Cheap Horsepower
09-01-2002, 10:51 PM
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Cheap Horsepower
This is a continuation of my "electric blower" post and the extra horsepower I've uncovered with the testing on my 87 auto.
After approx 15 test runs with my VC200 perforance computer, I notice an odd quirk with 1 of the runs. during all of my runs My car would shift at 5200-5400 rpm. I have a defective flappy valve and thought this low rpm shift was in someway related to this. This 1 run was exceptionally strong and the car shifted at 6300 rpm.
I pulled it into the garage and let her cool while I explored the Nichols and Tonys site for upshift info. When I first got this car in Nov of 2001 I adjusted the shift cable so first gear starts occured at 40-50% throttle as a side note. I did not find anything relating to upshift rpm timing except for the full throttle switch bypass. So I rigged the extra switch as described in Tonys article. While I was down there I tested the accelerator pedal movement and found a major conflict! Seems the PO had R+R the plastic carpet cover next to the pedal and the section towards the front of the car was not tucked behind pedal bracket! The only way I would hit full throttle position was to apply all the force I possibly could to sandwich this plastic piece. After removing and reinstalling the plastic part I gained an additional 15% travel in the pedal plus the pedal braket can depress the full throttle botton.
Next I moved into the engine compartment. I tested the range of movement in the throttle braket. With my wife pressing the Bawaaa pedal completly to the floor, I forced the throttle bracket as far open as possible. I found 3 problems;
1) The throttle spring, which keeps the linkage from bending incase the cables are to tight, had lost its bounce so that under heavy peddle pressure the back of the cable would "eject" instead of the cable moving the throttle bracket. This was easily rectafied by compressing the spring and adding a zip tie to the base of the spring. Wow! Talk about a much fast responding throttle. When I give it gas now the engine response is MUCH quicker.
2) The throttle cable coming from the interior had 1/8 th inch of slack in it. Easy fix, remove the lock pin, pop off the ball and adjust the cable with lock nut.
3) The cable going to the throttle body had about 1/4 inch left in it when the throttle was completely depressed from the inside. The throttle body plate wasn't even opening all the way!! Another easy fix, this cable has a large black box at the anchor point of the linkage. This box has an easy plastic screw adjustment nut that I was able to adjust with my fingers. Caution! If you over adjust this nut the throttle plate will remain a little open at idle and your idle speed will vary wildly. At least mine did. If this happens just back off the nut till the idle settles down.
These adjustments decreased my 0-60 times by .6 sec and the car feels like the supercar it should be. I used to make excuses about my cars' performace, not any more! TRY THESE TIPS! Especially if your not satisfied with your 928s' performance. Please post if has helped!
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
After approx 15 test runs with my VC200 perforance computer, I notice an odd quirk with 1 of the runs. during all of my runs My car would shift at 5200-5400 rpm. I have a defective flappy valve and thought this low rpm shift was in someway related to this. This 1 run was exceptionally strong and the car shifted at 6300 rpm.
I pulled it into the garage and let her cool while I explored the Nichols and Tonys site for upshift info. When I first got this car in Nov of 2001 I adjusted the shift cable so first gear starts occured at 40-50% throttle as a side note. I did not find anything relating to upshift rpm timing except for the full throttle switch bypass. So I rigged the extra switch as described in Tonys article. While I was down there I tested the accelerator pedal movement and found a major conflict! Seems the PO had R+R the plastic carpet cover next to the pedal and the section towards the front of the car was not tucked behind pedal bracket! The only way I would hit full throttle position was to apply all the force I possibly could to sandwich this plastic piece. After removing and reinstalling the plastic part I gained an additional 15% travel in the pedal plus the pedal braket can depress the full throttle botton.
Next I moved into the engine compartment. I tested the range of movement in the throttle braket. With my wife pressing the Bawaaa pedal completly to the floor, I forced the throttle bracket as far open as possible. I found 3 problems;
1) The throttle spring, which keeps the linkage from bending incase the cables are to tight, had lost its bounce so that under heavy peddle pressure the back of the cable would "eject" instead of the cable moving the throttle bracket. This was easily rectafied by compressing the spring and adding a zip tie to the base of the spring. Wow! Talk about a much fast responding throttle. When I give it gas now the engine response is MUCH quicker.
2) The throttle cable coming from the interior had 1/8 th inch of slack in it. Easy fix, remove the lock pin, pop off the ball and adjust the cable with lock nut.
3) The cable going to the throttle body had about 1/4 inch left in it when the throttle was completely depressed from the inside. The throttle body plate wasn't even opening all the way!! Another easy fix, this cable has a large black box at the anchor point of the linkage. This box has an easy plastic screw adjustment nut that I was able to adjust with my fingers. Caution! If you over adjust this nut the throttle plate will remain a little open at idle and your idle speed will vary wildly. At least mine did. If this happens just back off the nut till the idle settles down.
These adjustments decreased my 0-60 times by .6 sec and the car feels like the supercar it should be. I used to make excuses about my cars' performace, not any more! TRY THESE TIPS! Especially if your not satisfied with your 928s' performance. Please post if has helped!
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
09-02-2002, 02:02 AM
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Greggg:
Sounds interesting. I'll have to look into that. I saw a similar post from a 911 owner some time ago who had similar results.
Sounds interesting. I'll have to look into that. I saw a similar post from a 911 owner some time ago who had similar results.
09-02-2002, 09:56 PM
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Hey Kblair, nice to hear from you! We had a shark gathering here in Detroit and I tested the other 5 cars and everyones throttle was not fully opening! Quick check up, engine off, have someone push the accel pedal all the way down, under the hood, push the linkage to see if it can open the throttle plate any further. All cars were off between 1/4 to 1/2 inch. After adjustment the pedal action was much faster and the cars were noticably quicker.
Just goes to show how much these cables relax over time. <img src="graemlins/jumper.gif" border="0" alt="[jumper]" />
Just goes to show how much these cables relax over time. <img src="graemlins/jumper.gif" border="0" alt="[jumper]" />
09-02-2002, 10:01 PM
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Greg-
Thank for tuning up the linkage today. You must have increased my HP by at least 30HP! <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
Seriously, though... it does seem a little better. Hard to say as I had to take it easy with my son in the car. I'm off to Benton Harbor, MI tomorrow AM. Thinking of taking the 928. I'll let you know if I notice any improvements. I'll also post pictures as soon as I can.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
Thank for tuning up the linkage today. You must have increased my HP by at least 30HP! <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
Seriously, though... it does seem a little better. Hard to say as I had to take it easy with my son in the car. I'm off to Benton Harbor, MI tomorrow AM. Thinking of taking the 928. I'll let you know if I notice any improvements. I'll also post pictures as soon as I can.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
09-02-2002, 10:15 PM
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Hey Andrew. Nice to meet you and your son today! Thank you for the CD. I'm sure this will save me alot of time. I hope the throttle fix helps out although, your car didn't have too much adjustment needed. Hope to see you Thursday at Champs! <img src="graemlins/yltype.gif" border="0" alt="[typing]" />
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09-04-2002, 09:46 PM
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New update on the bilge blowing shark. From the earlier posts the best time 0-60mph at 71 deg was 6.21sec. Tonight with both blowers on full tilt I got 5.87 sec= .34 sec quicker.
I'm still trying to hook up my flappy valve. The ball fell off the socket/ stem of valve shaft. Anyone have an easy fix. I really dread r + r the intake. <img src="graemlins/yltype.gif" border="0" alt="[typing]" />
I'm still trying to hook up my flappy valve. The ball fell off the socket/ stem of valve shaft. Anyone have an easy fix. I really dread r + r the intake. <img src="graemlins/yltype.gif" border="0" alt="[typing]" />
09-05-2002, 01:30 AM
#9
Greg,
Lookin' good. KEEP an eyeball on the WOT lean zone. The brain should handle it.
Those wild variations you mentioned probably run the spectrum.
When new cap/rotor, wires plugs, coil can cause a 8 - 12+ HP gain (actually, just a return).
Then there is a little distributor advance testing throttle and shifter cable adjustment.
And as Steve C. might suggest a little working pressure adjustment on ye olde tranny. Probably even a fluid(s) change and higher/lower tire pressures (wheel size, too).
Lot of variables.
God forbid old sensor wires, a O2 sensor going south, intake and other vacuum leaks, clogged CAT , overtightened belts, locked up adjusters and those 2 sticking lifters, clogged air filter and the throat on the sensor(MAS/MAF) has a physical flat spot and doesn't seat right anymore. Did I mention clogged injectors?
Good work on the Blowers. Your list for power difference should have as many pages as the Manuals. Be Brave and drink plenty of brewed fluids... <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
Lookin' good. KEEP an eyeball on the WOT lean zone. The brain should handle it.
Those wild variations you mentioned probably run the spectrum.
When new cap/rotor, wires plugs, coil can cause a 8 - 12+ HP gain (actually, just a return).
Then there is a little distributor advance testing throttle and shifter cable adjustment.
And as Steve C. might suggest a little working pressure adjustment on ye olde tranny. Probably even a fluid(s) change and higher/lower tire pressures (wheel size, too).
Lot of variables.
God forbid old sensor wires, a O2 sensor going south, intake and other vacuum leaks, clogged CAT , overtightened belts, locked up adjusters and those 2 sticking lifters, clogged air filter and the throat on the sensor(MAS/MAF) has a physical flat spot and doesn't seat right anymore. Did I mention clogged injectors?
Good work on the Blowers. Your list for power difference should have as many pages as the Manuals. Be Brave and drink plenty of brewed fluids...
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
09-05-2002, 02:58 AM
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Hey John, couple things you said interest me. Distributer advance? Is this possible on these cars manually w/o changing the computer chips? Also accessory belt tension; is there a way to test correct tension?
I'm gonna do the plug wires but I didn't think too much about an upgraded coil. These look like a standard size domestic coil, does Accell or another manu make a better higher performing one. Also what about an MSD ignition sys?
I have the tranny filter and an getting ready to crawl on my back for that mess.
I think I've done everything else you mentioned. What I'd like to do is put together a list of all the most reasonable time and money wise upgrades so everyone whos interested can spend 1-2 weeks and maybe $500-$1000 and get MAJOR HP improvement.
One other little improvement I've found is to run aluminized duct insulation on the top of the radiator. Since all the intake air runs across this surface, the insultation only made sense. A little denser air.
Keep the ideas coming, I'll keep the vc200 cooken! <img src="graemlins/yltype.gif" border="0" alt="[typing]" />
I'm gonna do the plug wires but I didn't think too much about an upgraded coil. These look like a standard size domestic coil, does Accell or another manu make a better higher performing one. Also what about an MSD ignition sys?
I have the tranny filter and an getting ready to crawl on my back for that mess.
I think I've done everything else you mentioned. What I'd like to do is put together a list of all the most reasonable time and money wise upgrades so everyone whos interested can spend 1-2 weeks and maybe $500-$1000 and get MAJOR HP improvement.
One other little improvement I've found is to run aluminized duct insulation on the top of the radiator. Since all the intake air runs across this surface, the insultation only made sense. A little denser air.
Keep the ideas coming, I'll keep the vc200 cooken! <img src="graemlins/yltype.gif" border="0" alt="[typing]" />
09-05-2002, 04:39 PM
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That's the plan Stan! It's just that I had to take off early Tuesday Morning for Benton Harbor. No time to upload and post. I'll get to it. I do have my camera with me so I'll also try to snap a few of the BEER Night! <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" /> <img src="graemlins/drink.gif" border="0" alt="[cherrsagai]" /> <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
09-06-2002, 02:16 PM
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Here they are! The pics you've all wanted to see. You'll have to direct your questions to Greggg. I'm just the image dude! You can see more pictures of our Sharks in the Park event this past Labor day on my webpage (follow link below). There's even a speed picture now!
Here Greg is fixing up the insulation.
Here's a close up of the blower. It's the slight lump under the insulated tube where the bracket comes off the engine. Also note the wiring.
Finally, here Greg installed his micro-switch such that when the accelerator is depressed a certain amount it contacts the switch turning the blowers on. It's really pretty cool.
Here Greg is fixing up the insulation.
Here's a close up of the blower. It's the slight lump under the insulated tube where the bracket comes off the engine. Also note the wiring.
Finally, here Greg installed his micro-switch such that when the accelerator is depressed a certain amount it contacts the switch turning the blowers on. It's really pretty cool.