classicauto

iTrader: (3)

So, I've been playing around with my car trying to sort out a few issues lately and deicded I'd try and up the boost.

S5TII block, medium streetport
GT3574
325ml/min water injection
91 octane in the tank.

Should also mention the minor detail that the rear rotor has one chipped apex seal Should also mention, no I didn't pop it running this boost level. (I figure what the hell else can go wrong?? )

I've been running 18-19psi, and 23-25psi (much harder to regulate up there due to the 9psi spring...) for the past few days on the car and wanted to discuss the setup to find out the relative saftey of this boost level on pump gas.

EGT's: (all pre turbo)
20psi at 6500RPM would net around 1700-1750F on the front rotor(omitting rear rotor numbers due to lack of compression...) with the WI *ON*.

When I turned it off and ran 20psi, I could nearly reach 1850-1900F before 6K (was rising rapidly!!)....so WI appears much more effective at higher temperatures as running only 15psi with it on the EGT's are still only around 1700F, while WI off at 15psi would give 1800F solid. (BTW, the 15psi numbers are from before I blew the engine)


AIT's were hovering around 30-33C at25psi, no solid AIT's from 18-19psi - wasn't paying attention at the time.

Who else runs elevated boost levels (past the seemingly manditory 15) on pump gas? Am I wrong to feel that ~20psi would be safe on this setup after I rebuild the engine?

Discuss.

Viking War Hammer

iTrader: (8)

BUSTED7 Daily Drives his with 500whp and 93 octane. No AI is used, just straight pump gas. He's been running this forever, also beating on it and putting whoopins on big shot vipers.

classicauto

iTrader: (3)

500whp? nice.

See thats what I'm talking about...I'm thinking of sticking the T04-R back on with the new engine and shooting for closer to 500. I'm betting (if both rotors had good compression...) my 3574 would only be making about 440ish at 25psi, if that. Should be able to hit 450 by 20 on the 67mm turbo.

It seems like when you ask people about anything over 15psi, no one has any answers - or thinks you're running a billion octane race gas.

BUSTED7, if you're reading this, what kind of intake temps are you running? any special sauce in your recipe? You running 91? 93? 94?

NOPR

It seems like the quality of the set up starts playing a bigger role after 15psi. someone running 15psi with a stock top mount and an safc is probably much closer to the danger zone then a nice standalone car with a good cooling system and proper heat shielding and ducting.

classicauto

iTrader: (3)

Definetley!

But IMO, you *need* a good standalone and a solid setup before you really start going at it. But certainly a good point.

What boost level did you make 372 at on the T04e?

EDIT: Anyother experience with boost over 15psi? Any key aspects to watchout for?

sk8world

iTrader: (5)

on that topic, Busted has some nice heat shielding and his motor runs very cool from what I have heard.

Viking War Hammer

iTrader: (8)

Yep, Busted will post when he wakes up from his old man Nap. Dude is like 72 years old.

classicauto

iTrader: (3)

Heat managment definetly seems to be a priority as I think thats the largest factor in detonation, but I also don't think thats the only way blow an engine.

I guess the next thing to break down would be those of you running higher boost yet (25-35psi) on race gas, what types of AIT's and advances are being seen at those levels?

EDIT: Totally forgot to mention, I'm running 14* advance at 15psi, tapering to 12* at 18, then straight across to the end of the map.

NOPR

it was around 13-15psi. my gauge kinda sucks.

Busted7

Ok im awake now from my nap![thanks eric]

Ok i dont want to give bad info so bare with me: S4 t11 cermet coated rotors, large street port and cermet housings, dowel pinned and balanced rotating assy,
oil mods with busted7 twin oil coolers[b&m 42pass], 12x24x3 ebay intercooler frount mounted with a/c and koyo rad, 2x850inj 2x1680inj twin pumps, busted7 aluminum shields with dei 1700deg adhesive shield material mounted over the entire lim, ceramic coated header, hot side and down pipe, twin power, terbonetics 62-1, scoot style hood with intake holes and rad shield for intake filter, 10.5 plugs 10.4 taylor wires stock coils, 93 oct with 11.1 afr 17deg adv.

Air temps on a 70 deg day were not much higher than the car tuned just before me with meth inj. but i dont have the exact but Steve thought it was very cool.
Water temps when launching at the track will be 180deg at the turn off it drops to 175 deg.

I cant point to any one thing but i belive its the combo of all the little things.
Im running a 20 lb spring so i drive it with this set up all the time and hardly ever has it left the garage with out seeing 20 psi pull.

Dont get me wrong im not saying im smart but i tried to do everthing to keep it running and i heard heat was death to rotarys!
It makes 500 h/p and gets 20-22 mpg at 75-80 mph.
So far a year after putting it teogether im very happy with the results.

Let me know if i can help in any way!

classicauto

iTrader: (3)

Hmm, good to know, thanks for the info on the setup!

I very much agree that its a combo of things that make up the good setup, it has to work together...

I'm thinking my advance is very conservative and I'm hoping its not too little to cause any issues either....

I'll be going further into this after an EMS change and a few updates here and there. I'm planning on putting a cap at 20 because it seems to be the eaisest to control with this spring and I like the option of running at 8-10 so I don't get in *too* much trouble on these **** ontario roads

What are you running for seals? I think i'm going to use this same rotating assembly in the rebuild, but may have to mill out the slots if their damaged...so I'll probably end up going 3mm.

Who else has run with the scissors? lol

Busted7

The seals are rx7 specialities 3 mil [bendable]?

silentblu

iTrader: (1)

any pics of the setup?

NOPR

I'm interested in pics! I'm curious to see the intake manifold shield thing you speak of. how do you think that works compared to ceramic coating?

Howard Coleman

iTrader: (6)

"20psi at 6500RPM would net around 1700-1750F on the front rotor(omitting rear rotor numbers due to lack of compression...) with the WI *ON*.

When I turned it off and ran 20psi, I could nearly reach 1850-1900F before 6K"

ideal pre-turbo EGT is 1550, so even w WI you are running hot.

hc

classicauto

iTrader: (3)

Hey, thanks for the info howard! Again another topic no one seems to have answers on is pre turbo EGT's...

I had personally felt they were a little on the hot side, but only had post turbo numbers to go off of. I'm going to up my nozzle size to 500ml/min and see what changes I get. It's also possible, the slightly more volatile 91 is bumping the temperatures north...

Howard, what EGT's are you running in your AI meth car at say, 500whp? I'd ask about boost but no sense comparing 2 T04S compressors to one GT35....just mostly curious about meth vs. water on EGT's as I may try switching to meth before upping the nozzle....

classicauto

iTrader: (3)

OK - just tried switching to the larger nozzle (500ml/min)

All seems well, EGT's at 20psi are 1600F, much cooler now and still using only water. In fact even my 15psi EGT's are cooler (no ****....lol) I seem to be having a bit of break up, but its hard to say...being blown and all. Either way, the Electromotoive coils I'll be using are apparently the cat's whiskers, so if I am getting a little breakup from the extra water, it shouldn't be a problem on the new setup - but only time will tell.

Also, given Howards info on ideal EGT's it seems my setup runs a little hot in general, not good. Perhaps I may need a bit more IGN advance to pull out some heat? Thoughts? SUggestions?

Nismo Convert86

iTrader: (7)

Joe, you have another blown engine? I thought you fixed it? I'll give you $12 for the GT35 yes $12!

Busted7

The shields!

Busted7

Sorry about the big *** picts!

BDC

All of the things that Busted7 has done on his car re: heat are the reasons why he can run the times he does and make the power he does. This kind of approach however is largely uncommon in the modified Rx7 world. That's why I'm one of the people that errs on the side of caution and preaches tending towards conservative boost levels because the garden variety, modified FC and FD doesn't have the kind of attention paid to heat rejection/retention like Busted7's car does.

The problem to overcome is heat. The RE suffers from this problem worse off compared to the piston counterpart. Therefore the attention that needs to be paid to doing anything possible to reduce heat, where it needs to be reduced, is further stressed. Heat from water temps, oil temps, and intake air temps is what kills these things aside from improper tuning. Most enthusiasts don't monitor this kind of stuff. I am, however, excited that more folks are looking into AI as it's one of the most substantial ways of meeting this challenge.

That's my 2 cents on it as a heavy alcohol user and one who has and does do very high boost on pump gas.

B

Busted7

If i might add just a little to what BDC is saying! I spent 5 weeks just fitting and clearincing everything on my motor like brazing all the extra water lines and spare nipples on the intake. Makeing coil mounts to fit my liking and a ton of other little stuff, but when the motor went into the car it was ready to wire and mount exhaust and turbo. I made the header and turbo so it can be removed and installed in one piece becouse its hard to get to the bolts other wise. I used brake air hose and quick connect fittings becouse i dont like rubber or silicone but thats just me.

I love my car and its my hobbie so i put alot of time end energy into trying to make it hold up and last! But if you had to pay someone to do all the stuff i did it would be very expensive.

I have friends with 7's and there always short on money and time so they short cut and push things before the setup to do it. Thats why they call and tell me there haveing problems. I think these cars have gotten a bad rap becouse of some of the people that just keep pushing there luck with out a rabbits foot!

AI is a good way to go along with ethanol its problly the best insurance along with a good tune.

I dont want to brag or it might blow tomarrow!
Thanks for the compliment i think!

silentblu

iTrader: (1)

so how would you describe a non-garden variety rotary?
Looking at the Busted7's described setup for the heat dissapation department
1. Dual Oil Coolers
2. Ceramic Coat exhaust parts (i'm also ceramic coating the Intake parts)
Is the inside of the exhaust turbine housing coated as well or outside only? Also what kind of coating? Any thoughts on a turbo blanket?
3. Deflector for LIM
4. Cold Air Intake

5. I see a Koyo Rad, any rad ducting?
I also see an AST elimination. Evans or regular coolant?
6. Another key point, any water pump mods??
I'm still interested in seeing some more detailed pics of Busted7's setup if you don't mind.

What about the UIM? the area between the motor and UIM i believe would be another shielding point that i am considering accounting for when completing my build. My coils are moved to where the ignitor is, so its essentially just open space, other then the wire harness. I also understand that the Air Intake Sensor usually gets heatsoaked because of its location

I'm extremely fearful, especially living in CA's normal warm/hot weather/traffic , and 91 octane

classicauto

iTrader: (3)

Yeah, I fixed it, and then it blew up randomly when the Haltech was doing its own "I'm goign to advance the ignition to the max. allowable" thing on me and popped at 4Krpm while granny shifting.

Thanks alot for the tips guys! Heat managment is definetley a priority on my car, and I think I've done an alright job with little mods and tweaks here/there. On the rebuild, I'll be using an FD front cover/water pump setup with a Mazmart pump and am considering also adding some water jacket mods to the housings aroudn the spark plug area...*possibly* evans NPG also, but I'm not convinced its necessary yet.

Any other tips or tuning tricks to add to the discussion? This has been quite helpful!

re-rx7

iTrader: (3)

About the oil coolers. The stock FC oil cooler is pretty big. So why upgrade? i keep mine clean of debris and flushed. So there should really be not a reason for another oil cooler setup.