

I have run meth with a non intercooled whipple. It works. I used walmart -20 windshield washer fluid. It was a 30/70 blend of meth/distilled water and only $1.08 a gallon at the time.

The big restriction with a 2.3 whipple and s197 is the rear inlet. It's formed to fit the car and doesn't flow very well. I ran out of efficiency right at 16-17psi. Whipple uses their own design of rotor. They used Lysholm in the gen 1 blowers years ago but went to their own design due to issues with Lysholm. This is why a Whipple runs very cool. I would normally see iats (sensor mounted in rear runner) around 10 over ambient. The hottest I ever saw at the track when at wot was 114 degrees. That was on a 80 degree day.

Just like all roots aren't the same it also goes with twin screws. The thing is nobody believes it until they run a Whipple.

I'd like to try a tvs but I'm waiting for a good deal to come along. It will probably happen at some point. However, I am really enjoying what I have right now. I should get it on the dyno and see where it's at power wise. If I was to guess I'd say that right now on 92 pump it's somewhere between 500 and 525. With e85 I'd guess 575-600. There really isn't a good reason for me to get a tvs other than ocd insanity.

Yes, it is a roots, but it uses 4 lobes instead of 3, and has 160 degrees of twist vs 60.



The 2.3 liter TVS is rated up to 18,000 RPM



That's untrue. At the same displacement (2.3 liters) the 2.3 TVS is more efficient (runs cooler) vs. a twin-screw of equal displacement - it makes more power.

Google the Lysholm 2.3 blower maps and overlay them on the TVS maps and the TVS is superior.

When you read a head-to-head article on a TVS vs. a twin-screw, and the twin-screw defeats a TVS, it is always because the twin-screw is bigger (2.8 liters or bigger).

Back on thread track - Bruce - I like your build. If the E85 is not a direction you are headed, then I definitely think that either a TVS or some meth injection would be a great way to go to minimize IAT's and preserve the power you seek. Have you run meth before? I have a Snow Performance Stage 3 setup I'll be installing on my car later this week. I'm excited to see the results.

 

[stkjock]

4.0L Whipple. Just saying.......

 

[Dubstep Shep]

4.0L Whipple. Just saying.......

Hehehe this.

The Whipples aren't a typical twin screw, as Bruce said. The 2.3 and 2.9 aren't ideal like the 3.4 and 4.0 are.

 

[BruceH]

I'm not sure. I know that some of the coolant was 50/50. I think that about a half gallon or less was pure coolant. We will see what happens as I get more drive time with it.

I've run 19psi on a 10.76 motor. It was basically the same except it had a Mach block instead of iron. That was with e85 though. 550-575 is going to be challenging with the M122 imo. Higher compression will help.

Wow! That is a MASSIVE swing! Do you know what the ratio was? What it is now?



I would like to know this as well. That 11:1 motor you have is still an option for my neighbor. He wants to make 550-575 on 93. The only thing I am a little worried about is he could be blowing it up and not even know it.

 

[Department Of Boost]

I've run 19psi on a 10.76 motor. It was basically the same except it had a Mach block instead of iron. That was with e85 though. 550-575 is going to be challenging with the M122 imo. Higher compression will help.

I haven't pulled his motor yet to see what is going on. If it's smoked I'll probably have him buy that shortblock from you. I'll be setting him up, I just want to make sure its SAFE. I'm thinking with your 11:1 motor and 9psi or so he can make 550 on 93 with the M122. What do you think?

He will buy a 13-14' TVS if I tell him he needs one. I just don't like needlessly spending his money. He trusts me not to suggest stuff that isn't needed, I want to stay worthy of that trust. And it's not like I get paid for this, it's all pretty much charity.

 

[BruceH]

I think it would be tough if at all possible. I don't have much experience with the M122 so I'm probably not the guy to ask. With e85 I'd say probably. It's worth another 50 or so rwhp in my experience.

550 was about 15psi with the Whipple iirc. That was with a 9.5:1 motor and stock exhaust.

What have people been reporting back for numbers with the M122?

I haven't pulled his motor yet to see what is going on. If it's smoked I'll probably have him buy that shortblock from you. I'll be setting him up, I just want to make sure its SAFE. I'm thinking with your 11:1 motor and 9psi or so he can make 550 on 93 with the M122. What do you think?

He will buy a 13-14' TVS if I tell him he needs one. I just don't like needlessly spending his money. He trusts me not to suggest stuff that isn't needed, I want to stay worthy of that trust. And it's not like I get paid for this, it's all pretty much charity.

 

[Department Of Boost]

I think it would be tough if at all possible. I don't have much experience with the M122 so I'm probably not the guy to ask. With e85 I'd say probably. It's worth another 50 or so rwhp in my experience.

550 was about 15psi with the Whipple iirc. That was with a 9.5:1 motor and stock exhaust.

What have people been reporting back for numbers with the M122?

I think you're making more power right now than you think.

We made 495 (on a heart breaker dyno) with our stone stock motored shop car by accident at 13psi (2.75" pulley) when we first put everything together. And Link who had our first customer prototype made 525 (at JPC) on his first run with a stock motor and a 2.75" pulley (I can't remember the boost).

Crown can probably chime in too. He has gone from stock motor/M122 all the way to built motor overspinning the crap out of a M122 with his car.

I'm thinking with 11:1 that M122 will make 550. I'm just not sure how safe it will be on 93. I can always put it together, see what it makes and if he wants more I'll put a TVS on it. That's a super easy swap.

 

[BruceH]

So the weather has been warmer lately. Mid to high 80's which is pretty warm around here. The m122 is still functioning fine. In town iats are hanging around 12x to 13x. Heat soaked highway temps are running right at 30 over ambient which really isn't that bad considering what some other pd blowers run.

It appears that running 12:1 compression and 92 octane gasoline while boosted is working out just fine with 7psi, even is Pacific Northwest summer temps. I've done plenty of wot pulls. Sometime soon I'll be switching back over to e85 and see what, if any, difference that makes with iats. It may cool the heads enough to also cool the intake manifold and m122.

 

[Mike K]

I would think it will help quite a bit. Did you get it on the dyno yet?

 

[BruceH]

Not yet. It's fairly well tuned from street pulls. Maybe I'll see about getting an appointment on Saturday and see where it is on 92 pump.

I'm thinking 500-525rwhp. Based on previous experiences that would put e85 at 575-600rwhp which is just a little more than I want. I should try the small pulley with e85 and see what it makes with 9psi.

The way the motor is set up all I have to do for big power is change the clutch and injectors. The injectors should get me close to 700. They are the new 55lb gt500 injectors that flow over 72lbs at higher psi. The question is will my pump setup support the psi required? IIRC it's 58psi but I'm not 100% sure about that, it might be more.

I would think it will help quite a bit. Did you get it on the dyno yet?

 

[lethe]

So the weather has been warmer lately.

It's been nice. I think it's going to cool back down to the 70s or so.

 

[BruceH]

Dyno today. SAE corrected numbers are 569/509. STD and uncorrected are 585/523. The fuel system still has head room, it was showing 82% duty cycle. Those numbers are with the 3" pulley and an indicated 8psi.

There might be a TVS in the future, not sure right now. I still have the 2.65" pulley to try out too.

Dyno sheet:



Datalog from that pull:



I still have some fine tuning to do on the maf xfer. It's a little bit richer than I'd like in some areas. Might be worth a few hp and tq.

 

[Paps]

Congrats! Nice numbers with only 8 psi!!!

 

[Roush316]

I'll take it..

 

[SKEDDIE]

Definitely good numbers for 4.10's!

 

[Roush316]

I'm wondering what mine will do I'm 3.90s