1989 GTUS 4 rotor build....NOT! Hello Darkside..

[Christopher W.]

I have an over 13 year GTUS 4 rotor project.  I have been planning for a few years to do 4 rotor with Whipple.  I have now sold the Whipple and Defined Autoworks in Ohio is selling my 4 rotor.  I am over dealing with rotary stuff.  Even though in dream world the 4 rotor would be incredible, I don't care.  I just want my car to be finished and easy to deal with. 

That being said, I haven't hardly looked at RX7 or any other car forum for years.  I am 59 years old and really don't care much about this shite anymore.  But once a gear head always  gear head.  The thought of having to look into all the little ins and outs of putting this together is number one daunting and number two of no real interest. 

Logan of Defined Autoworks has done a couple of LSX swaps.  One a 240SX and the other a 3rd gen I think it was.   He will be doing the install.

Here is my thread on RS7 Club. 

https://www.rx7club.com/20b-forum-95/1989-gtus-20b-n-build-thread-812148/      (Fixed The Link)

Lots of work has gone into this car.  It started out a pristine 1989 GTUS with 48k and one owner.   I don't really want to go into all the work that has gone into it.  Logan has been great but other issues with people have caused problems.  4 months to do the metal wide fenders turned into two years with a jack ass in Missouri and the end result was shit.  So I had to pay another person almost the same amount of money to do over the work.  It turned out beautiful.  Logan wasn't the one that took 2 years to screw up my car.  But he did find a company near him to sort it all of the body and paint out. That and parts taking almost two years to get back from New Zealand put the project back and back and back.  Now the world has changed and I just want my car finished and usable. 

Enough bitching...I have some questions to glean information from people who have been there and done that concerning 2nd gen LS3 installs. 

I can't seem to get pictures to upload.  Here is a Google Drive link with some picts.   

https://drive.google.com/drive/folders/1JxaVGqbJj5KgAmsGkHdFIkqAziOzYqdU?usp=sharing

I will post some questions soon. 

[digitalsolo]

Welcome. 

[kinger]

Good choice, you will be driving soon!  Really hard to beat a LS.  Perfect engine for these chassis!

[Christopher W.]

I am going to ask for some leeway with my questions.  I just don't have the time or the drive to sift through thousands of posts for all the information. 

I want to look at macro possibilities before I dive into micro.

Just for simplifying my process and not get into the weeds at this point, I want to consider as if I was buying a GM Performance crate engine with all accessories.  This might not be something that is possible for all options but for me to drill down into the engine I will get I want to ask in this way.  I have to have A/C in Arkansas.  I have a depowered steering rack but might consider going back to power steering if the 2nd gen w/LSX can handle A/C, Alternator and P/S.  I really don't have any idea what will fit and not fit.  I know there are other LS and LT options and I want to consider all of them as long as they are aluminum block.  I was going for a 4 rotor Whipple so I am willing to go hard into the engine bay but I want a complete engine package and not to try to pull various parts together. 

So if you had a big bank account...I do not...and the GM sky was the limit, what engine package would you get that will fit and run without complicated mods. 

I assume you can make a LT1 work but I don't know how much extra work is involved or if it is worth it.  The LT would have cool factor.  No matter what engine I choose, I want to have around 500rwhp. 

I have a brand new TR6060 I bought a few years ago so that part is done.  I am not sure if I am going 8.8 or just use my Frankenstein stockish rear end for a while. I have a FC case and shafts with FD diff.  I also already have an Ronin 8.8 mount kit as well. 

At this point in my planning stage of car projects, I usually need someone to step in and tell me forget shooting for the stars dude...just shoot for the moon and be happy....if you get my drift.

[kinger]

I hear ya on the question but you will need details to understand this.  That said high level:

Ronin LSX mount kit, 8.8 rear, TR6060 mount, Radiator (this is coming out get it if your NA)

Any LS engine but you have to pick between Cathedral heads (early LS stuff, GOOD), rectangle port heads (LS3, LSA, LS9, BETTER), or LS7 (BEST) heads.  This can vary but real quick Cathedral will make 450 whp, Rec heads will get you 550whp, and LS7 stuff over 600 whp.  Cheapest is LS3 based engine stock lower end, ported heads.  LS3 intake is actually really good out of the box. 

You need a FBody 98-02 Camaro oil pan on any of them so if you did go crate you will have to swap the oil pan no matter what

Intakes, all stock fit well.  You will have to modify the back cowl, as small as trimming the lip on the firewall, to hammer and denting it a good 1/2" plus to fit FAST and MSD intakes, also may have to cut some webbing on the stock hood to fit the throttle body.  Stock to Fast 92mm fit easy, FAST 102 harder, and MSD Atomic hardest to fit.

You will need to extend the shifter roughly 3.5" and it will fit in the center of the stock hole.  Some minor hammer work inside the tunnel is needed. 

Wiring - Probably one of the worst parts.  You can go easy and try to leave as much OEM in tact as you can and just add the circuits for the motor, or gut the engine harness, and add all new and patch it back into the car where you can.  You can go mild to wild here.  You need to asses what your capabilities on this.  Hiring it would get expensive quick. 

Tuning - You go stand alone (Holley, Haltech, Megasquirt, Motec, etc) or with GM ECU.  The GM ECUs are fine if you just need it to run, us HPtuners to tune it (wire in the OBD port) has a learning curve but cheap, easy, effective, and well documented. 

Gauges - OEM ones can work with a Dakota Digital converter for speedo, or go aftermarket, my Speedhut gauges fit in OEM cluster with some work but look OEM now. 

Fuel just get a good Bosch 044 fuel pump and -8AN Feed and -6AN return lines.  Corvette regulator or any aftermarket.  Dial in 58psi of Fuel pressure

Battery - relocated to Rear bin

If you take each of those and search on it one at a time it will help you get to a decision point faster. 

Good luck!

[FC3S Murray]

I know you don't want to read a bunch of threads but check out mine. I have an '04 LS1 with all the goodies.
I started my darkside journey back in 2010 & I have lots of info in my build thread that will help you with chassis and electronic related concerns.


If I were to do it all over again, I absolutely would install an LS3 (or find an LH9, L92). The Gen 4 LS's just make outstanding power with the rectangular port OEM cylinder heads and a cam. I have tuned multiple L92's and they wake up with a good tune!!

GM's E-Rod option is great. You can change out the cam to something a little hotter and have a rocket for an FC. The factory PCM can be reprogrammed (the E-Rod came with the E38 PCM which in my honest opinion is the best Operating System).


Go with a Ronin 8.8 rear end with 3.73's and again, the TR6060 transmission OR a well built T-56 if you can find one.

Power steering and A/C can be done. Power steering info is in my build thread as well.

If you want to keep your OEM cluster, swapping in the guts from an Acura Integra works very well. There is a sticky in the Electronics Section of the forum. Not too difficult.

I used a PSI wiring harness for the engine. E-ROD comes with a harness.

I have had my swap done for 11 years and it hasn't skipped a beat. I am hard on it.


I don't miss the rotary at all. Torque is addictive

The swap only took me about 7 months. I had 2 kids who were 1 and 5 at the time, worked full time and am a military man. I would have got it done in 3 months if I wasn't tending to my responsibilities so much during that time frame.

The swap is a perfect winter project.


If you have any tuning questions, hit me up as well. I do GM PCM tuning with HPTuners as a side hustle. My Instagram link in my signature will point you that way.

[Christopher W.]

Thanks Murray and Kinger!  That sort of response gets me moving forward. 

Murray, I have been reading your thread.  Great information.  You two really set me in motion.  Now to get Logan in motion. 

I don't mind reading threads.  I needed some basics to get going instead of sifting through stuff to get the basics. 

Looking forward to this setup almost more than the 4 rotor.  Hey, I don't have to put oil in my gas tank.  I can start the car and not set off every neighbors car alarm and scare small children and my cat.  This has to be the smartest thing I have ever done with a RX7.. 

[FC3S Murray]

No problem man, my pleasure.


Make sure to skim through @largeorangefont's thread too. He has some great info in there as well.

[Christopher W.]

New crate engines are unobtanium for now and no one knows how long till they are available.  Plus there is a line of people already waiting.  I am going for a low mileage pullout.  I wish they would sell them without the transmissions as I already have a new one I bought from GNX7 a few years back. 

Let me clear this up so I can relax a bit in my new found LSX searches. 

I assume no factory supercharged LS engine is going to fit under a stock 2nd gen hood? 

How much of a hassle, or can it even be done to install a 2022 Camaro SS 6.2L Gen V LT1 Engine in a 2nd gen RX7.  It isn't supercharged.  I am asking in comparison to say a standard Camaro 2012 LS3 complete pullout.



 

[FC3S Murray]

Not many LT swaps have been done or at least documented for an FC.


The LSA or LS9 will not clear the OEM hood at all. Aftermarket cowl required which looks very redneck.

[kinger]

I forget the exact list of why the LT1 (newer one) will not fit but its exhaustive I remember.  No headers work, no mounts, no good oil pan, etc.  There has been one that I know of but that was in a FD.  Anything can be done with a lot of work but a LS vs LT is not that dissimilar to the 4 rotor to LS.  LS just is a better swap.  I really wanted a LT4 but its not even close to fitting plus all the work listed above and more.  LS7 based engine will make same power.  Any boosted LS will make 800+ whp.  Boost just makes it so much more complex, lots of heat, tight little engine bay, etc. 

I would be looking for LS3 and a good set of heads and rock 550whp and 18-25 mpg.  The shorter rods in the LS3 seem to get better mpg then the 4" stuff like I am in.  I avg 14-19mpg but its really only driven hard, I didn't buy it to putz around and get good mpg.  It is a cool perk in the ls3 though. 

[Christopher W.]

Definitely going with the LS3.  I seem to be focused on Hawks Motorsports....?  They sure have the inventory on hand.  I see on ebay that have a "Make Offer" button.  I wonder how much they might drop? 

I can probably swing a cam at first before the engine is installed.  Heads are not something I want to jump into right now.  I just want to get this moving.

Is it very difficult to change the heads while the LS3 is in the engine bay of the 2nd gen? 

The over complications of boost is nothing I want to deal with for sure.  Hey, my car is a GTUS.  At least I can continue some of the spirit of car with a N/A engine!

By the way, how do you put up pictures?  I try to load them but they never actually load. 

[FC3S Murray]

So heads not difficult to swap while the engine is in the car. Brake booster makes last head bolt sort of a bugger but not difficult.


Again, an LS3 with a proper camshaft (CamMotion highly recommended) is going make fantastic rwhp. Head swaps are not necessary if you are shooting for close to 500 rwhp.


Don't waste your money on a throttle body or aftermarket Intake, the OEM LS3 intake is hard to beat. Use that money towards good long tube headers, a proper X-pipe and mandrel bent exhaust.


So to post pictures you have to click the "preview" button next to the "post" button below the text box.


Once there, you will see "Attachments and other options"
You can upload pictures there. Remember phone pics are large in size so you will have to reduce their size to 1000kb max using your editor or Pixlr (I use that).

[Christopher W.]

2nd gen sexy rear end...

Front: 18x9 +23 Toyo R888 255/35R18
Rear: 18x11 +38 Toyo R888 295/30R18

ForgeLine center center lock conversion.

My freaking Toyo 888 are 10 years old and have never been driven on. I figure they are flat spotted at least.  I have not seen my car in 7 years or more.  I don't even remember.  God I bet the interior is getting brittle...ugh.

The second picture is how it was when I bought it. 

[shainiac]

I have the same tire sizes on my FC and the 295 R888Rs work pretty well on the street. My car is turbo and has boost-by-gear, but even on lowest boost (~450whp), it spins easily in 1st gear and can spin in 2nd if not warmed up. That said, they will hook over 600whp in 3rd and 700+ in 4th. My tires are 4 years old now and get stored in an garage without climate control. No noticeable drop in grip, but they are and always have been stupid loud. If you didn't know better, you'd swear my car has 4 bad wheel bearings lol.