Top End..

[B4_Maniac]

Took my Leggy on a long 800 plus mile road trip this weekend. All highway traveling...played with the "Cruise Control" (wich I never use) and tried to get in touch with more of it's "GT" qualities. :o After the long trip..and and a nice speeding ticket.. (damn lead foot).. :x I have only two complaints... first.. I think my legs are too long for this car..I have my seat all the way to the back..and I felt kinda squashed in.. Plus, I felt that the engine didn't have much going on in the top end.. If you look at the Leg's dyno..you will see the "mountain of torque" in the lower RPM range..I wonder if some of that could be spread out and assist the top end of the curve. Or, would a nice twin scroll turbo solve this problem..

[Th3Franz]

I think it's the way the cams and turbo are set-up to provide lots of mid-range torque. It's physics-related where the top end will suffer a bit depending on how the car is tuned. I agree that I can feel that the torque dwindles a little bit at the top end of the power band, but it's not that bad. I think a turboback exhaust system would help a bit along with a reflash or engine management. But besides that, if top end was really that important, it would take some changes with cam timing and a different turbo, I imagine.

[Deer Killer]

[quote name='B4_Maniac'] Or, would a nice twin scroll turbo solve this problem..[/quote] Ding.. JDM take-off headers and a slightly larger turbo sounds like a good cheap kit.

[Th3Franz]

Yeah a twin scroll turbo or a header change would help too. Just keep in mind that with headers, what you gain in the top end usually takes away from the low to mid-range.

[B4_Maniac]

[quote name='Th3Franz']Yeah a twin scroll turbo or a header change would help too. Just keep in mind that with headers, what you gain in the top end usually takes away from the low to mid-range.[/quote] I liked what you said about the turbo back. Cuz, I think you can actuly save some of the loss that would come from the top.. What do you think?

[SUBE555]

I'm also going to say it likely has a lot to do with cams, timing and profile specific. For the 'average' driver the low end is what they use and more important to them. I should gut that up-pipe cat once the last race of the season is done. Will be able to see how that affects things then. I've been told it's very noticeable.

[B4_Maniac]

[quote name='SUBE555']I'm also going to say it likely has a lot to do with cams, timing and profile specific. For the 'average' driver the low end is what they use and more important to them. I should gut that up-pipe cat once the last race of the season is done. Will be able to see how that affects things then. I've been told it's very noticeable.[/quote] Hmm..I thought about gutting my cat..but I didn't know if it would be worth it. I was waiting for one of you guys to do that first. We need a forum "guine pig"..who wants to rise to the job?

[SUBE555]

A number of WRX guys have done it already, I think there may be something about it in the walkthrough section. Personally, it's worth just buying the gaskets instead of buying a $300 up-pipe, I'm waiting for Cobb's Accessport + Stage 1 reflash/stock reflash so I won't get a constant CEL. Try it with the stock map, then go to Stage 1 with that. I'm sure we'll see a nice difference in power response and drivability, likely that stutter will be gone too. :)

[B4_Maniac]

What stutter? I haven't noticed one yet.. Besides my shakey front end..I haven't noticed anything like that.

[Deer Killer]

[quote name='B4_Maniac']What stutter? I haven't noticed one yet.. Besides my shakey front end..I haven't noticed anything like that.[/quote] [url]http://www.legacygt.com/viewtopic.php?t=1808[/url]

[Driver72]

It's a "GT" car...it wasn't tuned for top end like a S2000 or something. It's also an AWD car. Pushing power through 4 wheels is great at lower speeds, especially launching of course, but that AWD works against us at higher speeds. The engine has to produce more power to propel a 3300 pound AWD car down the road at equal speeds to a 3300 FWD or RWD car. It's also a single turbo car. Most turbo cars are tuned for low and mid range power, where MOST of your driving will be. Not too many single turbo cars have top end power, I honestly can't think of one off the top of my head. Twin turbos work better there, where the second turbo won't kick in until higher rpms. The old Audi S4 is a good example. The WRX ran with it to 60 and even the 1/4 mile, but the S4 walked away from it after that. Unless you retune your car for more top end, or do other modifications...your going to have to live with not having great top end. The LGT isn't a car you are going to want to "race" on the highway with other similarly powered sport sedans (like an Altima SE) which have FWD or RWD only and have a lot more top end power. About the seating...I don't know how tall you are, but you must be over 6 feet. If having lots of room was important to you, you should of noticed that on the test drive, or gotten a larger car. Sorry.

[Drift Monkey]

[quote name='Driver72']It's also a single turbo car. Most turbo cars are tuned for low and mid range power, where MOST of your driving will be. Not too many single turbo cars have top end power, I honestly can't think of one off the top of my head. [/quote] Large single turbo Supras....are highway MONSTERS... It's really not HOW MANY turbos you have it's the flow characteristics of the turbo...

[Driver72]

True the supras were highway monsters, but aren't they twin turbos too? They also have another advantage...6 cylinders!

[B4_Maniac]

[quote name='Drift Monkey'][quote name='Driver72']It's also a single turbo car. Most turbo cars are tuned for low and mid range power, where MOST of your driving will be. Not too many single turbo cars have top end power, I honestly can't think of one off the top of my head. [/quote] Large single turbo Supras....are highway MONSTERS... It's really not HOW MANY turbos you have it's the flow characteristics of the turbo...[/quote] Agreed Monkey.. Driver72.. I know how the engine and engine management works, don't need a lesson in it. My whole original point (wich many of you cought right away) Was the twin scroll could have been a soltution for this. Seth did take it to another level (wich was cool) but, I was mainly wondering if the twin scroll would have given it the top end it needed or for the map to spread out some of the boost to add more to the top end. And yes, this is a GT car made for "GRAND TOURING" so, it should have good top end for sustained highway travel.

[SUBE555]

Um, Driver72, the Audi S4 didn't have a sequential turbo setup, it was a bi-turbo setup, meaning they work in parallel, one for each bank of cylinders. This is what I would imagine would be the best turbocharging setup for an H6 as it keeps the piping short and light. B4_Maniac, someone across the state from me just put a twin-scroll turbocharger setup on his WRX STi from the Japanese STi. He said it helps on both bottom and top end.

[mmanus88]

it just seems a little wierd to me that some of u guys are looking for torque all the way through, yet opted to buy the legacy, a [i]4cylinder[/i] car. why didn't some of you go witha solution with a car with a v6 or v8?

[B4_Maniac]

[B4_Maniac, someone across the state from me just put a twin-scroll turbocharger setup on his WRX STi from the Japanese STi. He said it helps on both bottom and top end.[/quote] Now, that is what I am talking about. I wonder what kind of increases he saw with the increased displacement. I would like to read a write up about that. I would love to see what a twin-scroller would be like on this engine.

[B4_Maniac]

[quote name='mmanus88']it just seems a little wierd to me that some of u guys are looking for torque all the way through, yet opted to buy the legacy, a [i]4cylinder[/i] car. why didn't some of you go witha solution with a car with a v6 or v8?[/quote] Two problems with that. One.. the letter V in front of the number. Two increasing the number behind the letter isn't needed to get strong performance. Its a shame that is the typical American answer or perseption of vehical performance.

[mmanus88]

sorry mr. master mechanic :o you don't have to be a wise ass about it. i was asking an honest question.

[B4_Maniac]

[quote name='mmanus88']sorry mr. master mechanic :o you don't have to be a wise ass about it. i was asking an honest question.[/quote] Sorry dude..didn't mean to hit a soft spot with you.

[mmanus88]

whether you were being sarcastic or not, i accpet your apology :lol: also, i am not your average americna car shopper. i may not have much detailed knowledge about the actual details and mechanics of cars, but i have been researching for the past 2 years, jumping from car to car and going from forum to forum. i know that bigger engine doesn't nessecarilly mean more performance at all; look at the lotus and subaru's own wrx sti. i thought you guys just wanted torque, i must of misunderstood. no doubt a bigger engine is the easiest way to more of that twisting power.

[B4_Maniac]

Apology was genuine! Its all good. Thats why we post on forums, so we can share the knowledge that we acumulate. B4_Maniac

[John M]

I'll bet the top end is "limited" simply because the car is making only 10psi at its power peak. Tweak the ECU and there's power to be had in other parts of the powerband. If the top end is being artificially limited, we'll find out at that point. Don't worry, I'm buying my Legacy very shortly. I promise I'll begin modding right away. It'll be stock only long enough to drive it home from the dealership. Warranty be damned!

[B4_Maniac]

[quote name='John M']I'll bet the top end is "limited" simply because the car is making only 10psi at its power peak. Tweak the ECU and there's power to be had in other parts of the powerband. If the top end is being artificially limited, we'll find out at that point. Don't worry, I'm buying my Legacy very shortly. I promise I'll begin modding right away. It'll be stock only long enough to drive it home from the dealership. Warranty be damned![/quote] I thought the turbo was putting out 13.5PSI.. If its not...thats a whole new can of worms.

[RobY]

[quote name='B4_Maniac'][quote name='Drift Monkey'][quote name='Driver72']It's also a single turbo car. Most turbo cars are tuned for low and mid range power, where MOST of your driving will be. Not too many single turbo cars have top end power, I honestly can't think of one off the top of my head. [/quote] Large single turbo Supras....are highway MONSTERS... It's really not HOW MANY turbos you have it's the flow characteristics of the turbo...[/quote] Agreed Monkey.. Driver72.. I know how the engine and engine management works, don't need a lesson in it. My whole original point (wich many of you cought right away) Was the twin scroll could have been a soltution for this. Seth did take it to another level (wich was cool) but, I was mainly wondering if the twin scroll would have given it the top end it needed or for the map to spread out some of the boost to add more to the top end. And yes, this is a GT car made for "GRAND TOURING" so, it should have good top end for sustained highway travel.[/quote] The stock ones are twin turbos... The really really silly fast ones have single turbos. Its not how many turbos its the flow rate of the one you got in there. Most people swap out thier twins for a huge single. If you REALLY want top end dont waste your time with any of the JDM varieties. Wait for sombody to frankenstein the VF40 somewhere along the lines of a PE 1820 or 1818. Or go the custom mistusbishi route with an 18g or a 20g compressor. Were talking upwards of 300-350 WHP with these turbos. I hate to admit it but Mistsubishi makes much better turbos than IHI. The 18g pushes upwards of 50% more air than a VF30 with not that much more lag. The 16G found on the mitubishi EVO and the SRT-4 spoolls about the same as an IHI VF34 heats up the air less and pushes about 150 more CFM.