TE45a USERS....Please HELP!!!!

[Vader 87]

I went to the local 1/8 mile track last night and ran some very disappointing times.....my very first run netted a 7.43@93 at only 17.5 psi and no knock....but from then on it was hell on every run. I turned the boost up 2psi and got 2.0 degrees knock.....i was running rich so i turned the FP down on the next run which resulted in a 10 degree knock at 20 psi on the scaremaster. I was luck i didnt screw something up....so i turned the FP back up and the knock went to 7.0....every time it knocked i let out just past the half way point......i turned the boost back down a pound and the knock went to 5.0.....heres the dilemma....i think the problem is the fact that i'm not running double XP fuel pumps, im only running a single 340....but my O2s on every run are showing that i am rich....the lowest O2 i had all night was a 800.....i never did best my first run of 7.43 but on one run i came out of the whole with a 1.58 60 ft and let off half way down the track and coasted to a 7.50 @ only 81mph....that would have been a high 6 second run for sure but the high knock count scared me too much so i let out. I had another good run and let out about half way and coasted to a 7.8 @ only 72mph. Also, direct scan showed that i had consistent O2s all the way down the track......what do you think??? Is it the fuel pump?? I had 5 gallons of C16 in the tank along with 1 gallon of NOS fuel which is rated at 122 octane.......Another thing i thought was strange is that i can run 17 psi boost on the street with the te45a and ONLY 93 octane in the tank and ZERO knock even at over 115 mph!!! Anyways, after all this i decided to see what i run in street trim so i turned the boost back to 17 psi and put my street chip back in and went 7.6@89mph......not bad for daily driving and i also had a passenger with me on that run. Anyways, all help is greatly appreciated.
THANKS!!!
Jason

 

[Slo86GN]

Hmmm, sounds like your fuel pump could be a little on the weak side. Also..What size injectors? I didn't pay attention to your sig (brain fart on my part)...that could also be a prob. I've noticed that my 87 has transitional knock on launch (spins the hell outta the ET Streets), but down track knock drops to near nothing (average .4-.7). O2's tend to be a little high (810-830), but my EGT was nice (1560-1570). One thing I have discovered is my MSD 50's are close to the limit (96-97% duty cycle) at only 18-19#, so it's time to step up to 72's for me. That's one of the things I love about DS....you can see what the car is doing real time. The 87 has gone 7.32 @ 94.3 with only 18#, RA93 chip, and ET Streets (sucky 1.69 60ft)....on it's way to an 11.60 @ 116.7....Not too bad, but it went downhill after that...Turned the boost up and 60ft went to crap, thus the ET suffered. After that initial pass, best I could get was 11.73 but at 117.6 with 5-7 KR on launch and 1-2KR at top end. Never went over 20# because of the injectors, so who know what the car will run once new injectors are in and running.

 

[REDS HOT AIR]

what are you running for injectors?

when i went 98 mph in the 1/8 with my 50's and walbro 340 i didnt even have it hotwired yet and it never went lean even on topend at 121.54 in the 1/4 it was still rich

since then i have hotwired it and the pump sped up alot doing that.

that was with the 49 turbo at 22# ...after going to the 51 and going 26# it still never leaned or picked up knock of course till it broke..

 

[Slo86GN]

LOL....You just have a flyin azz car too Red. I wouldn't even think about leaning on my 50's that hard, especially not when I saw 96-97% duty cycle on DS during the 118.1 mph pass. Boost on that pass was 18-19#, so I'll be easy on the car til I get my 72s in. I really want to see what it'll run with more boost, but not when it's bordering on booommm.....

 

[azgn]

I am still running a single 340 & 55's and have gone 125 with 'em, so unless your pump is bad, doubt that is the problem.....you "may" not have enough gas in the tank and could be starving the pump under acceleration......recommend never running less than 1/2 tank when racing...I always keep 10 gal plus in....

 

[NOSjohnWE4]

times

I have to agree with Woody here. A Walbro 340 is good for 600-700hp IMO. Always use more than a 1/4 tank of gas in your car when racing. I'd have to say you're a little on the LOW side. You mention 5 gallons of 116 and then 1 gallon of NOS ? gas....WTF is NOS gas ? lol, never heard of that. oh well, learn something everyday. Try 10 gallons like Woody said and see where u come out. HTH....



John C.
LedSLED Motorsports

 

[c&cgn]

C16 eats O2 sensors quicker than a fat kid in a candy store. I don't care what anyone says about heated O2's. There readings are skewed after a couple of passes using C16. You need to get an EGT gauge!

With an O2 that had seen its share of C16 my O2's read 820's and my EGT's were 1700*

I did that twice and then switched to an new O2 sensor and @ 1650* my O2's were around 770-780.

At your level, with the #'s you are attempting to run you need an EGT. My guess is you were quite lean and not rich like the O2's were showing.

 

[REDS HOT AIR]

do it the old school way ...pull the plugs and go by them..02's nor egt will tell you if one injector is weak or if one is heavy but reading each plug will.

 

[REDS HOT AIR]

forgot to mention that if you get some missfire when you turn the boost up it will show knock

might wantta check them wires and plugs out...i recomend ngk ur-5 plugs at .032 gap for high boost ... autolite and ac delcos missfired at high boost in mine with the ngk's i've been 30# with no knock and no missfire. and i use msd super conductor wires

 

[Chuck Leeper]

KNOK KNOK??

Seems to me IF the O2's are showing fat and the engine is knoking, I go w/ the sensor being FUBAR w/ lead...
If the car runs well w/ street tune chip, then that says the timing on the other chip may be too much for the octane??
The 340 took me to mid 10's B4 it was outta breath.
W/ going mid to hi 7's in the 1/8th, you are not close to out running the pump,, unless like someone said, it's tired...
Sounds like you have all the scan tools necessary.. What about a check on FP at WOT?? Where's that found to be?? That will tell you right quik if the pump's FUBAR..
Another comment on the plugs.. Look CLOSELY at them w/ a plug inspection lite.. See any "fly sh$t" on the porcelan?? Toasty lite brown? Electrodes BLUE? All 6 the same? [probably 5&6 ain't great w/out a power plate!!]
where's the batt. volts at WOT on the DS??

lastly.. Is the engine tied down and are the mounts in GOOD shape?? As in the DP not hitting the frame, etc, etc??

 

[TurboDave]

Jason, lots of things determine whether you're going to get detonation or not.

THE primary determination is available/effective octane. NOT how rich or how lean you are. You can be very rich and still knock if you're low on octane.
By the same token you can be running VERY lean and not detonate, if you have enough octane.

You said you had 5 gallons of C16 along with NOS (totally crap). Are you convinced that the C16 was good? Why run a mixture. When at the track, pump out the pump gas and replace it with race gas. Don't mix it. You never really know what you've got by mixing like that.

Also could be the sensor, but sure sounds like you need to bump the octane up and try some runs on pure race gas.

Or did I completely mis-understand your post and you were running 5 gallons of C16 with NO pump gas?? If so, you're hooking very hard and may be uncovering the pump with only 5 gallons in that BIG tank. I prefer running 10 gallons and have NO danger of uncovering the pump and loosing fuel volume to the injectors.

 

[TylerDurden]

I may have missed something here, but if jason is running 17 psi on pump gas, but then tries to run a little more than that with race gas and ends up knocking a lot, my first question would be, what chip are you using at the track and how much timing is in it....you can be fat on gas and octane and still knock if timing is too high...

just another possible cause.....

dan

 

[Vader 87]

OK, i had 5 gallons of straight C16 in it with NO pump gas...the only reason i mixed it again with 1 gallon of NOS fuel is because that was all the C16 that Tachyon race shop had so i bought that and went to the track and only had enough for another gallon of the best Sunoco crap they had there at the track which they claimed was that NOS fuel rated at 122 octane......anyways, the O2 was put in the car 15 minutes before i went to the track.....the first couple runs had to be accurate on it because it was brand new.....and as for gas running out of the tank....my knock happened from 30 to 80 mph......not at the launch....would a starved tank knock at that mph or right at the start? The injectors i am running are 55's from Red Armstrong and i am running his chips, a 93 and a 107 from him. BTW, i do have an EGT gauge but i just never happened to look at it running down the track ....I wasn't thinking to look at it because i was watching the scanmaster the whole time in case i knocked again.

 

[REDS HOT AIR]

Originally posted by REDS HOT AIR
forgot to mention that if you get some missfire when you turn the boost up it will show knock

might wantta check them wires and plugs out...i recomend ngk ur-5 plugs at .032 gap for high boost ... autolite and ac delcos missfired at high boost in mine with the ngk's i've been 30# with no knock and no missfire. and i use msd super conductor wires

 

[TurboDave]

Yes actually, that's exactly when fuel starvation will occur, not right at the launch, but rather 60 - 300 feet out, when all the fuel is "platered" against the back wall of the baffle and tank.

It's not so much that you're not getting any fuel, but rather a lot of air getting sucked in with it, reducing the available volume significantly.

 

[Joe 1320]

This is a good example of why you should have a fuel pressure gauge that can be viewed from inside the car at WOT. This eliminates the guesswork of fuel pressure.

IMHO, the other replies about the possible causes are right on. Also keep in mind, as load increases, so does cylinder pressure during the combustion event. This is why the stock cars can usually run an extra pound or two boost in low gear, but will knock at that boost level in 3rd and 4th. You will also have a harder time firing the mixture as load increases. Knock can be caused by overly lean and/or overly rich. A misfire can show over rich condition based on what your O2 sensor sees, but in reality it could still be lean in the cylinders that aren't misfiring. If I were trying to sort out that combo, I would start with fresh plugs and wires to eliminate that variable.

 

[CraigT]

along with NOS (totally crap). [/B]

How so....I have used it exclusively since my last motor was built.

 

[Cool87GN]

Hang In There Jason!

You're car is running real strong! High tens are coming your way once you get this problem sorted out.

 

[Vader 87]

Re: Hang In There Jason!

Originally posted by Cool87GN
You're car is running real strong! High tens are coming your way once you get this problem sorted out.

Thanks....thats what is killing me though, if i wasn't knocking i wouldve went high 6's consistently i think. I think im going to get one more opinion and call up Red Armstrong tomorrow.....he'll probably know what it is right off hand. Right now i'm wondering if i did in fact have enough fuel in the tank.

 

[cool 84]

I agree with Red. I've gotten a ton of knock at high boost before I closed the plug gap down to .030. Got the same thing when I didn't press a plug wire all the way onto the plug. It ran fine up to about 17psi and then would knock like crazy no matter how much octane I had.