Toyota MR2 Message Board - View Single Post

keithlee21 · 02-28-2005, 08:26 PM

Gen III Differences

FYI: Gen III Differences
- MAP sensor instead of AFM
- Bosch D-Jetronic (Gen III) vs. L-Jetronic (relatively primitive) engine management
- CT20b turbo replaces CT26
- Boost raised from 10psi to 13psi
- Fuel cut raised from 12 psi to 18 psi
- Different ECU
- 4 wire O2 sensor
- Shim under bucket valve shims
- slightly more aggressive cams
- Revised internals (pistons, con-rods etc.)
- Revised cylinder head cooling passages/water jackets
- Revised intake manifold (8 'independent long ports' reduced to 4)
- intake manifold inlet air temperature sensor added. i.e. after turbo and intercooler.
- Revised gearbox with close ratio gearing
- lower compression ratio
- stainless steel head gasket
- factory 540cc injectors replace 430cc injectors
- revised fuel rail with bigger bore and relocated pressure regulator
- TVIS eliminated
- EGR eliminated
- LSD in 80% of them
- throttle body increased from 55mm to 60mm
- inlet valve lift increased from 8.2 to 8.7
- intake manifold inlet air temperature sensor added
- Less restrictive exhaust elbow
- Aluminum oil pan
- more rigid alloy sump and additional oil baffles
- Factory Catch can
- Better Oil Cooler and relocated oil filter (bottom)
- 4 Channel ABS coupled with Traction Control available
- No. 1 compression ring described as 'stainless steel' instead of just 'steel'. Oil ring is described as 'stainless steel' instead of 'a combination of steel and stainless steel'.
- The fuel pressure raised from 36 PSI (2.55 bar) to 41 PSI (2.9bar).

Gen III Debate

Now, there has been a lot of debate between the US spec engine and the Gen3 engine.

I have not been in the mr2 community for some time now. And, I have sold my car about 2 years ago. Since, then I've seen a lot of progression and development making the generations of the 3SGTE that much more reliable when increasing its power.

Now, my experiences and preferences for the building of my car may and, probably is very different from yours. Initially, when I bought my 93' MR2 I wanted to build something with huge power. And, within my own perception of power for the mr2 I succeeded with what I wanted but, also sacrificing 3 blown up US 3SGTE’s. Poor tuning on my part...all my fault. Thank god for tuning primers like RickyB now.

My new goals were to have something with great midrange power. I wanted to focus more on the throttle response and balance of the car rather than overpowering the platform. As many other high horsepower mr2 owners can attest to…flogging around a high horsepower mr2 is not the easiest thing to do.

I bought my Gen3 clip from Cartune in the City of Industry. They were able to locate and ship over the clip to my door. Now, to this day I’m not really sure what the clip had internally. What really surprised me after dropping in the clip was the amount of lowend grunt that the car had in the first 3 gears. I have a feeling that the previous owner of the clip in Japan must of swapped the ST185 1-3 gears into it while throwing in the KAAZ LSD. Hey, luck me!

Now, for the good part.

Was I ever completely satisfied with the Gen3? NO

Would I do it again? YES

Is there a better way of achieving the results? PROBABLY

These answers are probably very confusing to you. The Gen3 gave me almost everything that I could hope for with a complete drop in clip. I really did not have to touch it. But, that’s also considering that I did a basic intake, exhaust, and intercooler…plus, whatever the previous owner did prior to me receiving the clip. But, just as Ricky B pointed out the Gen3 was never meant to run in the US as you can see from the previous dyno plots. The Gen3 will run on 91 octane but, it definitely did not like it. There were the occasional hiccups from not being tuned. If I were to do this again I definitely would have thrown on some kind tuning parameter for the vehicle. At least that way I would not have to worry about the vehicle and it would have been even that much more reliable for me.

If I were to own another MR2 I would probably do it again. Many of your MR2 has approached and are probably over 150K mile mark by now. Transmission, engine components, sensors, wiring harness, etc have and/or are worn and tired by now. Now, a clip won’t give you new ones but, it will definitely give you items that have less mileage and years of wear. So, if you look at the whole picture you not only getting a newer engine and transmission but, also the components that come with the clip.

Now, is there a better way of achieving the same results I set out for? Most likely and probably. With the further progression and, development of research and products for the US 3SGTE it has show to be very capable and now reliable. Tuning is ‘THE ESSENTIAL INGREDIENT’ in the mix of attaining the goals of power for your vehicle. Even with the Gen3 it will need to be tuned to run reliably. But, the US engine can and will be able to give you the same results for cheaper.

Now, why did I drop in the Gen3? The most honest answer I can give you…Because I could. At the time I could afford it. So, why not? Why do Honda owners drop in JDM engines into their cars? Why do BMW and Porsche owners drop in Euro spec engines into their vehicles? Probably because enthusiasts and connoisseurs for the specific vehicle have a love and obsession for the history, development and, lineage of their vehicle. So, rather continuing to debate this topic…work on the development and tuning of both platforms. There is no real answer to this debate. It will not stop customers requesting more Gen3 clips and, dropping them into their cars. And, it will not stop the further development of US 3SGTE. Drop the debate.

02-28-2005, 08:26 PM	#1 (permalink)
keithlee21 No Skills Join Date: Feb 2005 Posts: 4 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	Gen III Differences and Debate Gen III Differences FYI: Gen III Differences - MAP sensor instead of AFM - Bosch D-Jetronic (Gen III) vs. L-Jetronic (relatively primitive) engine management - CT20b turbo replaces CT26 - Boost raised from 10psi to 13psi - Fuel cut raised from 12 psi to 18 psi - Different ECU - 4 wire O2 sensor - Shim under bucket valve shims - slightly more aggressive cams - Revised internals (pistons, con-rods etc.) - Revised cylinder head cooling passages/water jackets - Revised intake manifold (8 'independent long ports' reduced to 4) - intake manifold inlet air temperature sensor added. i.e. after turbo and intercooler. - Revised gearbox with close ratio gearing - lower compression ratio - stainless steel head gasket - factory 540cc injectors replace 430cc injectors - revised fuel rail with bigger bore and relocated pressure regulator - TVIS eliminated - EGR eliminated - LSD in 80% of them - throttle body increased from 55mm to 60mm - inlet valve lift increased from 8.2 to 8.7 - intake manifold inlet air temperature sensor added - Less restrictive exhaust elbow - Aluminum oil pan - more rigid alloy sump and additional oil baffles - Factory Catch can - Better Oil Cooler and relocated oil filter (bottom) - 4 Channel ABS coupled with Traction Control available - No. 1 compression ring described as 'stainless steel' instead of just 'steel'. Oil ring is described as 'stainless steel' instead of 'a combination of steel and stainless steel'. - The fuel pressure raised from 36 PSI (2.55 bar) to 41 PSI (2.9bar). Gen III Debate Now, there has been a lot of debate between the US spec engine and the Gen3 engine. I have not been in the mr2 community for some time now. And, I have sold my car about 2 years ago. Since, then I've seen a lot of progression and development making the generations of the 3SGTE that much more reliable when increasing its power. Now, my experiences and preferences for the building of my car may and, probably is very different from yours. Initially, when I bought my 93' MR2 I wanted to build something with huge power. And, within my own perception of power for the mr2 I succeeded with what I wanted but, also sacrificing 3 blown up US 3SGTE’s. Poor tuning on my part...all my fault. Thank god for tuning primers like RickyB now. My new goals were to have something with great midrange power. I wanted to focus more on the throttle response and balance of the car rather than overpowering the platform. As many other high horsepower mr2 owners can attest to…flogging around a high horsepower mr2 is not the easiest thing to do. I bought my Gen3 clip from Cartune in the City of Industry. They were able to locate and ship over the clip to my door. Now, to this day I’m not really sure what the clip had internally. What really surprised me after dropping in the clip was the amount of lowend grunt that the car had in the first 3 gears. I have a feeling that the previous owner of the clip in Japan must of swapped the ST185 1-3 gears into it while throwing in the KAAZ LSD. Hey, luck me! Now, for the good part. Was I ever completely satisfied with the Gen3? NO Would I do it again? YES Is there a better way of achieving the results? PROBABLY These answers are probably very confusing to you. The Gen3 gave me almost everything that I could hope for with a complete drop in clip. I really did not have to touch it. But, that’s also considering that I did a basic intake, exhaust, and intercooler…plus, whatever the previous owner did prior to me receiving the clip. But, just as Ricky B pointed out the Gen3 was never meant to run in the US as you can see from the previous dyno plots. The Gen3 will run on 91 octane but, it definitely did not like it. There were the occasional hiccups from not being tuned. If I were to do this again I definitely would have thrown on some kind tuning parameter for the vehicle. At least that way I would not have to worry about the vehicle and it would have been even that much more reliable for me. If I were to own another MR2 I would probably do it again. Many of your MR2 has approached and are probably over 150K mile mark by now. Transmission, engine components, sensors, wiring harness, etc have and/or are worn and tired by now. Now, a clip won’t give you new ones but, it will definitely give you items that have less mileage and years of wear. So, if you look at the whole picture you not only getting a newer engine and transmission but, also the components that come with the clip. Now, is there a better way of achieving the same results I set out for? Most likely and probably. With the further progression and, development of research and products for the US 3SGTE it has show to be very capable and now reliable. Tuning is ‘THE ESSENTIAL INGREDIENT’ in the mix of attaining the goals of power for your vehicle. Even with the Gen3 it will need to be tuned to run reliably. But, the US engine can and will be able to give you the same results for cheaper. Now, why did I drop in the Gen3? The most honest answer I can give you…Because I could. At the time I could afford it. So, why not? Why do Honda owners drop in JDM engines into their cars? Why do BMW and Porsche owners drop in Euro spec engines into their vehicles? Probably because enthusiasts and connoisseurs for the specific vehicle have a love and obsession for the history, development and, lineage of their vehicle. So, rather continuing to debate this topic…work on the development and tuning of both platforms. There is no real answer to this debate. It will not stop customers requesting more Gen3 clips and, dropping them into their cars. And, it will not stop the further development of US 3SGTE. Drop the debate. Last edited by DavidV; 03-01-2005 at 01:03 AM.