Need Boosted vs. Naturally Aspirated opinions...
 

I have the opportunity for a turbo 12A kit that would be a bolt on to my current motor. I have been told that tuning a holley carb with a turbo is quite difficult. My alternative to this turbo setup is porting and NA carb work.

First off I'd like to explain what it would be used for and my price range
-I will be using this car as my daily drive as well as an autocrosser for the summer.
-I am not made of money but have about 2k to spend.
-I am not completely car tuning literate
-Need Reliability over power
-I commute 50+ miles a day so MPG would matter


So my question is should I port and do other NA mods
or
boost the 12A with https://www.rx7club.com/showthread.php?t=738165

I am looking for 170+hp'

My current mods include:
Full catless exhaust
mechanical secondaries
Full emissions removal


Thank you for your input

Wow, a bolt on kit? Looks like a decent deal if everything is in good condition.

Turbo MPG is never great. Neither is a super ported NA engine. A large streetport with good exhaust and an AFM carb will put you closer to 170 but you are talking a 70% increase in power with only a few mods, not overly easy while retaining daily drivibility.

Id say go turbo, but i like turbo. It depends on what you like. That being said with a turbo set up you will easier make the power.

Him saying complete bolt on. Chances are you still need to do some porting. Probably not uber necessary but i would imahine your engine will be choking with the stock porting on the 12A

What if I port now and later see if turbo would be an option...turboed streetport 12A would easily make 170hp...

The motor the turbo setup would go on has 161000 miles and am unsure if its ever had a rebuild so I think boost would just blow out the apex seals like post-it notes....

Just get the bolt-ons. Carb, Exhaust, Ignition, Flywheel, then maybe some gears. For the power levels you are asking, you'd be fine. Port it later if you NEED to.

-DF

When you say bolt-ons...what does that mean exactly?

buy the kit, put it in a closet, then get all the power through bolt-ons. when the time comes to rebuild, port it then put the kit on. rome wasnt built in a day.

Directfreak are you saying buy the bolt ons mentioned AND the turbo, then port later if he finds its needed. or buy all the bolt ons without the turbo?

just curious what exactly you meant

Wouldn't the turbo setup be better for drags than DD and autocrossing?

Get the turbo kit. Keep stock ports. Easily around 170WHP, and if you stay out of boost (or not) you will get good MPG.

Use the S4 Turbo and build from there.

2 grand isn't a lot of money. You'll blow through it pretty quick.
Boosting a stockport will get you the power you want. It's NEVER a "slap on & go" deal. More power doesn't come that easy. Since you say you're not "completely car tuning literate", than you should know that "playing" with boost can have bad consequences if you don't know what you're doing. I'm not trying to dissuade you; go for it. Just be weary of a "deal", and make sure it has everything you need.

Sounds like the motor may be ready for a rebuild anyway. So, having said that I would recommend a decent street port and a good carb (cough, Sterling, cough). With the mods you already have you should be in great shape.

Besides, I don't believe a turbo would do you any good in autocross. Even with the best of tuning, you will have lag, and that can really mess you up when driving on the edge. You may also want to consider what class you would be in before you begin porting or forced induction work. And really, I never lost a race due to lack of horsepower, just lack of driving skill. Also, my Sterling works great in autocross, always providing reliably smooth power that makes all the difference, especially in the rain or on any other slick surfaces.

The last thing you want to do is try to turbo a motor that is in less than perfect shape. Use your money for a nice rebuild and possibly some porting, then slap a Sterling on there and off you go.

Feel free to check out some of my videos if you want to get an idea of the carb performance. Just keep in mind that this was on a stock ported motor with well over 200K miles on her. Go to www.youtube.com and search for Kentetsu1 and you'll find them. Good luck man! :)

If you want to keep your stock ports and just bolt on some extra power utalize your holly carb and bolt on a camden 7" supercharger. I have great drivability decent gas milage (staying out of the throttle) and excellent low end power. I havent tried the car at autocross yet but as soon as it starts up Im going.
Supercharging should give you the HP, drivability and reliability your looking for as long as you do the exhaust.

I got my turbo running garely good so far. I say grab it the camden is a good option and it sure is pretty much bolt on and go with very little fuss but its also alot more expensive. That kit while older and draw through is proven itself otherwise they wouldnt have sold it back in the day. When you get more serious you could dtich the intake draw through part get a regular holley mani and go blowthrough with intercooler

Once you go turbo you will never go back.

I would not want to do that to a commuter. Do you have some kind of open road or will you commuite in heavy traffic.. which would make a turbo useless for the mission IMO.

Get some piece of shit Honda or a truck to commute and fix up the RX7 with turbo.. since that's what your really WANT to do but treat it more of a weekend / night on the town ride. Just a suggestion..

Even if you turbo it you can drive around in heavy traffic not hitting boost and getting good mpg, while on the opener roads you can let it rip.

i would go for it but it all depends on your current motor if its old and tired the turbo is just going to cut life in half for it..

if its in great shape fork out and slap it on .

Holleys DO NOT like turns... Let me put it this way, I live right near/on a cul-de-sac. If I go up there and do a semi-quick 180, my car will almost die...

2 words-
Camden Supercharger.
Not in your price range but a sweet setup.:)

I just don't see the point in adding forced induction of any kind to a motor of unknown condition. What if he spends all his money to go turbo, then after a week the motor goes. Now he's got a broken car, with no money to fix it.

So I think the plan is to save the motor for this summer and rebuild/mild streetport, direct fire MSD ignition, and keep it NA.

I am going to save the boost for a 13B that is somewhat made of it. I have 2 cars to work with so I will have best of both worlds.

The 12A turbo is tempting, but here's where reality kicks in and like Kentetsu said, spend everything on this kit, then 3 weeks later when my apex seals go, im screwed. So i'll save the money and get it rebuilt this summer and keep it simple...

And having some cash on hand is always handy for when something breaks.

+1
go turbo and never look back :)
thats a smokin deal on that turbo kit

I had a Holley carb many years ago (on my 59 sprite with Judson SC) and it always crapped out on hard righthand turns. I replaced it with a Hardly Abelson 74 carb (brass casting with a toroidal balsawood float)which worked beautifully.

That turbo set up, looks like a nice deal! Turbo is the best way to go, imo. just dont surge or hit boost and you wont notice any difference in gas mileage. Turbos run really efficient, and only you will know more or less what your motor will take. The FBs Ive had have NEVER failed on me, but thats only in my case. If you have done all maintaince needed, you might have less to worry about. Good luck and keep us posted!