JETPILOT

iTrader: (51)

My car is making 565 whp on 93 octane and 16psi wit hthe Greddy kit.

I am having issues with my driver side crancase venting. it's blowing out oil into the intake and filling the intercooler. I assume this issue is created by roadracing my car and the fact it is boosted.

Since my car is really only driven on the track now would it be better for the motor to make the same power on pump gas and 16psi or 110 octane and lower boost? Discuss!

GTM

iTrader: (12)

Unless the 110 octane is unleaded I wouldn't run it, C16 either, 100 octane unleaded will be just fine, or VP 109 even better. Just get a good tune on 109 and you will love it, smells good too

Running leaded fuel will ruin your expensive oxygen sensors.

go-fast

if you are racing you should really consider crankcase evac.not only will you make more power,but your cooler will stay clean.

JETPILOT

iTrader: (51)

More info please.... The only ones I have seen have been for Ford/GM motors.

go-fast

you can run a pump(pricey) or use a moroso type setup(same results less glamour).by evacuating built up crankcase pressure you make "free" horsepower.this is even more valuable for boosted cars for obvious reasons and by dumping that vapor mist instead of forcing the engine to re-digest it you gain power as well,it's a win/win situation.

Audible Mayhem

iTrader: (48)

I have a ford pump sitting here that we are putting on a car. Not pricey at all.

ForcefedZ

iTrader: (2)

100 octane would work fine at those boost levels.

Are you having this problem with venting on the straights, or only after a series of turns?

go-fast

+1 o.e. pumps can be found cheap and work,the pricey pumps i was referring to were aftermarket.s10's have a nice pump that can be remote mounted to help the engine bay stay un-cluttered.if i was considering the low cost way to do this i would just go with moroso style crankcase evac,you can make your own kit out of old ford egr one way valves.done like this it's almost a free upgrade(provided you can weld).

gothchick

iTrader: (12)

+1

Vent it to atmosphere.

QuadCam

iTrader: (8)

larry,

on your original question. I would switch to race gas, run less boost, more timing, and a leaner mixture. It will more expensive to run, but you will have a great margin for error.

what about switching to an E85 setup? that stuff is somewhere arounf 107 octane. you'll need more injector and more fuel pump to do it though. I see that they are now selling E85 at the Ft. Pierce Turnpike Plaza.

GTM

iTrader: (12)

The problem with the Moroso style kits is that some people will argue that at higher RPMs and WOT it will actually not create enough vacuum if any, I remember reading somewhere that a guy had a pressure gauge hooked up to his and at redline it would pressurize slightly. A lot of controversy on this one.

The best way to do it would be with an electric pump, I thought about relocating my battery to have the pump and can stashed in the stock battery compartment but never went through with it. Right now my car is just VTA on drivers side with a catch can on the passenger side.

If you have additional information on this I would love to discuss, don't really see too many people discuss this on this forum.

thawk408

iTrader: (16)

I run leaded 110 and have no issues. The hating on leaded gas is funny to me. Yes it wears out sensors fasters, but I could care less about replacing a 100 dollar sensor once a year. I care about my motors safety more. And for around the same price as unleaded 100, ill take the higher octane rating. In your case jet 100 octane would be fine for 16psi.

rcdash

iTrader: (18)

I was under the impression that O2 sensor life was very, very short with the use of leaded fuel. Once a year isn't bad. Reference this article, which claims life at 200 hours. Maybe for many people that is a year's worth of driving...

JET's question was 16psi on pump gas or less boost on 110 octane (presumably with advanced timing for equitable power)...

GTM

iTrader: (12)

Well actually its not hating, its fact. When you run leaded fuel in your car, the oxygen sensors are damaged almost instantly especially newer ones, which will make them inaccurate, For me its more important to know my a/f vs. saving a few bucks on fuel. So sure you could replace your sensors once a year, they just won't be accurate so why even bother?

thawk408

iTrader: (16)

I dont drive my car that much, but mine lasted around a year on 110 leaded. I know its a fact...thats why I mentioned sensor life. No they are not instantly damage. From what I have read and gathered the NTK sensors are more accepting to leaded gas while the bosch sensors dont like it as much. The lead blocks the holes in the sensor, which prevents accurate reading. The bosch holes are smaller then the NTK, which is the reason they start to act up faster when using leaded. Any big boy gas you look at is going to be leaded, which is why its always used on high boost setups.

I never said anything about saving bucks on gas. 110 aint cheap and q16 isnt any cheaper. If I was in jets shoes with only 16psi I would just buy a barrel of unleaded 100. If I wanted more, then I would go leaded.

GTM

iTrader: (12)

You are correct NTK sensors will last longer because of the larger orifice but that is also whats makes them not as accurate as the Bosch sensors.

Once you run leaded fuel, the sensors (Bosch since most everyone is using them) will become inaccurate, I would not trust them for tuning on my engine after being exposed to leaded fuel.

As far as price I was comparing VP 109 unleaded to 110 leaded, I rather pay more for the 109 unleaded, then compromise my sensors accuracy - that's all.

Sorry for the misunderstanding

thawk408

iTrader: (16)

Yes the NTK sensor are not as accurate, but will keep accuracy a bit longer from what I have read. Mine read pretty accruate until the day it just died. Always read the same as when it was tuned.

There are many people in the supra world running leaded gas all the time and dont have any problems, except replacing sensors. And alot of them are connected to their EMS, so they must have some faith.

rcdash

iTrader: (18)

JET, to answer the question about lower boost with higher octane, my understanding is that you will only be able to achieve similar power output if you can advance timing, up to the MBT (min best timing) level for your engine. If you are already at MBT with pump gas at 16 psi (since I believe you have a FP shortblock with 9:1 compression), then running higher octane will not enable you to lower boost and still maintain the same power level. It will only allow you to increase power with higher boost. I'm inclined to think that the MBT point for an engine is NOT changed with a different octane fuel, but I'm not certain.

EDIT: I found this link on the EFI forums about octane and timing, but I'm still not sure since they don't talk about MBT so much as timing in general.

go-fast

moroso style is not perfect but provides 95% of evac that a $1000 vaccum system allows (for about $50 bucks).pressurizing on wot sounds like a faulty one way valve.on the flip side of your observation,detractors of the vaccum pumps claim that they are too efficient and can actually suck the oil out of your motor.i tend to err on the side of caution and prefer a system that is not 100% efficient as opposed to a system that is working at 120% and sucking my oil down along with my wallet.keep in mind that an evac system in any form is miles ahead of o.e. design and just venting is not much better than o.e.(unless you go really old school and create a road draft setup)the effort required to road draft is almost as much as moroso style,wich is why it's obsolete.audible had a good suggestion with the stock style pumps wich are much weaker than race stuff,kind of creating a happy medium between the two.we forget that brilliant people have been tweaking combustion engines for 100 years and that their countless dollars,failure and success are free to us if we only choose to listen.free horsepower is everywhere

rcdash

iTrader: (18)

Moroso is the exhaust draft/suction system? Why not just tap the intakes in similar fashion, which is theoretically pulling in as much (if not more) air as is going out the exhaust? Having the driver's side vent be an open breather allows ventilation rather than evacuation = less oil vapor being sucked out of the cc. No horsepower gain, but that's not the low hanging fruit for horsepower generation anyway.