I am trying to see how quik I can make my fully optioned '88 Convertable L98 using the stock shortblock. Before I modified
it at all it seemed to pick up a little power with the fuel pressure raised to 46 psi. as opposed to 43 psi.. Now I have big plenum,
big tubes, big manifold, and big heads for ~20% increased cross section throughout. The fuel pressure is at 43#.
For all the work and money the thing seems to have gained about zero HP. Oops!
Does WOT go to a map so car is leaner now (way to lean), than before mods?
Can I simply crank up fuel pressure for max power at WOT?
Good to replace injectors for 24-30# jobs? thanks

 

Using the stock short block using bolt ons a good realistic rule of thumb for a tpi car would be a 10th of a second improvement in your 1/4 mile times.
The things your doing you wont just feel and notice take it to the track and see the real results.
Want to feel it hit with a 150 shot of NOS. or a 100 or a 75 shot
you will barely feel a 50 shot.

 

Eh? You're saying all of that is good for a tenth and he won't feel a 50 shot at all? I find that hard to believe.

 

If you still using stock PROM and injectors you probably will need to crank up the pressure. What are the O2 saying during WOT?

/N.

 

OOPs nice catch Duron ..I was in a hurry..What I was trying to say was he could expect to get a 10th of a second per bolt on, on a stock 350 tpi.
example being if he ran a stock 14.79 bone stock now he would
Bigger plenum 14.69
exhaust 14.59
24 lb inj 14.49
and so on but they do add up and each one helps the other combined to help a little more.

 

Best for the car with convenience headers only was 98.6 @14.11.
I now have 58 mm b. fly., 1 5/8 tubes, opened up intake, t flow 195 cc heads, 1.6 rocker. I think this would all work great w/ a hotter cam but want to see how well things can work with everything but a cam.

 

...I'm thinking perhaps some good, maybe the only good of the big 58 TB would be to slow incoming air velocity and maybe feed cyl. 2 (maybe 4) a little better

 

The cam will be your biggest gain, of course, but the best thing you can do is tune it. You need to scan the car and start to tune that thing up, either that or contact someone for a 'custom chip' NOT jet crap or hyperjunk!

If you do not want to do your own tuning, contact Ed Wright and get one from him, he is very good with tuning the TPI.

High 13s are going to be about the best without a cam change, but make sure that the cam is complementing all the other mods on the car when you order one.

 

I agree, its hard to feel a tenth or two by the seat of your pants.

 

Yes cam would really do the trick but I'm in Ca. and afraid of the SMOG man
I have a pretty hi flo setup around and at the valve and believe
(hope) I can make the thing think it has some additional cam.
I thought of taking the car to the track and cranking the fuel pressure up a pound each run. If the fuel is programmed (map) at WOT the MPH (measure of HP) should increase ea. run.
PS My wife drove the car last PM and said it was "the fastest car she has ever driven"...Ha ! ....she's never driven a really fast car

 

Did she like it, or was she a little scared of it?

 

I think she really liked it. She may try to abscond with it, but that won't work..Ha! She is not fearless however..I took her for a ride in a Corvette that I drag race, it is a pretty fast car and way "slippy" on street tires. After about a block she sez "..well, we can go home now". I asked, "..but I thought you wanted to drive it?". She declined and said "..thats OK, I think its to powerful". I sez, "..but you only push the gas a little and you get little power and it goes as slow as you want".
She didn't want to drive it. HA HA! Thats fine, I don't want her learning to hammer the equipment.