Project Factory Optra

As for the future of the Optra, my original intention was to remove the turbo related parts and use every bit I could on the IS300, thus converting the Optra back to NA. However when I was at the shop I was convinced to keep it turbo, but with a setup oriented towards driveability, useful torque and quick spool. Essentially converting it to a factory turbo car.... how it should have come from the factory

We used a CT12B turbo which is one of the stock twins from a 1994 USDM Supra. Max power it can push is about 220whp. Here you can also see the modified section of the downpipe and the custom internal gate setup with a 6psi actuator. Also the manifold has been modified to fit the smaller turbo with a set of T3 flanges. The whole turbo/manifold package is very compact.



CT12B taken apart:




The following parts will be donated to the IS300 project (yet still allow the optra to run low-mid boost)

- Precision FMIC
- T4/T04B Turbo
- Walbro 255 Fuel pump
- Return fuel system
- Apexi AVCR
- Supra TT OEM muffler (in trade for the IS300 OEM muffler)
- Turbosmart 38mm external wastegate
- TurboXS BOV
- Water/meth injection kit

The Optra will be tuned for 91oct gas.

 

It wouldn't let me post more than 12 pictures at once!


Stock IS300 muffler adapted to fit the Optra:



The setup with new intercooler and a random oldsschool HKS BOV:




Stay tuned for more

 

Good luck with your new project! Are you going to sell your Optra?

 

Thanks. I'm keeping it for now, its nice to have 2 cars, especially soon 2 turbo cars!!

 

ha!! i was just thinking about you today how much boost/HP was the optra running? i like the new car!! should be a fun project looking forward to seeing more of the build

 

Thanks for thinking about me lol Well when the old turbo setup came off it was running ~13psi / 260whp daily. Now its running ~6psi on the CT12B, but boost tapers off in the top end, so I'm going to get a little manual boost controller to help level it out before dynoing it.

I'll post pictures of the Lexus build as it comes along if you guys are interested.

 

Please do post the pictures. I am really interested to see how your new project will turn out.

 

Just thought I'd post review of the new turbo setup since I've been driving it now for about 2 weeks.

This setup is actually still alot of fun to drive! The torque is available much earlier (as I get full spool 6psi at 2300 - 2500 RPM). You can even feel the added torque before its fully spooled down to 2000 RPM. I can literally drive 25km to work without shifting over 3000 RPM and still be getting ahead of most traffic Even just cruising around in 5th or 6th gear, you just dig into the throttle a little and theres no problem to pass anyone. And when you do rev it out the car is still quick enough (altho not as fast as before ofcourse).

For anyone looking for a suitable turbo to put on their Forenza/Optra to make under 200whp I would say this is a good choice. They are cheap and readily available and provide a nice bump in torque and power.

Now just waiting for my manual boost controller to be delivered

 

Update to the setup

Well its been quite a while since I've updated this thread, but I finally have some new stuff to post

Soo I'm changing the setup on the Optra a little bit.... My goal is for 200whp on the small CT12B turbo. To achieve this, I've collected the following parts again:

External wastegate (for more precise and stable boost control)
Apexi AVCR (the one I had went to the IS300 project. But this boost controller is absolutely amazing for RPM based boost - so I've acquired a second one)
Return fuel system (I already have the modified pump basket and Walbro pump, so I just needed to find another regulator)

Right now the car sits at about ~165whp .... so another ~35whp to achieve my goal

Oh I should mention... I'm still keeping the stock Lexus IS300 muffler on here for the near-OEM quietness...

Will the turbo actually do it??? Stay tuned to find out

 

Here's some pics of the new (and used) parts:

Another Used AVCR for progressive boost control




A friend hooked me up with this, after his project outgrew it lol. I must have return system to run any more than 8-10psi. Yes I could have just kept the car return in the long run, but I didn't have the cash to do that during the IS300 build.




Going back to external wastegate.... the internal one just sucks for precise and accurate boost control.

 

Here we have the new external gate welded on along with a slip fit recirculated dump tube...

Also if you look closely, you will see that we ported the compressor cover for anti surge and increased turbo spooling sound




More soon ...

 

looking good. nice to see you working on the forenza again. maybe this will help breath some life back into the forum. waiting for updates!!

 

Thanks! We started it up last night to check for leaks etc, and the turbo sounds awesome now when you put some load on it haha.

And ya, this forum does seem quite dead lately, especially the performance section

 

Here's some pics of the fuel system setup... I have switched my 2 additional injectors over to Siemens Deka 63 lb/hr as they are supposed to have one of the widest spray patterns which is well suited for the throttle body type injection they are being used for. We also tried to run as much hardline for the return as possible under the car (the line actually goes up into the engine bay).





Couple views of top and bottom of the turbo area / piping.

 

looks really good. i bet it does sound nice hopefully the turbo will keep up. makes me want to go turbo now!! lolol yeah mostly people join the forum ask a question or two and disappear. its to bad it used to be such a great forum.

 

looks really good. i bet it does sound nice hopefully the turbo will keep up. makes me want to go turbo now!! lolol

Yah man, the turbo sounds amazing now!!! I went for a first quick test drive last night and WOW.... lol I am in love with this sound. Can't really rip it until its tuned again, but that will be happening shortly and I'll post some vids.

 

yeah im curious to see what HP you get when tuned. i do love that turbo sound!!

 

forgive me for asking a dumb question, but how are you tuning the car? stock ECU or standalone?

 

Its all good, if you are somewhat new to the forum you wouldn't know the history behind the car. It is tuned with Emanage blue + additional injectors. I have left timing completely stock and it actually works out quite well. This project has changed over the years, starting back in 2006.

you can see the whole story since day1 here:
Daewootech.com • View topic - Turbo Optra - Squeezing a little more from a pea sized turbo

 

CT12 Dyno Results

Finally got this little badass setup tuned, and I'm quite happy with the results.




Despite the turbo being undersized for 2.0L we managed to squeeze out:

214 whp / 207 lb ft.




Through progressive boost tuning I was able to keep the torque nice and stable until about 5500 rpm where the tiny turbine starts to choke its life away haha. We were able to verify this by testing exhaust back-pressure pre-turbo during the dyno runs with a boost gauge. This is about as far as we dare to go on this turbo, and the numbers make perfect sense. Two of these turbos on a Supra 3.0L can crank out about 450whp max, so we are pretty much at the limit.



All in all not a huge amount of power, but this is quite fun to drive on the streets because the power is always there from almost any RPM.



Stay tuned for dyno video

 

nice results. you gotta love that quick spool up. a decent jump in HP. do you remember what your cars HP was before the turbo?

 

Do you mean stock? If thats what you are referring to, my stock dyno came in around 107whp with full exhaust and open throttle body. Granted that was with the turbo housing and manifold still in place, just no turbo in it lol. If I had a proper NA header, it probably would have been more like 115whp or so.

 

Dyno session video!

As promised, here are some dyno clips:

 

that looks like fun! good power curve, too... bet it'd eat a GTI, lol...

 

Stock and near stock ones are no problem

ooh yeh i was talking stock. that number is fine just wanted a rough estimate of what it might be. car looks great!!

Thx

 

ooh yeh i was talking stock. that number is fine just wanted a rough estimate of what it might be. car looks great!!

 

i was looking through your build again and man i need to get moving on mine. i have all the parts just a tad bit short on the money part tuning can get expensive thats the main issue. i cant wait to have everything put together. i just found and picked up a nice piece for the car. took a long time to hunt one down but i just got an official "Suzuki Sport Racing" steering wheel. since there is no more suzuki racing division, they sold everything to "MONSTER SPORT", there wont be any more made. been trying to find one for a couple of years now and finally lucked into one on ebay of all places!

 

Yes tuning is what makes or breaks the setup. You can spend $20k on parts and if the tuner doesn't know what they're doing it will run like a bag of shit or even worse be damaged.

Are you actually planning to go turbo?

 

yeah i have a great shop and tuner. just not all the money yet. im really not sure about going turbo in the future. right now i have the independent throttle body set up im trying to get put on should be a nice bump in power. most of the cars that come to the shop are turbo builds, im getting to like them more and more. i can always go turbo with the itb's, that would be nice unfortunately moneys just a little tight right now so the build goes little by little.

 

Amazing work you've had done man, looks outstanding. I've driven a few IS's and they can be a fun car to drive when done right.

Now I am curious about one thing here, as you mentioned something about your tranny now being rare and up there in miles. When you bought your lacetti was it an AT transmission? Or did you get the 5 speed w/ it and just do a swap?

I'm curious because I'm seriously considering converting my AT into a MT, and it would be nice to know that its been done before, and done succesfully. Of course this is something that used to be much simpler years ago.. (from what I've heard anyway)

 

Thanks man, if you are interested to see more about the IS, you can check out the build here:

GT40R IS300 5MT - TRD diff completed - my.IS - Lexus IS Forum

As for the transmission, I say its rare because I have the F28 Getrag 6 speed transmission. These transmissions were never sold in North America, only over seas in Europe, Japan, etc. And on top of that they were only sold in the 1992-1997 Opel Calibra's mated to the 2.0 turbo C20LET motor. So having said all that, my point was if I start making alot of power (>400whp) and I break the transmission, finding replacements is getting harder and harder. Although since the time of writing my initial concerns, I have secured a spare F28 and had it shipped over from the UK..... just in case something happens to mine

 

So I just realized I didn't even answer your question... Mine was originally 5spd MT. I only did the whole 6spd swap because I broke 2 of the stock 5 speeds... they are only reliable until about 200 lb ft of torque :< The 6spd is much stronger.

 

now, does the F28 bolt to the stock u20sed engine, or are you running a c20let?