[TheOdessa]

Seems like the best tech info I get is on here. Reddit and FB are rough. I've been googling and doing my research and I was hell bent on a procharger but after owning a 2018 F150 ecoboost I don't want to have to deal with lag.

This brings me to looking at a roots or a twin screw. After going to a local club meet I'm bent on going twin screw. I like kenne Bells offering for our motors. I am looking at the 2.1L kit. I'd like to buy new but my biggest issue is heat. I live in Florida and apparently these get hot. Real hot. I'd go with the 9psi intercooler option but I saw an additional cooler you can add that uses water and sits where the battery goes. There is also an air to air in the same application for further cooling. Can someone shed light on this or share insight? I'm very noob when it comes to blowers as I never could really afford one until recently.

The rest of the car is built. Just got the rear rebuilt with 3.73s and forged Moser 31 spline half shafts from a 28 spline. Trans is redone and full suspension with upper and lower control arm supports. I've done everything to prep for this.

Thanks all

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[Snorky]

I think froush runs a Kenne bell. Or at least did. He should be able to give you all of the 411 on that. To my knowledge they have air to water intercoolers and not air to air.

A centri blower like a paxton, procharger or vortech is what I do know about... offer air to air and can also be equipped with an air to water depending on the kit and what you want. I wouldnt fear a centri as the power comes on completely linear with rpm. It will run and drive like a normal car. However if you drop a gear so its at 3500-4500 rpm. It blows the tires off the car. Power comes on up to.

Pd vs centri.. it is all in what power delivery you are looking for and what style driving you do. As far as i can tell They seem to run similar times at the track.

Froush will probably chime in

 

[WickedSnake00]

You're right that with a PD blower like a Kenne Bell heat management is critical.

Air to air is usually pretty impractical for PD blowers, between packaging constraints and the fact that it's just plain less efficient.

For that, we can focus on liquid to air systems. There's three main levers for improving IATs:

1.) Flow rate. This just follows physics. The more mass flow you have, the more heat you can remove. Remove restrictions wherever possible, and bigger pumps help greatly. Keep in mind for pumps you should look at the flow versus restriction curves. Intercooler systems are high restriction, so pumps with a great free flow (no restriction) rating but flow drops off with restriction aren't helpful. A lot of the no name ones out there are pretty lousy. The Bosch one used by Cobras is more or less the standard. Kind of noisy, flows better than the no names, but not with the big ones. Stepping up to a Pierberg or EMP yields massive gains in flow.

2.) Heat rejection. The more heat you can dump from the heat exchanger the better. This means a bigger heat exchanger (check out the 13-14 GT500, or dual, or even triple pass aftermarket ones.) The better you manage airflow around it the better it performs as well. If it's just hanging there letting air recirculate around it, it's not working to its full potential. If you really want to go hard, there's the Killer Chiller system to actually leverage your A/C, similar to what the Demon does.

3.) Volume. Now the volume of the system doesn't actually remove more heat, but it acts like a big capacitor. The more volume you have, the longer it takes to heat up all of that water/coolant. It can soak up more heat than a smaller volume. There's also the added benefit of being able to ice it down when you know you'll need it.

If you're going with just 9psi on a 2.1, it's not going to be that crucial. A Bosch pump, an aftermarket HE and an aftermarket engine bay mounted reservoir should be plenty. But if you don't mind going to bigger and badder, it will only help you.

 

[TheOdessa]

You're right that with a PD blower like a Kenne Bell heat management is critical.



Air to air is usually pretty impractical for PD blowers, between packaging constraints and the fact that it's just plain less efficient.



For that, we can focus on liquid to air systems. There's three main levers for improving IATs:



1.) Flow rate. This just follows physics. The more mass flow you have, the more heat you can remove. Remove restrictions wherever possible, and bigger pumps help greatly. Keep in mind for pumps you should look at the flow versus restriction curves. Intercooler systems are high restriction, so pumps with a great free flow (no restriction) rating but flow drops off with restriction aren't helpful. A lot of the no name ones out there are pretty lousy. The Bosch one used by Cobras is more or less the standard. Kind of noisy, flows better than the no names, but not with the big ones. Stepping up to a Pierberg or EMP yields massive gains in flow.



2.) Heat rejection. The more heat you can dump from the heat exchanger the better. This means a bigger heat exchanger (check out the 13-14 GT500, or dual, or even triple pass aftermarket ones.) The better you manage airflow around it the better it performs as well. If it's just hanging there letting air recirculate around it, it's not working to its full potential. If you really want to go hard, there's the Killer Chiller system to actually leverage your A/C, similar to what the Demon does.



3.) Volume. Now the volume of the system doesn't actually remove more heat, but it acts like a big capacitor. The more volume you have, the longer it takes to heat up all of that water/coolant. It can soak up more heat than a smaller volume. There's also the added benefit of being able to ice it down when you know you'll need it.



If you're going with just 9psi on a 2.1, it's not going to be that crucial. A Bosch pump, an aftermarket HE and an aftermarket engine bay mounted reservoir should be plenty. But if you don't mind going to bigger and badder, it will only help you.

I appreciate the input! I will have to look more into this tonight after work. I appreciate you giving me insight and items you recommended. I shall keep you updated on what I plan on doing.

The more I look into this the more I see why people go centris versus twin screw or roots. I just have this feeling I won't be satisfied with a Centri.

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[WickedSnake00]

Let me know if you want any help with the intercooling system. I've learned my fair share in servicing and upgrading mine.

I'm not entirely sure why most people go the centri route, other than price and availability. If anything PD blowers are more compact and simpler to install. PD blowers just hit so hard and are so fun.

Also another big point on PD blowers compared to centris- they are much more sensitive to inlet restriction. So the more free flowing your intake and throttle body are, the better and more efficient it will perform.

 

[TheOdessa]

I appreciate it! That's my big draw to them is I want a steady power band through the rpms. On a track application I get centris as you're living in the high rpms but this is a street fun car. I want the power through the whole band if I'm going to be dropping the coin on this.

I'll look much deeper tonight and let you know!

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[Eagle2000GT]

While it is true that a centrifugal supercharger's boost is related to rpm they are not a turbo. They don't have what is normally thought of as turbo lag.

This type of information used to be all over this forum but activity is down and I had to go looking through my old spreadsheets. I found an old spreadsheet that compared a KB @ 9 psi to a P1SC maxing out at 8.9 psi. (The P1SC is mine.) I also found a spreadsheet that compared some centri track times to similar KB track time.

RPM.........KB @ 9 psi.........ProCharger P1SC
2500........171/345..............135/280 @ 1.8 psi
3000........209/367..............180/315 @ 2.6 psi
3500........245/370..............230/345 @ 3.4 psi
4000........282/371..............278/365 @ 4.2 psi
4500........316/369..............324/378 @ 5.0 psi
5000........347/365..............364/382 @ 6.1 psi
5500........367/350..............385/368 @ 7.5 psi
6000........376/329..............393/344 @ 8.9 psi
All numbers are STD corrected.

Note: A D1SC is more efficient than a P1SC and makes more power for the same boost. PeteGT reported his engine made 413/413 @ 9 psi.

Here are some old track times that I found.

member................supercharger......gears........tires...............60 ft..........time/trap
PeteGT.................D1SC @ 9 psi.......4.10.......ET Streets.........1.65..........11.9/113
No PI No Power...KB2.6 @ 9 psi.......3.73.......ET Streets.........1.72..........11.9/115
Thereal2v2fear.....V2 [email protected] psi....3.73......Hoosier Slicks....1.60..........11.6/118
BigBoy05.............KB2.1 @ 9 psi........3.73......ET Streets..........1.78..........11.99/118
P-51GT................KB2.1 @ 9 psi........3.73......MT Slicks............1.59..........11.5/118

Here are some other comparisons.

Steve03GT..............V3 @ 10 psi....................398/365
PeteGT...................D1SC @ 9 psi..................413/413
Thereal2v2fear.........V2 S-trim @ 9 psi............421/427
Baker FX4...............P1SC @ 9-10 psi..............427/???
40thAnnivGT...........V1 S-trim 13-14 psi...........418/410
YellowFever............KB 2.1 @ 14 psi................422/465
SaxmanJJ................V3 @ 12 psi....................451/408
Bullitt02875.............P1SC @ 15 psi.................440/450

This is an old comment under the spreadsheets: We don't race below 3500 rpm. Most people are launching at that rpm. It appears to me that the additional low end torque doesn't make much difference but as MustangMatt reported the additional heat and the resultant timing changes do.

This is just some information. Both superchargers are a lot of fun. And I completely understand the thrill factor of a positive displacement blower. After all these years supercharged I can't imagine my car without one.

P.S. Since you are interested in KBs I thought I'd throw this one in.

RPM...KB @ 6 psi..KB1 @ 8 psi..KB2 @ 8 psi...KB @ 10 psi
2500......171/362........165/345.........180/400........ 176/370
3000......212/348........200/355.........235/420........ 217/380
3500......252/378........240/360.........280/425........ 250/380
4000......285/377........275/362.........325/426........ 289/380
4500......318/372........310/362.........360/420........ 321/375
5000......338/356........342/360.........380/405........ 352/370
5500......351/336........366/350.........390/370........ 367/350
6000......362/316........374/327.........385/340........ 377/330

I did not write it down but I would assume the 10 psi numbers are on a KB1.

 

[TheOdessa]

Thanks Eagle! This is fantastic info. From the surface it seems the Kenne Bell looks more fun. Practical wise and money wise it seems a centrifugal might be the better way to go. Oh the options!! This isn't easy. One thing that caught my eye is the kit from Vortech with their air to water chiller on it. Does anyone have advice on this?

I also geared down thinking I was going with a centri (4.10's to 3.73s) and the centri seems to have more "manageable" power as it eases into the power versus a constant hit.

What would you guys do? I live in Florida. This is going to be a street car. I want reliability and dependability factored in as well. Everything is built suspension and drivetrain wise. Only limiting factor is my motor. It's in stock form and no mods above what OEM would call for. It's stout and recently tested. Only thing major needed was timing chain guides replaced. The more I look I dig the vortech kit with the air to water cooler. It seeming that is the way to go given the state I live in. It gets stupid hot here.

 

[Snorky]

Thanks Eagle! This is fantastic info. From the surface it seems the Kenne Bell looks more fun. Practical wise and money wise it seems a centrifugal might be the better way to go. Oh the options!! This isn't easy. One thing that caught my eye is the kit from Vortech with their air to water chiller on it. Does anyone have advice on this?

I also geared down thinking I was going with a centri (4.10's to 3.73s) and the centri seems to have more "manageable" power as it eases into the power versus a constant hit.

What would you guys do? I live in Florida. This is going to be a street car. I want reliability and dependability factored in as well. Everything is built suspension and drivetrain wise. Only limiting factor is my motor. It's in stock form and no mods above what OEM would call for. It's stout and recently tested. Only thing major needed was timing chain guides replaced. The more I look I dig the vortech kit with the air to water cooler. It seeming that is the way to go given the state I live in. It gets stupid hot here.

I cant comment on the air to air vs water to air in a floridian environment. In a colder environment, I would pick air to air without a doubt due to the lack of heat soak. The hot environment you live in may change things, i am not sure of the effects of hot air cooling the air charge vs. The heat soak rate of a water cooled setup.

Perhaps someone from the southerm section can comment on that.

Also.. guys run all types of gears with both KB and centri blowers. I had 4.10s with mine... it requires ET streets, LOL. I imagine the same would be for a KB with 3.73 gears. Either way you will have a blast with it. If your goal is 1/4 or 1/8 mile racing, gear selection is a little more exact.

 

[sneaky98gt]

I ran a PD blower for a LONG time. It was an old SVO blower, which is a non-intercooled Eaton M112 (roots blower, same as 03/04 Cobras and Lightnings). That thing was the epitome of HOT. For the last couple years or so, I had a Procharger D1SC. So I've seen both worlds, and I'll give my thoughts.

My SVO setup made around 12-13 psi and 450 rwhp, and ran mid 11s at 120 mph. That was on water/meth injection. Without it, the car made 100+ LESS horsepower, and was extremely hot (would peg the temp sensor at 254 degrees without the water/meth). An intercooled KB won't be that bad, but it will still heat soak somewhat if run hard, or in hotter climates. A good tune will pull some timing in these conditions, which means it'll probably make 30-50 less horsepower than when cool. Water/meth can completely eliminate these issues (the route I took), and something like a Killer Chiller (uses the AC to cool the water) can as well.

Even with the heat soak, they still make basically full boost off idle, which means TONS of torque on demand. This makes the car very fun to drive. There's no need to downshift for basic little sprints around slower cars, and you can accelerate from a stop very quickly without even breaking 3000 rpm. On the highway in overdrive, you can just roll on the throttle and go from 60 mph to 90 mph effortlessly. Everything is just so easy with it.

After like 6 years on that setup, which was pretty much maxed out at 450 rwhp, I sold it and bought a Procharger D1SC, which is kinda the mid-level blower. It's capable of making a LOT of horsepower. I turned it to a max of of about 16-17 psi. I took the water/meth off the car, and ran a big front-mount intercooler instead. I literally never saw the intake temps more than 10 degrees above ambient. The setup ran very cool, which made it quite easy to tune. And it ran great all the time; winter, summer, hot, cold, back-to-back runs, didn't matter. Always ran great.

I never dynoed it or took it to the track (life just got in the way), but it was absolutely wicked. Based on the datalogs, it was making somewhere around 575-600 rwhp, and I have no doubts it would run mid-10s at 130-135 mph, maybe quicker. I could downshift and roll on the throttle at 50 mph, and it would just boil the tires off. The SVO setup wasn't even in the ballpark in regards to the power, acceleration, etc. of the Procharger.

That said, it had some drawbacks. For one, it was loud. I think some of the newer, more expensive ones are better, but mine had the straight cut gears and a blow-off valve, both of which made a relatively lot of noise when driving (versus a PD blower that'd be silent). And two, it really didn't make any extra torque. Below 2500, it made basically 0 boost. At 3000 it was making maybe 2 psi, and by 3500-4000 it finally started hitting its stride. It's true that this doesn't make it any slower in a drag race, but it does make it a lot less fun on the street. No longer can you just roll through all the gears, short shifting at 2500 for each one, and still get to 60 mph in 5-6 seconds. If you want it to pull, you've really got to wind it out to 3500+ rpm before it starts making some power.

TL;DR

So, I had a car (sold it almost a year ago) that made 450 rwhp with a PD blower, and 600 rwhp with a centri blower. Which one did I like better?

Even with with a massive peak power advantage to the centri setup, I liked the PD setup a lot better. It was just much, much more fun to drive every day. If I had a race car, or I really cared about it being as fast as possible, the centri setup (or a turbo setup) would absolutely be the better route. But for an all-around fun street car that was actually going to be driven a lot, I'd pick the PD blower. Equal peak power to equal peak power, I don't think it's even a competition. The PD blower is just a lot more fun to drive and live with. (And by the way, a 400-450 rwhp PD blower car is still a damn fast car.)

 

[Froush]

I did run a kb 2.2 for many years. By the time I sold it, it was not a normal kit. Hell, at one point I even made my own inlet for it which worked pretty good. Heat management is critical. I had a 7 gallon tank in the trunk and a big dual pass heat exchanger. Even after hot lapping it or just driving in the dead of.summer I would only see 140 degree iats max. But I know 2.1s put out even more heat.

You could spray meth which would help a bunch. Honestly my recommendation would be a properly sized turbo or a centri. If you ONLY plan on mid 400s, a kenne bell would be a good choice but I would recommend looking at a better pd blower if that's what you truly want. Vmp and whipple are more efficient and tend to not create nearly as much heat. There is a shop named John's motorsports in Canada that sells 2v specific whipple 2.3s