3.6 KB vs VMP Gen3R test

CD07GT500

Klaus's Bitch
Established Member
Joined
Feb 23, 2010
Messages
2,564
Location
MS
For those claiming the KB was handcuffed for this test I agree since a boost vs boost comparison will give the TVS an advantage. However one of the advantages of the Eaton rotor pack is RPM. The KB twin screw design is limited to about 18000rpm while the Eaton is 24000+ reliable. So the 3.6 KB might be closer to maxed out than you think.
 
Last edited:

PM-Performance

Well-Known Member
Established Member
Joined
Dec 16, 2015
Messages
1,224
Location
Blandon, PA
Whats the benifit of the stronger bottom end if you dont get some more timing in it? Any plans for a bigger blower like whipple or KB?
I am sure this was a cheaper option than a L&M block, but I did not build it or pay for it. It was already in the car as a fairly fresh setup when I bought it.
I am sure I am at the limits of pump gas is the issue, but talking to Lund they said I wouldnt get any more timing on E85 than I get on their 100 octane tune anyway, so now I dont even think its worth going E85.
I am not sure if I will go with a bigger blower or not. Its moot without E85 anyway. Not sure I will push this one harder on pump either, or even at all because it just gets too heat soaked.
 

Handlebar Moustache

Well-Known Member
Established Member
Joined
Jul 29, 2017
Messages
577
Location
Louisiana
For those claiming the KB was handcuffed for this test I agree since a boost vs boost comparison will give the TVS an advantage. However one of the advantages of the Eaton rotor pack is RPM. The KB twin screw design is limited to about 18000rpm while the Eaton is 24000+ reliable. So the 3.6 KB might be closer to maxed out than you think.

I thought the 2.65 rotor pack redline was 18k RPM (?)

I also thought both the KB and the TVS could be overspun with some power benefits.

upload_2019-12-17_8-17-13.png
 

Catmonkey

I Void Warranties!
Established Member
Premium Member
Joined
May 20, 2011
Messages
3,854
Location
Louisiana
I can't speak for the KB, but folks have been pushing the 2.3 TVS, also rated at 18,000 rpm, well beyond that for years. Personally, I'd pick a bigger blower. The 2.4" pulley would put either the 2.3 or 2.65 just under 18,000 rpm with a stock lower at 6,000 rpm engine speed. Another 500 rpm of crank speed and you're over 1,000 rpm past Eaton's max.
 

CD07GT500

Klaus's Bitch
Established Member
Joined
Feb 23, 2010
Messages
2,564
Location
MS
I thought the 2.65 rotor pack redline was 18k RPM (?)

I also thought both the KB and the TVS could be overspun with some power benefits.

View attachment 1614606

Yes they can be but not like the Roots rotor packs. I spun my 2.9 to 20k and I felt like that was about the limit. If you call KB and tell them you want to spin their blower past 18k they would suggest you buy a bigger blower. The TVS on the other hand has seen 26k+ reliable.
E6740211-C996-45CE-9E91-FC348142CA0E.jpeg
 

Carbd86GT

You're Gator Bait
Established Member
Joined
Feb 29, 2004
Messages
5,838
Location
Jupiter, Florida
The smaller blower is coming into its sweet spot, while the bigger isn’t still a ways off. I don’t know why people put a big race blower with a massive wheel against a street blower. It’s a pointless comparison. Very few people buy the right blower for their needs and fuel availability. Small blower cars make such unreal numbers today that their is no need for anything massive except for bragging rights. It’s hard to compare big blowers to small blowers. Would be a better comparison to see the gen3 at 25psi and the 3.6 at 25psi. That might be a better comparison. I think that picture is painted pretty clearly, the kB starts losing at 5,500. It’s just getting started and dies because imo it isn’t spinning like it needs to be at those engine rpms where a dohc engine starts coming alive.

Watch the vid, they did exactly what you just suggested they do in this post
 

Poisonous West

Active Member
Established Member
Joined
Nov 23, 2013
Messages
246
Location
Back in US
This KB 3.6 vs VMP Gen-3R ONLY tells one thing - the NEW inlet casing design of the Gen-3R is MUCH better than the old KB 3.6 Mammoth inlet design, that's all period. The old KB 3.6 Mammoth inlet has a BIG depression to clear the EGR valve that obstruct the air flow as shown in the below pictures.

upload_2019-12-17_10-4-15.png
upload_2019-12-17_10-4-31.png


Remember 1320Junkie he modified the Trinity 2.3 blower to clear the EGR valve (similar to the VMP Gen-3R) and the dyno result shown an average of 35 RWHP gain.

I am NOT saying the VMP Gen-3R design is bad. In fact, the VMP inlet is super smoother and cleaner design when compare to the KB 3.6. The Eaton 2650 rotor pack design has been revised to better efficiency. The old KB 3.6 rotor pack is outdated design. But the only way to compare 2 different S/C with different rotor pack design is on a flow test bench without any airflow obstruction.

Below is my modified KB 3.6 Mammoth inlet that removed the EGR valve depression. There is another area at the very front inlet portion that can be improved but I have not done anything to it yet. I can bet that if my KB 3.6 was installed in this car it will make at least another 30 RWHP / RWTQ. In fact, I actually has another CAD design of my own Mammoth inlet that remove ALL the air flow obstruction for the KB 3.6 - much smoother and cleaner design. But the cost to 3D print it in special material is way too much (my estimates is ~ $7500 - 8000). Unless I can get a sponsor to 3D print this.

upload_2019-12-17_10-30-4.png


upload_2019-12-17_10-31-17.png


upload_2019-12-17_10-31-51.png
 

Handlebar Moustache

Well-Known Member
Established Member
Joined
Jul 29, 2017
Messages
577
Location
Louisiana
Yes they can be but not like the Roots rotor packs. I spun my 2.9 to 20k and I felt like that was about the limit. If you call KB and tell them you want to spin their blower past 18k they would suggest you buy a bigger blower. The TVS on the other hand has seen 26k+ reliable.

That makes sense; KB has a warranty to uphold and money to make by selling you a bigger blower. I agree...I'm sure if you call them, they're going to tell you to stick to their published specs. That said, I'm guessing if you called Eaton with the same question they'd tell you to limit your RPM to their published 18k spec as well...
 

CD07GT500

Klaus's Bitch
Established Member
Joined
Feb 23, 2010
Messages
2,564
Location
MS
That makes sense; KB has a warranty to uphold and money to make by selling you a bigger blower. I agree...I'm sure if you call them, they're going to tell you to stick to their published specs. That said, I'm guessing if you called Eaton with the same question they'd tell you to limit your RPM to their published 18k spec as well...
No I do not think they will as I believe they will tell you 24k is the suggested max of the higher rpm R rotor design.
 

manny231988

Active Member
Established Member
Joined
Oct 30, 2009
Messages
638
Location
Roswell NM
4D498B7F-A57A-4DF5-8269-D799759B3AC3.png

It’s also pinched against the firewall. The 3.6 is the biggest you can go with standard inlet IIRC and not have it pinched against the firewall reducing inlet size.
It’s also pinched against the firewall. The 3.6 is the biggest you can go with standard inlet IIRC and not have it pinched against the firewall reducing inlet size.
I see where it’s thinner around the firewall ultimately I plan on going to this set up to be at max effort
 

Robert M

800 HORSE FUN!!
Established Member
Joined
May 15, 2003
Messages
9,157
Location
Sunny, Fla.
The smaller blower is coming into its sweet spot, while the bigger isn’t still a ways off. I don’t know why people put a big race blower with a massive wheel against a street blower. It’s a pointless comparison. Very few people buy the right blower for their needs and fuel availability. Small blower cars make such unreal numbers today that their is no need for anything massive except for bragging rights. It’s hard to compare big blowers to small blowers. Would be a better comparison to see the gen3 at 25psi and the 3.6 at 25psi. That might be a better comparison. I think that picture is painted pretty clearly, the kB starts losing at 5,500. It’s just getting started and dies because imo it isn’t spinning like it needs to be at those engine rpms where a dohc engine starts coming alive.

^^^^Those were my thoughts..........Other than the fact that "these were the two blowers that were already available to be tested", it seemed a bit unrealistic. I know the 3.6 can not be spun like the smaller blower and it would not have to be, but I would assume it could be spun harder than what that installed large pulley would allow for. And on the flip side the Gen3R has an ultra small pulley, the next step for it would be to remove the pulley and machine the shaft with ribs.

I am not saying the Gen3R is not a Great set-up, especially if you are looking for the "bang for the buck", but I too would like to see some heat specs between the two. I could be wrong, but it seems to me that the faster you spin these blowers, the more heat they put off, some may be more efficient, but the heat still climbs with the "spun rpms".

Would a better comparison have been a "newer" 3.2LC with a small "snout diameter pulley" which is a similar size compared to the 3.6LC but is based on the smaller/lighter 2.8 case? Of course that would require forking over some cash to do that test.........if that blower is not "already owned" for test purposes as was the case with the 3.6.

..........and I also agree, realistically, the smaller blowers when set up correctly? they will do anything a street guy wants..........and has been mentioned, the bigger blowers, they can work on the street also..........and bragging rights.....<<<But in todays world that is a big part of this game....."The bigger stick".

R
 

Robert M

800 HORSE FUN!!
Established Member
Joined
May 15, 2003
Messages
9,157
Location
Sunny, Fla.
Yea that’s the way to go to get use out of them but you have to cut up the cowl.

I was thinking, at least originally, that anything beyond the KB 3.6 required the cowl to be modded for inlet fitment because the 4.0+ was a longer rotor pack and case? Has there been a redesign to the 4.0+ KB's or do they all require the cowl cut?

R
 

deepblue13

Active Member
Established Member
Joined
Sep 29, 2012
Messages
788
Location
Texas
I was thinking, at least originally, that anything beyond the KB 3.6 required the cowl to be modded for inlet fitment because the 4.0+ was a longer rotor pack and case? Has there been a redesign to the 4.0+ KB's or do they all require the cowl cut?
R

He was just referring to the BIGUN rear inlet needing the cowl cut. I am not sure about the new 4.9 but I haven't looked into it yet.
 

Users who are viewing this thread



Top