The car is supercharged, cam and headers. can the engine handle heads too? I really don't need a blown engine right now! that's why I'm asking here first before installing

 

I have the D1SC, AFR 225 heads, headers and exhaust, putting out 586 to the rear wheels. Best ET 11.2@123.7. Hae to replace the clutch, no other issues.

 

I heard it's hard to tune the heads with the Maggie, is that correct? anyone did that? P.S: the car is A6.

 

a buddy of mine has the same car and set up as I except he has the 122 maggie. He has the HP tune on his and puts out a ton of TQ

 

You don't need heads, just more boost. I run 26 PSI in my car. Beef up the botom end and turn up the bost!

 

Heads are a big help with forced induction systems. Basically, the engine is a big air pump. Anything that benefits flow, benefits power.

It may seem like the simple answer is more boost. However, if the internal flow capacity is not there, the boost will back up in the plenum. Your numbers on the boost gauge will go up, but so will the temperatures of the air/fuel mix, resulting in diminishing returns.

This is why the intercooler is used, to control temps under higher boost levels. This is especially true for the Maggie. The Maggie produces great flow at lower RPMs, so you can run heads with large runners, and not sacrifice port velocity at lower RPMs.

With centrifugal blowers and turbos, you can use aftermarket heads with larger combustion chambers to lower the static compression ratio. This will allow you to run much higher boost levels without risk of detonation. However, the lower compression ratio will diminish low end TQ, especially if combined with a high duration cam.

Aftermarket heads are certainly not mandatory, and you can make good power without them. But blowers are just like every other mod --- they do best when combined with complementary mods to achieve a matched combo of components.

 

Which clutch did you install?

 

RPS stage 4+ clutch and flywheel, the car really hooks up, can launch at 4500rpm

 

I did the SPEC III+ just a few days ago, does your clutch chatter much? I was told this would die down as the miles add up.

thanks

 

HITMAN, thanks a lot for the info but in general.. do you recommend doing heads? a friend of mine told me that will lower my boost number?

 

At first yes, and it concerned me, my mod shop told me it was normal. It has died down over time. I usually rev up to 12-1500 rpm to start off from a lite, etc

 

 

 

You'll find the answer to the head recommendation in the first and last sentence of HITMAN's post:

Since I couldn't say it any better, you'll also find the reason for the reduction in boost with better flowing heads in his post...you have to read between the lines a little, but it's there. His first paragraph talks about the engine being an air pump and flow vs power. Then in his second paragraph, he talks about internal flow capacity as well as boost not being the simple answer. Reading between the lines, what he's saying is boost is a measure of the resistance to flow. Just because you have more boost, doesn't mean you have more flow, but you'll definitely get higher air intake temperatures which will negatively impact power. In other words, you've reached the point of diminishing returns using the "internal flow capacity" of your intake/heads/cam combo.

You can have two engines exactly the same except for the heads/cam/intake/blower pulley and the engine with the lower boost making more power. If one engine has a smaller pulley (turns the supercharger faster) but the heads/intake flow more and the cam has more intake duration, there is less resistance to flow making the boost pressure lower but we get more air in because we have a smaller pulley and there is more "internal flow capacity". Since an engine is just an air pump, the more air we get in/out, the more HP it'll make...and that's what you're after. Don't worry so much about boost (except for the heating of the incoming mixture), concentrate on flow just like a NA engine...there really isn't much difference, they just operate at different manifold pressures.

 

I totally understand glass! thanks a lot HITMAN and glass, your info is really helpful.
but my only concern is the S\C boost! I'm afraid if I installed the heads I'll lose both boost and horsepower! I know you told me not to worry about my boost level but I'm just curious.
let me be more specific.. I HAVE 0.000% EXPERIENCE WITH SUPERCHARGERS!!! LOL
forgive my ignorance.
Thanks!

 

Ok, let me tackle this from a different way. If you change heads only to better flowing ones, you will lose boost pressure with no other changes (including pulley diameter) because you have less resistance to flow (same output/flow from the SC going through larger ports=less resistance). You'll experience a gain in flow (in CFM), but even if flow stayed the same, you gain in two ways. First, with the supercharger putting out less pressure, it takes less HP from the crank to drive it. The HP to drive the SC is given by the equation HP= PSI*CFM*C where PSI is the boost pressure, CFM is the flow, and "C" is a constant. Second, with lower boost pressure, the air is heated less (lower temperature) giving a denser charge/more HP. You can always put a smaller pulley on to increase the CFM output of the SC and HP of the engine to take advantage of the extra flow of the heads...then you'll see boost pressure increase (more flow through a given port=more resistance), but again, it's just a measure of resistance to flow. Boost pressure alone is not an indication of flow to the cylinder or how much HP an engine will make, but give me the flow alone to a cylinder, and I can make a reasonable calculation of how much HP that engine is going to make.

 

I'll try to answer your question as simply and directly as possible.

If you change to better flowing heads, and everything else is unchanged (including your static compression ratio), you can expect to see an increase in flow, resulting in more power. However, because the resistance to flow is decreased, your boost measurement will drop, and your air/fuel inlet temps should also drop.

What this will allow you to do is to spin your blower a little faster, by using a different pulley. This will increase your flow even more, raise the boost level as measure at the gauge, and raise your air inlet temps back to where they were before.

Bottom line is that you will gain power from the better flowing heads, and gain even more by optimizing the boost level.

Have you ever used a hand-held hair dryer, or a leaf blower? The smaller the nozzle on the air outlet that you use, you get more velocity but less volume. The motor will also go up in RPMs, because it has to work harder to force the air through a smaller orifice. You're getting more boost (resistance to flow), but less overall flow.

Same principle applies on a vacuum cleaner, especially a shop vac. If you use the big hose with the big opening, you suck in a lot of air, but at a lower velocity. Put a crevice tool on the end of the hose, or place the suction end close to a surface, the motor works harder, but you're actually sucking in less air.

 

Thanks a lot, got it!
I really appreciate your help guys.
Thanks a lot again!

 

I had the lingenfelter stage 2 heads and gt2-3 cam in my car before I had my A&A vortech installed. Afterwards, I was getting detonation above 5200RPMs. I was told there was too much compression with the LPE heads. A set of AFR 225's with 74CC chambers took care of the detonation. My car was tuned on a 95 degree day here in Dallas with no detonation, so I am ready to go for the summer.

Good luck

 

Thanks, I think MTI heads will do the job