Papasmurf

Hey guys, I need some help with my drag RX7 that I was selling, but decided to finish the project. I have a totally gutted 80 that I ripped out the dash completely, and I am fabricating a sheetmetal one, I am also making a lightened steering column support.

Okay, what I need is help with the engine setup. I have a TII engine ready for some mods. I want to stay away from standalones and such because it is ONLY a strip car. I don' t know what kind of turbo to run, people are talking To4e's and such and T66's, but basically the way I am looking to set it up is:

1) I want to run race gas
2) I would like to run a blow through carb, but lack knowledge on the blow-throughs, like which type is best for my application, and which ones work best for race gas.
3)I want to run a 12at distributor and upgrade the ignition part big time.
4) A large turbo for the track, don't know which one would be best for this application.

I don't know of anything else I can add, I will probably switch to a 9" after all of this, but right now I am addressing the engine. If there is anything that someone would like to add, do so. Before anyone runs off there mouth and says I don't know what I am doing, then don't answer. To me, the blow through carb setup is a whole new ball game for me, I want to keep this simple for the track. If anyone has examples or pictures that would be great too. Thanks for anyones help.

vipernicus42

iTrader: (4)

Umm...

the first question that comes to mind is:

If you have a TII, out of a Second Gen.... Why the **** would you wanna put a distributor back on it? It already has direct electronic ignition, I don't understand your wish to re-distributor it? Especially with the distributor out of a 12a no less!

And before you think turbos, think porting. Porting a stock TII (with it's stock turbo) is a great way to get power. I don't know *crap* about turbos, so I'm not gonna say what type you should use or how, but I have heard that sidedraft carbs are good for turbo setups.

Good luck
Jon

pillage6

I have a set-up similiar to what you want, but it is my street car, so boost is set at only 12lbs.

The turbo is capable of like 26lbs., but my car couldn't handle that power. I lose traction more than anything on the street, but I would rather do that than start breaking trannys and stuff.

Directfreak

iTrader: (2)

Because you can't use a CAS without the stock ECU or some kind of aftermarket ECU. The distributor works flawlessly in hundreds of Turbo rotaries. Plenty running 7's and 8's in the 1/4 on a slightly modified stock 12A distributor. Remember there are plenty of Fuel-only ECU's that require distributors. There's nothing wrong with them. It's simple, and it works.

The Stock TII has a decent sized port from the factory. Don't bother opening up a perfectly good engine just to port it. After the engine is running (under boost), keep working on all the other items before porting. a Good street-port will only net you about 10% more power than your stock port. You can easily exceed 10% more power with more boost, better intercooling, better fuel, etc.

In the long run, Porting AND all the bolt ons would be the way to go, when you can't get any more power out of her.

As far as your Turbo Sizing, - that depends on what your end HP levels are going to be, and what porting you're going to run. A regular and inexpensive 60-1 will easily get youj 400 HP at reasonable boost levels.
On a light Racing Frame - that equals 10's if you hook up.

If you're going for BIG (470+) power, you will need to port the engine to push a bigger turbo (i.e. T-78)

My Turbo (63-1) will easily support 500 rwhp on a rotary, and still be extremely streetable, and is designed for both street/strip with extremely fast spool-up.

They Holly 600 or 650 DP works well in drag cars. The sidedraft cars are nice too, but can't flow as much as the big holleys. It's also cheaper to use a Holley carb as parts are plentiful, and manifolds and carb hats are a dime a dozen.

Mr BiG G

do a search there is an australian rotary developer who sells ceramic apex seals which they claim are good for upto 20 lbs of boost for daily driving and a whole lot more for race applications...they said they have been running 20lbs of boost for 3 months pf daily driving and there has been no problems with the engine....try getting those they are deffinately a good investment and then port it and run ur blow thru setup....should be good to go

peace,
Gufran

Papasmurf

I don't want to open it up and port it yet, it has low miles and the gaskets and such are another set back. If I get everything together first, I can see what I am working with, if I need to run faster or need more power, then I can port it.

The distributor, even the one for the turbo 12a is simple, and that is what I am looking for.

Turbo size- I would like to dip into the 10's but my goal is to get into the 11's. I am not driving it on the street, maybe a quick cruise(side exit exhaust, open wastegate!) but that would be it. This car will be lightened like crazy, and when I see I can easily dip into the 11's with slicks and a decent rear end, I will build a cage. The 60-1's power sounds great, but I think I would want a little more. And I don't need 500 hp right now, how about a 62-1 directfreak? I appreciate your guys comments on helping me. One more thing, are the hollys good with race fuel, 105-108 octane or so.

I dont want to stick with my stock turbo, this is a drag car, this car represents my shop, skills, and products.

Directfreak

iTrader: (2)

Well, for reference, that 12A Turbo (bridgeport) I posted a few threads back does 497 to the rear wheels on a 64-1 and 28 PSI, Full interior, cage, etc. Ran 10.17 letting off the gas at the end.

He since got a T-66 and make a little more power at lower boost (22psi)

If you want to run lower boost to achieve the same power or better, you need a bigger turbo. Post on the single Turbo thread. Sizing a Turbo is tricky, as you have to take into account many different factors:

Exhaust manifold shape
Boost Levels,
porting
Peak efficiency,
Powerband
intercooling,

and many more..

Again, You need to decide on how fast you plan to go, to calculate necessary power levels.

If you're really at 2100 or so lbs, 300 will get you in the 11's, and 370 or so into the 10's.

Using the stock port and stock Turbo, you can reach 300hp. After that, you're really stressing the system by overspinning that little turbo and creating lots of heat (which causes detonation).

Good Luck.

Mr BiG G

i have a question direct freak.....some people measure their boost in lbs...they say 16 lbs of boost and some others say 26 psi....is there like a conversion number or does it depend on the engines displacement?

thanx,
Gufran

Directfreak

iTrader: (2)

PSI = Pounds per square inch.

"16 lbs" = "16 psi".

Also, in metric measurements,(used outside of the US)

1 Bar = about 15.5 PSI

Mr BiG G

ahh now i get it.....ok so wat do u think would be the max boost on a stock 12a motor?

seanrot

iTrader: (2)

i thought 1 bar was 14.7 psi actually im pretty positive of that.

Sean

Directfreak

iTrader: (2)

That sounds about right.

1 Bar = Sea level pressure as well.

I just forget what's sea level pressure in PSI.

Directfreak

iTrader: (2)

There are just wayyyyyy to many variables to answer that intelligently.

Stock engine with no intercooling -- 8 psi max.

After that, it's all about the tuning and the combo. I have seen 45 PSI on rotaries several times, with no problem.

I've also seen them pop and detonate at 12 psi.

Mr BiG G

45psi....holy ****...thats a lot isn't it? on the mazspeed site they said they have ceramic apex seals which thay have found to handle upto 20 lbs of boost for up to 3 months with no engine wear and i thot 20 was a lot for a rotary 12a

mwatson184

Pic of my old setup. Blowthrough carb is rock solid when tuned correctly, and the 12at dizzy is what I ended up running too. It is a realy great setup but it is all in the tuning. Good luck and send me a pm if you are interested in my intake mani, carb, carb hatt, turbonetics t60-1, and exhaust mani.

-Marques

Papasmurf

Thanks for all the replies. I probably wouldn't want to run any more than 22 psi on the stock motor. I will search the single threads to see what I can come up with.

MWATSON184, do you have any more pictures and performance numbers with that setup?

Papasmurf

The 60-1 sounds like a good starting platform. If anyone thinks different, than say something. Like I said, 425 should be a start for a horsepower goal. Everything and anything that is not structural and does not make the car run faster, is being removed. I already started mocking up an aluminum dash, and the doors will have aluminum panels as well. I don't know what I want to do with the glass yet. Remember, I will run race gas. MWatson184, what kind of carb are you running? It also looks like there is no use of an intercooler, what kind of fuel are you running? If anyone else has experience with blow thru systems, please respond.

pillage6

Robert at RotaryShack.com runs about 15psi without intercooling.

I think that is crazy, but I guess it is all in the tuning.

FB II

always always!!!!! IN THE TUNING!!! if anyone sets up a turbo on their rx7 (any car for that matter) and just goes without extensive tuning to make sure everything is perfectly in check deserves to have their engine detonate. sorry, not trying to sound like a biatch, but it's not only for reliability concerns but tuning can give you that brink of the edge top performance capability! WOO WOOOOOOOO! dyno's OWN, and so do egt gauges. LOL

Papasmurf

They say on the site that the engine puts out 680 hp. I would like to know more about that system he's running but that must be the racers secret. But if you also run alcohol, there is no real reason to use an intercooler.

Papasmurf

Disregard my last post, I see he is using a water to air intercooler, or whatever.

mwatson184

You still use an intercooler when running alcohol for air densitys sake, not for detonation (same in diesal motors)

The Carb is a holley 600 (modified by racing beat)

The intercooler is from a turbo Volvo (25 - 60 dollars at junkyard)

92 octane at amoco is the best I can get where i live (suburb of kansas city), so that is what I run.

happy to answer any more questions.

-Marques