Sup guys.....
This spring I'll be going with the Haltech. My question is "How much boost can I run at the track safely?" (with race gas) I've read some of you pushing 25psi and up and was wondering how because I was told our motors just couldn't hold up to that much boost......
TIA,
Ernie

 

With 1650cc secondaries and 550cc primaries, HITman says I should have no problem flowing 30psi. Thats with about 45-50psi static fuel pressure.

You should be able to go close PROVIDED the tune is up to scratch.

 

waynespeed helped me with my Wolf 3D, and he said that if I run race gas I should be able to run 25 PSI. Ray at SR Motorsports also said that 25 PSI is ok if it's tuned properly. I know of people who have run 30 PSI without breaking anything...except axles.

 

Ernie T, the real answer to your question is this...The 13B late gen turbo engines can take up to and over 3 Mpa BMEP (proven safe for endurance) combustion pressure, provided the following limits are adheared too.

Charge temp no higher than 45degC (113F).
Ignition advance no more than 15deg BTDC.
Fuel octane 110 or higher.
Plugs 10 - 11 or higher heat range.
AF ratio no leaner than 11.3:1.

Now alot is dep on the charge temp (temp at the intake port) this is usually 15deg C higher than the temp at the throttle body due to heat transfer from the engine coolant etc, so what ever you measure there at WOT full boost add 15deg C to get your charge temp.

Now, if you stay within these limits you can run as much boost as you wish so long as you do not exceed the BMEP limit of the engine. This limit equates to the following setup for two popular engine configurations.

700bhp BP13B engine 23 psi 8000rpm within charge temp limit.
700bhp SP13B engine 31 psi 8000rpm within charge temp limit.

You realy must know these limits I describe above to take the guess work out of how much boost you can run, remember these change (boost levels) change depending on atmospheric conditions, ie: if it's realy hot day your charge temp will be much higher for same boost level hence you will need to lower your boost to stay within these limits.

Hope this helps you.

 

Peter, in reference to:"700bhp SP13B engine 31 psi 8000rpm within charge temp limit." Can the leading and trailing plugs fire at the same time under the above mentioned?

 

Thanks for the help guys.......I guess what I really need is a damn good tuner. Too bad Ray Lochead is on the west coast...

 

If you're going to go with the Haltech come to NY and get it tuned.

 

New York is a BIG place....
Give me a little more info......please.......Thanks.....

 

Yes, so long as your EMS is accurate enough...ie: if in doubt leave a split between T&L of 5deg to be safe so as to safeguard against trailing firing before leading (which can be fatal).

I know with Haltech this is what I do (Just for saftey, not because they are that bad), With PFC I run them the same with no problem. With mechanical (electronic dizzy) Ignition I run them the same.

I think you get the drift, you will get more power with them closer or together, but there is a risk in doing this if your EMS is not up to it.

If you're realy off the ideal running conditions (at WOT full power) in terms of huge charge temp a split of 10 or more will sometimes stop detonation also the leading spark is retarded to around 5 deg BTDC, all at the expence of best engine power. Sorry to go of topic.

 

Hey Peter, I was actually thinking of using two leading coils on the trailing igniter. What do you think about that?

 

New York City. There are alot of people in Queens who can help you. If you don't want to go there you can have Ito at JR's in Patterson help you out. He's doing vosko's car right now. Maybe you can wait and see how his car turns out.

 

Ernie, I've been 26-27psi on the dyno in my car (haltech, 1600&550, BB-T70 turbo) with no problems. This was just recently, I was doing high boost tuning I would've upped the boost more but I ran out of VP. I think some of the "key factors" have to do with the fuel and the tuner. If you really are making 450rwhp@15psi w/pump gas on a street port 13b, I'd guess your tuner is doing something right. The best I've seen is 427 rwhp, and I personally think that that was an exceptionally well running car. I think that about 400 rwhp is about the norm. 50 rwhp is no small feat to gain at the same boost level with similar porting and turbo. Sorry to ramble on guys. Where in MD are you located?

 

Im in Abingdon/Bel Air area......you?

 

Ernie Call Extreme Motor Sport. Try to get in contact with demitree ( I know the spelling sux) rotor_dee. They are now doing rx7 tuning.

 

Ernie,
My name is Rob, i have spoken to you before, i have a white 3rd gen, and was at cecil county a few months ago, we spoke breifly. I have been assisting Demetrios K. with his black 3rd gen drag car for months now. My first piece of advice: never belive much you hear over the internet, just as I most likely dont belive your HP or 1/4 mile numbers with your psi numbers, just dont match, but you know that . Noone is going to give away secrets as to their success. Let me just say this, with 550 primaries and 1600cc secondaries, we ran out of fuel at above stock fuel pressure and a very large amount of fuel coming from the pump at only 23psi on extreme's dyno. This was done with a garret T series ( or something like that ) which was very large compared to a T-78. Demetrios is now sponsored by extreme motorsports. Now i know everyone talks about the various RX7 tuners, but let me say this, have you ever heard of an RX7 which doesnt pop, smoke, shoot fire, or miss EVER? Demetrios's car runs more smoothy than ive ever heard ANY rotary car run in my life, it doesnt even really sound like most rotaries and makes quite a bit over 500 RWHP without nitrous with not that much boost. I recomend you contact me, and i can speak with demetrios about some dyno time. Sean is very good, and tuned D's haltec E6K no problem. Demetrios also builds motors any way you like for much cheaper than RX tuners, and his motors are very good, shown by his mid 10 second time slips with full interior and no NOS. Email me at Robplanb@aol.com, and ill see what i can do, plus provide you with my and D's phone number.
Rob
93 Rx white w/ blue pearl
soon to be powered by garret T-70/ haltech
" F#%K a viper"

 

Hi Ernie. when your increasing boost the possibility of detonation is always present. boost with out the proper fuel ratio = higher combustion temperture = kaboom!!!!! Ernie for a safe boost zone, keep your EGT's at a safe level and your air fuel ratio too. timing and fuel octane is very critical when your increasing into high levels of boost. Ernie if you keep doing your homework you will be ok From 1 rotorhead to another, good luck!!

"we live in a Rotary solar system, are we all rotorheads from birth? if it aint a rotor is a really big waste of time!!!!

 

So, Why should he believe you then? I know that there are alot of people here that are willing to give out helpful hints and tips.

 

Why should ANYONE believe the "secrets" you would be preachin'. Say your piece and show some respect. This is a forum of awesome experience and guys that want to help out the fellow rotor-guy. Why would someone give bogus advice when he lives in Australia??? I would tend to believe "RICE" than you - no disrespect intended...

Using the forum to 'dis all the others so you can fatten your wallet - shame on you!

Sorry guys, his message was a

Rick
1993 RX-7
In my experience, those that talk in riddles are not to be trusted!

 

I am really trying to bite my tounge here but here it goes.
One, I agree with carcrazy, there are some good, very sharp and helpful people on here.
Two, his buddies over there at X... have done the same thing or worse here. Posting overinflated dyno charts to sell thier garbage.
Three, and back to the subject, do you need to run so much boost? Isn't there a point where you are just spinning the tires and breaking parts? The dyno charts are nice, but at what point is the horsepower ineffective? We see it all the time with the Supra guys pushing 1000hp but still losing to a 450hp RX7.

 

If you're running close to or over 400 RWHP you'll be spinning tires alot.

 

In an effort to keep the thread to the point, I will PM Machinehead you his my remarks.

To all else. sorry for the regression.

Rick
1993 RX-7

 

I should jump in and help Rob out here, as some people did not understand where he was coming from. Rob knows ernieT and was offering help which has nothing to do with money. I have met ernie T on many occasions and would be willing to help him set up his haltech as a favor. As far as dyno time it is extremes dyno and thier rates are posted on thier site. So rob nor I would not benefit from helping a friend.

As far as the whole don't trust what your hear we all know that alot of times we get half the truth from internet, magazines etc etc. But we can combine all these half truths with our experiences and usually come up with the information we need. I havew had this happen to me with many things like HP potential of turbos, and fuel system and ignition requirments to get my car to perform the way I wanted it to.

Thanks for the compliments on the car rob I'll see you next
weekend.

I rarely ever post just usually read and can say rice's advice always seems to be on track and I do not see any where in robs post where he disagrees with him at all.

Now that all that is cleared up let me speak to the question. Ernie It is true at 45psi of fuel pressure I ran out of injector at around 23psi of boost and it was not due to fuel pressure droping. If you due the math and take into account the brake specific of a turbo charged rotary wich is not the typical .50 of a na piston motor more like .70 you will see the formula works out. Bottom line due your math to ensure you fuel system can support the power level watch yor egt's as Ito said and you will be just fine.

Just wanted to clear my name

 

I would like to thank everyone for their help on this especially Rob and Demetrios. I will be in contact with Demetrios and Extreme when I get my car back.
Ernie