91 355 z28

ok so im in desperate need of a new fuel system.. ive had 3 fuel pressure regulators break on me.. im looking into the holley stealth ram with the holley fuel rails and a kirban fuel reg.. or modifying my fuel rails for an external reg. im just wondering comparitevly not a dyno chart but driving the cars does the stealth ram have that low end torque that tpi does? with the shorter runners i just dont think it will and thats wut i love.. torque at 2 grand ive read a bunch of the other threads and none of them realy addressed the feel rather then the numbers

Sprayed92

Well we just finished my Hsr swap on my 92 bird. Yeah I lost a little low end not much at all really but my car also has a 2800 stall converter though too so it does help with the low end but now the car pulls smooth to 5500 rpm with no other changes but the intake same stock size throttle body also. If I were you I would consider the swap you might need a converter if you don't already have one though just my opinion.

Street Lethal

iTrader: (16)

^ Swapping to an HSR will result in some lower end torque loss over the stock TPI system, but this very same torque can easily be brought back with the proper camshaft....

Orr89RocZ

iTrader: (20)

i just did the swap from TPI to HSR on my all stock L98. i did notice a little low end loss but i have a 2800 stall converter. from a 30 mph punch it doesnt have the kick it once had, but its not that big of a deal. it still has some kick, just not as much. The top end gained over 4000 rpms is what makes my day. big improvement.

i did 1/4 mile testing and so far, it appears my 1/8 mile trap speed is alittle slower than it was with TPI, but the top end is 1 mph higher on average. ET's are fairly close to each other but TPI was raced in cooler weather.
i went 1.75 60 foot with TPI and ran 8.59 1/8 mile. with HSR i ran 1.82 60 foot with alittle spin, and ran 8.62 1/8 mile. that shows how much better HSR is over TPI even on a stock motor.

91 355 z28

hmm.. that kind of turns me off.. my absolute favorite part about my car is that low end kick.. not sure now..

Orr89RocZ

iTrader: (20)

well i mean its there its just not quite as strong as before. its not a big difference tho. the HSR makes a flat torque curve which is better to have anyway.

the only way i'll know for sure is when i take the car out to the track in november when its cold outside and see if i can match TPI's best 60 foots. i have a feeling it will be close to them but maybe a hundreth or so off. that kinda difference you cant really feel

TransAM Joe

iTrader: (6)

I'm running and HSR, vortec heads and an LT4 Hotcam with a 3000 stall and 3.73 gears and the car is a torque animal from stop to 5600 rpm. Don't forget about suspension mods to get all that new power to the ground. You just have to match all the components and not just slap on a steath ram to a stock setup and expect it to be a monster. I wouldn't be surprised if you just put a steath ram on a stock tpi engine that you would be very disapointed with the performance from 0-4000 rpm, where 99% of street driving is.

Zepher

iTrader: (1)

I gained 5mph in the 1/4 with an HSR on my bone stock 305.
It's still quite slow though, 15.2@93mph.

327_TPI_77_Maro

iTrader: (8)

If you want to sacrifice a ton of HP above 4500 rpms, where you need it, for a little more low end grunt, TPI is for you. If you are running somebody WOT all the action is going to be above where TPI performs. I swapped TPI to HSR and did not notice that much of a low end power loss at all. I can still burn the tires from a slow roll with the HSR, throttle response is still excellent.

gmgod

Well said 327. I've never understood peoples love affair with tpi. So you gain a couple of ft lbs around 3000rpm's, big deal. After that the things run like a late 70's smogger, and they're a pia to work on. First chance I get, I'm throwing mine in the trash.

327_TPI_77_Maro

iTrader: (8)

Don't trash the TPI, it's worth $300 to someone who likes the tow truck intake. The one thing TPI does do, is look really really cool with the stock drawn aluminum tubes. I didn't want to look cool and lose power as an expense though.

Orr89RocZ

iTrader: (20)

i happen to like how the HSR looks. i painted it along with the valve covers and i think it looks pretty good.

Street Lethal

iTrader: (16)

I'm in no way saying that the stock TPI system should be preferred over the Holley Stealth Ram, but the stock system isn't really as "bad" as most people here imply. Here's an old vid from Raceway Park ( Click Here) of a C4 Corvette utilizing the stock TPI system. Not too shabby for a street car, if you ask me....

Orr89RocZ

iTrader: (20)

probly that setup with a HSR or miniram would have went 10's at 120+. TPI can be made to go somewhat fast but your working with a 0-5000rpm range and only so much power can be made from that.

shocker89bird

There is one good way to overcome this and that is with a turbo system on the car. Then you have what guys with 3.8 turbo cars have and keep the power below 5500. You do break less parts that way. I am happy wiht my stealth ram though and being able to pull past 600k and be making power was a good feeling.

Street Lethal

iTrader: (16)

Orr89RocZ, there is no question that an HSR would perform better, especially with a camshaft custom ground to maximize on it's performance potential. But you have to admit, that is a pretty damn impressive time for a stock TPI system (albeit ported out). Oh, and the owner of that vette has since ran it into the 10's (that's an old vid). I'll try to find a more recent run....

Street Lethal

iTrader: (16)

Here you go, same exact car.....

Click Here

Orr89RocZ

iTrader: (20)

i am VERY impressed with that time. I'm actually curious if you know anything about the setup? it sounds like a wild setup tho. If someone could replicated those times with a streetable combo then sure, keep the TPI you'll love it!! I didnt want the TPI system since i wanted to rev to 5500-6000rpms, and planned on a larger inch motor which needs more air anyway. I do love that lowend TPI stuff, it was fun for the years i've owned it. Just didnt fit my goals and i didnt see anyone running the times i wanted to run. Low mid 12's was about it, and although that is fast, i want to run high 11's on motor and its easier to do so on a HSR/Miniram/LT1 etc

Street Lethal

iTrader: (16)

^ Could definitely find out for you bro, just gimme a little time. A few of those guys run every now and then on the nights that I usually go to the track (Wednesday's & Friday's), w/the majority of them mainly running on Saturday's & Sunday's....

Orr89RocZ

iTrader: (20)

thats cool man, i thought maybe they would have the combo posted on a vette site or something. i'm on a few of the vette sites but its been awhile since i browsed through there

Abubaca

iTrader: (3)

Guys, like all things in life, everyone wants something different. For all out performance, i think most of agree that the TPI is NOT the choice. Some of us are strictly show, some are just drivers, some just don't want to do too many mods. There are plenty of FAST TPI cars out there, but in the end, it's not a top notch performer anymore.....

...but I still love mine.

shocker89bird

Well stated. I loved mine too and love my third gen.