Poor performance, Low timing?

2 QK 4 U

Banned
Joined
Feb 14, 2003
While my car has been down I have been doing some thinking about my Low Performance issue.

1. Low Timing? Could it be possible for the relucter ring to move on the balancer throwing my timing out of wack? Can I put a timing light on it? If so what do I look for?

2. Cam Sensor? Could I have installed my cam sensor wrong? Or can you even mess that up.

3. Chip? I also have reasons to believe my chip is not right. It was burned for my application but it does not cycle the O2s like it should. I did this with 3 O2 sensors and then swapped chips with "silentbutdeadlys' TT chip and it started cycling the O2s.

4. I know there is something holding back it's potential and it would be nice to find it?

Any help would be appreciated.

Thanks,
Jason
 
Just for reference this is the cars performance:

60ft - 1.8441
330 - 5.49
1/8 - 8.52 @ 80mph
1/4 - 13.4892 @ 96.77

...and this is what I have on the car:

1986 3.8L 109 Block
Bored .030 over
TRW forged Pistons
Moly rings gapped at ring mfgs specs
Stock Rods w/Clevite 77 brngs and ARP bolts
Stock crank w/King brngs
Speed Pro hyd camshaft 204/214
Cloyes True street roller timing set
HV front cover
Stock balancer/flexplate
A/C Delete
Ported 8445 Heads w/125lbs springs, stock valves, 9441 HGs, ARP studs
Ported stock Intake w/stock unported upper plenum & TB - no power plate
PTE Front Mount Intercooler w/all RPS silicone hoses
PTE GT6776 Turbo 3" in - 2" out and HD WG actuator
PTE Turbo Saver Kit
Terry Houston SSTL downpipe, race dump, Hooker catback system
Denso O2 Sensor
AC CR42 plugs w/factory 7mm wires
57lbs Seimens Injectors
237 fuel regulator
Griffen Aluminum radiator w/electric fan
Walbro 340 Fuel Pump w/hotwire kit
LT1 MAF sensor w/Translator set correctly
Precision Vigilante Single disk Convertor LU 3500 stall speed
Extreme Automatics Stage II transmission w/transbrake and Art carr deep pan
B&M Super cooler trans cooler w/10" electric fan set for 190 deg
Driveshaft safety loop
Stock Driveshaft and U joints
Stock Axles
Stock untoched rear suspension and brakes
Stock untoched front suspension and brakes
Centerline Convo Pro 15x8.5 w/hoosier quick time pro 27x11.5 w/rim screws
VDO oil,water,boost,trans temp gauges. Autometer Fuel psi gauge on hood
Scanmaster and Direct Scan
Bob Bailey commander chip for 93 octane set on open loop idle
 
When I read your time & MPH, I thought good times for a stock car...then I read your MODS.
What boost & gas?
You need to post a DS file to let people see what your problem might be.
 
Yes you can use a timing light. Let the engine idle and look at directscan to see what the commanded advance is, then check with the light. Aside from the O2 behavior, how did your car run with the borrowed TT chip? I see you have an open loop idle chip - that means the O2's won't jump around at idle, only during cruise. Most TT chips are also open loop idle. When you say it wasn't cycling the O2's, was that at idle or driving at light, steady throttle? Was the cam degreed in? Any chance it's off a tooth? Check the compression, and even do a leakdown test if you can to make sure all is well mechanically. The cam sensor could be 180 degrees out which would make it a little harder to start and could affect wot some. Start it up, unplug the cam sensor (which will turn on the check engine light), and go for a drive and see if it is any different. Once you shut it off you will have to reconnect the sensor before it will start again.
 
Try a lower stall converter. For the cam your running, a 3500 stall converter seems excessive. I would think a converter in the 2800-3000 range would work a lot better.
 
Well, you stated you have a commander chip with open loop idle, so that would explain why the O2's don't cycle at idle.
 
Yes you can use a timing light. Let the engine idle and look at directscan to see what the commanded advance is, then check with the light. Aside from the O2 behavior, how did your car run with the borrowed TT chip? I see you have an open loop idle chip - that means the O2's won't jump around at idle, only during cruise. Most TT chips are also open loop idle. When you say it wasn't cycling the O2's, was that at idle or driving at light, steady throttle? Was the cam degreed in? Any chance it's off a tooth? Check the compression, and even do a leakdown test if you can to make sure all is well mechanically. The cam sensor could be 180 degrees out which would make it a little harder to start and could affect wot some. Start it up, unplug the cam sensor (which will turn on the check engine light), and go for a drive and see if it is any different. Once you shut it off you will have to reconnect the sensor before it will start again.

I only ran the other chip at idle, didn't drive it cuz it was a 110 race chip and i had 93 in the tank. I didn't degree the cam, just installed the sprockets at 12 and 6

I did a compression but no leak down. cylinders were between 145 and 152

I'll try the cam sensor disconnet and see what happens.
 
Try a lower stall converter. For the cam your running, a 3500 stall converter seems excessive. I would think a converter in the 2800-3000 range would work a lot better.

Not with my turbo. I have a lockup converter so that puts me back in the power band on the big end.
 
Well, you stated you have a commander chip with open loop idle, so that would explain why the O2's don't cycle at idle.

But you have to set that in the scanmaster everytime the battery is disconected. The O2s won't cycle in either open or closed.

I'm putting my trans back in today. It's been down since I broke down 2 exits from National Trail a couple weeks ago. So, I'll try some things and see what I can come up with.

thanks,
Jason
 
I think you may want to put 2 things on your xmas wish list.....an adjustable fuel pressure regulator and maybe an egt gauge.
At that boost level, you are probably down 150hp, so start looking for a major problem. Torque converter may be a bit on the high side, but it should be a blast out of the hole if you can hook it up.
 
125# valve springs will kill the performance of your car. The car will just not rev.... Put a set of 90-100# valve springs with that cam...
 
The converter has to match the RPM range of the cam and turbo. He is right about there for his turbo. There seems to be a timing issue somewhere. Your 60' times are way down from where they should be with the t-brake and stall.

Why would 125# springs kill performance? It seems that heavier springs would keep down valve float......unless they caused a wiped lobe. That's something to check.
 
It takes a lot more effort/resistance to open the valves. Those lifters will bleed down faster as well as throw off valve timing at lower oil pressure/rpm. With our cars having lower oil pressure those lifters will not completely pumped up either. You also risk the chance off wiping the cam lobes... Same thing with running to high oil pressure, can rob HP..
 
Just to follow up on this thread.

My performance problem was the torque converter.

I have some new numbers from direct scan, not the track.

5ps launch it went 101mph in 7.1 seconds. How does that compare to a 1/4 or 1/8 mile time?
 
Jason, sounds like a low 11 second 1/4 mile. I have see people run low 7's in the 1/8th @ around 100 mph. That is usually a low 11 second run. Nice!
 
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