Dispelling Myths about the G54B Bottom End!!!

[lionbull]

the idea that the stroke of this engine is someone hindering it any way is as an idea that belongs in the 80s just like those who think backpressure is a good idea on a turbo car.

 

my car made over 300hp at 7000rpm and on my next tune i bet it will make 350. our heads flow plenty enough.

 

there is only one and only one reason that other engines make more power than ours. its becasue they came MPI originally and a lot more research, testing and money went into them vs. what we experiment with in our own garages every once in a while, or else our engine hardware is just as good if not better than their "powerhouses"

 

if there were 5000 shops modding G54 instead of the G63, I bet it would leave that engine in the dust even with it extra 8 valves.

 

 

 

you can have all the valves in the world but if the engine isn't singing to a good tune, it won't be worth listening to.

 

 

 

amen

 

It's simple...

 

The displacment of this motor is based on a longer stroke, that longer stroke/ smaller bore limits valve size and the maximum RPM.

 

The question is would it help to reduce the stroke? IMHO no...

 

What would be better? A larger bore and head to match.

 

The big picture? The maximum HP you can make per CI may be lower but its a larger motor than most fours so its less of an issue. You would care if you were racing in a class that had a CI per pound factor.

 

For the street, bigger is better.

 

It is correct that most of a motors potential is in its breathing. And the factory left us plenty of room to improve. For its time the turbo system was good, that was a long time ago.

 

The intercooler pipes are small, the exhaust very restrictive are the two biggest weak points... and The EFI is limiting.

 

The good points of the 2.6? Very strong block, strong rods, strong crank, OK cyl head. You dont need to do a whole lot to keep this motor in one piece.

 

No block supports are needed , closed deck, lots of iron.

 

What would a 4 valve head get us? About a 15% increase in valve area and better port geometry. So the flow increase would be signifigant. The upside is the motor is 30% larger than most fours.

 

 

As an example:

 

However if a four vavle 2.0 can turn 9000 rpm (vs 7000 for a 2.6) and has a four valve head its going to be able to make more peak power (15%+ or more).

 

The upside is with a lower RPM motor you dont need as much cam, so its likely to be more streetable and have HP and TQ thats very easy to use.

 

Kevin C

 

I was blind but now I see the light

[xtremeboost]

I'm one thats staying with the G54 for my project !!!! I couldn't care less if I made the power at 8000rpm or 5000 rpms as long as I'm able to do it !!!

[Boosted_One]

If I was looking to make the most of the a Starion for competition I would probably swap in a 4G63.

 

The fastest current Starion is the 4G63 Buschur Starion that ran in the 9's.

 

I kept the 4G54 because I have had the car for 15 years and the 4G54 means something to me in that car, and it is something different than the norm.

 

I just wish the head flowed as nice as the 4G63 does. Don't tell me the 2V can flow the same because my port work is documented and levels above many here that will give an opinion as such.

[jinx]

you say "many here". Is there one single person on this forum who doesn't know that 4v flows more ? I hope they don't need a test to figure that one out.

 

I'd say "many here" don't see that head flow doen't even begin to tell the whole story of what happens at the rear tires.

 

Even if our head did flow more, what level of street performance are we after that a 54 hasn't proven already ?

If the goal is more torque in the mid to upper rpm range, we won't ever see that without "proper cam".

Might have to say goodbye to our low end tq tho

[xtremeboost]

i smell a build off in the air and a dyno test to prove the theories :twisted:

 

 

 

 

 

That would be nice to see !!!! I'll provide the Dyno !!!! 8)

[xtremeboost]

hey, ive got a NA 2.6 im building up for my truck we could throw into the mix too.

 

+.040, forged pistons, starion rods, SS swirl tipped vlaves, Non-jet valve head, weber 32/36 carb. lightened flywheel. its sopposed to have a 9.5-10:1 compresion on it when its all done. Cant run a turbo but could be nteresting to see what it could do with out one.

 

 

would say ; at that compression level you'll be lacking tons of power ! If I was building an N/A 2.6 I would run no less then 11:1 or maybe better .

 

 

regards

 

Frank

[Chad]

the ralliart 16 valve motor origionaly had HKS high CR pistons with the stock rod/crank, made 240 HP. They changed the rods/crank for a different rod angle and slight de-stroke, and changed the dome on the piston to get to 270 HP.

 

if you want some dimensions, I have the origional set of HKS pistons, and one that is the higher compression prototype, it was labled as 11.5:1, but this was for the smaller chambered 16 valve head...

[tigertron]

I have been checking out some of the dyno sheets of the more powerful starquests here. From my observations the motor makes power too fast!! From 4500rpm the car has made 400hp and flattens out at 6000rpm and then power begins to taper off. Is this the same head flowing problem or is it the motor's design that is doing this. Is the solution a bigger turbo and NOS!!?? We just agreed the bottom end is solid right??!!

[cheaterparts]

hey, ive got a NA 2.6 im building up for my truck we could throw into the mix too.

 

+.040, forged pistons, starion rods, SS swirl tipped vlaves, Non-jet valve head, weber 32/36 carb. lightened flywheel. its sopposed to have a 9.5-10:1 compresion on it when its all done. Cant run a turbo but could be nteresting to see what it could do with out one.

 

If its any help with your N/A build I run one in my hillclimb car here in aust

that is being rebuilt atm

old spec

twin 45 mm DCOE webers with 41 mm chokes

magna head some porting

cam adv in 296 deg - 267 deg at 0.050 103 lob cent 0.471 valve lift adv ex 310 deg - 267 at 0.050 110 lod cent 0.473 valve lift

9.6 : 1 comp lightened astron 1850 flywheel

4 into 1 header 1 3/4 primarys 32 " long to collector and 2 1/2 " system

140 rear wheel hp with a good spead of power 3000 - 7000 rev range

and will still pull cleanly under the cam from 2000

 

new spec

quad 50 mm T/B with prob haltech computor and multi coil

magna head with more porting

same cam as above

11 : 1 comp with up 0.060 flat tops

lightened crank polished + peaned rods

10 pound billet flywheel 10 1/2 ring gear

same headers as above although I would like to try some with 1 7/8 primarys

 

cheater

[cashsaudio]

I don't know where you guys been but the most HP I've ever seen outta a any 4cyl is this car with the G54B motor 868HP that runs mid 7's yea its not a street legal car but you guys always want to see HP but nothing going to be street legal.

http://www.sakuramotorsports.com/

[heefner]

I don't know where you guys been but the most HP I've ever seen outta a any 4cyl is this car with the G54B motor 868HP that runs mid 7's yea its not a street legal car but you guys always want to see HP but nothing going to be street legal.

http://www.sakuramotorsports.com/

 

Brent Rau

The car, a radical tube chassis Mitsubishi Eclipse, on alcohol under full boost producing 900 horsepower from the 2.0 liter 4G63.

Best e.t.: 7.36

Best speed: 184.55

[cashsaudio]

I just remember my buddy told me that there is a 2.3 ford that has 1000+ HP with a supercharger compressing air into the turbo to help spool it up. But the most HP outta a G54b is 868HP

[artinist]

I am pretty sure there is a shop that has a 1000hp street driven evo.

 

I cant remember their name. AST or something like that.

[Boosted_One]

I don't know where you guys been but the most HP I've ever seen outta a any 4cyl is this car with the G54B motor 868HP that runs mid 7's yea its not a street legal car but you guys always want to see HP but nothing going to be street legal.

http://www.sakuramotorsports.com/

 

We've known about Sakura for years, and the $20,000 - $40,000 custom billet head it needed to do that.

 

Yeah...brent rau has the fastest 4 banger... 4g63...

 

http://videos.streetfire.net/search/rau/0/...6A2C1E94DE7.htm

[chrisviper]

A turbo engine is just a normally aspirated engine with positive manifold pressure , right ? The VE curve of a turbo'd motor will follow that of it's NA brother , just multiplied by what ever pressure ratio is at hand .

 

So my approach to making big power is this . Make the motor as efficient as possible ( i.e. make as much NA power as possible) then add a turbo that matches the motor (at what ever pressure ratio you have in mind) , and tune away .

 

We got Ivan's car fired up last night . Soon enough we will test out my "power curve" theory . It was too late to drive it much , but I will say that I am amazed at how fast a gt35r spools on a starion .

[Siance]

Awesome vid! When building a fast car the head is the heart of what your trying to do......Remember the head is power the bottom end is reliability!!! sure it's posible to make lot's of power with a 4v head or with out....either way you look at it, a engine is a pump the more air in and out will net big gains...The g54b is not meant for reving 8-9 grand, would you want to rev like that with a engine with a stroke as big? i wouldn't.... the perfect street g54b would have a redline to about 7000 rpm making 500hp@7000 575tq@3500 rpm talk about something that would shread tires with ease!!! I think t4 turbos are a start....mabye some more research with the 2g magna head....And mpi is off to a good start already... I want to do a 4g63 swap but maybe this thread can change my mind :wink:

[eeaston]

A turbo engine is just a normally aspirated engine with positive manifold pressure , right ? The VE curve of a turbo'd motor will follow that of it's NA brother , just multiplied by what ever pressure ratio is at hand .

 

Kind of depends on whose definition of VE you're using. Most define it as the mass of air that enters the cylinder divided by the mass that the cylinder would theoretically hold at the same pressure under static conditions. That aside, the VE of an NA G54B will differ from its turbo counterpart because of different valve timing, more restrictive exhaust tract, etc.

 

You're dead on with the max efficiency idea. People that say that porting, intake and exhaust tuning, etc. aren't as important on a boosted engine are NUTS. Anything that increases efficiency will increase NA power and have an even greater effect in a boosted engine. The more efficient the engine is the less boost you have to run for a given power output, and of course the more power you put out at any given boost pressure.

[chrisk]

so if there is a 4v head for our car where can we get them? and does anybody on here haveone? info on it?

[JustPaus_88TSi]

No. Not gonna happen. Go 4g64/4g63 hybrid if you want displacement and DOHC flow capabilities. :wink:

 

 

Chad owns the HKS DOHC g54b.

[xtremeboost]

so if there is a 4v head for our car where can we get them? and does anybody on here haveone? info on it?

 

 

 

 

 

 

 

 

 

 

 

:wink:

[Vanishing Point]

I have been checking out some of the dyno sheets of the more powerful starquests here. From my observations the motor makes power too fast!! From 4500rpm the car has made 400hp and flattens out at 6000rpm and then power begins to taper off. Is this the same head flowing problem or is it the motor's design that is doing this. Is the solution a bigger turbo and NOS!!?? We just agreed the bottom end is solid right??!!

 

You will find the same problem with all 4 cylinder turbo engines. Different combos blur the line alittle, but basically its the same for all. Fast spooling small turbine turbos make power early in the RPM range, but plug things up at the higher RPM level. Torque peaks early. Since HP is a product of Torque and RPM HP numbers are lower.

Big turbine housings (A/R) slow spooling turbos make peak boost and torque later in the RPM range. Since HP is a product of torque and rpm HP numbers are higher.

Since torque is king on the street you can see which is better for a daily driver. HP takes advantage of gearing and will make your car faster and is better for a racer,but not as good on the road.

There is alot more to it, like cam timing, intake and exhaust velocity, Fuel, timing, and so on.

I believe Mitsubishi designed the 2.6 to make good low end power as evident of the small intake, exhaust, and turbo.

You can make more power by changing this stuff, but you are still left with the same head that was designed in the late 70s.

We are stuck with this head since there is no money in Starquests to lure engineering companies to make a better head.

 

Tony

[Vanishing Point]

If we are stuck with this cylinder head what can we do to improve power and drivability?

If we can not improve flow through the head maybe we can gain air mass with the same flow, ACTUAL cubic feet per minute.

In laymans terms MORE BOOST.

DAH, but to make more HP (More boost at a higher rpm) we need one of those slow spooling turbos that peak to late to have any useful power, and low octane pump gas.

 

FIP is using NOS to spool a huge turbo. That will help solve the problem, but cause a need for alot of bottle refills.

I like the idea of super charging. This can be done without the turbine headaches only the Compressor problems.

W/A injection and improved intercooling will help the octane pump gas problem.

 

I like the 2.6, but in the end its caught in a time warp forever. Best bet is to move on to newer engine designs, and product support with an engine swap.

You could have a V-8

 

Tony

[lonestarion]

i have always heard that numericaly square block are better for high HP.

look @ V8 specs not all are suare (bore to stroke wise) but most are very very close just like the g54. i never had any doubts these blocks couldnt produce BIG HP #'s, most people dont build the block the way it should for these #'s(O ring,balencing, & so-on). if we could get a complete head onto a flow bench, start out with porting. hundreds of hours could be spent just fine tuning the intake ports just to gain 5-15hp, the same with the exhaust side. when you max the flow out then start working on the cam. turbo'd engines love duration, lift doesnt really affect HP "to much"

in most cases some lift is needed, but rarely .500" is ever needed.

 

 

maybe we do need to mod the intake port floor?

 

maybe a 4v head is needed? it wouldnt be very hard to design us a new 4v sohc or dohc head. a few CAD programs can even flow test on the computer. check out www.cadalyst.com all kinds of cad programs from price ranges of $500-$8000

 

 

maybe we need to start bringing ideas from the dash engine,

3valve head from japan?

 

 

could we modify the jet valve to actualy be a 3rd valve?

 

the quest for more HP just doesnt happen over night. it might take sevral weeks,months or even a few years.

[tigertron]

If we are stuck with this cylinder head what can we do to improve power and drivability?

If we can not improve flow through the head maybe we can gain air mass with the same flow, ACTUAL cubic feet per minute.

In laymans terms MORE BOOST.

DAH, but to make more HP (More boost at a higher rpm) we need one of those slow spooling turbos that peak to late to have any useful power, and low octane pump gas.

 

FIP is using NOS to spool a huge turbo. That will help solve the problem, but cause a need for alot of bottle refills.

I like the idea of super charging. This can be done without the turbine headaches only the Compressor problems.

W/A injection and improved intercooling will help the octane pump gas problem.

 

I like the 2.6, but in the end its caught in a time warp forever. Best bet is to move on to newer engine designs, and product support with an engine swap.

You could have a V-8

 

Tony

 

 

They flow very well on the intake side. The problem is the exhaust. This is why i tell guys stop putting baby turbos on mpi equiped cars. An equal length exhaust manifold should then be employed with nothing less than a 60-1 PERIOD. Just watch your compresion ratio as I have come to understand most us of dont even know ours. This will need to be tailored to where your big turbo's sweet spot is or else eject your head/gasket to oblivion.

[Lidoidol]

this is from another forum

 

If I saw a functioning 42R on a quest I think I would get a chubby

 

seriously though, I want to be able to run a 6" megaphone back from the turbine into the downpipe... We have done some experiments with this design on DSM's snd supras and had pretty good results. My buddies 900whp 2jz supra is spooling about 600rpm sooner with the same T88 since we turned to this style... My goal is to run the biggest turbo possible while sacrificing the least bottem end...

 

My game is efficiency at this point. If you CC our intake runner and figure a theoretical flow rate at 100% VE, then compare to what it actually does flow, well I belive the VE of our stock head to be around 62% roughly... about the same as a 1940 -50's V8

 

I have a buddy in north florida thats going to cut apart a couple diff casting heads to see which he can raise the ports the most on... we are working in mm's and smaller. Porting these heads, while sure to improve performance (read: flow) to a point, is no comparison to the gains that could be made by raising the port floor and roof equally thus decreasing turbulence.

 

With our stroke, combined with the size of our ports, we have the ability to draw in massive quanities of air. And remember it is in fact air that makes Horsepower... the more air you can cram in a motor, the more fuel that motor can burn, The more horsepower it can make. Without the air, all you do is see pretty green lines on your pillar and black puffs in your rearview

 

Notice I am talking about the VE of the HEAD only