L98 Air Flow Help
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Joined: Apr 2013
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L98 Air Flow Help
I have an 88 coupe automatic. I am looking to do cheap bolt ons for slight increase in power but don't want to break my wallet and modify internally just yet. I already did my Magnaflow cat back and now I'm looking into an open lid and K&N filter. I searched a lot on this forum but I'm wondering if this setup has the same effect as putting a front license plate ram-air system on or one of those Vortex air systems. Please if anyone had had any experience with this help me out. I'm looking to purchase this weekend. Thanks!!!!
Race Director
Joined: Feb 2003
Posts: 16,475
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From: Kingman AZ
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St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16
You might want to read this before spending any more money:
http://temp.corvetteforum.net/c4/vader86/
http://temp.corvetteforum.net/c4/vader86/
Safety Car
Joined: Aug 2009
Posts: 3,751
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From: Melbourne, Victoria, Australia
Long tube headers knocked almost a second from the quarter mile, they are the best bang for buck.
Adjustable fuel pressure regulator next, 45-50 psi in conjunction with headers really wakes these L98 engines up.
I went from standard 14.4 quarters to 13.6 a week later with long tube headers, next was cold air intake and adjustable fuel pressure regulator set 48 psi , new plugs leads filter and tune got it down to 13.3 in the quarter mile.
That was around ten years ago, now she is blown forced induction is just what these L98 intake system needs to go quicker.
Drifting
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From: ft myers FL/Munising MI
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Joined: Dec 2000
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From: SE NY
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I agree on the dubious merits of a ram-air system. I had one on my prior 35th Anni and no better than the K&N with cut lid on my current '88.
I essentially agree with the mods listed by Vader86. Cheap mods that have worked on my '88:
-remove the "frisbee" from the front of the WP pulley
-cut lid with K&N
-replace the front Y with a 2 1/2" mandrel bent unit and hi-flow main cat
-TB coolant bypass is mostly a convenience for later removing the TB
-bump base timing to around 8 deg BTDC
-advance the TPS to about 0.67 Vdc at base idle or around 0.75Vdc at normal idle
-stock AC Delco spark plugs with base electrodes cut back & dressed
-an AFPR with fuel pressure set to around 48psi
-run 1/4-3/4 tank of fuel; 1/2 tank of fuel ~60lb==6hp gain
-toss the spare & jack; ~40lb==4hp gain
The above should put your '88 well into the mid 13s in the 1/4 mile run.
If you want to increase the SotP fun, install a TransGo shift kit and feel the tail wag on the 1-2 upshift...
Some of the above are free while others are relatively inexpensive and sime are labor intensive (e.g. AFPR installation).
I essentially agree with the mods listed by Vader86. Cheap mods that have worked on my '88:
-remove the "frisbee" from the front of the WP pulley
-cut lid with K&N
-replace the front Y with a 2 1/2" mandrel bent unit and hi-flow main cat
-TB coolant bypass is mostly a convenience for later removing the TB
-bump base timing to around 8 deg BTDC
-advance the TPS to about 0.67 Vdc at base idle or around 0.75Vdc at normal idle
-stock AC Delco spark plugs with base electrodes cut back & dressed
-an AFPR with fuel pressure set to around 48psi
-run 1/4-3/4 tank of fuel; 1/2 tank of fuel ~60lb==6hp gain
-toss the spare & jack; ~40lb==4hp gain
The above should put your '88 well into the mid 13s in the 1/4 mile run.
If you want to increase the SotP fun, install a TransGo shift kit and feel the tail wag on the 1-2 upshift...
Some of the above are free while others are relatively inexpensive and sime are labor intensive (e.g. AFPR installation).
