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@redspencer mind if I pick your brain a little?? I was able to convince my wife not to trade in her 08' IS250 6sp. She's currently getting an '18 toyota Camry xse v6 and now we have an extra car because my daily driver is an 2008 toyota sequoia, and with two boys it's perfect...lol My initial plan was to swap in a 2jzgte but, after finding out it will be well over 15K with engine swap and fabrication it was not going to happen with two kids, a wife, and a mortgage lol. There's one guy that seemed to have pulled it off with an IS350 and automatic transmission who lives down here in south Florida but, the shop is closed and he seemed to have vanished.
But anyways, I work in law enforcement and while working a detail at dolphin stadium sometime back, I saw cars whizzing through cones at a moderate speeds nothing ridiculous and it seem like these cars were not heavily modified. Every single driver had a smile on their face once they completed the course. And I though to my self what is that??? These were normal looking cars with taped on numbers and some had magnetic numbers, the drivers had helmets some even had shorts on lol.. This reminded me of the police academy when we had to take the squad cars around the track for tactical driving and learning how to apex into a curve that was fun!! The cool thing about what I saw was at the end of the event everybody got into the same cars and drove home . Nobody loaded their cars into trailers or anything like that . My question is to you how many times a year do you track your car?? And with all the suspension upgrades for the track does it benefit on to the street?? I've been following your build thread for a while now and it inspired me to keep this car and use it for autocross I know it's not a IS F or GS F and it does not put down tons of power but, with some suspension upgrades it can be fun on the track. Also the Mazda Miata must be a popular car because I saw a bunch of them out there on the track. This kinda fits my weekend warrior lifestyle I also found a club down here Equipe Rapide Sports Car Club they have events right down the street from me at the BB&T center where the Florida Panthers play I'm going to check them out soon. Thanks for you input in advance.
Welcome to the forums and that was a very nice/detailed first post! Yes, the person that did a 2JZ-GTE swap to his Lexus IS several years back seems to be MIA. On the plus side, the USDM ECUs for the IS350 have recently been cracked and the opportunities for putting down some big power (400+ rwhp) with the 2GR-FSE via forced induction are finally a realization.
Are you planning on keeping your 6MT IS250 or potentially selling it for an IS350? Though you won’t likely lead the pack at an autocross event with the IS250, you can most certainly have a great time using the IS250 as your gateway vehicle to experiencing the thrills of an autocross event in a very safe and controlled manner. When it comes to the track layout of an autocross event (typically held at a large parking lot or a modified track layout), many of the larger vehicles with high horsepower ratings will be at a disadvantage due to the struggle with putting power to the ground, especially in the tight corners. Your IS250 would be a great platform for learning about vehicle dynamics that you wouldn't be able to experience safely on the streets.
Not sure if you had ever participated at an autocross event but I highly recommend you give it a try and talk to the Club that you found to see if there’s an open registration at a future event. You can also visit sites like https://www.motorsportreg.com/ that have a full listing of events in your area.
I would just make sure that your tires and vehicle fluids are still in good condition prior to attending an autocross event and have fun! I wouldn’t worry about making any changes to the suspension until you get a feel for the car and how it behaves around the corners. You would also need to pay close attention to your driving style and habits to see where you can improve. If there’s an instructor available at the site for free or for a nominal fee, I recommend you go that route so he/she will provide you with direct feedback as you are driving on the course.
I also highly recommend the book Winning Autocross Techniques by Ross Bentley (you can find the eBook version fairly cheap on Amazon) which will provide an easy to read guide on vehicle dynamics, how to read the course at an autocross event, and how to proper engage each corner.
Once you're comfortable with being at an autocross, the next step I recommend is attending one of the local Tire Rack Track Night in America events. Since you're in South Florida, the best location would be to go to PBIR: https://www.tracknightinamerica.com/locations/1981680 There's a beginner class with available instructors to teach you how to safely go through the track.
Thanks for all the info @redspencer I plan on keeping the IS250 6MT it's a reliable car, not that fast but the manual transmission makes it fun to drive.I know the majority of parts are for the IS350 is compatible with the IS250 so once I get the ball rolling I'll keep the forums posted on upgrades and my experience on the track. I don't know why I did not find out about autocross earlier . Your thread is very detailed and I will definitely use it as a reference to future modifications to my car. Thanks again.
Glad I could help. If you're keen on doing some mods on the IS250 to improve on your spirited driving, here's a few suggestions that won't break the bank:
1) F-Sport Short Shifter- I heard from several CL members that this upgrade really helps with improving the shift feel of the 6MT.
2) F-Sport Sway Bars or equivalent- These will help keep the IS250 more composed during any type of cornering. If you don't wish to splurge for both the front and rear sway bars, get the rear sway bar at the minimum.
3) High Performance Tires- There's plenty of summer tires to choose from that will help with maintaining tire load when cornering. It all depends on your budget.
This would be a good list to improve the driving dynamics and fun factor of your IS250 6MT. If you're still interested in doing an engine swap, you can follow the trail of CL member Jeff Lange who successfully swapped a IS350 2GR-FSE engine into his IS250 6MT. Now he has the best of both worlds.
It's been a while since I posted an update but I can say that after some surprising turmoil to getting the ECU reflashed, the CEL has disappeared and the IS350 is pulling very strong at all RPMs.
As I was one of the very first people to get the ECU tune for the 2IS350, I didn't have the portable OBD unit to tune the car and I had to mail my ECU instead. I purchased an OBD unit from RR Racing two weeks ago and after I provided all the necessary ECU readouts, I received my updated tune. When I attempted to upload the revised tune, the OBD unit was stuck in limbo for over an hour. Sensing something was wrong with the upload process, I had to disconnect the OBD unit from the OBD2 port. Lo and behold, when I tried to start up the car, I received absolutely no response from the engine. I feared the worst and thought that I bricked the ECU. I tried to re-upload the stock ECU file and but that wouldn't upload either. As I prepared myself to potentially remove the ECU to mail it to RR Racing for repair, I decided to see what would happen if I removed and reinstalled the negative terminal of the battery. To my pleasant surprise, the IS350 cranked back up and it managed to keep my previous tune file.
After some back and forth emails with RR Racing, we determined that the issue had to do with a communication error between the OBD unit and the ECU. Once Alien Tech provided a firmware update, the new tune was finally transferring to my ECU and it finally removed the constant CEL I was receiving due to the primary cats missing.
I noticed that the updated tune was considered to be "Revision 4" and I noticed some subtle and positive improvements with the throttle response, the smoothness of the power delivery, and surprisingly even more initial torque when you press on the gas at idle (as I would have thought some low end torque would have been sacrificed from the PPE header upgrade). It's very fun to do random WOT pulls and listening to the exhaust sound while also being pushed back into the seat.
I'm planning on taking the IS350 to a local tuner shop in April or May to see what RWHP its pushing out on a dynojet so stay tuned for that! I also plan on doing some 0-60 runs using the Torque Pro App to see if there is any noticeable differences with the times (particularly from 40-60 which I previously was able to record a 1.8 sec time before the header upgrade).
Any updates on possible gains with headers? I know the tune update might skew it some but I'm still curious. I'd be interested in comparing numbers with you. Is there a reason you haven't opted for higher revs? I have had no issues going out to 7400rpm, and logs suggest the power still carries out that far.
I'm scheduled to do a couple of pulls on the dynojet this Friday
That's great to hear that there are still no issues from anyone with the 7400 rev limit. I guess I'm hesitant to request for the slightly higher increase due to that range potentially being at the upper limit before there's a risk of valve float. With me enjoying an occasional track day or two each year, I worry that the constant revving to 7400 RPMs under these heavy loads could be detrimental to the engine. I figure with the Lotus 2GRs pushing 7200 RPMs at the track consistently, it should be a decent safety margin for my IS350 as well.
I don't remember the exact details but valve float happens after 7400rpm according to ovt. I think stock exhaust manifolds are a restriction by then but I haven't seen any drop off that high. Would you mind logging the mad, timing, and afr when on the Dyno?
Attached is a combination of a handful of logs throughout last year. You can see the maf readings climb with RPM all the way through 7400rpm.
Yeah, I'm supposed to be receiving the AFR readings with the RWHP dyno readings but I'll check with the operator to see if any additional data from the runs can be provided as well at no additional cost.
You can log all of that work the torque app. I can overlay the information if you can set it up to log rpm, maf, timing, and measured afr. We don't really have a lot of info like this out in the open. I think it would be nice to get an "estimated hp" chart made from these numbers. I've been debating getting my car on a Dyno this summer to do this, getting data points from more than one vehicle would be nice.
Today was the day where I finally had a chance to take my IS350 to the dyno (I forgot to bring my OBD2 bluetooth scanner to collect data. Sorry DickH).
Unfortunately, the end results were much less than I expected. I thought with all the power mods that I had (RR-Racing ECU tune, PPE Headers, F-Sport exhaust, F-Sport Intake, and lightweight wheels), I would break past the 300rwhp barrier. Instead, the best the car was able to pull was 282rwhp. On the plus side, the powerband curve looked great and the IS350 sounded fantastic at WOT.
Not sure if the warm FL temperatures or the Air/Fuel ratio of 11.5-12.0 at WOT were major contributors to the less-than-stellar rwhp results. I do know that different dynos = different results so maybe I should try again at a different shop to see if it pulls more favorable numbers?
You should get with RR-Racing to fix your tune, I bet you could get them to send you an OBD unit to avoid constantly shipping your ecu. Nearly 15:1 at WOT seems dangerous, followed by a massive loss in power from running too rich? I am not saying they messed up, but you clearly have an AFR issue and they should fix this if this is what they are sending out to people. My car (according to the fron o2 sensors) is almost always pegged in the mid 13:1 range, sometimes its in the high 12:1s and I have not seen where it has ever pulled timing. You went pretty rich after 5k, and you can see that it is costing your power after 6k. Mixing my maf readings with your dyno it looks like you should be ~310hp. You hit 280hp at 6000rpm, which for me is ~200g/sec. At 7200rpm I am averaging ~220g/sec which is a 10% gain. If everything scales right, that is a potential 308hp if your AFR was good. Of course this is just quick math from not enough data points for a rough estimate. You can see that even if you follow your curve you should at least level out ~300hp. Looking at my scatter plot it looks like my car levels out between 6k-6.5k and then picks up again which is likely some resonance thing between the intake and headers. You can see a similar thing happening with your car just before 4k, and again just slightly at 5k. You can verify this for yourself by logging airflow, you should continue to make more power up until your maf reading starts to drop off. I have a hard time believing that your car has a bottle neck that severe compared to mine.
You should get with RR-Racing to fix your tune, I bet you could get them to send you an OBD unit to avoid constantly shipping your ecu. Nearly 15:1 at WOT seems dangerous, followed by a massive loss in power from running too rich? I am not saying they messed up, but you clearly have an AFR issue and they should fix this if this is what they are sending out to people. My car (according to the fron o2 sensors) is almost always pegged in the mid 13:1 range, sometimes its in the high 12:1s and I have not seen where it has ever pulled timing. You went pretty rich after 5k, and you can see that it is costing your power after 6k. Mixing my maf readings with your dyno it looks like you should be ~310hp. You hit 280hp at 6000rpm, which for me is ~200g/sec. At 7200rpm I am averaging ~220g/sec which is a 10% gain. If everything scales right, that is a potential 308hp if your AFR was good. Of course this is just quick math from not enough data points for a rough estimate. You can see that even if you follow your curve you should at least level out ~300hp. Looking at my scatter plot it looks like my car levels out between 6k-6.5k and then picks up again which is likely some resonance thing between the intake and headers. You can see a similar thing happening with your car just before 4k, and again just slightly at 5k. You can verify this for yourself by logging airflow, you should continue to make more power up until your maf reading starts to drop off. I have a hard time believing that your car has a bottle neck that severe compared to mine.
Thanks for the detailed input. The dyno shop wasn't able to go WOT on the car at 4th gear until the MPH had reached 75+ which was already at 4500RPMs. That's the reason for the sudden changes with the AFR at that range.
I spoke with RR Racing and they believe the rich A/F ratio is attributed to the dyno at the shop being hot with fans not providing sufficient airflow. This would cause a high intake temperature and as a result the car would lose power significantly. If heat soak was an issue, would that cause the ECU to counter by creating a rich fuel mixture?
In order to verify this theory, the next course of action I plan on doing is using the more detailed functions of the Torque Pro App to observe my A/F ratios as I do several pulls on the highway. Hopefully, if what RR Racing is stating is correct, my AFR will be in the 12.5-13.0 range as I do several pulls on the highway which should have sufficient airflow then. Does that sound like the next path forward?
Did you acquire your MAF readings from the Torque Pro App as well? Does the app actually record and store data or do I have to glance at the screen while at WOT to acquire my data? I've only used the 0-60, 40-60, and HP guesstimate display so far with the app so I guess I'm forced to learn the more advanced features of this tool.
EDIT: I found this video which does show that I can record certain items for datalogging:
That story doesn't sound right. Ambient temps will not make that violent of swing. The OEM map tries to maintain 14.7 until you romp on it. Yours staying there under load is hurting it. Then jumping under 12 is killing again on the other side.
Do you know exactly how and where they grabbed the o2 data from? Is your exhaust leak free? And the next bit of data is ignition timing. You need to know why that dipped under 12. These combustion chambers are pretty happy in the 12.7 13.1 range maybe as low as 12.5:1 when you stab it. If the data is right, ignition where is should be and no leaks, you'll pick up some tq getting that back towards 12.8 from 4k on. Which is pretty much the beginning of the happy spot for the valve timing.
I may have to go play with Torque and see what it will show me....
03-12-18, 11:15 AM
