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Some info:
- 2006 IS250 with an unopened 4GR-FSE 2.5L and a standard 6 speed auto
- GTX3076r Garret single turbo
- custom Turbo manifold to 45mm turbosmart external gate
- 3" downpipe into a custom midpipe with a valve actuated 3" exit
- 3.5" MAF pipe with Synapse BOV
- IS350 direct injectors
- full auxiliary methanol system with braided Teflon lines into dual intake mounted nozzles (around 1200cc)
- trunk mounted methanol tank and DO pump
Car actually used to be supercharged with a modified LMS kit with a rotrex c38-81 blower unit. People would be familiar with these kits from members like Stewart Smith and Mike from a handful of years ago. After years of not really being happy with the car and issues with the Supercharger I decided to go the turbocharger direction. In the future I'll cover the suspension mods done or to be done to the car as well (also fairly extensive).
The goal with this build is to avoid opening the engine while making over 400whp. The engine should now have more than enough fuel for even 450whp. The transmission is still a big unknown and we can only speculate from how the A960e trans holds up in turbo BRZ/FRS and RX8 cars. Obviously if we need to build the transmission we will. I'll post everything as it happens but right now we're in the process of getting the car tuned.
Here's where it's up to so far -
Constructing the manifold and down pipe with the external gate. Obviously looks a bit confusing but it needs to also feed from the other bank.
3" downpipe and midpipe all fabbed up. You can see how the other manifold bank feeds the turbo from here.
Intake side all fabricated with a 3.5" MAF housing and a synapse blow off valve. You can also see the braided lines to the methanol nozzles mounted near the throttle body.
7 Gal/ 26L rear mounted methanol tank and DO pump. Had to use nylon push style hose as the pump I already had from when I Supercharged the car only has push style fittings. Will trial straight methanol and dilute as necessary. No shortage with nearly 30L of methanol sitting there for tuning the car.
Cool! Looking good. What kind of boost were you running with SC and what held you back or made you pull it? The lack of fueling?
I am not the expert but the bank 2 feed into the bank 1 header has me a little concerned regarding back pressure from bank to bank, like it will induce an imbalance in your fuel trims. Let us know how it goes and thanks for sharing.
Love to see where this goes! This is exactly what I would do if I was building a DIY kit. Where are you tapping the turbo oil feed line at?
I have a local tuner who uses BitBox/BitEdit to tune Denso stuff. Car is hitting the dyno hopefully this weekend. We used the oil pressure sensor location on top of the oil filter housing for the low side and then we tapped the sump for the high side.
Originally Posted by 2013FSport
Cool! Looking good. What kind of boost were you running with SC and what held you back or made you pull it? The lack of fueling?
I am not the expert but the bank 2 feed into the bank 1 header has me a little concerned regarding back pressure from bank to bank, like it will induce an imbalance in your fuel trims. Let us know how it goes and thanks for sharing.
I was running around 12psi on the Rotrex supercharger but it lacked torque for my liking. Being honest the whole design of those LMS style kits just wasn't great.. at first we dealt with belt slip so we swapped to a Gilmer (cogged) belt system like Stew did which then introduced bracket flex. We then reinforced the bracket and added lips to all the pulleys. A lot of work for not enough return.
We'll have a better understanding of the bank 2 feed once it hits the dyno but the same approach has been used by a lot of 350Z single turbo builds with no issues.
Sorry for the lack of updates, it's been a big year and a half.
Had the car up and going on a conservative 8-9psi and it made around 290hp on a mainline dyno (fairly low reading probably around 310-315hp on another dyno). Plan was to have a few gremlins worked out and get it retuned by the end of the last year.
There were some major fueling issues even at a tuning level that we couldn't fix so we were going to move to a microsquirt and auxiliary injector like RR use on their supercharger kits to account for the extra fueling but unfortunately before we got to that stage the car developed a major misfire issue on two of the cylinders. After a few months going back and fourth trying to address the issue it turned out due improper installation the IS350 injectors had been leaking and igniting around a damaged seal. Replaced some injectors and tested them all (they appeared ok) ran the car for probably a week before one of the injectors failed under boost and melted a piston.
I had actually started to part out the car but had a change of heart recently and bought a 2014 4GR engine with around 20k miles on the clock. So I'm in the process of stripping the car and getting ready to install the engine.
I've addressed a lot of smaller issues such as the intake manifold flaps not working (even contemplated removing it like people do with 2JZ-GE NA-T swaps), bought all new genuine IS350 Direct Injectors and bought a microsquirt along with a 1000cc injector and the necessary fittings to tap the fuel system. Once the new engine is in and the car is back together I'll send it off to be retuned and hopefully see 350whp on a mainline dyno.
Just to add some previous content from BEFORE the engine blew - ended up turning my attention to some handling mods and cleaning up the interior last year.
Installed a full H brace, subframe brace kit by Megan Racing, RR Racing LCA, IS-F front Sway Bar (same size as the F-Sport bar), 19mm rear sway bar, Ultra Racing rear tower bar, RR Racing Front tower bar AND a 2012 IS-F steering ECU. I did previously have Advan RG-D wheels and KwV3 coilovers but have since sold them and moved to OEM Blade IS-F wheels that I'll use spacers to have them flush. I've opted to move from the Kw's to Silvers NeoMax R's - for people unfamiliar with the NeoMax's they're the coilovers used to make RR's road and track suspension (they use the NeoMax S while I opted for the slightly higher spec NeoMax R). The KW's were far too soft out of the box and definitely better suited to a lighter car.
I'll probably look to add a 4.1 Ratio LSD diff out of a BRZ in the future, upgrade the bushings with new rubber ones (don't want poly bushings as I'd rather keep the car a bit softer and keep NVH down), add solid steering rack bushings (only exception to the rubber bushing statement) and finally add the RR Racing upper control arms. After this I'll look to leave the car as it is.
Cleaned the inteiror up but have some big plans for this year including having the OEM dash wrapped to hide the damage from the defect, modifying the OEM seats and a few other small details. For now the mods ive done include carbon overlays on the trim pieces (the real carbon overlays you buy online). Elvin Carbon Fibre Steering wheel, OEM F sport shifter, Tesla style headunit (which I've since repainted in interior trim black to blend better and added android auto and carplay to it), hard-wired a wireless charger, diamond car mats and a LED swap. I did temporarily have a 2008 IS-F cluster but I needed to fit a RPM signal converter since the cluster is programmed to read a signal from a V8 not a V6 so I opted to sell it and just do a blue LED swap on the original.
I see man, good and bad news, still it is awesome the project continues!
Have a few questions, before you go MIA on us, ha ha... Have you had a chance to tear up the damaged engine? if so, was there crankshaft, rods failure, or was it only the piston?
To check air fuel ratio, is it with a Innovate wideband?
And how much did the engine cost you?
I have seen on other boosted applications, like on K20s (Honda motors), they get rid off/disable variable valve timing, I think it was because boost compensates for the higher cam profile need and resolved a lot of their tuning issues. On Mazdas V6 2.5L engines, on the MX-2, on boost, it would make ridiculous power, the infamous KL-ZE.
Last edited by GrizzlyMan; Aug 17, 2022 at 07:47 AM.
IS250 Single Turbo build
