TPI Questions

George M. Dailey gmd at tecinfo.com
Thu Aug 21 01:31:46 GMT 1997


I'm wondering if water injection would be a better alternative to EGR? 
GMD

At 06:33 AM 8/18/97 -0700, you wrote:
>George,
>
>6 deg is not bad on 87 octane, on leaded (96 octane) I can't run anymore
>than 3 deg (allowing for small safety margin) without the engine starting to
>ping (well, sound like a machine gun).  With the avgas (BP100) I can safely
>run 6 deg.  Mind you I'm not using the standard ecu, so there's no knock
>sensing or retard facility, hence it's critical that I leave a safety margin
>as well.  However, I had come to the conclusion the pinging was mainly due
>to the extremely high compression the engine has (between 220psi and 240psi
>per cylinder).
>
>In fact, I can run 10 deg static if I don't load the engine heavily, ie.
>stay below 2500rpm in all gears.  Which is fine for city driving (less than
>80kph), but you can't put your foot down at all.
>
>Dan     dzorde at geocities.com.au
>
>>Hi Dan, what were you able to set the timing too without getting excessive
>>detonation? I could only getabout 6 degrees with my egr plugged.
>>
>>GMD
>>
>>
>>At 06:10 AM 8/12/97 -0700, you wrote:
>>>I'm lost, for a performance engine, do you want egr or not ?  When I built
>>>my tpi 350, I pulled the egr valve and stuck a blanking plate over the hole
>>>instead, oh, I also put the little metal plates in the manifold gaskets
>>>where the egr is meant to breathe through.  Was this a mistake (I don't care
>>>about economy, only power)? 
>>>
>>>Dan     dzorde at geocities.com
>>>>> Thanks for the help.
>>>>> 
>>>>> This P/N thing is confusing.  I have the JTR book (and a bunch others)
>>>>and
>>>>> most say not to ground this pin.
>>>>> If I remember correctly something to do with idle and deceleration. 
>>>>Should
>>>>> I be concerned????
>>>>> I think a lot of this is tied to an automatic transmission, not manual. 
>>>>Is
>>>>> this true?
>>>>
>>>>I left mine open..sortta.  I'm using Aluminum Corvette heads that do not
>>>>have the internal EGR passages in combination with a '86 VIN "F" TPI
>>>>manifold.
>>>>
>>>>The EGR valve is still present and connected, but doesn't actually do
>>>>anything since there isn't a supply of exhaust gas to the valve.
>>>>
>>>>Grounding the EGR feedback wire will set off the SES light (it simulates
>>>>the EGR being stuck in the open position)
>>>>
>>>>Leaving it disconnected will also occasionally set off the SES light (there
>>>>are a few cases where the ECM will command the EGR to actuate, then look to
>>>>see what happened.)  Fortunately, temps down here are high enough that this
>>>>doesn't happen often.  (been about 4 months since the last time the code
>>>>went off) It will also clear itself within a few minutes of driving.
>>>>
>>>>Someday I'll have an EGR flange welded to one of the exhaust headers to
>>>>supply external EGR.. but it's a low priority.
>>>>
>>>>Curt Martin (cmartin at america.com)
>>>>Ormond Beach, FL
>>>>http://www.america.com/~cmartin
>>>>'87 350 TPI Camaro.. (used to be a 2.8L V6 :)
>>>>
>>>
>>>
>>>
>>George M. Dailey
>>gmd at tecinfo.com
>>
>>
>
>
>
George M. Dailey
gmd at tecinfo.com




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