Speed Density Questions knowledgable tuners needed

[William Bowers]

I recently purchased an 88 LX 5.0 from a transplanted Yankee. He had to sell it cuz his homeowners association wouldn't let him have more than 2 cars in his yard.1 owner bone stock, and in very good condition(interior brand new,everything works nothing broken). 1800 dollars seemed cheap to me!It runs and drives fine but I would like a little more power/sound.I intend to add :shorty headers,x-pipe,Flowmasters,Pulleys,phenolic spacer,Remove smog pump and intake silencer,3.73 gears,adj clutch cable,Cold air intake,new ignition,plugs,wires,coil,bigger fuel pump and pressure regulator,and a 70 mm throttle body. I do not want to open the engine in any way(yet) cuz it runs really goood and only has 88,000 miles.My question is the speed density system, I keep hearing that it needs to be changed over to mass air. WHY? It runs really good and I can't seem to justify the expense.Will it not work with the add ons I am considering.The only other things I might ever do to it is change the heads and the cam. I don't want to go to bigger injectors or change over to mass air. It is only a street driven car(I only drag race import bikes). And besides if I get the bug I have a 4 cyl body and 460/C6 sitting in the corner just waiting for me to get the time to mess with. I don't want to affect the streetability of the car cuz I don't intend to take it to the track anyway.

Is there anything else I can do to improve the performance,besides those I listed ( and that don't require opening the engine)and are any of them (that I have already chosen)not worth the trouble.Thank you in advance.

[William Bowers]

almost forgot about how much Hp did the average stock speed density car make and how much do you think that the mods I am considering will increase my HP/TQ.

[Conman]

for what you want to do the speed density is fine. I actually think it is better for your application because you don't need it and it's less things to worry about. Once you start adding a lumpy cam, heads and bigger injectors the mass air can better manage the engine.

Wait till Dark_5.0 or 88workcar come in here to give you more advice. They both still have speed density and are pretty quick. 88workcar runs 12's

The 88 5.0 stock was rated at 225hp/300tq.

I think your list of upgrades looks pretty good. It is definately a good start. If you plan on driving the car hard and maybe powershifting at all I would look into an aftermarket shifter. I have the pro 5.0 and it gives the car a whole new feel when I'm banging through the gears. The steeda tri-ax is also another great piece.

[William Bowers]

BTW where should my timing be on this engine? ( It will be daily driven and probably on 87 octane)

[chuck88]

I would think about adding subframe ctrs. In my case the car wasnt faster but it sure felt faster. One of the better mods I did without touching the engine.

Chuck88GT

[slow87GT]

sd'll work great w/stock cam and injectors

I'd go w/mac prochamber over x and keep stock throttle body and spend money on cobra intake, get some 1.7 roller rockers

[slow87GT]

wow thats old sig, car has c4 w/Hservo, 3800 stall, E303 w/1.7's, 24lb injectors, nos 5115][, and its prolly slower n/a, 308 now, big and littles

[Dark_5.0]

Hey whats up, What you wanna do will work easy with speed density. Just one thing go with a 65mm TB instead of a 70mm, the 70mm is too big and will hurt your performance.

I have 65mm TB with 67mm egr spacer, ported GT-40p intake with a 3/8 inch phenolic spacer, Mac cai, ported polished and milled stock heads, E-303 cam, Aeromotive FPR, Jacobs ignition, 1 5/8 equal length BBK headers, O/R X-pipe with 2 chamber flows dumped, 3.73 gears and slicks, sub frame connectors. etc...

All of that and my speed density works like a charm. My 88GT convertible went mid 13's before the cam and TB.

I am dropping the engine in a 90LX and am hoping for mid 12's.

Later,

[drtbiker]

i put my 70mm tb and it seems to be running extremely strong now. Cant wait until i hit up the track. When weather gets nice of course