3800 throttle plate size. (Page 1/1)
Dave E Bouy JUL 19, 10:35 AM
Does anyone happen to know the size of the 3800 Series II throttle plate? I'm just starting a 3.4 DOHC swap and am planning a custom intake plenum. Wondering if I could use a 3800 throttle body to increase airflow since the 97 DOHC and the 3800 share the same pcm.
Dennis LaGrua JUL 19, 12:48 PM
I believe that the stock 3800SC throttle body size is 69mm. I did the N* upgrade and now have a 75mm throttle body.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Dave E Bouy JUL 19, 06:08 PM
Thanks Dennis. May I should be thinking about a N* tb. It should work with the 3800 PCM.
Dennis LaGrua JUL 20, 06:43 PM

quote
Originally posted by Dave E Bouy:

Thanks Dennis. May I should be thinking about a N* tb. It should work with the 3800 PCM.



When going with the larger 2000- N* throttle body you really need the larger early LS1 MAF sensor in tandem. This makes the engine breath much better. If you decide to go this route the LS1 MAF table values need to be imported into the program and the MAF transfer function adjusted for air volume vs injector flow. You will need a PCM program editor to do this or rely on someone capable of making the changes. You follow your fueling via the STFT, LTFT and O2 values and use the percentage differences between ideal O2 values and actual readings. You do this at cruise and WOT, Then you scale the MAF curve to match the needed fueling.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Dave E Bouy JUL 20, 08:26 PM
Thanks again Dennis. I know virtually nothing about the tuning. I will just leave that to someone else.

DF