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.

Twin turbo when do they kick in???

sorry im really new to this. just bought a vr4 1997 galant TT and wondring if anyone knows wat rpm do the turbos kick in??
 

DR1665

Well-known member
Joined
Oct 19, 2005
Messages
4,642
Location
Iowa City, IA
Um, I'm thinking you'd know when the turbos kick in by the boost gauge reporting 1psi or more.

You might want to check out ClubVR4.com, my Kiwi friend. 99% of the people here have the earlier VR4s. You know, the ones that look like Nissan Maximas with the four cylinders. :p
 

eleventy??? i feel the turbo kick in around 3 or 3.5'rpm? but this is twin turbo so im guessing there a problem somewea. either the primary or secondary turbo is not working.
 

fuel

Well-known member
Joined
Feb 23, 2009
Messages
2,165
Location
Toronto, ON, Canada
the turbos aren't sequential (ie not primary and secondary), there are two turbos working in parallel - one turbo per bank of three cylinders given it's a V6 engine. The turbos are quite small, they are twin TD025 which is about 2/3rds the size of a TD04 on a 1.8L Lancer GSR Turbo. They should spool up just about instaneous from approx 2000rpm but will run out of puff towards 6000-6500rpm.
 

cheekychimp

Well-known member
Joined
Apr 19, 2004
Messages
7,333
Location
East Sussex, U.K.
Correct!

Mine were off and running hard by 2500 rpms. Power does drop off in the upper rev range but I never noticed it as low as 6500 rpms, my recollection could be hazy though as I got my turbos upgraded. I'm also not convinced that power falling off at higher rpms is really an issue unless you are going so fast you are battling serious drag and or going uphill. After you overcome inertia it takes less power to keep you moving. As a rule of thumb if the rpms are rising steadily and you don't have any slippage (clutch on it's way out or spinning tyres etc) you should still be accelerating fine. I guess more power just means you accelerate faster but unless you have built an engine capable of very high rpms, that rev limiter comes up very quick!
 

This might help. This was tuned a bit, but shows the general torque curve for my old Legnum. Peak boost was around 2250.



 
Last edited by a moderator:
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
Top