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2.4 Auto S256 - 444 awhp @ 25psi

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VETDRMS

15+ Year Contributor
340
21
Jun 1, 2006
Vancouver, Washington
Almost a year after starting this project, I finally got it dialed in and over to the dyno.

Huge thanks to Aaron @ English Racing. It's been a long haul but I can't say enough good things about the guys at ER.

I went through 100 gallons of E85 last month commuting and trying to get it dialed in on weekends/nights. AFRs match target AFR well and timing is pretty conservative for E85. It has been running great. The current setup has about 6500 miles on it. Recent compression test was perfect so it seems pretty healthy (knock on wood).

A link to my build thread is in my signature, but basic setup is:

  • 2.4L - 9.8:1- Eagle/Wiseco HD
  • GSC S2-R Cams (11.7mm)
  • Evo III Intake/TB
  • BW S256 ETT - BEP .55 Housing
  • 2g Auto - 4500rpm Restalled Converter
  • FIC 2150s / Aeromotive 342

First pull at 23psi made 412 awhp, which was much higher than I was expecting. There was some knock noise similar to what I have been seeing on the road, but Aaron said it didn't look like real knock considering the fuel and low timing. We turned the boost up a little to 25psi and power increased to 423 awhp but we were seeing 1-1.4* of knock retard starting at 7000rpm. Aaron was pretty certain it was just noise so we turned the knock sensor off and made another pull at 25psi and made 443.5 awhp.

Pulls were made to 7800rpm. I was really surprised the .55 housing and Evo III intake didn't choke the 2.4 but it pulled really well past 7000rpm and made peak power at ~7500rpm.

We only made 4 pulls but I was very happy with the results and didn't want to get greedy. For a conservative tune at moderate boost through an auto I am stoked. Timing/fuel setting stayed the same as when I drove it in so I was happy my setup was pretty close to on. I have some phone video I will try to post later.

This combo has exceeded my expectations, the car commutes perfectly with no drive-ability issues.

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I can't wait to finally get out to the track. I think my goal of having an 11.5 ET "everyday" commuter full-weight 2g is attainable.

Video (Sorry all I have is crappy cell video - click for external link):

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Datalog:
 

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Nice! Cant go wrong with a BW turbo! I've been running an S256 on my SRT-4 for a few years now with absolutely zero issues, and it has seen up to 28psi on the dyno.
 
Thanks guys, I always wanted to try what I thought was an under-rated turbo. I may look into testing an S259 bat-mo-wheel in the future in both the DSM housing and a 0.70 a/r T3 housing. :sneaky:
 
Thanks guys, I always wanted to try what I thought was an under-rated turbo. I may look into testing an S259 bat-mo-wheel in the future in both the DSM housing and a 0.70 a/r T3 housing. :sneaky:

that S259 can be a nasty set-up. My S256 uses an .63 a/r T3 from AGPturbo.com
 
I would think with that power and an auto it should be low 11's at 120ish? How much power does the auto suck up vs a 5 speed. Meaning, what would this car dyno at if it was a 5 speed.
 
Aaron: Thanks man, it's great to just drive the d**m thing and have the jackstands stowed away for once.

bastarddsm: Aaron could certainly comment on this better than me but I think you lose an additional 10-15%? Based on this, a guess would be around 500whp with a manual.
 
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Great numbers!

What are you using to control boost and did ER say anything about it? I ask because it seems to build boost slow for a 2.4l (25psi at 5.7k?) then dips/raises throughout the rest of the powerband. I would think that your setup would be at full boost around 4k and should hold to redline, is why I ask.

:dsm:
 
Corey: Thanks. Boost is controlled in Link with the IR 3-port solenoid using a fixed duty cycle. I have not had a chance to mess with the error correction yet.

The logged OMNI 4-bar is a better measurement of actual boost and it is stable over the pull. As you can see we didn't go WOT until 5300rpm to prevent a downshift. Typically if over 35mph it won't downshift into 1st but Aaron just leaned into it to make a clean pull. There is a leak before the wastegate but the spool is good on the street. With the converter stalling between 4200-4500rpm the motor is loaded different but I usually see full boost around the stall speed. Autos are weird. :hmm:

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I see, thanks for clearing that up. My car started as an A/T but I never put it up on the dyno until after the M/T swap. Lets see a 1320 pass in 11's or less now! :thumb: :dsm:

The tracks should open up in March so I have to wait a bit. I'm probably going to run this tank of e85 out and switch it to pump for the rest of winter. I'm curious to see how the 2150s behave. Boost will probably be ~15-18psi on pump. I'm not sure what I can get away with considering the higher compression.

I have a clattery lifter on startup when cold it clacks pretty bad. I've pulled the valvecover and it looks like the #1 exhaust lifters bleed down. I can still hear a faint clack with a stethoscope when hot, which might explain some of the knock noise. I might pull the cams and replace lifters. :dsm:
 
Can that tool be used with the beehive springs and Ti retainers? Not much of a ledge to push on.
 
To answer a few questions I noticed.

Stock converters chew up between 11-12% power in a DSM over a manual. This is restalled so I was estimating 15% (4500rpm) where something like Jeff's is 22% (dyno proven).

As autos make more power the flash on the converter goes up with the power. I was rolling into this slow just to make sure it wasnt doing anything I didnt want but thats not abnormal. In the Evo we just swapped to an Auto it looks like it lost 1000rpm but its just the converter taking that much more time to approach converter efficiency and "lock" up hydraulically. As a sidenote, it is on a stock converter and "lost" 13% power.

This combo on a manual would be high 3s or low 4000 spool I would presume.
 
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I had a compounding transmission failure due to gear fatigue from a bad pattern created on the transfer gear when the previous owner installed the gear backwards. It had an audible decel whine from the start that went away after about 8,000 miles. I meant to check the transfer gear but didn't get around to it. It was coasting when a tooth let go on the transfer gear, took some teeth off the center diff and half a tooth off of the main gear. Also, one of the planet gears lost half its teeth from debris.

Thankfully the case was salvageable and with the help of Mark @ Metro Transmissions I got a new complete gear set that was sent to be cryo-treated. I got the transmission back in yesterday and I just have to put everything back together and it will be back on the road in a few days. :)

Note: Helical gears have a rolling contact, when the contact is bad it becomes a sliding contact. The sliding contact wears a groove in the tooth creating a stress riser and eventually..boom Every tooth on the transfer gear has a little divet worn into it where it failed.

I will post up some carnage pictures later, I'm just thankful it didn't fail on a test run or while under load, or it would of destroyed the case for sure.
 
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