Does anyone have any experience with keeping the stock turbo on a stroked (2.3L) motor? How much faster is the spool up? Does it run out of boost on the top end more noticeably? How is the driveability?

(by stock turbo I assume a 10.5 hot side).

 

prob like taking steroids and not going to the gym.. no sense strokin it unless you want to impress..

 

I been in a 03 Evo with a 2.0 built motor with a MR turbo. It has a lot of power and torque on the low end but once it hits about 5k rpm it doesnt pull any more.

 

the turbo will spool really quick and run out of steam early.

 

I am grateful for all of the input but I am wondering if anyone has actually done this yet? Speculation is nice but I would like feedback from someone who has experienced it.

 

He built it without cams? Or is the turbo getting out of its efficiency range?

 

it has everything including ported head etc...

 

I was wondering this too, but I guess the stock turbo would die too soon.

 

What would be the purpose of this? You planning on roadracing w/ n/a like response. No point in stroking to 2.3l if your going to leave the stock turbo on. It will run out of steam quicker than with stock displacement.

 

i would assume it would feel similar to a lightly modded sti

you probably wont find many (if any) people who have gone this route...if that tells you anything

 

VERY FAST spoolup but you may not be able to hold boost up top. It'll be a torque monster fore sure, easilly 400FP's very low.

 

I have seen a 14b on a 2.4 motor. Started making boost at 1800rpm. Fully spooled at 2100rpm. Actually very fast car from 2-5000rpm.

The 2.3 with the evo8 turbo would be a blast. It will spool the turbo 500rpm faster. The party will stop at about 6700rpm. With supporting mods it would make 400whp and 475 ft lbs

 

so the stroker kit will only help if upgrade to a larger turbo? T56 for example? For the issue of the top end rpm not pulling... can cams solve that issue easily? along with some form of engine management system?

 

I'm running a 2.3L stroker on mine with the standard evo4 turbo, and this comes with a 9T exhaust housing.

Great response and spool up, but I can't say anything about the top end as i've been keeping the revs under 5000.

I'm still running the standard computer and i'm concerned about killing the engine again (the reason why I went with a stroker).

I'm after quick response, low and mid range torque so thats the reason why I havn't chucked a larger turbo on.

 

Everyone so far is pretty right on when it comes to the stroker/stock turbo question.. You increase the displacement, and you cause a bit of a mismatch for the turbo size.. The 10.5t housing helps a bit, but you will need to perform some porting.

Spool will be very quick when combined with a TME type turbo, almost instantanious, but it will definitely taper at higher RPM, this is where other modifications to the turbo itself could be beneficial, clipping for example would help a bit in this situation since spool can be sacrificed in this specific instance.

The big issue with the stock turbo is the compressor, once you are at higher RPM with stock displacement, you get to a point where the turbo will no longer efficiently move air. Mostly it has to do with the compressor wheel, can no longer get air either through the turbo's inlet, or the slot (I think its called a nozzle on the compressor side too) or the outlet of the turbo..

What is very important is understanding that every change you make, has a relative effect on other things, which means you need to somehow increase the efficiency or ability of the stock compressor to move more air. I have made several modifications to a stock compressor 2005 Evolution MR cover, without changing the 16G wheel itself, which would likely help on a stroker motor simply because it increases the amount of airflow the compressor cover can handle, at the sacrifice of a bit of percieved spool (its not producing as much boost as fast, but in reality its actually moving a little more air) I was able to move a bit of material on the inlet, I honed the inside of the snail portion and outlet, and I increased the nozzle (slot that transfers the air into the snail portion). I have not been able to run any real tests on this turbo since my life is completely on hold right now because I'm in the process of packing, selling my house, and trying to find a house and convince my job that relocation IS a good thing... Anyway, This modified compressor cover was not any sort of accurate engineering voodoo, it was an "I have this part, and may be worthwhile to test" experiment. But In the end, I think I shifted the turbo's efficiency into a range where it can still produce acceptable boost at higher RPM without choking on a stock 2.0 motor, and probably be better matched to a 2.3l stroker...

I'm not a big fan of the aftermarket turbos, simply because I don't particularly like drag racing (Yes, even though I'm fairly good at it, I don't enjoy it, I use it as a method to test things) And most of the bigger turbos are just not all that much fun to drive every day on a smaller displacement motor, but thats for another conversation, and driving style, preference, and intended purpose are the biggest factors you folks need to take into account. Especially after seeing the King of all Evo's wreaking havoc in the midnight club, I can only imagine all of the new GT35r kits going out the doors, if you really want one of those, wait about 6 months, there will be tons of them for sale cheap.

I actually think that my end results may end up being similar to the Buschur 21G only without needing to replace the wheel, but I think the 21G turbo will probably produce significantly better high-rpm boost.

Engine management, and addressing inefficiencies EVERYWHERE is what makes power, you can bandaid a inefficiency with a big turbo, or you can make the entire system more efficient and not have the mismatches and sacrifices in drivability.