Contour Enthusiasts Group Archives Forums General Dyno and Drag New 2.5L Turbo Benchmark thanks to Chris!

Here is my best reasoning why the secondaries are needed for this intake manifold (both uim and lim):

-The fuel injectors are in the primary runners

-The secondaries are slightly larger in diameter than the primaries.

-Fuel doesn't travel in the secondaries.

-When there isn't a whole lot of air running through the primaries, the swirl and tumble of the air doesn't pick the fuel up properly, leaving the fuel not as suspended (big droplets and it sprays on the sides of the walls.)

-Most of the air goes through the secondaries at any RPM (if the secondary butterflies are open)

-SINGLE runner, like on the 3L would eliminate that problem, and possibly provide a better running path for pressurized air.

-So, it isn't until 3000-ish RPM, when the secondaries open up, that the air in the primaries is swirling/tumbling enough to keep the fuel off the walls and pull it nicely down the runner.


Conclusions:
1. With dual runner manifold, you NEED to have the secondaries shut off at lower RPM's.
2. Pretty plastic 3L upper WITH big oval lower (with siamesed intake head ports) could be a righteous option for the turbo.

Oval port 3L with split port manifolds...

Fuel to both valves while retaining the larger ports.


Heck... Oval porting the 2.5L heads just like the touring race teams did. (I've had those pics for years even)

They never used secondaries either but then again they drive a bit like I do. Below 3000rpm means the car is parked.

(* taking notes: 'Oval porting 2.5L heads' *)

I am new to the board. And do not mean any disrespect, or offense by this question. I do not see why you belive that 388 is the max for the 57 trim. Perhaps max for its max effciency but max by no means. i mean step it up to a 1.2-1.3 bar, and increase the flow of your head and you are still able to kick up the power by a ample amount. Unless your motor just does not breathe well. How did you come up with teh conclusion that the 57trim was all "used up"? By a comp map? If so then there is alot more involved than a compressor map. There are turbine maps to be looked at as well as volume efficiency of the engine. I know for a fact that a 57trim can go way over 388whp. I have built many 4cyls that have a 7000rpm redline and made more than 450+whp @ 9.2 comp @ 18-20psi. Many folks over at hondatech have done it as well. Now its won't be the most effecient but it will still be up past 400whp. i would say that all the upper trim levels 57, 60, 60-1, and 62-1 (this one is a bit much), can make over 450whp. Hell in the honda community they do with 60-1's that turbonetics still can't fathom. again this is not a offensive post just some fyi that i have seen with my own eyes.

also other peoplr have as well. Look on vwwortex.com, honda-tech.com, etc.

on another note, if you want more power i would suggest to you a sc61 or its61... Its is a t350 turbine in a .63 a/r t3 housing, with a 61mm inducer compressor wheel with a 56trim, and can be configured with a t04e or s comp cover (i would definately suggest the e cover considering the space available). Now this turbo is supposed to only make 450whp... But i have produced over 620+whp on this turbo.

sorry for the long post, and congrats on the power achieved and very nice numbers for pumpgas, whats your compression?...

PS: what do you mean about the car ripping itself apart? does it feel unsafe at those levels? WHo has made the most power out of teh 2.5l? And how much is it?

Thanks again.

Off of PTE site. SC-34 is what they call a 57 trim. comp wheel overal diameter 56mm, Inducer size 2.230", Exducer - 2.950", turbine wheel - T31 also known as a stage 3. inducer - 2.559" , exducer -2.121" 69 trim. Max rating of 545 bhp... Now PTE is moderate when they list there turbos. Typically it isn't BHP is more like WHP.

this is a 1jz toyota engine i-6 2.5 liter, 22psi on a 57trim full t4. But just to show you that the 57trim doesn't run out of breathe.

And Warmonger is absolutely correct. Of course you were gonna lose lowend. But I garauntee you when you find your performance bottle neck (ie: reason why 388 is the max power of your 57 trim), you would rather have the extra umph uptop then downlow.

Well the fact that it hits 16psi and then falls back to 15 is one indicator. It could be that the turbine housing being only a .63 could be where the restriction is. Either way I'll be sure to redyno it again shortly to test your theory. I hope you are right. BTW that is the highest recorded number on a dyno jet for this car.

What kind of boost controller are you using? Wastegate? Boost gauge? Sometimes its not the turbo. Hell all dsms do that. Typically is a wastegate issue, the effeciency of the compressor wheel should not make the boost drop. And sweet congrats on the record

PS: it couldn't be the .63 housing being the restriction as all the examples i presented to you except for teh 1jz have all been on the .63 a/r housing. Unless there is too much exhaust presure causing the wheel to cavetate... but what are teh odds of that happening.

Hey whats your AIM name i would love to chat about this with you. Do you work for street flight? Or is it just a street flight project car?