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was hoping for about 350whp, got 260

yubh8tn

Well-known member
Hey, so I'm just a little confused. Everything I've read on this forum and the dsmtuners.com forum say that fuel system, turbo, front mount, exhaust, ecu (dsmlink), intake filter, and supporting stuff like gauges, clutch, and safety will get you about 300-400hp with a tune. Is this information believable? I have a 68hta with fp manifold, 1000cc fic injectors with a 255, 2.5in turbo back straight pipe, stock gvr4 intake snorkel with a 3rd gen eclipse MAF, a treadstone TR6 front mount with admittedly shoddy piping (no leaks though), and a tial wastegate on a new 02 housing. Manual boost controller. At 20lbs of boost with all that stuff, is 260 wheel where its supposed to be? If it is, so be it, but it seems low. The guys at English Racing who tuned it didn't say much. I blew up the motor anyway by re-doing timing incorrectly and I'm trying to figure out if I should get cams or not for round two. I'd really rather not. Thanks for whatever help I get.


Edit: for a bit of clarification, it was on a dynojet dyno on 92 octane pump gas. I have beehive springs with tit retainers from MAPerformance on it and im at 2200 feet above sea level. Using a 92 or 93 N/A Galant knock sensor, should be the same thing though.
 
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gvr4ever

Well-known member
Sounds more like crank, not wheel, but so many variables. Why 1000cc injectors? Have lower octane? Could be phantom knock, or some other variable that is causing timing to retard. Humidity and temps play a HUGE roll with turbo cars. On the worst humid day, I feel like I have a boat anchor, and on a cool fall day, I feel like I have a jet engine strapped to my car. I don't dyno my car for every change, but whether seems to play a HUGE roll. 80+- HP?. Sure feels like it sometimes.
 

JNR

Well-known member
Elevation plays a role, as well...Higher up, less air density; less power of course. Compressors (e.g. turbo, supercharger) can overcome some of that, but still. Take it you're not much 2k ASL though?

What is the efficiency of that turbo (not familiar with those)? Imagine it would be good for 20 psig...Otherwise when they get "out of range", start becoming more of a heat pump than increases.
 

CutlassJim

Well-known member
I'm thinking stock head and cams as well here. The 4G63 doesn't flow nearly as well as heads these days and the cams were designed for midrange so you are probably making a healthy torque number but it falls off after that. You need to carry that torque higher in the rev range.

People have gotten away from psi and towards mass flow because that's what matters. 20psi through a "restrictive" head might only be 35 lbs/min which is ~350 crank hp then multiply by ~0.75 for drivetrain loss and you are around 260whp. Get that head flowing and turn that 20psi into 45 lbs/min and now we are at 330ish whp.
 

tyeler18

Well-known member
20psi is barely in the operating zone of that turbo. Stock cams, intake, intake pipe and the 2.5" exhaust are doing you no favors but on a mustang dyno 260whp sounds "normal" for 20psi. I've had link estimate just over 300whp on a similar setup, e85 and 23lbs. The car went 12.0 @119 the drivers first time out at the track.
 

turbofonz

Well-known member
The stock intake tube is a major restriction from what I've noticed personally. Replace that and it should wake it up.
 

yubh8tn

Well-known member
gvr4ever,
I got 1000cc because I didn't know what to pick and I figured they'd do the job and lower duty cycle would be better anyway. Not a humid area and temps were fairly low at the time of tuning. 60's if i remember right. I think intake air temp was 72 on the dyno? Phantom knock is an interesting mention because my knock sensor was cooked. I put in a knock sensor from a 92 or 93 non-turbo Galant in there. It's Mitsubishi original, and from all the research I've done they're all the same. Guys at English agreed, but if this wasn't the case and it started reading knock early that could make sense.

JNR,
Yeah, about 2.2k ASL. Not sure of the efficiency of the turbo but from what I've read they go a lot further than 20psi.

CutlassJim,
That's a pretty good point. I'm sure a porting job and some cams would definitely help. And you're right, I made like 280 wheel torque at peak, about mid range. And it sure does fall after that.

tyeler18,
That makes me feel better in the way that nothing's wrong and worse in the way that I need to spend more money for power lol. I can't get e85 around here unfortunately so the best I can get is 92, so that all adds up.

turbofonz,
That's what the guys at english said. It's the only thing they said, but I figure it'd be worth it to switch over to speed density and get a less restrictive intake. Thanks
 

turbofonz

Well-known member
Stock head and cams shouldn't be an issue at that power level. 300whp on a 16g sized turbo with basic bolt ons is the norm. I'd think until mid 300's a bigger cam would start seeing gains. More boost certainly would help too.

I can't remember the specifics, but I know with a supported evo3 16g on my car, with the stock intake setup, to a 3" SD intake, boost went up a solid 3+ psi and seat of the pants was a huge increase without making any boost/ tune related changes. It made me question if I pinched a boost line as the car felt substantially quicker.
 
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