So apparently a 454 TBI and a Stroker do Mix...
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From: Detroit, MI
Car: 91' Pontiac Firebird
Engine: 388 ci Small block CHEVY (4.060x3.75), Dart Iron Eagle Platinum 200cc, Performer intake, 454 TBI, Long Tubes, True Dual 3" GPs
Transmission: 700R4, B&M, Governer Recal, 20,000 GVW cooler
So apparently a 454 TBI and a Stroker do Mix...
I just got my engine finally in and 98% of all the components in (still gotta wire the heated O2).
I bolted on a 454 TBI unit onto my 388 (4.060x3.75) with 200 cc heads (Dart Platinums 2.02/1.60) and 72cc chambers. I am running a TBI cam about 218/224 .454/.464
Today I just pulled her out and did some data logging on the stock chip (for the first time)
I did a light accel log and a WOT log.
Under light accel (9.4% TPS) the BLMs chilled at 128.
At WOT she pulled real hard and the O2 read <.930
I havent read the plugs yet though.
My only concern is the AE(right?), when I punch it, it just bawgs (<-- help me)
I bolted on a 454 TBI unit onto my 388 (4.060x3.75) with 200 cc heads (Dart Platinums 2.02/1.60) and 72cc chambers. I am running a TBI cam about 218/224 .454/.464
Today I just pulled her out and did some data logging on the stock chip (for the first time)
I did a light accel log and a WOT log.
Under light accel (9.4% TPS) the BLMs chilled at 128.
At WOT she pulled real hard and the O2 read <.930
I havent read the plugs yet though.
My only concern is the AE(right?), when I punch it, it just bawgs (<-- help me)
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From: Moorestown, NJ
Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
It could either be too much/too little AE or some combination of that with knock counts being picked up by the knock sensor. This will cause the computer to pull alot of timing.
Speaking of that, that reminds me
.
If you are having trouble with detonation on tip in, there are some things in the computer that can agrivate the problem. In the 8746, there is a transient delta rpm SA correction table as well as the launch mode logic. The transient RPM SA correction table goes from -200 - 200 RPM. This is shown as 0-400, but I beleive its the former. Basically with that one the computer subtracts timing if the engines rpms are dropping and adds timing if the engines rpms are rising. This may make the motor more responsive to change. What it seems to do is just make the engine run unpredictably. There is also the launch mode logic that adds timing in when the car is first starting off to help get the tc spun up and get the car moving. This one could also cause problems if it pushes the SA past what the motor likes. Zeroing the base SA (LD1CC) for launch mode and the transient rpm SA (LD1E6) might make the motor run more predictably while your trying to tune it. I think these can be useful, but they seem to be a pain in the butt when your trying to get everything else worked out.
Heres those tables from RBobs hac.
Speaking of that, that reminds me
.If you are having trouble with detonation on tip in, there are some things in the computer that can agrivate the problem. In the 8746, there is a transient delta rpm SA correction table as well as the launch mode logic. The transient RPM SA correction table goes from -200 - 200 RPM. This is shown as 0-400, but I beleive its the former. Basically with that one the computer subtracts timing if the engines rpms are dropping and adds timing if the engines rpms are rising. This may make the motor more responsive to change. What it seems to do is just make the engine run unpredictably. There is also the launch mode logic that adds timing in when the car is first starting off to help get the tc spun up and get the car moving. This one could also cause problems if it pushes the SA past what the motor likes. Zeroing the base SA (LD1CC) for launch mode and the transient rpm SA (LD1E6) might make the motor run more predictably while your trying to tune it. I think these can be useful, but they seem to be a pain in the butt when your trying to get everything else worked out.
Heres those tables from RBobs hac.
Code:
;*================================================== ;* 2d lkup ;* ;* Base SA for Launch Mode SA vs delta map ;*================================================== LD1CC: FCB 0 ; ;--------------------------------- ; SA ; delta map ;--------------------------------- FCB 64 ; 0 FCB 160 ; 10 FCB 224 ; 20 FCB 255 ; 30 FCB 255 ; 40 FCB 255 ; 50 FCB 255 ; 60 FCB 255 ; 70 ;*================================================== ;* ;* MAP mult for Launch Mode SA vs s/d map cnts ;* ;* tbl = mult * 256 ;*================================================== LD1D5: ;--------------------------------- ; mult ; s/d map ;--------------------------------- FCB 0 ; 20 FCB 0 ; 25 FCB 0 ; 30 FCB 0 ; 35 FCB 0 ; 40 FCB 0 ; 45 FCB 8 ; 50 FCB 14 ; 55 FCB 14 ; 60 FCB 14 ; 65 FCB 14 ; 70 FCB 14 ; 75 FCB 14 ; 80 FCB 11 ; 85 FCB 11 ; 90 FCB 9 ; 95 FCB 9 ; 100 ;*================================================== ;* delta tps & rpm SA term mult vs delta rpm / 25 ;* ;* Indexed Lookup vs delta rpm/25 value ;* ;* SA mult of next table ;* ;* tbl = mult * 64 ;*================================================== LD1E6: ;---------------------------------- ; SA ; delta rpm ;---------------------------------- FCB 240 ; 0 FCB 243 ; 25 FCB 246 ; 50 FCB 248 ; 75 FCB 250 ; 100 FCB 250 ; 125 FCB 250 ; 150 FCB 250 ; 175 FCB 0 ; 200 FCB 247 ; 225 FCB 6 ; 250 FCB 8 ; 275 FCB 10 ; 300 FCB 13 ; 325 FCB 16 ; 350 FCB 18 ; 375 FCB 20 ; 400 ;*================================================== ;* delta tps & rpm SA term vs rpm / 25 ;* ;* 2d lkup w/upr limt in 1st tbl entry, lwr limt in B ;* by rpm / 25 ;*================================================== LD1F7: FCB 128 ; uppr rpm/25 limit ;---------------------------------- ; Mult ; rpm ;---------------------------------- FCB 96 ; 400 FCB 96 ; 800 FCB 96 ; 1200 FCB 64 ; 1600 FCB 48 ; 2000 FCB 32 ; 2400 FCB 24 ; 2800 FCB 18 ; 3200 ;*================================================== ;* IAT mult for Launch Mode SA vs iat adc cnts ;* ;* tbl = mult * 256 ;*================================================== LD200: FCB 4 ; line cnt ;---------------------------------- ; Mult ; iat ;---------------------------------- FCB 0 ; 200c FCB 64 ; 80c FCB 176 ; 48c FCB 255 ; 23c FCB 255 ; -40c
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From: Moorestown, NJ
Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
Oh, BTW, youll also need a WB-O2 to tune the AE. The stock sensor wont really be of much use.
Thread Starter
Banned
Joined: Jun 2005
Posts: 118
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From: Detroit, MI
Car: 91' Pontiac Firebird
Engine: 388 ci Small block CHEVY (4.060x3.75), Dart Iron Eagle Platinum 200cc, Performer intake, 454 TBI, Long Tubes, True Dual 3" GPs
Transmission: 700R4, B&M, Governer Recal, 20,000 GVW cooler
I did another log and I went for about 5 minutes cruising lightly and getting up to about 60 mph. Then I turned around and I got up to about 30 mph at 18% TPS then let up and wopped to WOT. I went from 1 knock count, to 35 at that quick snap of the pedel. Also at the end of the log, I revved the engine before I shut if off and got about 23 knock counts from that.
I did a couple more stop and WOT runs, I did one where I gradually went to WOT(traction problems ) and got 1 knock count (probably headers or something). The other was the same no knock (1 count).
I was mistaken about the car running perfect, it is running a little rich, on the long and steady cruise at 60 mph my BLMs were around 118-121.
From what I could understand from your reply, I am having a computer timing issue, because my understanding is rich does not cause knocking.
Should I force Open Loop (disconnect O2) and try WOT runs, should I retard base timing, or I can't think of what to dooo.
I did a couple more stop and WOT runs, I did one where I gradually went to WOT(traction problems
) and got 1 knock count (probably headers or something). The other was the same no knock (1 count).I was mistaken about the car running perfect, it is running a little rich, on the long and steady cruise at 60 mph my BLMs were around 118-121.
From what I could understand from your reply, I am having a computer timing issue, because my understanding is rich does not cause knocking.
Should I force Open Loop (disconnect O2) and try WOT runs, should I retard base timing, or I can't think of what to dooo.
Last edited by TWICEtheRICE; Jul 15, 2005 at 05:35 PM.
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iTrader: (2)
Joined: Jan 2002
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From: Moorestown, NJ
Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
The o2 is out of the loop in WOT. One thing you may want to look at is the %TPS threshold for PE. This may be a bit high for your motor. Id try to get into PE by the time the MAP is around 75 kPa or so.
Id say its a possible timing issue, or a lean issue, or some combination of both. The stock O2 and the slow datarate may mask this. Id start with the timing and VE tables before you get into the AE. The ammount needed changes as the timing and VE changes.
As for those above tables, Id definatly zero them out if your picking up knock on tip in. It may be false knock, but either way its better being safe then sorry.
Id say its a possible timing issue, or a lean issue, or some combination of both. The stock O2 and the slow datarate may mask this. Id start with the timing and VE tables before you get into the AE. The ammount needed changes as the timing and VE changes.
As for those above tables, Id definatly zero them out if your picking up knock on tip in. It may be false knock, but either way its better being safe then sorry.
Thread Starter
Banned
Joined: Jun 2005
Posts: 118
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From: Detroit, MI
Car: 91' Pontiac Firebird
Engine: 388 ci Small block CHEVY (4.060x3.75), Dart Iron Eagle Platinum 200cc, Performer intake, 454 TBI, Long Tubes, True Dual 3" GPs
Transmission: 700R4, B&M, Governer Recal, 20,000 GVW cooler
Thanks man, i'll see what i can do about that TPS enable and what not.
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