Figured id share this overlay of S2's vs S3's on a large build. Steves car is still being dialed in (ill share once we up the boost 40psi+), but this is interesting data to share for others to see for now.

This is the S2's back in 2012 on the car vs the S3's now on the car in 2013 that was done just a few days ago. Nothing has changed other then the cam swap on the car & of course boost lowered.

ECU: stock ecu + tephra v7 SD / ecu boost
Fuel: E85

The mods on this car are:

Evo 9 GSR
MAP 2.3 Block with Wiseco HD Pistons, Manley TT Rods, Manley Billet Crank
GSC S3
Kiggly Valve Springs and Retainers
Buschur Ported Intake Manifold
Buschur 65mm Ported Throttlebody
MAP Top Mount Turbo Kit with Precision 6466 Turbo and Turbosmart Hyper-Gate 45
MAP 3" Downpipe, Invidia Test Pipe, Greddy 3" Cat-back
ETS 3.5" Intercooler
Buschur UICP with Turbosmart Race Port BOV-VTA
Spoolinup COP
Denso IKH24 Plugs- Colder
FIC 2150cc Injectors
Aeromotive FPR- 43 PSI Base Pressure
AMS Fuel Rail
Buschur Double Pumper
Grimmspeed EBCS with larger 1/4" fittings

Graph:



I can't say the results don't surprise me. its the same stuff as before from the 2.3 and 2.4's. not really any loss downlow, but tons of gain top end.

theres a difference of 4-5psi right there, and the s3's are dead on with the s2's. this car should be nasty with 42psi on the s3's.

heres what the engine bay looks like for those interested in the map top mount kit:

 

wow i'm glad i picked up the s3's instead of the s2's lol, I can only imagine how mine is going to react from stock cams to the s3's. nice comparison Tom.

 

The car feels great on the S3's! I can't wait to get the boost back up. Thanks Tom!

 

Maybe its just me but I see that the s3's are making less power. I'm sure its due to the lowered boost. How much did you lower the boost by?

 

he's showing that even with 4-5lbs of boost less, the s3's still are within 10whp of the s2's

 

ahh ok. Thanks for the info

 

I don't have the logs with me right now, but I believe the timing was also less aggressive in the S3 tune. This was the first WOT log on the S3s. The 6466 really seems to start making power over 40 psi. It should be over the 800hp mark at 42psi.

 

Thanks for the info, here are some observations I have on the comparison.

There is a significant amount of power left on the table in the AFR through the mid range on the S2 cams. Unless the motor is so on-the-edge that it needs to be that rich to avoid detonation, I've seen 20-30 Ft-lb gains at those power levels on E85 going from ~10:8 to ~11.5 AFRs. Also, based on the dates on the graph, the weather conditions look to be about 2% different, in favor of the S3s. These two combined could easily mean there is a 40-50 ft-lb difference from 5000-6500 RPM range that isn't being fairly shown here.

In the end, at the same boost level, I imagine the S3s are going to be right there on mid-range though with the S2s and then significant gains on top. This chart just makes the loses look less significant then they likely really would be in a more back to back comparison with the different boost levels.

 

no problem at all

on paper you would expect the s2 to spool alittle quicker than the s3 downlow yes. however i do have 10~ back to back s3 vs kelford / s3 vs stock evo 8 cams / s3 vs stock evo 9 cams, s3 vs hks, s3 vs s2, etc. they always surprise you at spool area by not losing much on the larger stroker applications.

now on the 2.0L lets say you go from a s2 to a s3 or kelford to a s3 on a bigger setup, you get around a 400RPM lag and it hurts the low end quite a bit on a larger turbo. but the top end comes alive big time. I've got a back to back with Scotts car on kelford 272 vs S3 and it hurt downlow a lot. I cant find it though. that was with the 6266 and 2.0L. so on a 2.0L it will kill the low end depending on the cars mods.

so what you may think is going to happen downlow on the comparison most likely won't because of the larger 2.3 displacement here.

heres a stock cam evo 9 fp black car 2.4 vs dropping in s3's for example: (stock size valves and unported head)



same boost, same afr, and temp within 5F of each other.

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regarding the afr changes on the 6466 overlays. its because that was only like the 3rd WOT pull i believe on his car at the time on the s2's. i start on the richer side then lean it out as im tuning the car. ive never had a car where i couldn't lean it out on e85 before.

 

Thanks. its not 100% back to back by any means, but it does show the s3's work great. thats all i wanted to share really. in a technical standpoint it should be done on the dyno for the best back to back feedback with no interruptions in a controlled environment & weather temp staying the same as 03whitegsr is suggesting.

Thanks Steve! boost up and its going to fly! I hope over 800, but i don't think so at 42psi. but at 44psi definitely.

Pleasure is mine.

Sorry its alittle confusing maybe because of way it was done. the bottom part of the dyno graph is the boost curve, the s2 was running 42psi, while the s3 was only running 37psi , so if you add the boost back to the s3 you will have about a 40-50whp gain and that would be the difference in the cams as far as peak power goes. maybe even 60whp. it just depends how restrictive the cams were being on his particular parts combination. i'm not going to put myself in the corner though, so i'm gonna just say at around 44psi we should see past 800.

I just looked, the timing is the same on both. the only thing we played with was the fuel map. i think at 44psi it'll do over 800.

 

Interesting...

It would be good for someone to do a similar compairson but with a set of GSC R2's thrown in the mix!

 

Out of curiosity what sized housing on the 6466?

 

.82 v-band

 

I think you misunderstood what I said. We are on the same page though, in a back to back with the same boost level, the S3s will match torque and spool of the S2s while gaining a ton up top. It is a very impressive result.

That's what I figured. I've tuned above 45psi on E70 and it still reached MBT without detonation. Just thought I would ask why it was so rich.

 

same boost level would be better.