Help with reading these maps!

[turbovanman²]

I am comparing these 2 maps, left is non ported cover, right is ported, 3rd is the billet compressor wheel, so in plain english, what does it mean. I can see that the surge line is moved, which makes sense, but then I don't really understand the rest, thanks.

[Shadow]

Very interesting maps. What is the difference (if any) of the intake size between the non-ported cover and the ported cover? (ie. 3"-4"?) Anyone who thinks that more intake on a turbo this size make no difference in performance should look at these maps!

First pic has low PR and brutal surge line for your mtr, it would need a super efficient mtr and would top out around 630WHP.

Second pic with ported cover has Way better PR and will sustain higher boost pressure without loosing efficiency. It also has the best surge line for your mtr and will support near 700WHP on a super efficient set-up.

Third pic clearly shows that the billet wheel is capable of 800WHP, but surprizingly Lower PR than the second map?(but not by much) You would deff want to consider the third map if your looking to make more than 600WHP, but you would also want to increase efficiency of your set-up as it has a slighly more intrusive surge line that the second map.

[Juggy]

Very interesting maps. What is the difference (if any) of the intake size between the non-ported cover and the ported cover? (ie. 3"-4"?) Anyone who thinks that more intake on a turbo this size make no difference in performance should look at these maps!

First pic has low PR and brutal surge line for your mtr, it would need a super efficient mtr and would top out around 630WHP.

Second pic with ported cover has Way better PR and will sustain higher boost pressure without loosing efficiency. It also has the best surge line for your mtr and will support near 700WHP on a super efficient set-up.

Third pic clearly shows that the billet wheel is capable of 800WHP, but surprizingly Lower PR than the second map?(but not by much) You would deff want to consider the third map if your looking to make more than 600WHP, but you would also want to increase efficiency of your set-up as it has a slighly more intrusive surge line that the second map.

oh cool. so the skinnier the map looks, the more capable it is of surge.
how do u convert that to WHP??? is it through the PPM?? like X amount of air makes X amount of HP???

[Shadow]

Surge is defined by your VE vs the dotted line on the far left of the map. So, does Not nec mean that the width of the map = less surge or better surge line. Look at the 3rd map, it is the widest map and it has slightly Worse surge line than the second map.

WHP is simply the PPM vs the PR your set-up will need to get you there. A super efficient set-up will generally make slightly More WHP than a factor of 10 X the PPM rating. Although most will fall short of this so the average Very efficient will make roughly 10 X the PPM. So a turbo that flows 60 PPM will usually be a 600WHP capable turbo, at what boost pressure you make that 600WHP (or IF your set-up is even efficient enough TOO make 600WHP) will tell you how efficient your set-up really is.

[turbovanman²]

Thanks, I need to take a course on map reading 101.

All intake sizes are 4", the 2nd and 3rd both use ported covers, Garrett recommends them with the billet wheel. I was reading their site last night, hence my questions. Also found this from a BMW site, a back to back test, billet vs regular-

[Shadow]

Keep in mind this is only My perspective and most seem to read maps differently than I do. lol I am also speaking directly to how these three would perform on Your current platform with the info already available from you own experience with the first two maps.

Biggest problem I see when ppl are trying to choose a turbo from a map is the total lack of info/ability to understand how the map will work with different turbine A/R's and turbine wheels. This is where the turbo calculators fall short,they don't give accurate enough info on the shaft speed vs where you Really are on the map vs turbine/wheel choise. (IMO)

[turbovanman²]

Thanks again. I was curious to how it all worked and intertwined, lol. I guess the other maps with the pressure ratio based on the turbine size also helps. Looking at putting a .63 on this year.

[GLHNSLHT2]

Think you should ditch the GT35 and go GT30 or Holset

[Shadow]

The .63 Should wake your whole build right up! Your not using the .82 A/R to anywhere near it's potential so your just running lower shaft speeds and loosing big power under the curve.

Remember, the higher the shaft speed the further you move to the Right of the map towards the choke line and Away from the surge line. Because I knew that I would be working with a restrictive build (8v 2.2) I have alway run the smallest turbine wheel/tubine housing possible to produce the power I'm looking for in order to retain the Highest shaft speed at any boost level.

This is the single biggest reason I have never had any problems with surge on the Charger, even with the 57 trim that ppl told me would surge like crazy..........

[turbovanman²]

Think you should ditch the GT35 and go GT30 or Holset

I have a Holset, if anything happens to this, its going on.

The .63 Should wake your whole build right up! Your not using the .82 A/R to anywhere near it's potential so your just running lower shaft speeds and loosing big power under the curve.

Remember, the higher the shaft speed the further you move to the Right of the map towards the choke line and Away from the surge line. Because I knew that I would be working with a restrictive build (8v 2.2) I have alway run the smallest turbine wheel/tubine housing possible to produce the power I'm looking for in order to retain the Highest shaft speed at any boost level.

This is the single biggest reason I have never had any problems with surge on the Charger, even with the 57 trim that ppl told me would surge like crazy..........

I think the .63 will be alot more fun on the street and makes sense about the surge line. Maybe I should put the non ported cover back on?

[Shadow]

I think the .63 will be alot more fun on the street and makes sense about the surge line. Maybe I should put the non ported cover back on?

That's a Big NEGATIVE good buddy! Don't put the old cover back on! You Want the second map, regardless of how much power your making at present, there is No downside and it IS the better match to your set-up.

You would only want to run that cover if you were a Honda that was only gonna run 15-20psi boost and take advantage of the better surge line below 2.5 PR, other than that it Sucks compared to the second map in every sense of the word!

[Reaper1]

I look at it like this:

I want to make a certain amount of power at a certain boost goal. The boost goal is the PR. The power is the PPM.

I then try to take into account where the boost is going to come on so I know how much air the engine is moving and at what PR, so I can see how close the compressor will get to the surge line.

Now, I'd LOVE to know how to take into account the turbine and housing, or if in a way I'm already doing that.

Keep in mind that a surge line is NOT set in stone and does not mean that the compressor can't operate to the left of that line. The surge line is chosen by an engineer to keep the compressor in the best operating conditions vs. the "life" they want to see out of the components. The efficiency islands continue on the other side.

It looks to me like the ported housing is capable of making more power at lower PR and can continue to make power in the higher PR's, In between it's kind of a wash. The billet wheel moves the whole thing over to the right a little, but the maximum efficiency island is HUGE. If I'm taking what Shadow is saying correctly, then choosing an exhaust side that would start to spool a little later would be a better choice there, BUT, once it's spooled it's game on!

[turbovanman²]

Ok, that is good info, thanks again.