luisturbog
UNDERDOG HOT AIR !!!!!!!
- Joined
- Mar 30, 2007
Does anybody know what the most boost you can set your hot air at; It seems I cant go over 10#'s without it having a real bad knock.
the most boost possible!!!!
- Thread starter luisturbog
- Start date
when my car was stock i got it tuned so i could run 20 pounds on pump gas. With my current setup i have run it a few time as high as 28 but i have it set at 26psi and that where i like to keep it. if you cant even get over 10 you got a problem somewhere. you got any scan tool data we can look at.
Do you have a hotwired fuel pump? What is your fuel pressure? What is the chip make + type? Did you do the MAF tap test?
No hotwired FP means poor fueling. Poor fueling = knock. Low fuel pressure also = knock. Hypertech chips (if your still running it) are known for a ton of timing which can result in knock. Bad MAF will also do the same.
A good-running hot air should be able to push 15psi with no knock on pump gas easily. I ran 18 on the street on 92 octane and 22 at the track on 110 octane.
No hotwired FP means poor fueling. Poor fueling = knock. Low fuel pressure also = knock. Hypertech chips (if your still running it) are known for a ton of timing which can result in knock. Bad MAF will also do the same.
A good-running hot air should be able to push 15psi with no knock on pump gas easily. I ran 18 on the street on 92 octane and 22 at the track on 110 octane.
Jerryl
Tall Unvaccinated Chinese Guy
- Joined
- Dec 14, 2004
That is awesome guys!
What is the outside temps and what is your chip timing at?
What static compression and cam?
I am not doubting you at all, just think maybe "I am an idiot" cause I can't get past 12 on 93 on an 80 deg day, 80% hum, 17 deg chip with verified actual timing, blah blah
Sounds like I got a lot more tuning to do. Great post!
Turbo Riviera
New Member
- Joined
- May 29, 2001
This is not what I would call normal hot air behavior... LOL n00bs, probably don't want to crank up 20 psi on a stock motor and pump gas. Fuel, timing, and engine condition have to be spot on to get this performance.
Depending on altitude, fuel system, and chip timing 12-15 should be very doable for most stockers with ease.
My experience has been that much over 15 psi, I started needing octane at my altitude and temperatures. I live in the desert, so it's typically really hot here...
With the stock turbo, I have yet to see benefits above about 21 PSI at my altitude (4400 feet). It's just too small. Bigger turbo's have a much easier time running big boost numbers without detonation. At sea level, my boost gauge will go straight to 30 PSI though on VP C16 and no alky. This is in my Riviera Stocker.
That is awesome guys!
What is the outside temps and what is your chip timing at?
What static compression and cam?
I am not doubting you at all, just think maybe "I am an idiot" cause I can't get past 12 on 93 on an 80 deg day, 80% hum, 17 deg chip with verified actual timing, blah blah
Sounds like I got a lot more tuning to do. Great post!
When I started tuning, I worked up from 45 psi line off fuel pressure and 12 psi boost. Standard street chip with 17º timing for 42.5# injectors. I ran a 94 octane ethanol blend. Normal temperatures varied from 70º and 50% to 80º and 80% (the first time I raced was under those conditions). It was way too rich, dropping fuel pressure to 43 psi helped a bit, still no knock. Upped to 15 psi boost, still rich, still no knock. Went all the way to 18 psi, still rich, still no knock. 42 psi line off seemed to be the sweet spot, would start knocking at 40-41, no problems at 42, still slightly rich averaging 790 - 805 on O2's depending on weather. Stock block/heads/cam with home ported intake, TA33/42.5# hotwired pump and cold air with ATR DP and open exhaust. Tuning done on adjustable wastegate and FPR.
Jerryl
Tall Unvaccinated Chinese Guy
- Joined
- Dec 14, 2004
Agree.
I am running PL and WB with target AFR of 11.3 - 11.0 was sluggish. 11.2 seems to be the "safe sweet spot" in the heat (for now) untill other/future changes. Sure I can get 22 psi with alky and no KR with 93/alky target of 10.9. I realize every car is different but guess I won't be winning the lottery anytime soon. :smile:
http://www.turbobuick.com/forums/general-turbo-buick-tech/222689-nb-vs-wb-what-you-already-know.html
Lottery reference :smile:
http://www.turbobuick.com/forums/alcohol-nitrous-propane-tech/196626-chasing-knock-problems.html
Mine was done with EGT/NB/plug reading before WB was widely available but yes - with the low cost of WB nowadays there is no point doing it any other way. MAFT Pro and LC-1 and 3-bar MAP make engine management a breeze - most power for least work.
jerryl what does the 02's look like when the wide band is reading 11.2
once the new motor gets in my car im going to start tunning but i have alot to learn. how much time my car likes what a/f she likes how much boost i should run and all that goood stuff. i like running 25 i think thats a safe boost level but i might bump it up a pound.
once the new motor gets in my car im going to start tunning but i have alot to learn. how much time my car likes what a/f she likes how much boost i should run and all that goood stuff. i like running 25 i think thats a safe boost level but i might bump it up a pound.
BRAD_PADGETT
Well-Known Member
- Joined
- Jan 22, 2004
I have come to the same conclusion. For my purposes I think a DS will be enough for me.
By the way- I am at 23 pounds boost but not properly tuned. Scanmaster is great but very difficult to tune when you get to this level. All you do is guess . Good Luck- Brad
Jerryl
Tall Unvaccinated Chinese Guy
- Joined
- Dec 14, 2004
Right around 748
Jerryl
Tall Unvaccinated Chinese Guy
- Joined
- Dec 14, 2004
10.3 is around 795
10.5 is around 785
Back to the thread
;How much boost were you running at 810?
Edit
FWIW - I verified my mechanical boost gage with PL (3 Bar map) and it was within 0.3 at 14 psi
Turbo Riviera
New Member
- Joined
- May 29, 2001
Speaking of Phoenix...
This is my Riv at Firebird. The boost gauge was past pegged at this event. LOL I worried that I may have had a head gasket let loose, but it hadn't. Just me worrying.
i wish i would have know last year that it was just a leaking head gasket on my motor into the valley. i would have tried to tighten the stock bolts some and see if she stoped. but if i would have known that the motor was coming out due to a hurt piston i would have put some C16 in it and turn the boost to 30+ and see what she would do leaky head gasket or not. damn if i only knew the motor was coming out that day. 30+ boost would be sick. how about a 30 pound lauch
Turbo Riviera
New Member
- Joined
- May 29, 2001
i wish i would have know last year that it was just a leaking head gasket on my motor into the valley. i would have tried to tighten the stock bolts some and see if she stoped. but if i would have known that the motor was coming out due to a hurt piston i would have put some C16 in it and turn the boost to 30+ and see what she would do leaky head gasket or not. damn if i only knew the motor was coming out that day. 30+ boost would be sick. how about a 30 pound lauch
LOL
When I first started racing my Riv, it had the stock D5 converter in it, same as in the Regals... It was on it's last legs, and would stall up to 4000 RPM
, so I let 'er rip a couple of times up in Boise Idaho at 20 psi off the line. Sometimes it did well... 1.86 60 foot. Other times it did this:
Snapped 5 axles in 3 attempted passes straight. :biggrin:
Front wheel drive sucks. LOL!
