More Fuel -Boost -Timing - Zero Knock - LOWER MPH

Mr86t-type

New Member
Joined
Feb 25, 2007
Guy's,

Really can't figure this one out, the car was running Great, with a Best MPH of 108.00 on my Stock Setup, but I was UBER LEAN, 740's n the 02 at the top of third, and only Mid-50's fuel pressure..So I installed a new pump, now I have
PLENTY of fuel, pushing 70psi and 810 and the Very End of third (Zero Knock of course).
So I upped the timing AND Boost from my previous 20lbs and 23/21 timing to 23lbs and 25/24 timing (0.0 retard), and went Back to the track EXPECTING better MPH...well Heres what I got instead:

Pass 1: 12.963@105.23 84.49 1/8th 0.2 retard 796 lowest 02 23PSI
Pass 2: 12.966@104.93 84.42 1/8th 0.1 retard 808 lowest 02 23PSI
Pass 3: 12.921@104.85 84.44 1/8th 5.6 retard 800 lowest 02 24PSI

I was FLOORED as Peviously, running OUT of fuel I was getting, an Average with LESS BOOST and TIMING:

12.800@107.50's 85.65 1/8th @ 20PSI and 24/23 timing with some knock 2.0-3.5 and 740's at the top of third

So WHAT NOW?? Pull Fuel from the Chip?? Turn the Boost Back Down??:confused:

The Weather played a MINOR role, as it was @ 85degrees/slightly humid, as opposed to 72degrees/not humid, but remember I had MORE BOOST and TIMING so that "SHOULD" have MORE than made up the Difference!!
 
Your tune is way too aggressive for a stock turbo and probably inlet track on pump gas/alky.

Seeing that much knock is something you are going to regret so back off the boost and timing.

The MPH could have come from the fact that you were running so lean it was making more HP up top and was not showing knock because you weren't pushing the cylinder pressure like you are now. If 800 is your lowest 02 MV, then you are too fat now but I'd recommend staying around this to be safe, or get or borrow a wideband and dial it in with that.
 
I agree with getting a wideband to tune with. I have .720 02 counts all the way thru my WOT runs. BUT my WB shows good A/F mixture. Bring your boost down to 18-19 and put your timing at 23/21.

Set your FP at 42-43 psi line off and go from there. Get the car running good at those boost levels before cranking it up.

What 02 sensor do you have? Have you run race gas with it? It could be fouled and not reading correctly. In any case a WB is the way to go in order to keep your headgaskets in place.

A car thats too rich will lose MPH. Lean is mean...but start low boost and work your way up to the big boost numbers.
 
Yo figure your air fuel numbers at low boost. And dont experiment at high boost.

In other words you put the boost to like 18 PSI and then adjust your fueling to see what O2's your car runs the best at. Look at the 1/8 and 1/4 MPH increments. The higher the differencial, the closer you are. Meaning 75 in the 1/8 and 90 in the 1/4 is a 15 MPH pickup. If you make a change and the mph goes 75 in the 1/8 and 93 in the 1/4 then the pickup is 18 and your on the rite track.

Also.. your scanmaster records highest knock.. but there is a huge difference between seeing 6 degree's of knock at 10 MPH vs seeing 6 degree's at 100 MPH. False knock will show itself and get recorded. Place the scantool on top of the dash and look at it in 3rd gear.. and tune for zero knock. If it starts coming up..1..2..4..6.. LIFT and get out of it. Running down the track and hitting the recall at the end of the run.. is not the best. Mash both buttons and it will tell you what MPH you saw the knock at.

Sounds like your car likes a leaner mixture. But work on this having ZERO Knock.

HTH
 
Razor Thanks, and Yea, since the Mid-90's I've allways used Turbolink, but I recently got a Scanmaster, and I guess I got too used to it. Especially at the Track Turbolink's MUCH better, as I have a Decent Log of whats going on..and I can also see knock counts...anyhow, I turned the boost back down to 19-20 PSI, and Raised the timing to 26.5/24.2 and it Feels(I Know thats Normally Meaningless), but now on my same "test track" I allways use, I get wheelspin from a 2mph rolling start (the same method I allways use) whereas before (even in Cooler Temps) it did NOT - when I was running Lean & Mean...of course my O2's came down a Little Bit as well..lowest of 790@105 (0.9 retard) but we'll see next Wed. I might make a another Track Trip...

Thanks as Allways for your help!
 
Razor Thanks, and Yea, since the Mid-90's I've allways used Turbolink, but I recently got a Scanmaster, and I guess I got too used to it. Especially at the Track Turbolink's MUCH better, as I have a Decent Log of whats going on..and I can also see knock counts...anyhow, I turned the boost back down to 19-20 PSI, and Raised the timing to 26.5/24.2 and it Feels(I Know thats Normally Meaningless), but now on my same "test track" I allways use, I get wheelspin from a 2mph rolling start (the same method I allways use) whereas before (even in Cooler Temps) it did NOT - when I was running Lean & Mean...of course my O2's came down a Little Bit as well..lowest of 790@105 (0.9 retard) but we'll see next Wed. I might make a another Track Trip...

Thanks as Allways for your help!

No probs.. get a direct scan or power logger. The frame rate is unreal :)

The T-link is only as fast as the SM2. Which is not very much.
 
No probs.. get a direct scan or power logger. The frame rate is unreal :)

The T-link is only as fast as the SM2. Which is not very much.

Just a heads up for those interested, a TT Chip now offers an upgrade that allows your scanmaster to refresh data 3 times faster. Not as fast as DS or PL but faster than usual.:cool:
 
You went from .740's to .810? Thats where your mph went. Even with the added boost. You need a better scan tool that reads wideband sensors. Id back the timing off.
 
I noticed the title of the thread. More fuel, boost,...and timing? I would be very careful with adding timing until you have the boost and fuel thing straightened out. If anything take timing out to be safe until you know what you have. More timing is not always a good thing.
 
**Update**

Got my MPH Back! Yesterday evening, with just about Identical Conditions
Best of 3 passes:

60' 1.993
330' 5.457
1/8 8.328
MPH 85.57
1000 10.81
1/4 12.918@107.48 ZERO knock (0.9 in One frame)

What I did was Turn DOWN the Boost to 21Lbs, and bump Up the Timing
to 26.9/24.9....this time I used Turbolink instead of Scanmaster so I could look at Everything, Especially KNOCK which was Zero, and the aforementioned 0.9 at my 85mph Lock-up....the Other two passes were 0.0 and of Course Zero Knock Counts

Alch is on the Default 5.2 setting...Now if I Increase the Alch would that help if I UP the boost??

Thanks!
 
**Update**

Got my MPH Back! Yesterday evening, with just about Identical Conditions
Best of 3 passes:

60' 1.993
330' 5.457
1/8 8.328
MPH 85.57
1000 10.81
1/4 12.918@107.48 ZERO knock (0.9 in One frame)

What I did was Turn DOWN the Boost to 21Lbs, and bump Up the Timing
to 26.9/24.9....this time I used Turbolink instead of Scanmaster so I could look at Everything, Especially KNOCK which was Zero, and the aforementioned 0.9 at my 85mph Lock-up....the Other two passes were 0.0 and of Course Zero Knock Counts

Alch is on the Default 5.2 setting...Now if I Increase the Alch would that help if I UP the boost??

Thanks!

Understand if you crank the boost up, your alky will also spray harder :D

So only give it more alky if it shows sustained knock. The blips on the screen less than 1 degree are meaningless... unless they are constant.

So if you see... .5,1,.5,2,.5,1.... constantly.. then it needs more alky.

Glad to see you having fun.
 
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