The carbon canister purge has been disabled in my ecm software.

I am assuming with this line hooked back up to the carbon canister, it is just soaking up the gas fumes and serving no other function? I still had the hose from the canister to the throttle body connected also, but without the signal from the ecm to the purge valve telling the valve to open and close, I'm not sure if these vapors from the canister are really getting sucked into the intake stream or not?

 

Unless purging to the engine is active the canister will saturate and the fuel odor issue will return. It would be best to enable CCP purge in the ECM.

RBob.

 

I hooked back up the evap line to the charcoal canister before driving around testing last night and checked the garage this morning, gas smell is gone. That canister does some absorbing of the fumes even when not being energized.

I think I found my issue. I wrapped the fuel feed y-block with a left over starter heat shield blanket and drove around, the car didn't shut off like it did before, but still spit and sputtered after the coolant temp got to 197.

Next step is to extend the feed lines and move the y-block over to where the fuel pump relay is to get it away from the header and head heat. The temp gun pointed on the y-block was around 180 degrees, not sure at what temp the fuel boils.

 

Some of the braided AN hose stinks of fuel. Some brands do, some don't.

I have a small filter on the vent line by the tank. My car is in the shop, sitting on the lift 11.9 months out of the year and no smells.


Cool build.

-- Joe

 

Well it isn't going to smell if you don't drive it Need to heat the fuel for it to vaporize.

RBob.

 

I suppose. I figured that between heating/cooling the shop, or seasonal conditions..

-- Joe

 

Hit the 1/8 mile track tonight. Not sure what to make of the results.

1st run was 7.50 @ 93 with 10 degrees timing and a/f high 10's at 6 lbs. This is what the car normally runs on motor only with 28 degrees timing n/a.
2nd run was 7.30 @ 97 with 12 degrees timing and a/f low 11's at 7.5 lbs-tightened belt.
3rd run was 7.29 @ 98 with 14 degrees timing and a/f 11.2-11.4 at 7.8 lbs.
4th run was 7.10 @ 99.45 with 17 degrees timing and a/f 11.3-11.4 at 7.8 lbs. best 60 ft was 1.70 on the 4th run of 7.10, the rest were 1.75-1.77, track or my tires are no good.
5th run was 1.77 60ft 7.22 @ 99.10 with 17.5 degrees timing and a/f 11.3-11.4.

Didn't check the plugs, but the mph going down is where I stopped adding timing. Wasn't sure how far to push it with 10.5:1 compression and 100 octane in the tank. IAT's started at 97 and ended at 122 at the end of the run. No knock on any of the runs.

Using the Wallace racing calculator, 99.5 mph in the 1/8 and 3600 pound car equals 550 hp at the flywheel.

Does this sound right? sounds low to me I thought every 1 lb of boost was 20-25 hp depending on how efficient the motor is. That would make 7.8 * 20 = 156 hp added from boost. I guess I was expecting to et and mph the same as my 175 nitrous shot which got me to 10.39 @ 131 (6.65 @ 105.5 in the 1/8).

I guess my cam could be costing me hp. It is 230-230, .600-.600 107 lsa, not sure how much I would pick up going with a vendor who custom grinds a cam for my combo?

Next:
1. turn up the boost? Current pulley is a 3.47 and I have 3.33 and 2.95 pullies waiting to go on. The 2.95 pulley at 6100 rpm puts me at the t-trim's max impeller speed of 55,600 rpms. I would run 110 leaded at the track for these runs. it is $11 per gallon at the track.

2. buy meth kit and get IAT's lower

3. Get custom cam

 

Picked up 5 gallons of 110 leaded sat night, so the plan is to put the 2.95 pulley on it, lower the shift rpm to 6100 to keep the blower at the 55,000 rpm limit, put in the 110 and start back at 10 degrees timing adding 1 degree each pass to see what I end up with this Friday night.

 

On the 7 lbs of boost runs, i would be tempted to try a 11.8:1 fuel mix vs 11.3. Maybe even 12:1.

On higher boost move towards mid 11's.

On 110 vp fuel stoich is 15:1. So tuning for lambda .80 or so will be closer to 12:1. High 11's on that would be safe. Check te fuels stoich value if some other brand 110 oct

Whats plug gap and heat range on this motor?

 

plugs are R5671A-8 gapped at .028

I was trying to keep things on the conservative side since I have 10.5 compression with the -8 plugs and 11.3 afr, but haven't checked the plugs after a pass yet. They do drive fine on the street though.

it's renegade 110 which has a similar stoich to the Sunoco 110 standard which is 15.0

 

Thats good heat range. Gap should be ok on that boost. Could go .024-.025 andnot hurt anything

 

Got the 2.95 blower pulley on the car last night and got 10.8 lbs max on the street at 6000 rpm and 10 degrees timing. Should add another 2lbs at the track with a higher load on the motor this Friday night with the 110 leaded fuel in the tank.

2.95 blower pulley and 7.8 crank pulley at 6000 rpms puts me at 55,000 max rpm of the blower. Funny thing is, I saw a test article comparing the t-trim and ti-trim in an engine dyno session and they got 985hp out of the t-trim at 62,000 rpms, even though the max 'safe' vortech rpm is 55,000, so I'm not sure how high I can spin it safely.

Plans for this Friday night:
1. run at 10 degrees timing and 6000 shift for a baseline
2. add 1 degree of timing each pass until mph stops getting higher
3. take off air filter which is right over driver's side header to see if it picks up
4. raise shift rpm to see if mph increases

I will take my hand drill and hacksaw to cut the plug threads off of the spark plugs at the track to see the fuel ring, too hard to do at night and with a crappy flashlight.

Driving around last night the part-throttle bucking and running lean is still there. Not sure if this is related to my fuel system mods or bad injectors or what. Car was running down the freeway at 70mph at 14.5 afr, then starts to buck and sputter with afr ratio going to 17 and back down to 14.5. Took my foot off the gas and afr went to 22 and stayed there for like 3 seconds, you can give it gas and it will drive and recover, but still pops and sputters at steady state cruising speed. Came of freeway and drove it home, sputtering the whole way until I got under 40 mph or so and it drove with no issues. Might have to swap injectors to see if these are bad, or check for fuel pressure and pump voltage while driving. There is slight smell of gas in the car when driving, and I am using the old 5/16 return line as the new tank vent, and the old 3/8 tank vent as the new return. Evap line is hooked up and I turned on the evap solenoid also. Not sure what the issue is, but it runs fine wot.

 

Any fuel smell to your oil? I just put in new injectors last week had the lean pop going on at part throttle fuel in oil then it started missing worse so pulled all the plugs found number 3 to be fouled all others looked good. Put in a new plug with new injectors no more pop.

 

Nope, oil smells fine. I need to find someone with some spare injectors and swap them out to rule the injectors out. The pulse width goes down to almost nothing when this issue happens, but like I said, if you give it gas, it will still accelerate.

 

That's the only time mine ran right was wide open cause my injector was stuck open.

 

Just talked to martin at tick performance about my cam, and he says I am leaving a lot of power on the table with my current 107lsa cam with boost blowing out the intake valve.

Gonna get a cam from him so I can get my power back, he says 50hp or more with the right cam.

 

107 lsa or ica?

I've run on 112/108 and it ran great.. 107 is quite tight. Probably bleeding off a lot of boost.

-- Joe

 

Have ValveMotion run his software on it to see what it wants

 

Took apart the big white gas tank vent valve and cleaned it in soapy hot water and put it back together and my bucking/surging issues went away. I guess that thing did some work for 26 years being dirty until now.

Got a cam spec from martin at tick performance and he said 230-246 .600 .580 114+4 for the cam. Waiting for a cam spec from steve morris until I decide which one to go with.

 

Made 5 runs last night. Still not where I want the car to be, but I will have to wait until I change cams and add meth to get there I guess.

1st pass on 110 leaded and 10 degress at 9 lbs was 7.34 @ 94
2nd pass at 12 degrees at at 11 lbs was 7.09 @ 98.38
3rd pass at 13 degrees at 11 lbs was 7.05 @ 101.15
4th pass at 15 degrees at 11 lbs was 6.96 @ 103.34
5th pass at 17 degrees at 11 lbs was 6.76 @ 105.23 with at 1.60 60ft. All passes were on the stock GTA wheels up front. Running my front runners would have been another .10 and 1 mph off these times.

On the 6.76 run, I see in the data logs the injector duty cycle hit 102% at 6439 rpm, 179 map 11.86 afr. I am running fuel pressure at 43 lbs, so I need to bump up the fuel pressure to 50lbs to see if I can get more out of these injectors. I thought 80lb seimens deka's were good to 900 hp?

They won't let me run anymore at that track until I get a rollbar, so I have 1 chance on Nov 9 to hit gainesville and run the 1/8 at that track and hit the brakes before the finish line before I get kicked out again. Not sure if I want to put a bar in it with as little as it hits the track. Might try to find a bolt in 5 point and throw that in, then if i change my mind I could always pull it back out and sell it to reduce the cost of an 8 point or 10 point cage.

 

80lb injectors are good for over a thousand horsepower. The problem is a lot of your fuel is going unburnt out your exhaust valve due to your cam overlap.

You're running 105mph in the 1/8th, which is about 640 flywheel horsepower.

-- Joe

 

If its vp 110, try leaning out to 12:1 afr. Stoich is 15 so it can tolerate alittle leaner.

But 80's should be good to 800-900 hp. Thats about where i was when it went over 80% dc

 

Pulled off the front bumper cover and cut the bumper support to move the i/c forward about 4 inches. Car runs cooler now, about 165-170 driving down the road now that the radiator is uncovered.

Car still cuts off like it is running out of fuel though. Manually jumped the 2nd fuel pump and issue still exists. Car goes lean while driving after 20 minutes and pops and stutters and afr guage goes to 22.4 max out. I can give it half throttle and it will take off, but off throttle it is starving for fuel. I make the gas tank vent 3/8 but still having issues. Going to try and swap injectors to see if i have some bad ones.

 

If your not loosing fuel pressure you might wanna check the coolant temperature sensor

 

ordered a new walbro pump from summit, should be here Tuesday, hopefully that will solve it. I already took apart and cleaned the vent valve so that shouldn't be the issue. I drove on these injectors a few months ago for an hour back and forth to the dyno with no issues, so I don't think it is the injectors.

This issue only started after I put the dual pumps in the tank, put in the bigger fuel lines and added the aftermarket fuel regulator.

 

Hows it going?

I still think you should have went with the larger 400lph pump, instead of a dual pump.

-- Joe

 

I just got the walbro pump and put all the stock wiring back in place, taking out the racetronix stuff. I dropped the filter sock in the tank because it wasn't the right sock, so I ordered one online, should be here on Sat. Not sure if any parts stores have the sock for a walbro 340, but didn't want to waste time trying to explain it either.

I made a front air dam/diverter for the intercooler also. I will take a pic when I can.

 

Hey Joe, I am curious why you are suggesting a single pump? Unless a fuel pump speed controller was used, wouldn't this just heat the fuel unnecessarily when not under boost? Seems the majority of his driving will be on the street.

 

I doubt it. A single pump is easier to plumb and wire. I'm running a 400lph walbro turbine style pump. Sure, 90% of the fuel is returning to the tank when not in boost. I don't see that as a problem.

-- Joe

 

Glad to hear that cooled down your temps. You see any change in your IAT?

For your fuel issue, have you checked the reg? It could be hanging up and creating an issue. Wouldn't hurt to check the regulator bolts on the spring cap for tightness, also pull the inlet and outlet connections to ensure no dirt or left metal shavings form manufacturing inside the diaphragm.

 

All of my issues started when I added the second pump and changed the wiring on the sending unit and in the tank, added bigger feed and return lines, added regulator, had fuel rails bored out, etc. Not sure what the issue is, but since it happens after about 15 minutes of driving time (heat related), I am assuming it is not one of the upstream systems and the issue is in the tank.

I used the racetronix new bulkhead with 4 pins and their intank harness, and it is not grounded on the feed tube like the stock ground is. I am hoping that putting the stock wiring and walbro pump fixes my issue. Tired of not being able to drive the car for longer than 15-20 minutes.

 

Racetronix told me that the single walbro 420 won't support 1000 hp, so that is why I went with the 2 255's. I should have done a walbro for stock driving and a 340 pump for coming on in boost instead of s 255's.

 

Agreed. I am running a single 340lph pump, ethanol compatible as well.

 

The 400lph @ 14 volts flows:

110 GPH at 42psi
100 GPH at 50psi
93 GPH at 60psi

So let's assume you're running a lot of boost, and your regulator runs around 60psi.

Gasoline is about 6.4 lbs per gallon at 93 octane.

93 GPH = 595.2 lbs /hr

Your BSFC now comes into play. Naturally aspirated motors are typically between .45 and .50, where supercharged motors are .50-.55 typically.

So let's say worst case scenario, 595.2 / .55 = 1082 horsepower

I've yet to see a t-trim on the dyno make more than around 750 horsepower, and Vortech rates them at 950 horsepower max.


-- Joe

 

... just some friendly advice, the only real way to determine what your engine is making is through your trap speed and vehicle weight. You are trapping 105-mph in the 1/8th, and at approximately 3500 pounds, you should be seeing about 538-RWHP, which would embellish only a 50% need in Duty Cycle at that horsepower level with your 80# injectors, yet your seeing 102% in your datalog at that level, so you are clearly wasting fuel, either through too much camshaft overlap, or a possible flaw in the sensors and tuning. To put things into perspective, at a 102% Duty Cycle running 80# injectors your should be right at 1100-FWHP, which would put you at 5.5x in the 1/8th at over 140-mph. IMO, you do not need a 420lph pump, especially at the timing you are planning to cap it at, you don't even need twin pumps, you really only need a single 340lph pump and a camshaft tailored for centrifugal boost.

 

Agree with first part Street, 105 mph is more like 500-530 whp or so assuming 20% loss in autos

However 80's will not be enough for 5.5's and 140 1/8 lol not at 43-58 psi base pressure we run. Think calc is off there

I've run 80's to 700 whp with room to spare. I might see them doing 800 whp from a stalled auto. Thats a low 6/maybe high 5 1/8 if u launch and 117-120 mph.

 

Supercharger will always need more fuel to make same power as turbo car because of the hp lost to drive the blower. Twin 255's should do 800-900whp fairly easily on reg gas. I did 1034 std but you have to keep fuel pressure down below 65 psi total with boost.

If it takes 20 psi to make the power then your base pressure should remain less than 45

Your problem sounds like bad pumps if car is dying in 15 min. Something aint right.

Also look into ignition and plug gap. Make sure its lighting off everything. If you are really dumping in 102% dc on 80's then you are not burning off all the fuel, or its going out the exhaust, or the converter is blowing thru maybe.

 

640lbs / hr. .55 bsfc = 1163 fwhp. 20% loss, 930whp.

Keep in mind, you have turbos. Your BSFC is probably .65 or .70.

He's running one of the most efficient superchargers available.

I made 565hp on a S-trim with 36 lb injectors. Static, at 42psi with a 1:1 regulator that put me around a .50 BSFC. The T-trim is supposedly even more efficient.

-- Joe

 

Correct, it's 128-mph for the 1/8th at 3500 pounds and 1100-FWHP, not sure why I put 140-mph in that post. Seeing duty cycle exceeding 80% up over 100% with his 80-lb injectors, at that weight he would be in that zone, and there would be no way for him to mistake double the horsepower from what his trap speed had revealed. At a max of 80% Duty Cycle he would need 103-lb injectors at 0.60 BSFC to see 1100 Horsepower, but at 102%, which is utterly static, he would see 1100 horsepower with 80-lb injectors and 0.60 BSFC. At 3500 pounds and 1100-FWHP he is a solid 9.0 car in the 1/4 mile. He needs a cam with a lot less overlap, as well as to recheck his fueling in the tune. Keeping duty cycle down to 80%, he will be happy at 1000 horsepower and .060 BSFC w/those 80-lb injectors...

 

The 80% duty cycle is an imaginary limit. Injectors don't know what duty cycles are, they just know that then are open or closed.

Duty cycles make us feel better, like "Let's keep it under 80% of capacity". But there is no sound reasoning for this.


-- Joe

 

Not necessarily, because if it was, then so is boost. Just because the MAP depicts a numerical value does not underline it is reaching the combustion chamber. 80% Duty Cycle is the injector tolerance based on its' size, and boost pressure is a resistance measure. The 02 correction through an algorithm gives us an approximation, but every engine is different...

 

No way in hell i'm that high on bsfc.

And its not about charger eff. That has nothing to do with it. Compressor Efficiency just states how well it can compress the charge to a certain pressure vs temperature produced.
Only other efficiency that would help is reducing gear drive losses in the blower itself. Blowers always seem to have to pump out more cfm to make same power as turbo because turbo isnt tied to a set shaft rpm like a blower is, and turbo can change speed on demand to make up for an engines air flow demand. Blower cars typically need more fuel to supply same dyno power because losses are greater

Engine bsfc is about how well the induction system and head chamber works. Extracting most energy out of given fuel input. Blower or turbo cant help that to a degree because two things need to happen. 1 you need to run richer to keep charge cooler to prevent detonation. 2 reduced timing is required to control detonation. Higher oct helps abit tho to keep a FI motormore bsfc efficient.

 

None of that has anything to do with injector duty cycle.

Duty cycle is simply a calculation of time open vs available time.

For example, at 6,000 RPM, a batch fire system has exactly 10 milliseconds of available time. At 8 milliseconds you are at 80% "duty cycle".

The injector doesn't know or care how long it's open for, so the imaginary threshold of "80%" only makes humans feel better.

It's not like Bosch says "Our injectors are rated to be open 8 milliseconds at a time".. The duty cycle is going to depend on the RPM and firing strategy used. On some vehicles 100% duty cycle might be 10 milliseconds, on others it might be 5 or 20 milliseconds.

My point is that shooting for 80% duty cycle is like only drinking 80% of a carton of milk and throwing the rest away.

-- Joe

 

I'm not arguing with you guys anymore...

But here, let me just break this down for the OP and let it sink in for him...;

* Most 80# injectors at 100% DC are good for over 1000-FWHP.
* Your 80# injectors registered 102% DC while trapping using only 50%.
* Your air/fuel remained consistent at 11.86 at 11-psi of boost (179 MAP).
* O2 sensors register vapor, not raw fuel.
* You are running a camshaft with a lot of overlap...

 

I emailed racetronix and they told me that the single walbro wouldn't support 900hp, also have seen them post it on ls1tech multiple times. Not sure if they know some data that we don't or are just trying to sell a bunch of dual 255 set-up's.

I would guess the car is closer to 3700lbs with the addition of the blower, brackets, intercooler, etc. I also had my full size front wheels on the car on those passes and the car with the skinnies weighed at the track years ago with no nitrous bottle was 3590 with me in it. The wheels are an extra 42lbs difference by themselves (skinnies are 23lbs, stockers are 44lbs each).

My junk may very well not be right. At the 102% duty cycle the air fuel was still 12:1 with the 110 race gas at a commanded 11.3 afr in the tune. I have the new cam in the garage waiting to go in and it is 230-244, .580-.575 114lsa vs the 107lsa cam I have in it now. was wanting to fix this fuel issue with the pump and get another baseline run on the front skinnies to compare before cam and after cam, but the 1/4 mile track isn't open again until Jan 30. I have been banned from the 1/8 track which is 20 minutes from me for not having a roll-bar. Could drive to Orlando but that is 2 hours each way driving and I don't want to drive that far again on the et streets, so I would have to change all 4 wheels at the track which isn't fun.

 

Vp 110?

If so, back that bad boy off to more like 12.5:1 afr with 11 psi. Do it slowly tho watching mph at track. Mycar on 30 psi so far runs alot better at nearer 12:1 afr on vp110

Other brands may have slightly different stoich

 

It was renegade 110 which I think is 15.0 stoich. They sold it by the gallon instead of by the 5 gallon pail and it was cheaper at $11/gallon.

 

Blowers create parasitic drag, but centrifugal superchargers are very efficient in terms of compressor airflow vs heat.

Turbos don't cause parasitic drag on the crank, but is basically like a giant butt plug in the exhaust. This causes the exhaust ports, valves, etc to be almost red hot. Turbochargers also generate a lot more heat than centrifugal superchargers for two reasons. 1) Because they are mechanically connected to 1600+ degree exhaust and the thermal transfer between the parts, and 2) Because the impellers are smaller and spin much faster. This creates a much hotter charge.

BSFC is simply the amount of fuel required per horsepower per hour. You're using some of this fuel to cool the charge, cool the cylinder, pistons, exhaust valves, etc.


You should be able to calculate your BFSC by showing your injector pulse width + fuel pressure during your dyno sessions. You should be able to calculate how much fuel you are using. Also, what are your IAT temps like?

Looking at my logs from 2004 when I ran the S-trim, at 14psi boost and no intercooler, I was seeing 184 degrees IAT temp on a 72 degree day.

I saw about the same temperature at IDLE with the T76 a few months ago

-- Joe

 

You know.. 107 LSA is probably a major factor.

What ECM are you running again?

-- Joe

 

411 LS1 pcm, it is the EFI connection pcm kit with the reluctor wheel behind the timing chain and 8 ignition coils. tuning using EFI live

I also move the intercooler forward and made an air scoop for the intercooler, so the coolant temps and IAT temps should be lower all around. Wrapped the driver side header with header wrap and put on a header blanket to keep air coming into the blower intake as cool as possible instead of pulling in hot header heat. I was thinking these changes should pick up some power, but not sure how much.

I guess I would be wasting time trying to get another base line and should just swap cams before the track opens again.