The Top Mitsubishi Galant VR-4 Resource

Join the best E39A 1991-1992 Mitsubishi Galant VR-4 community and document your GVR4 journey.

  • Software Upgraded - Reset Your Password to Login
    In order to log in after the forum software change, you need to reset your password. If you don't have access to the email address you used to register your GVR4.org account, you won't be able to reset your password. In that case, follow the instructions here to regain access to the forum.

4g63 limits question

ma70t

Member
Joined
Oct 7, 2010
Messages
10
Location
springfield va
my current set up is a key driver stage3 chip and my motor is on pte 50 trim turbo hks 40mm external waste gate, safc,avcr ,walbro pump 3g mas #482 not the #609 and 720 cc injector how much boost can i really run?? so far im at 1.5bars with no knock yet the motor has cams valve spring retainer and arp head stud but im still on stock fuel regulator im asking this to see what the senior member think about this cause they got more experience with 4g63 i been tuning 7mgte for almost 10 yrs now and i have push the stock ct26 beyond its limits my supra is still boosting a little over 21psi on stock fuel pump and system im waiting for the turbo to grenade itself so i can put my sp61 on but so far nothing haha but i really need some opinion on my #266 galant please dont trash talk or tell me i cant do it cause im doing it i just really want to know the limit to the stock fuel system im open to advice thanks for reading /ubbthreads/images/graemlins/smile.gif
 

cheekychimp

Well-known member
Joined
Apr 19, 2004
Messages
7,333
Location
East Sussex, U.K.
Yeah, if you have a good working pump, the 4G63 fuel system is actually very, very good. I think people have run 500-600 hp on essentially a stock system just using upgraded pumps and injectors. So I tend to agree with the post above. I think poor tuning of the engine due to a lack of proper fuel management is more of an issue. There is nothing wrong with the Keydiver Chip and S-AFC combo, but I presume your chip was programmed for 720 cc? You can probably put in 1000cc injectors and with enough pump still be okay, but your hardware won't allow you to tune for those changes well. Put in something like ECMLink and I think there is a serious chance (as suggested) that you will run out of turbo before you run out of fuel ... unless your pump takes a crap.

Kind of depends on how stock you keep things, I mean 'technically' putting bigger injectors in is cheating right? If you keep stepping up injectors on the car and change nothing else then I say the Walbro will become the next weak link together with the stock fuel filter restricting flow. 'Technically' the Walbro is not STOCK either /ubbthreads/images/graemlins/wink.gif
 
Last edited:

jepherz

Staff member
Joined
Aug 8, 2004
Messages
7,877
Location
KC, Missouri
Quoting FavNumber:
I think the keydiver and safc is holding you back. If you get ECMlink you can run as much boost as you need for a 50trim.

I see you're in springfield, there is guy in Fredericksburg who can tune the 4g63 with no problem. Do you go to the RevX meets or the VArides meets?



First, he never said he was using a keydiver chip, which if he isn't, that's a problem. Second, can you explain why you think a keydiver chip would even be holding him back if it was setup properly?
 

Terry Posten

Well-known member
Joined
Dec 16, 2003
Messages
9,009
Location
Davenport, Iowa USA
I just went ECMLink V3 with speed density (used to have keydiver/SAFC/482 MAS). I only have a Walbro 255 pump, 750 injectors, and all the supporting mods.

I made a safe 445 crank HP (361whp) on 93 octane at 18psi (zero knock - street tune). Was told to expect at least 100 more whp with C16 running around 28-30psi.

Click on the link in my sig below to see the dyno graph and vid if you want full specs.
 
Last edited:

ma70t

Member
Joined
Oct 7, 2010
Messages
10
Location
springfield va
i am using jeff key driver chip and i must say its very nice to have the knock sum light it came up on me one but since the safc i added more fuel in that rpm at wot and never came back since. seem like the more i push the boost the closer i get to blowing it up i feel like pushing this car futher and futher is like playing with a double edge knife like it could go on me at any giving moment
 

turbowop

Well-known member
Joined
Apr 29, 2001
Messages
11,971
Location
Yakima, WA
The Keydiver "ceiling" can be removed and raised by reburning the chip. I wouldn't say it's "holding him back". I'm still running a Keydiver chip and have run several different ones throughout the years.
 

jepherz

Staff member
Joined
Aug 8, 2004
Messages
7,877
Location
KC, Missouri
Quoting FavNumber:
Quoting jepherz:
Quoting FavNumber:
I think the keydiver and safc is holding you back. If you get ECMlink you can run as much boost as you need for a 50trim.

I see you're in springfield, there is guy in Fredericksburg who can tune the 4g63 with no problem. Do you go to the RevX meets or the VArides meets?



First, he never said he was using a keydiver chip, which if he isn't, that's a problem. Second, can you explain why you think a keydiver chip would even be holding him back if it was setup properly?



Like Paul said the keydiver is most likely for those 720 injectors so it cant evolve with his car/mods if he was to step up to lets say 1000cc inj and 20psi on that 50trim. I had a stg 3 keydiver then i got some 1150cc injectors so guess what...out goes the keydiver chip in came V3. Keydiver is nice if you're going to keep things the same but OP sounds like he likes push turbos to their limit. My keydiver stage 3 isnt going to work very well with these 1150's and this fp green i plan on running 25+ psi on 93oct gas with. The keydiver has a ceiling and thats is why it is holding him up.

Quoting ma70t:
my current set up is a key driver stage3 chip



I'm pretty sure he said the car was setup on a keydiver chip too...^^^^



My bad, I searched for "diver" and the OP spelled it "driver" /ubbthreads/images/graemlins/rofl.gif Given that he mentions it in the first sentence makes you wonder why I needed to search at all /ubbthreads/images/graemlins/dunno.gif

Anyways, I agree that the keydiver chip is going to be an issue when upgrading the fuel components again. Sometimes I just get the feeling that people think DSM link is somehow different then burning new Keydiver chips. That's the way I took your original comment.

Given the original question of "how much can the stock fuel system handle", I'm assuming the OP is maybe questioning the supply side (lines, etc.) so it doesn't sound like injectors or ECU setup are under question.
 
Last edited:

4thStroke

Well-known member
Joined
Oct 22, 2007
Messages
1,864
Location
Vancouver, WA
I made 557whp on completely stock fuel lines with an intank 255 and inline 255, spliced in between the fuel filter and fuel rail, using the existing rubber line. The 1250cc injectors were the limit. The duty cycle could have been lowered if the fuel lines had been revised for more flow, but it just goes to show that you can make a lot of power through stock lines.

As far as enhanced fueling and timing maps and a few other features, the Keydiver chip isn't that different than ECMLink. Being able to have one the fly auxiliary maps, O2 narrowband simulation, solenoid controls, user defined fuel and timing maps, and several other features on the fly ECMLink is the way to go. I feel that my car is never fully tuned and am always playing with different features and adjusting fuel, in this sense, the Keydiver chip is outdated. It's funny though, 5 years ago when I was looking into VR4s, the Keydiver chip was the way to go... just 5 years ago!
 

brisvr4

Well-known member
Joined
Feb 13, 2004
Messages
955
Location
brisbane australia
^^ +1
I'm currently using stock lines and a intank 255 feeding a 044 in the engine bay with -8 soft line to the rail and I've just maxed out my 1450cc injectors at just over 90% duty.
I wouldn't bother changing the hard lines any time soon unless they are in bad shape.
The main restriction is the banjo on top of the stock filter.
 

AnotherNewb

Well-known member
Joined
Apr 25, 2010
Messages
1,472
Location
Orlando, FL
Jeff stopped burning new chips a little while ago, however, if you were a customer before he stopped he will reburn your chip for you.
 

4thStroke

Well-known member
Joined
Oct 22, 2007
Messages
1,864
Location
Vancouver, WA
Quoting Terry Posten:
I just went ECMLink V3 with speed density (used to have keydiver/SAFC/482 MAS). I only have a Walbro 255 pump, 750 injectors, and all the supporting mods.

I made a safe 445 crank HP (361whp) on 93 octane at 18psi (zero knock - street tune). Was told to expect at least 100 more whp with C16 running around 28-30psi.

Click on the link in my sig below to see the dyno graph and vid if you want full specs.



Terry, how are you figuring 445bhp?
 

Terry Posten

Well-known member
Joined
Dec 16, 2003
Messages
9,009
Location
Davenport, Iowa USA
Just by figuring the estimated drive line loss ratio of 23%.

I arrived at that figure by searching the web and taking a middle of the road figure from all those experts out there. /ubbthreads/images/graemlins/grin.gif

The 361whp is directly from a Dyno Jet AWD setup at Rev Hard.

As a side observation, I find it very hard to believe that anyone can run 25psi on 93 octane gas without knock. Unless they are injecting meth and if that is the case, that statement was very misleading.
 

4thStroke

Well-known member
Joined
Oct 22, 2007
Messages
1,864
Location
Vancouver, WA
Aaron with English swears it's not based on a percentage in our cases, but rather 60-70hp loss. I'm not sure what logic he's using to arrive at this, but it has came up before.

I was running 26psi through my HTA3076R with minimal knock. At 24psi, it made 440whp. I wanted to do some experimenting, so I turned the boost up to 26psi and pulled some timing. I'm not sure what the whp figure was after that, but it still felt equally as strong.
 

Terry Posten

Well-known member
Joined
Dec 16, 2003
Messages
9,009
Location
Davenport, Iowa USA
Not to jack the thread but when we turned up the boost from 18 to 20, I started seeing knock so we backed down timing. The result was more psi but the hp did not go up.

So we backed it back to get zero knock at 18 and I do creep to about 21 at 7500 and still have no knock.

What I have been told by the tuning is if I want to get C16 I can turn the boost up until it knocks and then back it back to where I see no knock.

He estimated I could go easily to 26 to maybe even 30 and not touch the link programming. I should get approx 100whp more. Then just turn it back down to go back to 93.
 

ma70t

Member
Joined
Oct 7, 2010
Messages
10
Location
springfield va
i have no way to even mess with the timing cause im on key driver chip and im doing 21 to 22 psi on 93 octane but havent dyno anything any guess to what power i might be making its a 50 trim turbo and i do have one big axx intercooler 31x12x3 i think its enough for this turbo but i dont even know if im making good power or im just making noise hahahah any advice or ideal on what i should do or can do to make it faster cause i just ran a evo10 with cobb protune and bolt on and hes fast i cant even hold down this makes me want to sell the car hahaha but i like the car so ill just keep it
 
Support Vendors who Support the GVR-4 Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications RixRacing RockAuto RTM Racing STM Tuned

Recent Forum Posts

Top