Lousy MPH?

[icepicker62]

I was wondering if there are any glaring reasons a car with my set up would run good 60 ft, fair e.t's but a slow MPH? Car leaves hard but doesnt seem to MPH like I think it should. I only have a scanmaster, so I cant go over all the data like I would like. But, O2 never dropped below .789, no knock by either scanner or alarm, car sounded good, not breaking up or anything.
See sig for mods, running new valve springs. 52 lbs fuel pressure. 28 lbs boost! I know the boost sounds way high but I tried with 2 different boost gauges with same results.
Could too much boost with stock innercooler cause this? Again, no knock so I'm confused.
My best 1/8 & 1/4 were 91 & 115 mph but usually more like 89 & 111 mph.
Ets 7.5 & 11.8 avg.
Some things not in sig, translator with LS1 MAF. Cold air kit. Electric cutout, (same et's, mph with it open or closed.) 62 mm TB. My TT chip is the old kind thats not adjustable, so timing is set at 24 degrees.
When I installed cam,(Poston grind# GN107T, part # 107degree lc- 4degree adv)) it said "Timing data is shown at 4 degrees advanced. I set it with dots aligned, didnt do any cam timing. (didnt know how) Heres specs, shows 430/430 lift on spec sheet but 269/269 on graph? 254/254 duration on spec sheet & 202/202 on graph? 0 overlap, Could not doing cam timing properly cause lots of torque but poor HP? I know I'm asking a lot, but maybe somone has seen this before. I got the feeling I'm going to be pulling the cam back out & setting up properly. Thanks.

[Blazer406]

IMHO... you need to look close at the timeslip and look at 1/8 mile trap speed and 1/4 mile trap speed....off the same slip....

You are quoting trap speed numbers for 1/8 and 1/4.... but I am not sure they are on the same run.... 22mph is decent pickup from 1/8 to the 1/4 (89 - 111)

What is a PPC converter?

[TurboDave]

Observations: IF your torque converter is a non locker, then your ET and MPH are not out of line for the quoted ET and MPH (11.7@115) in your sig.
Mine mustered 114's from some 11.7's, but running a locked TCC picked my mph up to 117+, same ET's.

Why so much fuel pressure?????

For the setup you have, I don't see anything terribly out of whack. A data logger of some type would help a ton though.

[icepicker62]

Originally Posted by Blazer406

IMHO... you need to look close at the timeslip and look at 1/8 mile trap speed and 1/4 mile trap speed....off the same slip....

You are quoting trap speed numbers for 1/8 and 1/4.... but I am not sure they are on the same run.... 22mph is decent pickup from 1/8 to the 1/4 (89 - 111)
What is a PPC converter?

No, they were different runs, but almost the same. 1/8 was 7.5 @ 90 & 11.83 @ 113

Pats Performance Converters

Originally Posted by TurboDave

Observations: IF your torque converter is a non locker, then your ET and MPH are not out of line for the quoted ET and MPH (11.7@115) in your sig.
Mine mustered 114's from some 11.7's, but running a locked TCC picked my mph up to 117+, same ET's.


Why so much fuel pressure?????


For the setup you have, I don't see anything terribly out of whack. A data logger of some type would help a ton though.

I have the converter locking at 90 MPH in 1/4.
I thought I needed it with such high boost. Adjusted it as per instructions on turbo buick site.


Yeah, I know, I gotta get something this summer. Thanx.

[QUIP'6']

Fuel Pressure Maybe One Issue. With Alky Cutting Fuel Down When Testing And Tuning Can Make A Dramatic Difference Also Why 4 Degrees Advance On Cam? This Will Give You More Bottom End But May Hurt You On Top. I Would Tune With Trimming Base Fuel And Then See Where That Takes You. I Ran A 11.60 At 114 With 25 Psi And 27/24 Timing With A Duttneck So I Think That You Are In The Ballpark For Your Set Up. By The Way Nice 60 Foot. Are You Running 28 Inch Or 26 Inch Tires If You Have 26 Inch Then I Think You Need To Step Up To 28's. I Gained 3 Mph Just Switching

[Blazer406]

Most would recommend 43-45 psi with the engine running... vacuum line off....

Then starting at a low boost... make a pass... and see what the 02's do.... start tuning from there.

[icepicker62]

Originally Posted by lpaulabbott

Fuel Pressure Maybe One Issue. With Alky Cutting Fuel Down When Testing And Tuning Can Make A Dramatic Difference Also Why 4 Degrees Advance On Cam? This Will Give You More Bottom End But May Hurt You On Top. I Would Tune With Trimming Base Fuel And Then See Where That Takes You. I Ran A 11.60 At 114 With 25 Psi And 27/24 Timing With A Duttneck So I Think That You Are In The Ballpark For Your Set Up. By The Way Nice 60 Foot. Are You Running 28 Inch Or 26 Inch Tires If You Have 26 Inch Then I Think You Need To Step Up To 28's. I Gained 3 Mph Just Switching

The 4 degrees was on the spec sheet, I just set it up with the dots aligned, I run 26 MT DR's. Need new ones, what do you recommend? (size)

Originally Posted by Blazer406

Most would recommend 43-45 psi with the engine running... vacuum line off....

Then starting at a low boost... make a pass... and see what the 02's do.... start tuning from there.

I'll try that come spring. I think I had the pressure set at 48lbs w/ line off. When I set it around 45, I got some knock retard on scanner. I'll re try. thanx.

[QUIP'6']

Originally Posted by icepicker62

The 4 degrees was on the spec sheet, I just set it up with the dots aligned, I run 26 MT DR's. Need new ones, what do you recommend? (size)

I'll try that come spring. I think I had the pressure set at 48lbs w/ line off. When I set it around 45, I got some knock retard on scanner. I'll re try. thanx.

I THOUGHT YOU ADVANCED IT ON TOP OF THERE SPECS WELL THATS GOOD THAT YOU DIDNT. I WOULD RECOMMEND 275 60'S YOU WILL GAIN AT LEAST 3 MPH AND MAYBE 2 TENTHS. WHEN YOU GET INTO 11'S YOU NEED A TALLER TIRE. I WOULD LEAVE THE FUEL AT 48 PSI GET A NEW CHIP AND PLAY WITH TIMING. I AM AT 28/24 BUT EVERY CAR IS DIFFERENT

[icepicker62]

Originally Posted by lpaulabbott

I THOUGHT YOU ADVANCED IT ON TOP OF THERE SPECS WELL THATS GOOD THAT YOU DIDNT. I WOULD RECOMMEND 275 60'S YOU WILL GAIN AT LEAST 3 MPH AND MAYBE 2 TENTHS. WHEN YOU GET INTO 11'S YOU NEED A TALLER TIRE. I WOULD LEAVE THE FUEL AT 48 PSI GET A NEW CHIP AND PLAY WITH TIMING. I AM AT 28/24 BUT EVERY CAR IS DIFFERENT

275 60's will fit no problem on stock steel rims? I do have new springs all 4 corners & air bags in both rear. I am going to get a new chip from Eric, but I'm kinda holding off cuz I may be installing a new innercooler & turbo. Want to go with 60lb injectors. Eric sells a injector / chip combo. Figure do it all @ one time.

[UNGN]

Originally Posted by icepicker62

275 60's will fit no problem on stock steel rims? I do have new springs all 4 corners & air bags in both rear.

If you currently are running 275/50's, the 275/60's will rub the frame less as they are slightly narrower.

[Mr.Spool]

icepicker62,there is nothing wrong with your mph.i wouldn't drop fuel preesure if your mv are at 789 at 28psi.your mv could come down a little but at 28psi and without a wideband you could pop a headgasket.your sticking alot of boost and fuel into the motor.that's a nice timeslip on the 49 turbo, the 28inch tires should help you mph more.