moto67

Anybody running a 3.0 pulley with a mp112 on a stick 5.3? If so, how much boost are to getting?

Thanks,
Jonathan

LS1-IROC

iTrader: (4)

Stock heads and cam? Whats the rear pulley ratio?

moto67

Yes sir, stock heads and cam for the moment. Probably won't touch the heads. By the time I think about touching the heads I hope to be thinking about stepping up to an LS3. Although it will be stock can for awhile, I do plan on swapping cams once I decide on which one. Keep hearing about the lingenfelter GT2-3. That being said, for now let's assume all stock. The mp112 unit Im running is a radix unit so no jack shaft or rear pulleys.

NitrOmm

iTrader: (1)

So ..... Rear Pullleys are 1:1 ?
On a 5.3 I'm estimating You will see about 8 lbs.
Take away a couple lbs if headers/ exhaust are involved.

There are quite a few good off "the rack " cams for PD blowers. Low overlap is the key for the little MP112. Need to keep all the boost you can.
Lots of fun for street driving.

I'm not sure who is a sponsor or not so I don't want to post cam recommendations. If you want my 2 cents just PM me.

moto67

I did forget to add that I a running headers and no cats. As I'm new to the boost game, I didn't know that it had an impact in boost. I was thinking it was going to be closer to 9-10psi. So I am not much of a cam guy and reading cam specs is like trying to dicipher code. Do you know if the GT2-3 is a low overlap cam? The specs on that cam are:
207/220 duration @ .050 lift -.571/.578 lift with 1.7 rocker 118.5 CL

LS1-IROC

iTrader: (4)

My guess is you will see 5-6lbs of boost with your set-up.

moto67

The stock pulley is something like 3.4 right? So if the Maggie is supposed to be putting out a claimed 7psi on a stock motor, you would think it would bump boost up on a 3.0 pulley. Am I missing something?

LS1-IROC

iTrader: (4)

I can tell you my totally stock LS1 made 6lbs on a MP112 with headers on a 3.0 front and 1:1 rears.

moto67

My thought would be that it would be a little higher on the 5.3 vs your 5.7 due to the smaller displacement. The guy I got it from originally had it on a 6.0.

NitrOmm

iTrader: (1)

Correct. Not much more but yes a 5.3 will see a little more than a 5.7.
Gt2-3 is a good choice but you have to determine your goals. Yes the headers make a difference. The concept is that you are moving that air & charge out faster with less resistance. You are making more power on the motor with less restance ( boost).
I had my Maggie for a few years & loved it. Some advice would be "Don't get so hung up on peak numbers". The shining light of a Maggie is that they make boost quickly, so you get a tremendous amount of power (under the curve) early. You may see 5-6 lbs by 3k rpm. Your TQ will be instant .... Then carries flat till red line. With that said, your peak numbers on a stock motor aren't much more than maybe 475/450 TQ. But .... You will have 400 lbs of TQ by 3k. This will get you moving & put a big smile on your face.

Re: cam. The GT2-3 is a very low overlap ( I believe it is even a negative amount of overlap). I personally wanted something a little more aggressive with a chop at idle. What I know about cams is enough to get me in trouble ... But I can share a formula so you can calculate the overlap and this will help in your quest.

Take the durations and add them together. Then divide that number by 2.
Take the LSA ( lobe separation angle) multiply by 2. Then subtract that number from durations. this gives you your overlap.

Example of my cam that I used with my Maggie.
Cam 239/242 on a 114.

239+ 242 = 481
481 divided by 2= 240.5
114 x 2= 228

240.5 - 228 = 12.5 * overlap.

I mention this as an example of how to calculate only ( not as a recomendation). This was on my 6.0 and in my opinion was too aggressive. It chopped like a prostock & made good power where I wanted it but a little hard to tune. Drivability suffered. Too much cam for the MP112. You may want to look for something in the middle. When it comes time for the cam speak to some of our sponsors and tell them your goals, your engine specs & if this is a truck or fbody etc.. They will lead you in the right direction.

At the end of the day I added everything I could to make more power on the 6.0 with the MP112 and could muster a respectable 550/500 on a mustang dyno.
My point being, enjoy the Maggie for what it is, a great street setup & tons of fun to drive. If you chase more boost & more power ( peak numbers) you will get frustrated.

moto67

First off, Excellent response and write up Nitro! I appreciate you taking the time to give so much detail. Very informative.

That being said, as much as I would like to say that I am not really focused on the numbers, I was hoping to get into the 500hp realm. I feel that 500hp would give me enough without being too driven to chase more. 475/450 is still very respectable and I was driven towards the maggie for those exact reasons. I didn't want to deal with lag. I want the power when I push the pedal. One thing I did gain was the Radix came with the 90mm J-tube vs the stock 78mm. Thats said to be worth 30-40hp.

I too would like a choppy idle. Love the sound. I don't want it at the sacrifice of drivablity though. So overlap is a good thing? I dont know the first thing as far as cam selection. I was looking at picking up a TVS1900 from a gentleman in Houston. He was running it in a 5.3 Colorado. He had some youtube videos and heres one:


Sounded pretty mean. The Corsa mufflers definitely help as well. I also thought 11's were pretty good out of a 5.3. I would be very happy to get that out of mine. He was putting out over 500hp and the cam he was using was the Vengeance Racing VRSC-1. The specs on that cam is 223/231 .610/.617 115+4. I did call them a few weeks ago but the gentleman I spoke to at vengeance wasn't very helpful as far any advice in the performance of the cam in a 5.3. He stated that they dont really have any experience running that cam in a 5.3.The guy from Houston put out some pretty good numbers but I dont know about overall drivability. It is not a truck nor an F body.

Its in a 55' hard top Bel Air that I actually drive very often. Part of the motivation of swapping in the ls was the reliability, drivability and having the option to take the car wherever I want.

Am I right in the thought that the maggie brings power on quick but that it fall off after 5000 rpm? I though I researched somewhere that they fall off up high.

I love the sound of the maggie, instant power and reliability. I just want to get it close to right the first time as much as I can. I dont have bottomless pockets and I hate when my car is down for any period of time. I plan on throwing the maggie on the stock motor for a bit till I gather more funds for the cam and springs.

I'm am very confident that I will love the maggie and the power that it will bring even in stock form. It will be my first boosted motor and I am excited!

moto67

I forgot to ask, since you seem very knowledgeable, do you think the 42lb injectors that the maggie comes with will be adequate?

NitrOmm

iTrader: (1)

Experience ... I have .... Knowledge, well the jury is still out.

My opinion, 60 lb injectors and upgrade the fuel pump to at least Walbaro 255 & get a heavy duty belt tensioner.

That Vengance cam is a great choice. Good example of the +4 on the LSA. The effective overlap is 5*. Sounds great & runs well. Your 500 hp goals are very attainable.
55 Chevy !!! This is going to be fun.

Do you own the MP112 ? If you have opportunity to get a TVS1900 at a good price ... Get it. While I loved my 112 & it sounded crazy ..... I was always wishing I had a 2300 or even 1900 for the extra push. The internal air temps on the later two mentioned are far better
(more efficient blowers). Less issues with belt slip ( which we didn't discuss yet). My limitations were due to fitment, an body has very little clearance. You on the otherhand have the Grand Canyon under the hood.

NJmooch

Just to add my 2 cents, Magnuson makes a 1.9 kit for the Chevy Colorado with the 5.3 and comes with everything. Since you have the stock heads/cam, this setup may be what you need for now.

They made around 360 RWHP from what I remember. That is on a totally stock LH8 5.3 with 6psi. Your setup will make way more power if you run a smaller pulley and have headers/exhaust.

Making over 400 RWHP with a stock 5.3 is totally doable. Like posted above, bigger injectors and a good fuel pump, are required if you raise the boost.

If you are going to raise the boost, you should reduce your chances of belt slip by adding an 8 rib pulley setup, also SFI approved balancer/pulley that is pinned to crank. The change of pulleys will be worth it.

I plan on going to 9 or 10 PSI, (as much as possible without meth) once I get my 1.9 Maggie for my 5.3. That will make over 500 to the tires since I already installed the blower cam (220/228, .598/.598 115 LSA +2). A good tuner is needed if you go this route.

Hopefully this info will help you out with your 5.3. Good luck!!!

moto67

Thanks Nitro! So it sounds like your say it would be a great cam for performance and regular streetability? I already have a Aeromotive EFI tank with a 340 Stealth pump. Should be more than adequate I believe (or its supposed to be). So it looks like 60lb injectors for the win. I already do have the MP112 with a 90mm J-tube. I would love to have picked up a TVS1900 but unfortunately I couldn't find one at a decent price. I payed $2800 for the MP112 with the 90mm J tube and an extra pulley. Plus, the shop where the guy has his work done is going to flash my ECU for my setup that way I can run it and drive it until I do my cam and get her in for some tuning. It was oringinally a toss up between the 112 and the 1900 mostly due to how much I loved the sound of the 112. After I didmy research I learned how much more effecient the 1900/2300's were with the newer rotor design and the fact that you didn't have to spin them up like the 112 creating a lot less heat. Even more so, the option was there to add a rear cog setup to gain the 112 sound if desired. When it came down to it, I just couldnt pend the extra coin at this time as I have already invested 5 times as much as I originally planned (don't we all haha). I think I willl enjoy the 112 until farther in the future when I can justify spending more money. All in all, I'm trying to look at the fact that I'll have a 55' chevy with an supercharged LS and that my friends makes me feel very fortunate and blessed already

Thank you sir! I think my reply about addressed both of your guys' input. I really appreciate it. I am definitely interested in doing the 8 rib swap with a HD tensioner. I have heard of the slip issues and don't want to deal with that headache either.


I truly do appreciate all the input from everyone!