3800 - lower manifold coolant plugs? or throttle body spacer with coolant blockoff? (Page 1/1)
DimeMachine JUN 10, 12:55 PM
Question for the 3800 crowd and first hand knowledge.

My air inlet pipe and rubber coupler is getting more heatsoaked than I would like. I see a lot of the GTP crowd plugs the two holes in the lower intake manifold thus blocking coolant flow to the M90 supercharger and throttle body. I am not concerned about winter icing as I do not drive this car in the winter.

If anyone has done this mod, I would be very curious for any observations you have to share as far as supercharger temps and inlet track temps - before and after.

PS. Fiero Video for fun. https://www.youtube.com/watch?v=upkKsxPQqfw&t=0s

Thanks in advance!

Dime.

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84/87 NB, 3800SC, E-85, VS Cam, 2.8 Pulley, 4T65E-HD, HP Tuners, AEM Wideband, Regal GS Gauges, S-10 Brake Booster. 1/4 mile -11.85 at 114mph

randy86 JUN 10, 01:59 PM
I did this on my corvette, but I did not plug the hoses, I got a coupler and connected the hoses together under the TB. Not sure I would block the flow of coolant.
Dennis LaGrua JUN 11, 06:53 PM
I drilled and tapped the coolant holes in the intake manifold and put in flush hex head pipe plugs. IIRC they were 1/4 NPT size. The objective was to eliminate any possible leakage and keep the supercharger cooler.

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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 "

OntarioKev JUN 12, 09:14 PM
Take a look at the pictures on ZZPs site:

https://zzperformance.com/c...achined-lower-intake

When you get a ported manifold from them they weld the coolant ports. It gives you an idea of what you may want to do.
Lou6t4gto JUN 18, 08:05 PM
shows nothing for gen 2 though
DimeMachine JUN 18, 09:14 PM

quote
Originally posted by Dennis LaGrua:

I drilled and tapped the coolant holes in the intake manifold and put in flush hex head pipe plugs. IIRC they were 1/4 NPT size. The objective was to eliminate any possible leakage and keep the supercharger cooler.




Thanks Dennis. Did it seem to keep the TB and SC cooler with the coolant blocked off - (I imagine - YES) and more importantly, do you believe it yielded more power due to cooler denser charge and perhaps a tad more timing without KR?
Dennis LaGrua JUN 21, 07:29 PM

quote
Originally posted by DimeMachine:


Thanks Dennis. Did it seem to keep the TB and SC cooler with the coolant blocked off - (I imagine - YES) and more importantly, do you believe it yielded more power due to cooler denser charge and perhaps a tad more timing without KR?



Haven't done a before and after test but the engine feels smoother and pulls harder. Since I also added a SSIC the test might be a bit flawed but IMO anything to lower intake manifold temperatures is beneficial.

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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 "

Dennis LaGrua JUN 21, 07:32 PM
duplicate post removed

[This message has been edited by Dennis LaGrua (edited 06-23-2019).]