(TURBO) The Chronicles of a Turbo II Swap
Senior Member
Joined: Feb 2004
Posts: 264
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From: Montgomery, TX
Good job Scott, now when are you going to take that bad boy to the track? I've been quirious about what kind of times it would generate ever since our test flight-lol. By far the fastest RX-7 I've ever driven.
If you're worried about breaking something there I could always bring my truck and a trailer. I've been wondering about the truck also, might want to run you
8.1 liters naturally aspirated vs. 1.3 liters turbocharged, 4700 lbs. vs. 2000. I would think you'll kill me - LOL.
Vernon
If you're worried about breaking something there I could always bring my truck and a trailer. I've been wondering about the truck also, might want to run you
8.1 liters naturally aspirated vs. 1.3 liters turbocharged, 4700 lbs. vs. 2000. I would think you'll kill me - LOL.Vernon
Originally Posted by NewRXr
Good job Scott, now when are you going to take that bad boy to the track? I've been quirious about what kind of times it would generate ever since our test flight-lol. By far the fastest RX-7 I've ever driven.
Originally Posted by NewRXr
If you're worried about breaking something there I could always bring my truck and a trailer. I've been wondering about the truck also, might want to run you
8.1 liters naturally aspirated vs. 1.3 liters turbocharged, 4700 lbs. vs. 2000. I would think you'll kill me - LOL.
8.1 liters naturally aspirated vs. 1.3 liters turbocharged, 4700 lbs. vs. 2000. I would think you'll kill me - LOL.Good to hear from you, its been a while.
Scott
Last edited by Rex4Life; Dec 8, 2004 at 06:43 PM.
Originally Posted by NewRXr
Scott we could take our junk to Baytown one weekend, there are times when you can test and tune or run street cars for kicks.
Vern
Vern
Scott
RB Powerpulse Muffler--Sounds Great
Well a few weekends ago I had a new RB muffler installed and here's what it looks like.

I did it just like Iotus's setup--81/82 street port muffler with a 2-1/2" piping over the axle.
Sounds just like they say in the RB catalog, "an improved note-deep and throaty, with no metallic character". And when you really get on the gas, it sings praises of the rotary engine--I love it. Putting around it's loud enough to be noticed but not obnoxious.
Oh and I don't know why people don't like the looks of it, I think it looks great and really matches the car well.

I did it just like Iotus's setup--81/82 street port muffler with a 2-1/2" piping over the axle.
Sounds just like they say in the RB catalog, "an improved note-deep and throaty, with no metallic character". And when you really get on the gas, it sings praises of the rotary engine--I love it. Putting around it's loud enough to be noticed but not obnoxious.
Oh and I don't know why people don't like the looks of it, I think it looks great and really matches the car well.
Last edited by Rex4Life; Dec 10, 2004 at 10:06 PM.
it's restrictive enough for stock 
might as well just use stock muffler... or in this case, i would've just bought a used FD muffler. almost same traits, except i'll bet the FD is less restrictive than the RB muffler

might as well just use stock muffler... or in this case, i would've just bought a used FD muffler. almost same traits, except i'll bet the FD is less restrictive than the RB muffler
Yea I would have liked to get the RB muffler for the FDs--now that's a sweet muffler, but $500 IMHO is too much. I looked at a few stock FD mufflers and I wasn't impressed.
FWIW this primaflow is the special "high flow" version used for road racing, it's louder and less restrictive than the standard primaflow. Honestly, this muffler is on my limit for being too loud--any louder and I would not like it-remember this is my daily driver.
Right now my biggest HP loss is my MBC. The boost response is very fast when I turn up the boost (so the system is flowing good), but it's a PITA tuning that thing for different air temps. Once I tune in the MBC it works great till the temp changes significantly. An EBC would solve that problem nicely.
FWIW this primaflow is the special "high flow" version used for road racing, it's louder and less restrictive than the standard primaflow. Honestly, this muffler is on my limit for being too loud--any louder and I would not like it-remember this is my daily driver.
Right now my biggest HP loss is my MBC. The boost response is very fast when I turn up the boost (so the system is flowing good), but it's a PITA tuning that thing for different air temps. Once I tune in the MBC it works great till the temp changes significantly. An EBC would solve that problem nicely.
I just spent 4 hours reading this thread, and your attention to detail is nothing short of outstanding! it appears that you met all of your design goals and are quite happy, Congrats: I will be doing the same soon I just got a 1984 turbo lSE limited (JDM) (i live in Japan).
I was inline to buy one that was already done see thread https://www.rx7club.com/forum/showthread.php?t=375313 but I ended up getting a 12aTurbo model instead. I will be doing the 13b swap later after the funds get replenished. Would you know if the JDM computers, and harness use the same layout for the ECU pins? remember all of my wiring is on the opposite side of the car, but as long as the ECU's pins are the same it should work.
regards
Kenn
I was inline to buy one that was already done see thread https://www.rx7club.com/forum/showthread.php?t=375313 but I ended up getting a 12aTurbo model instead. I will be doing the 13b swap later after the funds get replenished. Would you know if the JDM computers, and harness use the same layout for the ECU pins? remember all of my wiring is on the opposite side of the car, but as long as the ECU's pins are the same it should work.
regards
Kenn
Originally Posted by d0 Luck
rex4life, when u passed smog i'm presuming that you are using the airpump along w/ what catalytic?
Originally Posted by kenn_chan
I just spent 4 hours reading this thread, and your attention to detail is nothing short of outstanding! it appears that you met all of your design goals and are quite happy, Congrats: I will be doing the same soon I just got a 1984 turbo lSE limited (JDM) (i live in Japan).
I was inline to buy one that was already done see thread https://www.rx7club.com/forum/showthread.php?t=375313 but I ended up getting a 12aTurbo model instead. I will be doing the 13b swap later after the funds get replenished. Would you know if the JDM computers, and harness use the same layout for the ECU pins? remember all of my wiring is on the opposite side of the car, but as long as the ECU's pins are the same it should work.
regards
Kenn
I was inline to buy one that was already done see thread https://www.rx7club.com/forum/showthread.php?t=375313 but I ended up getting a 12aTurbo model instead. I will be doing the 13b swap later after the funds get replenished. Would you know if the JDM computers, and harness use the same layout for the ECU pins? remember all of my wiring is on the opposite side of the car, but as long as the ECU's pins are the same it should work.
regards
Kenn
Sorry but all I know about JDM engines is they come from Japan. I've heard they are very similar to our engines so most of the info will probably be good, but you'll have to decide that by yourself.
Scott
Throttle Cable Routing
I was recently asked about the throttle cable routing and thought it would be a good idea to post it on the thread.
I used a stock S4 T2 throttle cable. Basically there are five attach points: stock FB firewall throttle cable hole, custom aluminum bracket for UIM, air pump bracket, BAC valve, and the stock S4 UIM throttle body.
The hardest part of this was the custom aluminum bracket. I made it out of 1-1/2" by 1/8" thick aluminum. Since I ditched the TMIC and it's large ugly bracket, I had to make something to hold up the drivers side of the UIM. This bracket is basically an L shape and really easy to make. Wish I had drawings and pics of it but take my word for it--easy. I decided to also use this bracket to mount one of the throttle cable attach points. Works like a charm.
Here are a few pics of the install. Actually it looks better than the stock S4/S5 cause it is recessed down lower so it's not so obvious and sticking out. Perhaps in the future I will try to remount the BAC attach bracket to keep the cable from rising up at the end there--but I think that will require a new type of bracket.



As a bonus: also shown is one of silverrotor's FD alternators installed on the S4 engine.
Scott
I used a stock S4 T2 throttle cable. Basically there are five attach points: stock FB firewall throttle cable hole, custom aluminum bracket for UIM, air pump bracket, BAC valve, and the stock S4 UIM throttle body.
The hardest part of this was the custom aluminum bracket. I made it out of 1-1/2" by 1/8" thick aluminum. Since I ditched the TMIC and it's large ugly bracket, I had to make something to hold up the drivers side of the UIM. This bracket is basically an L shape and really easy to make. Wish I had drawings and pics of it but take my word for it--easy. I decided to also use this bracket to mount one of the throttle cable attach points. Works like a charm.
Here are a few pics of the install. Actually it looks better than the stock S4/S5 cause it is recessed down lower so it's not so obvious and sticking out. Perhaps in the future I will try to remount the BAC attach bracket to keep the cable from rising up at the end there--but I think that will require a new type of bracket.



As a bonus: also shown is one of silverrotor's FD alternators installed on the S4 engine.
Scott
Last edited by Rex4Life; Jul 24, 2005 at 08:13 PM.
AAAHHHHH, my favorite thread of all times is back to life! Anyways, can you please post a larger pic of the top view of your engine (the one from your sig)

Are you still running the stock turbo? What size intercooler piping are you using? How quickly's the tubo spool? I noticed the nice reducer coupling from the turbo to the intercooler piping, I'm gonna need some of those couplings. My buddy tells me to keep my piping from turbo to intercooler the same size as the outlet on my turbo which is 2" (bnr stage 2 hybrid), then go up in size from intercooler to throttlebody and that will keep lag down to a minimum. I would like to do 2.25 h to intercooler and 2.5 from intercooler to tb. Just wondering how quickly yours spools?
Now that youve had some time to enjoy your car, how's it feel?
thnx

Are you still running the stock turbo? What size intercooler piping are you using? How quickly's the tubo spool? I noticed the nice reducer coupling from the turbo to the intercooler piping, I'm gonna need some of those couplings. My buddy tells me to keep my piping from turbo to intercooler the same size as the outlet on my turbo which is 2" (bnr stage 2 hybrid), then go up in size from intercooler to throttlebody and that will keep lag down to a minimum. I would like to do 2.25 h to intercooler and 2.5 from intercooler to tb. Just wondering how quickly yours spools?
Now that youve had some time to enjoy your car, how's it feel?
thnx
Last edited by RotaryRevn; Jul 24, 2005 at 08:49 PM.
Originally Posted by RotaryRevn
Are you still running the stock turbo? What size intercooler piping are you using? How quickly's the tubo spool? I noticed the nice reducer coupling from the turbo to the intercooler piping, I'm gonna need some of those couplings. My buddy tells me to keep my piping from turbo to intercooler the same size as the outlet on my turbo which is 2" (bnr stage 2 hybrid), then go up in size from intercooler to throttlebody and that will keep lag down to a minimum. I would like to do 2.25 h to intercooler and 2.5 from intercooler to tb. Just wondering how quickly yours spools?
Now that youve had some time to enjoy your car, how's it feel?
thnx
Now that youve had some time to enjoy your car, how's it feel?
thnx
It still runs good but with the S4 ECU I inherited the dreaded 3800 rpm hesitation. So long as I get on it, the problem is not there, but when easing on the throttle--sometimes I get the hesitation. I've been thinking about the megasquirt ECU but right now I don't have time for another project. I think I'll just enjoy the nice ride for now.
Scott
Originally Posted by Rex4Life
Yes it's still the stock S5 turbo. I'm using 2-1/2" aluminum piping. The biggest factor was affordable and available. The best I could find at the time was 2-1/2" mandrel bent tubing at <http://www.roadraceengineering.com/mandrelbends.htm>. They now have 2-1/4" available. I don't notice any boost lag but I'm sure it has more than the stock setup. The boost gets up there pretty quick. With the setup I have I could easily move up to a bigger turbo and still have sufficient fuel and intercooling. The Porsche front mount has done a great job. Once I measured the outlet temp it was pretty close to ambient. I know it is way better than any TMIC I could install on the FB. I have installed the FMIC with all the stock PS and A/C still in place, pretty hard thing to do. I know I have some pressure drop due to the piping length, reducers and bends, but the bigger piping helps alot. I remember calculating the pressure drop and it was less than 0.6 psi at 280 FWHP.
It still runs good but with the S4 ECU I inherited the dreaded 3800 rpm hesitation. So long as I get on it, the problem is not there, but when easing on the throttle--sometimes I get the hesitation. I've been thinking about the megasquirt ECU but right now I don't have time for another project. I think I'll just enjoy the nice ride for now.
Scott
It still runs good but with the S4 ECU I inherited the dreaded 3800 rpm hesitation. So long as I get on it, the problem is not there, but when easing on the throttle--sometimes I get the hesitation. I've been thinking about the megasquirt ECU but right now I don't have time for another project. I think I'll just enjoy the nice ride for now.
Scott
Originally Posted by Directfreak
You have a Cat, and No Air pump? If so, how has it survived?
sweet dude, i im working on a 1984 gslse and i want to super charge, but i have never done this before. my car is not turboed so i have no clue what to do or how to do it. please help





