I am running the Magnus Race at 2.4 bar on race and 2.2 bar on pump. It has been working well. I've never compared it against any other inlet manifold, so I can't speak to performance.

Did run a 10.9 braking before the end of the track, not flat shifting, and running a 1.86 60ft.

That said, given so many people complaining about failures, I'd go with the AMS or Kansai inlet if I could do it over. Although I suspect if it fails Magnus would replace it at no cost.

I do wish I just paid the bucks and got the Kansai one.. I think that is prolly the best performing in the absence of real data. Just from looks it seems the most smooth. Of course I have no idea what makes a good manifold!

Dave, I've been there when Shep blew an intake manifold up from a nitrous backfire, I helped him push his car off the track when it finally made it to the end. It looked very much like that one. That was NY
And I was there for the one that blew up his intercooler and his end tank and his throttle body, I lent him mine from my car to keep racing. That was the shootout 03 I think

What we have here is a failure to understand the concept of what causes backfires in the intake manifold, something as simple as dirty injectors can do it.

The most common are here in order that we get them

Methanol backfire: usually a guy gets a little overzealous and bounces off the limiter in 1st or second, engine hits the limiter, methanol doesn't. 2000cc nozzles of meth and you can imagine how much atomized fuel is in there in a split second, it like building a potato gun with no potato. Witnessed this one with my own eyes 2 years ago, scared the **** out of everyone in the dyno room.

Nitrous: you'd be surprised how many people don't know how to follow instructions, don't spray below 3500 rpm, or my personal favorite too much fuel jet, bogs it, it drops below 3500, then blows it up. (I did that one once myself by accident, but the hood came clean off the car)

Uneven spray patterns and badly misfiring cylinders can cause unburnt fuel to puddle up in the intake manifold and then "BANG" your intake manifold is dust. Saw some guy on DSMtuners, describe that the car was running on 2 cyl for miles before this happened.

I wont let your car on my dyno unless I know your injectors have been cleaned and flowed. I'm sick of guys lying to me, and then having to mop up the dyno for hours when they're learning how to tune their cars.

Also I'd like to point out many customers will call me and say "hey I had a nitrous / methanol backfire, blew the intake to pieces, it was our fault, can I buy another?" At that point is usually when I give that person a smoking deal on a new one. Why? Because I appreciate honesty and intelligence. This guy knows what he did and why, and he is ready to pay for his mistakes. For that he gets a deal for being a repeat loyal customer. That has happened on dozens of occasions before. If this guy calls I'll expect a written apology.

And don't even talk to me about Al, He straight up blew his up the same way, but preferred to run his lips in a national publication and on the net rather than ask an experienced tuner wtf happened, or maybe even the manufacturer.

If there was a small crack it would leak boost and lessen the pressure slowing boost response, and not allowing you to build up that pressure. So this argument is pointless. So if the welds were weak, (as some of these experienced "INTERNETZ WELDORZ" have stated, it would not blow up like that, the car would lose response and go slower and slower, until you realized you had a problem.

When you bend 1/8th thick aluminum, (Which s what we do here!) it requires over 300 lbs of force on a brake across 18 inches of plenum. Picture a 2000 lb brake with a 100 lb counterweight on a 3 ft cantilever. If it takes that much force to bend it, You have to have a serious explosion to bend it back to straight. Its simple math. It cant be done with 30 psi of pressure or 100 psi of pressure for that matter. You need a sudden burst with more force than I have described.


There is just a sampling of what I have to deal with on a daily basis. This is because there are so many of these out there, in the hands of experienced and not so experienced users. So it goes to show you, it even happens to the pro's, being able to identify the problem is what is going to make you smarter, and avoid it from happening again. I hope this lesson in intake manifold backfires goes to the archives.

BTW these parts I sell you guys, are the same parts on my car! And I run 171mph with it.

Love Magnus!

Well Said Magnus!!! For the owner of the car.. Stop *****ing and send it in to get re-welded.. I run a Magnus manifold on my 91 Talon and seem's to be money well spent 9.94@138 (Auto)

Even if I were to blow it up I wouldnt start a thread about "any one considering a magnus manifold check this out" So I take it everytime you break a part( your fault your gonna start a thread about the company?

Whats next?

if you considering a Shep tranny check this out ... After you broke it!!

You get my point..

Then accept my apology...if I knew about meth/alky explosions, I would have known better to name this thread something different, like, "Holy Meth backfire, Batman" or something similar. I was ignorant regarding meth explosions and the like.

I have seen first hand many intakes cracked. Not blown apart but cracked threw the welds. I have fixed a ams that split about 6inchs threw the weld. Lots of people over look the real problem here. Its easy to tell that a manifold cracked from a pore weld or burst open from a back fire. Harmonics along with week over heated welds will crack usually threw the weld. Bent or bowed metal clearly states a back fire. If you guys want a solid intake look into heat treating it. You want the welded area brought back up to the parent metal.

Btw- isn’t it ironic that the fastest 4g63 in the world runs a simple round plenum with little design behind it. Intake design on forced induction (30psi +) has little effect on performance. Keep in mind that there is not a steady state of flow. Valves are closed at some point. You are filling a space with air pressure. You can put a dam lunch box on your car with great results. lol

Keep in mind these are not high volume production pieces. They are hand build from good old fashion blood and sweat. People make mistakes. You guys need to give big props to Marco. He makes good on his products and deals with lots of pro tuners(like Al)lol. That fu#$ there stuff up and point fingers to the next guy.. Keep doing your thing Marco and let the internet racers do there thing.

you guys are funny..

Stop backfiring your engines and you won't need to replace intakes anymore.
and if your intake doesn't break something else will..

I have never had a backfire on my car and my old magnus intake craked more that 10 times. Every time I took the time to take the intake out and repaired it. There was a time, that one of the arms that hold the fuel rail cracked and two of the injectors came out of place, so you know what happen there. I talked to Marcus and he told me he would change the intake (that never happened). I have know the AMS intake for more than a year and 0 problem.

My magnus race intake manifold held 61psi no problem

Not to mention the OTHER 4 I've had in the past.

JVELA - Considering you had to repair it "10" times during any of those repairs did you think or try to get the manifold flange surface checked? Sure sounds like someone warped the **** out of it.

Im not sure why you guys think methanol/nitrous backfires are so unheard or uncommon. Its common place for this in the v8 crowd and blows carbs/filters & hoods clean of their car when it happens.

I could see this happening to almost ANY sheet metal intake manifold under the same conditions.

Hi Eric.

Well the one thing I have to admit that I'm not understanding is....

Where are the reports of AMS manifolds failing?

It just seems odd because we know there is a ton of AMS inlets on cars running meth... and you'd think we would have seen some instances of it so far. Maybe AMS can comment on how often they see failures?

That said, I have to agree with Marco it seems unlikely boost pressure alone could bend aluminum like that.

There is a lot of stuff that doesn't make it onto the forums. I have heard plenty of rumors regarding plenty of vendors, none of which I'll repeat. Suffice it to say that nothing is indestructible. For example, people have blown up their Shep trannys. Does anyone for a second question the build quality of a Shep tansmission? No, it just means people put a lot of abuse on their vehicles and its parts.

yeah, just because it doesn't show up on the intardnet doesn't mean it doesn't happen. Conversely, just because it shows up on the intardnet doesn't mean it did happen either.

Ahh, the good old Intardnet. Unfortunately, I contributed to the Intardnet by mis-titling this thread.

I was standing in the staging lanes at Maple Grove with Shepherd. He cranked the engine, huge backfire, like a bomb went off. The car either had our old sheetmetal intake on it or BJ's, I believe it was ours at the time. The explosion split the FMIC tanks, blew up couplings and bent the throttle blade. John took the blade out, flattened it out, we built some make shift i/c pipes and eliminated the FMIC all together, he won the race. This is when he was still on gasoline. Intake manifold was no harmed.

Matt Smith split two intakes, as I have said and was told they were early designs and the design was going to be changed...............Marco did replace it. It was then sold and replaced with AMS's. Nothing else was changed and it has never split again.

I have never seen an AMS intake manifold crack/split or explode. You would think with all these crazy *** methanol backfires and explosions that are being talked about I'd see one or hear one atleast once in awhile. I'd personally think it would cause a bent throttle blade atleast with the stock intake/throttle bodies that I prefer to run. Or you'd think with that much pressure in the intake manifold all these crazy back fires and explosions might even pop off a vacuum line attached to the intake manifold...........................

One other thing. When we were racing the tube chassis car and Conquest we had our sheetmetal intake manifold on them. Since the cars were automatics we triggered the nitrous to work at ANY RPM as long as the pedal was at WOT. The car's constantly triggered the nitrous between 1500-2000 rpm. I NEVER had any explosion and in hundreds of passes with those two cars never split an intake manifold. We have the tube chassis Honda down in Aruba, has a 4G63 we built in it, 2 liters, running 150 shot of nitrous, same deal. That car has been there about 4 years now, has gone 7.66 at 175 mph, runs our old sheetmetal intake on it still and has never had one of these crazy explosions or hurt the intake manifold.

I gave my input and it appears as though we are all idiots here except for one guy, how's it feel to be a genius...............................?