Lexus is250 engine swap with gs300 engine (3GR-FSE)
#17
Racer
iTrader: (2)
Hey Jeff where have you been buddy!It s been a long time since I see you post here.I m not sure which diff will suit my sc now.The promblem is that first and second gears are too sort now and the car just spins without doing anything.The other gears are ok I guess.I see 200km with 4th gear and 245km with the 5th gear before I switch to 6th.I m not sure if a shorter diff would help.In my mind if first gear was not that sort would be the best
#18
Intermediate
At the risk of completely ignoring Park's intent for the thread...
PAVGR, I'm of the opinion that the ring and pinion you have is probably the best for you, but it's bolted to a pegleg differential that only sends power to the tire without traction. If your car lays parallel lines in a burnout, I'm wrong; but if you're only doing a one-wheel peel, replacing the diff with something that'll send power to both wheels (like a Y38, OBX LSD, etc) will reduce the length of burnouts you lay down because your engine's doing twice the work...and turning it into actual work, instead of spinning.
When it comes to swapping the ring and pinion onto the new diff, I'd be looking at thannp and redspencer's posts on the process. They're the two that come immediately to mind, anyway.
PAVGR, I'm of the opinion that the ring and pinion you have is probably the best for you, but it's bolted to a pegleg differential that only sends power to the tire without traction. If your car lays parallel lines in a burnout, I'm wrong; but if you're only doing a one-wheel peel, replacing the diff with something that'll send power to both wheels (like a Y38, OBX LSD, etc) will reduce the length of burnouts you lay down because your engine's doing twice the work...and turning it into actual work, instead of spinning.
When it comes to swapping the ring and pinion onto the new diff, I'd be looking at thannp and redspencer's posts on the process. They're the two that come immediately to mind, anyway.
#20
Lexus Test Driver
iTrader: (2)
Thank you for the reply Ultra4.I currently use the OEM IS250 manual diff and first gear is useless with my supercharger set up.Second gear is spinning until red light and only when I shift to third gear the car is able to handle the power down the road.That’s the reason my 0-100 is 6.5sec which is bad for the BHP the car made.
========================================================
Calculate Speed with Axle Ratio and gear selected
RPM * PIE * Tire Diameter (inches)
----------------------------------‐---------------------- = Speed in MPH
Axel ratio * Gear Selected * 1056
3000 * 3.14159 * 26.031"
---------------------------------------- = Speed MPH
4.083 * 1 * 1056
245336.1879 / 4311.648 = 56.9 MPH
Sample is IS-350 w/ 4.083:1 rear axle, at 3000 rpm, in 4th gear having a ratio of 1:1. Due to torque converter slip and other losses, calculated value may vary.
==========================================================
Tire Diameter calculation: Sample is 255 40R18
(Width [mm] / 25.4 * (Aspect Ratio * 0.01)) * 2 + Rim Dia [inches]
Diameter => (255/25.4 * (40 * 0.01)) * 2 + 18" = 26.031"
==========================================================
/Thread return
EDIT: fix an error and add that tirerack.com offers tire diameter and rolling information.
Last edited by 2013FSport; 05-12-22 at 03:47 PM.
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MrHarris (05-14-22)
#22
Intermediate
Here's how it looked before I took the hood off, flew the 3.0L in the foreground and marred up everything within 6" of the transmission bellhousing with the two exhaust flanges. That's why I say fly the engine with the LHS exhaust torqued and the starter in place, both exhaust flanges don't clear the bell, steering shaft, firewall, subframe and heat shielding. I ended up landing the last time with no exhaust on at all, and fought the LHS exhaust manifold and starter for a good day or two, so I tell everyone to position the starter, torque the LHS manifold, install the engine etc, etc...
#23
this is awesome! never knew the 3.0L v6 from a GS300 would fit in a 250 relatively bolt on running the stock ECU and wiring!
if i read this correctly, essentially all that is changed is the long block? pretty cool, albeit lots of work.
pardon my ignorance, but why will the 2GR-FSE (is350) engine not work? more wiring changes, not-truly bolt on due to extra injectors at the least? 6-speed trans will not bolt up?
lastly, is the 3GR-FSE direct injected like the 4GR-FSE (is250)?
if i read this correctly, essentially all that is changed is the long block? pretty cool, albeit lots of work.
pardon my ignorance, but why will the 2GR-FSE (is350) engine not work? more wiring changes, not-truly bolt on due to extra injectors at the least? 6-speed trans will not bolt up?
lastly, is the 3GR-FSE direct injected like the 4GR-FSE (is250)?
#24
Intermediate
Fast-forwarding through a lot of details, there are two general types of *GR engine: 6-injector and 12-injector. The 2GR-FSE gets the 12-injector topend, while the other v6 engines in the 2IS lineup get 6 direct injectors and a couple air doodads (SCV and ACIS) in the intake tract to control intake air charge velocity and control fuel stratification at various loads. The 2GR-FSE essentially runs a nitrous shot without the giggle gas, so it's air paths are significantly lower restriction/lazier at lower speeds. Intakes and electronics do not swap between 6- and 12- setups.
Apparently we have one member that has done the 3.5L bottom-end under a 6-injector topend ran by a 4GR-FSE ECU, but I'm unaware of anywhere he's gone into specifics about it, but the heads are swappable between the family, including the port-injection-only *GR-FE heads (See: lotus owners putting -FSE tops on -FE bottoms). So, y'know, that should work for adding bigger fuel injectors and inviting Spoolius Caesar to the party...
You're on your own for auto transmission info, though. I know nothing of non-US slushboxes.
Apparently we have one member that has done the 3.5L bottom-end under a 6-injector topend ran by a 4GR-FSE ECU, but I'm unaware of anywhere he's gone into specifics about it, but the heads are swappable between the family, including the port-injection-only *GR-FE heads (See: lotus owners putting -FSE tops on -FE bottoms). So, y'know, that should work for adding bigger fuel injectors and inviting Spoolius Caesar to the party...
You're on your own for auto transmission info, though. I know nothing of non-US slushboxes.
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Yodog (09-30-23)
#26
Pit Crew
#27
Anybody know ?
Thank you
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GeorgeSeb (05-13-24)
#29
Lexus Test Driver
iTrader: (2)
It's a little more complicated than that. You need the ECM, injector driver, and the whole engine / ecm wiring harness and other things I'm forgetting. Look at Jeff's build, he's done the work and installed a 2GR where a 4GR once sat in his MT 2IS. It is a real project where you need to follow every detail to be successful.
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