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Lately Ive been building quite a few turbos for people, And of course I get asked all the time about horse power, spool, and why certain parts options are better than others. So I decided to do a ton of testing this year on every turbo option and sizew I can possible build, even the ones people don't really want. Its very easy to compare some of the turbos I've built to ones on the market of identical size and specs, but I would really like to provide good data and actual results, while giving real back to back comparisons when switching turbos on the same vehicle.
So the Goal for this thread will be to show what my personal evo 9 will make with a bunch of different turbo combos at the same boost levels (25 psi) and using the same amount of ignition timing at peak torque and redline (2 at peak and 12 up top). Also will be testing different oil feed line and measuring oil pressure entering the turbo.
First we will start with what my car has done:
Engine: (just refreshed less than 1000 miles ago)
Standard 2.0 liter Curt brown Racing short block.
Bored .020" over Manley 9.0-1 pistons
150mm Turbo tuff rods ARP 2000 bolts
Curt Brown Racing Ported head
Stainless valves with Kiggly springs and retainers
GSC S2 (non billet) Cam
Curt ported intake manifold with standard Throttle body
Curt Ported FP race Exhaust manifold
MAP 2.5" LICP
ETS 3.5" intercooler widetank
ETS UICP 2.5"
Megan 02 housing
Megan downpipe
HKS sportback exhaust
walbro 450 fuel pump on stock wiring
FID 1000cc injectors
Transmission:
evo 8 Buschwhacker stage 1 standard final drive
RS transfer case
Comp stage 2 clutch
car roughly weighs 3100lbs with out the driver.
The car will be tuned on a MAF with a Tephra V7 rom by myself.
Things I will be monitoring that are important for the tests: (but will include all logs from testing)
-Boost pressure
-Exhaust turbine backpressure
-Turbo oil feed pressure (and will specify which type of feed line/restrictor sizes/and make of bearing housing as aftermarket bearing housings have different size oil ports and can effect turbo life on different feed lines)
I like to keep the fuel tuning pretty standard, spool up at 12.5, peak torque 11.8, and the rest of the powerband at mid to low 11's. I want the tune relatively the same minus adding or taking fuel away where needed between the different turbos.
The only changes I will be making to the car over these tests will be the turbo and types of oil feed lines when and if needed.(unless otherwise specified) Also im running on a stock intake pipe which will be changed out for an FP intake when I switch to the bigger compressor inlets.
Alright now that ive said all that, in the next post I will show results from the very first turbo I will be testing:
its an evo 9 turbo (cold side) that will be using an unported evo 8 9.8cm turbine housing. it will have an aftermarket wastegate actuator that is rated for 18 psi.This is to get the lowest baseline possible and to see how restrictive the 9.8 housing is over the 10.5 when used at the same boost level.
is this a bit much? yes, but for me its a lot of fun, and im sure there is lots of other people out there that would love the info. ill have the next post done here soon with the first results
I agree this will be a good thread if the testing results are comparable. It would be easier to compare if you could replicate similar conditions. I would think IAT and EGT data logging would be helpful.
IAT and EGT would be great as well, unfortunately I do not have those as of now. Also as much as I’d like to tune the setups to there max, I want the least amount of changes possible between setups. I would think leaving timing alone and making fuel and boost the same for each would be the best back to back comparisons, no?
Alright to kick this off I got my car on a local dyno jet of last weekend at PRLmotorsports dyno day. Only got 3 pulls in but I believe plenty enough to get the data I needed to open the door for any suggestions or questions that may help further testing.
this turbo is a Evo 9 cold side with a evo 8, 9.8cm2 turbine housing. Completely stock rotating assembly. Using as aftermarket 18 psi waste gate actuator. Also has the OEM intake tube on the car as well, with a 4.5" Green air take filter. The first run the car was spiking 2i psi and causing this massive torque spike then falling off, so for the second and 3rd run we toned it down to 25 psi and adjusted fuel as needed. Temps in the dyno room were hot, the dyno sheet says 97-99 degrees.
also this is on Sheetz 93 octane pump gas.
attached is the log from the last run (green line) the turbo seems to spike 25 psi and slowly fail off to 17-18. from what I've gathered this is just what the stock turbos do, even with tons of waste gate duty cycle, it wouldn't hold anymore up top, so I figure if I plan on running all these turbos to spike 25 psi, ill make them hold up to 25 psi as best as possible to redline (if possible) and should dictate the capabilities of said turbo over the one before. that said, ill be using the same waste gate actuator with the same preload.
Also attached is the back pressure video. My back pressure sensor is tapped into my #1 runner on the exhaust manifold, a few inches from the turbine housing inlet. Back pressure during peak torque/boost it would be around 18-20 psi, then fall some and build up fast once coming up on 5500-6000rpm and peaking at 32-34psi at 7500 rpm. That would mean of the turbo is making 18 psi at 7500rpm, and back pressure is 34 psi, thats almost 2 to 1 ratio, seems a bit overdriven? from what I've read thus far about back pressure a 1.5:1 ratio seems to a comfortable ratio for a street car but 2:1 is getting pretty bad from what most have in mind.
If link is not public please let me know so I can fix.
so any comments, questions or thoughts on this are very welcomed! I'm still thinking of pushing each setup to the knock limit, but at this point, showing each one at 25 psi I think would be best for comparison. maybe after the 25 psi runs are done, ill push each setup just to see what they can do. Pics in next post of my car and engine bay setup.
IAT and EGT would be great as well, unfortunately I do not have those as of now. Also as much as I’d like to tune the setups to there max, I want the least amount of changes possible between setups. I would think leaving timing alone and making fuel and boost the same for each would be the best back to back comparisons, no?
You can't leave boosts the same because it could be outside of a certain turbo's efficiency island and that won't be a fair comparison. It will favor snaller turbos. You will need IAT to show turbo's efficiency at different boost pressures. And tuning for max is one way to see the trade off (boost increase as power increases starts to taper off with hotter air temps). It shows the advantages of cooler air. It makes sense to add more timing and lean out lower boost in lower RPM range to compensate for the cooler air (that you can't consistently get with smaller turbos).
You can't leave boosts the same because it could be outside of a certain turbo's efficiency island and that won't be a fair comparison. It will favor smaller turbos. You will need IAT to show turbo's efficiency at different boost pressures. And tuning for max is one way to see the tradeoff (boost increase as power increases starts to taper off with hotter air temps). It shows the advantages of cooler air. It makes sense to add more timing and lean out the boost in lower RPM range to compensate for the cooler air (that you can't consistently get with smaller turbos).
Yea I agree if we take a look at compressor maps and flow rates at different boost pressures a turbo's behavior will be different at those efficiency islands. Meaning some IX turbo combinations would be more efficient at higher boost rather than at low boost.
In the end, though it's better to have the data rather than no data at all.
I would like to view the log on VD and I need the parameters for your Evo. Third Gear ratio? Tire Diameter? Stock Final Drive? Weight?
Yea I agree if we take a look at compressor maps and flow rates at different boost pressures a turbo's behavior will be different at those efficiency islands. Meaning some IX turbo combinations would be more efficient at higher boost rather than at low boost.
In the end, though it's better to have the data rather than no data at all.
I would like to view the log on VD and I need the parameters for your Evo. Third Gear ratio? Tire Diameter? Stock Final Drive? Weight?
stock transmission with stock final drive. Tire size is 235/45/17, and my car roughly weighs 3100. Also remember that log was from the dyno pull, not sure if that will make a difference in VD
You need to get a handle on your boost control, I've tuned hundreds of stock turbo cars without spikes like that.
I took a look at your log. Your wgdc tuning needs some loving. Correction is nuts too.
Same with AFR lean spike after the boost spike and drop...
Time to smooth things out.
thanks for the tips! I’ll def work on those things! I figured it just didn’t want to hold, but I’ll try my best to dial it in better. I did all my tuning on the street, and when I finally put it on an actual dynojet, things changed a lot, or atleast VD wasn’t showing how spiky the torque curve was
Alright to kick this off I got my car on a local dyno jet of last weekend at PRLmotorsports dyno day. Only got 3 pulls in but I believe plenty enough to get the data I needed to open the door for any suggestions or questions that may help further testing.
this turbo is a Evo 9 cold side with a evo 8, 9.8cm2 turbine housing. Completely stock rotating assembly. Using as aftermarket 18 psi waste gate actuator. Also has the OEM intake tube on the car as well, with a 4.5" Green air take filter. The first run the car was spiking 2i psi and causing this massive torque spike then falling off, so for the second and 3rd run we toned it down to 25 psi and adjusted fuel as needed. Temps in the dyno room were hot, the dyno sheet says 97-99 degrees.
also this is on Sheetz 93 octane pump gas.
attached is the log from the last run (green line) the turbo seems to spike 25 psi and slowly fail off to 17-18. from what I've gathered this is just what the stock turbos do, even with tons of waste gate duty cycle, it wouldn't hold anymore up top, so I figure if I plan on running all these turbos to spike 25 psi, ill make them hold up to 25 psi as best as possible to redline (if possible) and should dictate the capabilities of said turbo over the one before. that said, ill be using the same waste gate actuator with the same preload.
Also attached is the back pressure video. My back pressure sensor is tapped into my #1 runner on the exhaust manifold, a few inches from the turbine housing inlet. Back pressure during peak torque/boost it would be around 18-20 psi, then fall some and build up fast once coming up on 5500-6000rpm and peaking at 32-34psi at 7500 rpm. That would mean of the turbo is making 18 psi at 7500rpm, and back pressure is 34 psi, thats almost 2 to 1 ratio, seems a bit overdriven? from what I've read thus far about back pressure a 1.5:1 ratio seems to a comfortable ratio for a street car but 2:1 is getting pretty bad from what most have in mind.
If link is not public please let me know so I can fix.
so any comments, questions or thoughts on this are very welcomed! I'm still thinking of pushing each setup to the knock limit, but at this point, showing each one at 25 psi I think would be best for comparison. maybe after the 25 psi runs are done, ill push each setup just to see what they can do. Pics in next post of my car and engine bay setup.
I wonder if the back pressure is forcing your wastegate open at redline. 18 psi boost seems low. You have a better flowing intake, but I didn't expect that much drop in boost.
May 30, 2018, 03:23 PM
