Limiting the turbo for max HP on an 8V?

[mopar2ya]

Im not a fan of the 57 trim, as far as hybrids go the 50 is the best of the hybrids. Pressure is nothing but a measurement of restriction, you want a turbo that moves the most air in the most efficient manner. If your running say 25 psi, a 50 trim will deliver more air than a stock turbo at the same 25 psi, it also delivers more air than a 57 trim at 25 psi.

[Ondonti]

Quote:

Originally Posted by Shadow 50/50 mix. 50% 94 pump/50% 110 race.

What compression was letting you get away with 35psi and that fuel mix?

[Ondonti]

Quote:

Originally Posted by mopar2ya Im not a fan of the 57 trim, as far as hybrids go the 50 is the best of the hybrids. Pressure is nothing but a measurement of restriction, you want a turbo that moves the most air in the most efficient manner. If your running say 25 psi, a 50 trim will deliver more air than a stock turbo at the same 25 psi, it also delivers more air than a 57 trim at 25 psi.

People still seem obsessed with this "I need a turbo that move less air/pressure because my heads dont flow"

What they are missing is the 50 trim has a much fatter map, and much better efficiencies. I dont care how inefficient your head is, I bet that if you (not wallace since he knows this already) actually did some compressor map reasearch you would find that the 50 trim map will give you better efficiencies even if you arent moving a lot of air.

Then we can talk about the 57's unforgiving surge line.

If you really arent moving a lot of air and trying to run a lot of boost, you will be surging on the 57.

Just to point out how incorrect that idea of the 57 trim being a high pressure/low flow turbo.

Compare it to a 50 trim. 3.0 bar and 32lb/min or less.......57 trim is SURGING, 50 trim is running 74% compressor efficiency

The 57 trim is a horribly designed turbo.
At 3.0 bar, which is where TD guys seem to like to get up near, the 57 trim can only push 33-40lb/min above 70% efficiency (any less then 33lb and you are surging.
The 50 trim will push 30lb/min to 48lb/min and be above 70% efficiency.


THe 50 trim will do ANYTHING the 57 trim can do, and do it better in all aspects

Any point on the 57 trim map can be found to be a higher efficiency then the 57 trim map.

There is a reason people in other car communities dont use the 57 trim. THey jump straight from the 50 trim to the 60 trim or better.
the 57 trim will work, but dont think anything about it besides "i could have had a better turbo for the same price."

[Shadow]

Quote:

Originally Posted by Ondonti What compression was letting you get away with 35psi and that fuel mix?

The only drop in compresion came from the bowl work we did on the head.
As for the turbo, the reason the 50 trim shines so well with a higher preasure ratio than the rest of the To4e wheels is because it is a taller wheel. You should have read my post more carefully, I didn't say I was running a normal 57 trim. For a matter of fact, I was going to run the 50 trim until my turbo guy discovered this wheel. A 57 trim with the same hight as the 50 trim. As I stated already, this wheel moves the same lb's/ min as the 50 trim, and it has an even higher preasure ratio. I have never experienced "surge". Not with this wheel or any other for that matter. My street tune is 20psi....no surge.

[mopar2ya]

Bowl work cant drop the compression, its on the wrong side of the valve. The wheels are the same diameter, its the pitch of the blades which determines how it moves the air. I cant find any compressor maps that have a 57 trim close to the 50, in fact the 50 trim can move 48 lb/min at 65% and the 57 trim doesnt even have a map that gets close. I dont know what turbo guy discovered what, but some tech data to show us would help explain what your saying, because all the data Im finding and know is the opposite of what your saying...Help us out.

[Shadow]

Sorry, I meant to say chamber, it's kind of shaped like a bowl. lol I'll see if I can post the map.

[Shadow]

K, maps away! BTW, I started the year thinking I had to be carefull not to run too big of a compressor because of the 8v head. I think a little differently now.

[mopar2ya]

What brand is this? The compressor surge line is pretty intrusive, similar to the standard 57, but a broader map.

[Ondonti]

Quote:

Originally Posted by Shadow The only drop in compresion came from the bowl work we did on the head. As for the turbo, the reason the 50 trim shines so well with a higher preasure ratio than the rest of the To4e wheels is because it is a taller wheel. You should have read my post more carefully, I didn't say I was running a normal 57 trim. For a matter of fact, I was going to run the 50 trim until my turbo guy discovered this wheel. A 57 trim with the same hight as the 50 trim. As I stated already, this wheel moves the same lb's/ min as the 50 trim, and it has an even higher preasure ratio. I have never experienced "surge". Not with this wheel or any other for that matter. My street tune is 20psi....no surge.

I saw you were running the super 57 trim. I wasnt talking about that turbo though since its a different turbo

[Shadow]

Quote:

Originally Posted by Ondonti I bet that if you (not wallace since he knows this already) actually did some compressor map reasearch

Now that we've straightened out who "is" doing their research, would you like to attempt to answer the original question of how much HP I was making at said boost level?

[Ondonti]

410?

The "You" is everyone posting here in general besides wallace not just "shadow"

you arent even using the turbo that was being talked about :P

[Shadow]

Quote:

Originally Posted by Ondonti 410? The "You" is everyone posting here in general besides wallace not just "shadow" you arent even using the turbo that was being talked about :P

I figured I was over 400whp, and there's no way to know for sure, that's why I asked for someone elses input. I obviously read that wrong, taking "you" as a singular term. Either way, it's really no problem, as long as some good info is getting out there. Thanks for your input!

[Ondonti]

yeah I used your trap speed but since your car was running sorta bad i dont know if your trapspeed really means anything.

[Shadow]

No doubt the car was rich down low, but it was my lack of ability to keep the car at the top of it's PB that really killed things. Believe it or not, the 11.6 we ran last year(in a different car) was done without powershifting, or hardshifting the car. For the last 6 years I've gotten used to the 568's and 523's in cars I've built for other ppl. They didn't like to be shifted too hard. So I got used to lifting my foot, just a bit, while I was shifting. Shift the 555 in the Charger like that, at 35psi, and the turbo drops off like a stone. Then, it's soo rich down low that your waiting forever for it to come back on. You'd think that in 5 pulls I could adjust. It was unbelievable, run after run and my damn foot would lift! In the end, I think the fear of breaking the car from a bad shift (being so out of practice) got to me. Bummer is that now I have to wait till spring to really find out what the car has in it.

[JacksRage]

Car squats HARD, just doing something with that gets you your 100 mph 1/8 I bet.