Turbo recommendation for ~450 wtq? Stock location...

[fahr_side]

Nice result! Makes me 2nd guess my own choice of 8cm2 housing.

 

Regarding the tuning question... The dyno is an invaluable tool for finding things like MBT, optimal AFR and at what point you should stop turning up the boost. It's also the best way to tune AVCS timing as that's really hard on a road tune. TBH most customers only care about the peak numbers and accept some driveability issues as part of the parcel of owning a tuned car. Many even prefer rude and rough behavior at part-throttle or in spool because racecar.

To get really OEM-like smoothness in all conditions takes many hours of work, perhaps in quite different environments. For example I'll work on part-throttle boost tuning on a pass road, EL comps and fine injector setup on longer freeway trips and so on. This amount of work is not something a pro tuner and a customer can easily reach an acceptable price point on. I strongly encourage owners to learn how to interpret data and polish their own tunes. A pro tune is a great place to start but can always be improved on (in terms of smoothness) with more time and patience to tweak the small details.

 

 

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[need bb]

Great results. I am a little surprised the Dom 2.5 doesn't make much more power up top compared to the 1.5.

[jcole05]

Great results. I am a little surprised the Dom 2.5 doesn't make much more power up top compared to the 1.5.

 

I know. It DOES finally catch and surpass it at the very end but I agree that the shocking performance of the Dom1.5 with the larger 10cm exhaust housing, while hopefully useful/valuable to others choosing a turbo in the ~47-50 lb/min range, is almost certainly related to the very specific details of my build, ranging from the camshaft chosen, maybe other things like my higher CR pistons, etc. etc.

 

I mean, the general adage is that a larger A/R should lead to more peak power but less low/mid-range (although the guys at PRE were discussing situations where this isn't true and my car is obviously one of them).

 

I had a good feeling that the Dom1.5 10cm would be the best compromise for my car but had NO expectations that there would be NO compromise at all. Actually minimally BETTER spool up compared to the 8cm with a fatastic power band and >30whp more power.

 

Sometimes when doing these builds, I guess we just have to say

[joeleodee]

When you get the car back, go back to the 50-80, 60-80 acceleration thread and post the updates.

 

Edit: Nevermind, won't work. You have a 6 speed now.

[fahr_side]

Great results. I am a little surprised the Dom 2.5 doesn't make much more power up top compared to the 1.5.

 

 

Me too, but it could be that the higher the air flow goes the more his UEL header holds him back. I also expected the bigger snails to take better advantage of his cams but that doesn't seem to be. Theory only gets you so far!

 

 

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[jcole05]

Me too, but it could be that the higher the air flow goes the more his UEL header holds him back. I also expected the bigger snails to take better advantage of his cams but that doesn't seem to be. Theory only gets you so far!

 

 

Sent from a device using some software.

 

Fahr - does it make theoretical sense at all that the larger exhaust housing would help? Not even talking about the magnitude of effect but just that there was a positive benefit at all.

 

PRE tends to think that it has to do with allowing my GSC S1 cam to help a bit through the midrange while (as the testing of the nine turbos seems to show), the smaller exhaust turbine helps down low.

 

In terms of horsepower restrictions up top, I have no doubt my midpipe resonator is affecting it somewhat as I lost about 5-10 hp even on my 16G once I installed that (but gained about 5wtq and 100-150rpm spool). I also have no doubt that the header is also playing a factor as even the optimistic Tomei ELH vs UELH graph shows a loss up top with the UELH. Finally, we may be getting into the range where my catted downpipe comes into play, or maybe my y-pipe(?).

 

I just read through Jackal's entire thread on the 5th gen forum - man what a nightmare and realized - a lot like in medicine - that for all we know there is a whole lot we don't know.

[jcole05]

When you get the car back, go back to the 50-80, 60-80 acceleration thread and post the updates.

 

Edit: Nevermind, won't work. You have a 6 speed now.

 

I know man. Had already wanted to do this bc if these dyno #s are correct those 50-80 and 60-80 times would have been ridiculous. Like you posted in that thread, I really wish it was more active as I think that says a lot about at least a certain kind of power ( which I happened to care a lot about).

 

Maybe I can find some sort of conversion factor and post but I bet it will be more complicated than that.

[fahr_side]

The testing that Top Speed did showed similar results. If you're always running E85 the 10cm2 housing seems to be the way to go. On pump gas you'd see some difference in spool I think.

 

Props to PRE for sticking with this to the bitter end and going above and beyond the call of duty to make you happy!

 

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[Rhitter]

How does the car feel on the street?

[gkinslow]

What does the butt dyno say??

[jcole05]

It is killing me to wait but due to the Portland International Auto Show being this weekend, most of PRE was out of the office. Today they are putting in my carbon fiber drive shaft, putting on some new tires and checking that I'm all good to go. Hope to have it this PM but recognize that with the way things go it could be tomorrow.

 

I will give feedback and try to get an airboy too, just to compare to my prior Tomioka plot which I posted somewhere about page 4ish...

[jcole05]

Update isn't a good one. Can't complain compared to some other sagas I've read here on LGT.com but A) somehow my carbon fiber driveline was made 2 inches too long and B) the spec B 6MT that they sourced appears to have been sold by someone lacking a sense of integrity as it is performing very badly I hear.

 

Going to meet in person tomorrow to discuss options. So still haven't driven this sucker.

[rebourne]

And this is where Season One of the Netflix LgT exclusive series "450ftlbs?" ends with a cliffhanger!. Stay tuned for Season Two!

 

Edit: Dood! That sucks^2!!

[jcole05]

Update. New tranny has been sourced. The current one is drivable but A) makes a horrible whining bearing-like sound all of the time and B) twice now has led the car to start shaking uncontrollably, lose power with the check engine light flashing, etc. until it finally both times has righted itself after ~15 seconds.

 

Luckily, the owner of PRE was in the car with me the first time and the tuner also experienced this more severe issue in a test drive. So they are clearly going to help me get a new used tranny at limited cost to me. One they found was a nice low mileage 2010 STI but I just dropped too much money to now have the spare change to also install a DCCD, control knobs, etc. So another spec B tranny here we come.

 

Have plenty of graphs to upload once I get a small break from work work work.

 

However, the early report is holy *%&^. Like the dyno states, this car has some frightening power. I've never experienced torque 'steer' like this when I'm going in a straight line. Feels like a wild animal that needs to be domesticated. Finally, when I made the mistake of flooring it in second I said to Jason, 'well...there goes my clutch' since the needle shot essentially immediately to redline. He said, 'nope, that's just how fast it gets there even with the clutch intact.'

 

I am bummed about the delay on the CF driveshaft and the tranny issue but am confident that both will be fixed in two weeks or maybe slightly less. Until then, it is killing me to baby it a bit since I didn't like the car going into a version of limp mode (Jason thinks maybe the severe tranny vibration and gyration might have triggered misfire and/or knock sensors). But safety comes first.

[boxkita]

Update. New tranny has been sourced. The current one is drivable but A) makes a horrible whining bearing-like sound all of the time and B) twice now has led the car to start shaking uncontrollably, lose power with the check engine light flashing, etc. until it finally both times has righted itself after ~15 seconds.

 

Luckily, the owner of PRE was in the car with me the first time and the tuner also experienced this more severe issue in a test drive. So they are clearly going to help me get a new used tranny at limited cost to me. One they found was a nice low mileage 2010 STI but I just dropped too much money to now have the spare change to also install a DCCD, control knobs, etc. So another spec B tranny here we come.

 

Have plenty of graphs to upload once I get a small break from work work work.

 

However, the early report is holy *%&^. Like the dyno states, this car has some frightening power. I've never experienced torque 'steer' like this when I'm going in a straight line. Feels like a wild animal that needs to be domesticated. Finally, when I made the mistake of flooring it in second I said to Jason, 'well...there goes my clutch' since the needle shot essentially immediately to redline. He said, 'nope, that's just how fast it gets there even with the clutch intact.'

 

I am bummed about the delay on the CF driveshaft and the tranny issue but am confident that both will be fixed in two weeks or maybe slightly less. Until then, it is killing me to baby it a bit since I didn't like the car going into a version of limp mode (Jason thinks maybe the severe tranny vibration and gyration might have triggered misfire and/or knock sensors). But safety comes first.

 

you have a pm about that 2010 sti transmission.

[fahr_side]

You can run a DCCD trans without a controller btw. It stays at max rear bias the whole time. Get the controller later. With this much torque, it's really useful.

 

 

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[BrianEarlSpilner]

I didn't see this link referenced but PRE did a write up as well.

http://preracing.com/stock-location-turbo-showdown/

[rebourne]

I didn't see this link referenced but PRE did a write up as well.

http://preracing.com/stock-location-turbo-showdown/

 

That's a fantastic, no nonsense article. I'd want to overlay the hta71, steam 67+, and the two 1.5s, all at 21psi.

 

One thing that struck me was the huge gains the 10cm 1.5 has between 21 and 25 psi: 40hp, while the 67+ only made 6, and the M8265 17.

 

Be really curious to see a 10cm 3" inlet 2.5xtr!

[fahr_side]

Note the same sort of difference (22hp) on the 8cm XTR

 

And for readers getting XTR fever: http://legacygt.com/forums/showthread.php?t=247910

[cBax]

^^ Why did I buy a new vf52? At least my 5EAT's death will be postponed a little. I'm holding off on the TMIC upgrade because I'm trying to talk myself into a FMIC. After that, I may have a low mile VF52 for sale..

[jcole05]

I didn't see this link referenced but PRE did a write up as well.

http://preracing.com/stock-location-turbo-showdown/

 

Lol they told me they were writing it up but didn't mention it was online yet.

 

Guess I don't have to post all those 19-21psi graphs now! Thanks for posting.

[Rhitter]

PRE seems like a pretty good shop. I am very impressed with how they have worked with you Jcole.

 

Curious as to what their rational is for UELH v ELH though...

[jcole05]

As promised, here is a Virtual Dyno view after I've driven my car a bit. I went ahead and plotted this in Virtual Dyno mode and not dynojet even though the latter makes the numbers look even better. Either way, the turbo comparison still stands in terms of relative numbers.

 

Here is the Tomioka GT28 after my engine build as compared to the Blouch 1.5xtr 10cm with added EWG and FMIC. Of course I had to alter the parameters to account for my new 6 speed tranny so I used the VD choice of a spec B wagon in 3rd gear but adjusted the weight accordingly. I then altered tire height as my new tires are 245/40/17s versus prior 225/45/17s.

 

First is the combination plot, then just the new Blouch alone.

 

The difference in power and torque are fantastic of course, but it is the difference in spool WITH those other features that I care most about. Between now having a 6 speed AND the better spool, it feels like a whole new car even under partial boost.

 

 

 

 

 

[rebourne]

^^ Why did I buy a new vf52? At least my 5EAT's death will be postponed a little. I'm holding off on the TMIC upgrade because I'm trying to talk myself into a FMIC. After that, I may have a low mile VF52 for sale..

 

Depends on what you paid for it, and your goals, right? You have all the fueling and hexamods? Getting retuned on the bigger turbo once you get all that supporting stuff is a small price.

 

I need to get Moore blast plates, robust clutch, and a 1000cc top feed setup to run one of these bad boys. OR! I can run a VF52, still make big gains over stock, not destroy my clutch and start collecting the above goodies. Eventually the VF52 would be for sale... Or maybe with an elh and corn the 52 will be all I really need?! Keep the 5MT, reasonable effort clutch, etc.

 

I'll have to look/hope for some Dom 1.5 dynos on pump 91, and see what that looks like compared to a healthy vf52 on E85.

[jcole05]

A bit off topic but had an appt today and was chatting with my doc about cars. He said 'want to take my R8 for a spin?'

 

Never driven a near-supercar before. While it doesn't have the wild animal feeling of my car when that torque peak hits, it simply kills it in handling, braking and, no-surprise, all around fit and finish. Maybe should have just said no lol.