What are the best mods to make that have the best Dollar spent to HP ratio?


Figured this could be a interesting thread... Although its all speculation...

 

Your prolly going to get yelled at for not using the search feature..
I can never find what I need when I need it..

 

tried it but hard topic to search for since it could be worded in so many different ways

 

i see u have a tbi do u also have a tpi but either way full exhaust is your best start.

tune ups go a far way to

 

yeah swapping to a L98 this winter have the motor almost built and ready to go. pretty much redoing the whole car. swapping the rear to 3.73 posi, rebuilding the trans, already redid the whole steering and suspension system. trying to get the car to run under 13.5 on the stock heads but with full intake mods - big mouth base, slp runners, ported plenum, air foil. then plan on doing 3" exhaust with shorty headers...

 

what about a camshaft?? didnt see it would help with a good port job as well from ure local shop or ure self

or take em to a shop and get them to do it

theres a bunch of cams for sale on the classifieds

also if u havent already get a good feul pump if ure throwing this in ure tbi 91 bird

but u got a good start i believe u should see around high thirteens

 

Heads, Top Swap, Exhaust, Tune.

Pretty much switching away from the stock stuff GM put on it.

 

I think you should stick to 3.42 gears at the most.

 

anyone every dyno siamese porting the stock runners?

 

the stock heads flow well ported n polished is all over tgo so depends on the price of the machine shop

i got exhaust ported n polished all the way and intake gasket matched with some polishing around intake valves

and intake fully ported n polished looks amazing and some plenum polished up with sand blasted for 240 i thought as a good deal

same size valves though. . . . seeing wat these heads would do he quotes 25hp



any who stock heads do good also weight reduction aluminum drive shaft throw out ac and smog back seats aluminum pulleys waterpump etc

will do good for ya as well

 

oh yeah i got a crane 2032 cam too

 

why 3.42 over 3.73?



Iv heard the 3.73's will pose no problem for daily driving even on the highway

 

If you don't mind taching it up all day you'll be fine.

 

no, 373's are too much,especially with an auto 700r4. First gear is already like having a 373. In a 5 spd,it may be ok,but tpi still lives in the lower rpm's

 

I just put 3.70s in mine, and if I didnt have my .50 overdrive gear, and was stuck with 5 speed's fifth gear, which is pretty close (around .70) to a 700r4 ovedrive, I'd be going nuts on the highway. I also blow through first gear pretty quick, and the T56's have a tall 2.66 first gear.

 

what do you rev at on the highway? i was told on the 700r4 in overdrive when the converter locks up i should rev at about 2500 at 65mph

 

you will have no 1st gear if you put in 373's. Gear ratio for 1st gear in a 700 r4 is already a 3.06! way taller than a t5's 2.66. You will be quicker with 342's.

 

Yeah and now at 65 you are at 1800 with your 273's. You may be out of your Useable powerband too quickly with 373's.

 

Change to a th350 3 speed and go carb or holley stealth ram and then u can use 373's.

 

already got the 700 and the motor just about built with the tpi setup so i guess ill just take everyones advise and go 3.42's but what stall speed converter would be best with that?

 

3.73 with my NWC T5 are a little short I might go with a 3.23 later on but I have no issued on the expressway.

Here are my ratios


1 2 3 4 5
2.95 1.94 1.34 1.00 .73



If I had a T56 I would def keep them but I really love having awesome acceleration in each gear.

 

free stickers dont they add 20 or more ponies

 

My experience is a cam is one of the best mods for the cash.

 

Long tube Headers.

 

for an otherwise stock/mild motor a 2500 stall should be good.

 

will that suck for off the line for everyday use? the car will be used regular street driving 95% of the time.

 

you probably wont be able to tell its there unless you powerbrake it. You having a shop do your rear end?

 

yes i manage a trans shop so having my techs do it

 

On my T56, Im at 1750ish RPM's at 70mph in 6th gear with the 3.70s. You wouldnt be anywhere close to that... 2500 RPMs in the low 60s sounds about right.

 

I just rebuilt my dif or I would swap to a 3.42 set up.

 

i did go with a 373 gear. I have been driving it on the streets every day and on the highway with no problems. What problems do people say you will have with the 373? My mpg are very good two 15 City 25 highway.

 

Something like this would help. Not a bad asking price, either!

http://swmi.craigslist.org/pts/2726097900.html

 

this, and headers.

 

Now you have no 1st gear at all. Going 60 down the highway and it feels like you need to shift. It is like being stuck in third with 2.73's and going 60. Also, will go through the usable powerband too quickly at wide open throttle.

 

This is more so a problem with having an auto. I have a 2.95 and it's pretty decent. Someone with 3.42's should post their opinion.

 

The best mod you can do right now is add slicks/DOT race tires of some sort, and a 2800 stall. LCA relocation brackets and control arms if your suspension is lowered

Then do headers/exhaust, set base timing up from 6 to 8 or 10 deg...i liked 8. really could burn a custom chip to get the best timing curve for WOT performance. Bring timing in faster by 2800-3000 rpms.

Free mods like gut the TPI air box if you use the camaro style intake. Or build a CAI for a firebird since it looks like you have a bird.

My stock TPI car with the above mods went 13.63 at 97mph in good air. Just exhaust/3.42 gears/advanced base timing, and 2800 stall with slicks.



If you go aftermarket TPI, your goal will be even easier to meet as long as the car aint over 3500 lbs with you in it My buddy's 88 formula went 13.5's on street tires with 3.70 gears, TPIS base, SLP runners slightly siamesed, but corvette L98 heads, but they dont gain much if anything over iron L98's. Maybe a few ponies. He is on street tires with stock converter too! 1.93 60 foots. Thats not very good and still runs great ET's. Almost shifted to 4th on the 1/4 mile pass. Slicks and converter, he'd be 13.2's

If you have slightly siamesed runners to extend your powerband, 3.73's will be fine. Alittle too much for stock TPI, 3.42's would be better for that. First gear goes by fast but it gets you off the line HARD with TPI torque. TPI cars use the launch to run ET's, so more gear does help alittle. Daily driving is nicer with 3.42's and lower tho.

 

how much heavier are the convertibles?