Some advice please.

[Krash]

Some advice please

Hi y’all, it’s been awhile since I posted here about my purchase of a ‘96 LT4, but now I’m looking for a little advice. It’s stock except for a K&N air filter. I want to do a few mods but want the most bang for my buck. Here is a list of what I’m thinking about . I would appreciate any input.

1. 52mm throttle body.
2. Headers “shorty”
3. Corsa…or B&B cat-back exhaust….this is the hard one for me, I want a good throaty sound at idle and when revved but I would like it quiet at cursing speed .
4. Clutch…also need help here. I’m torn between going back to the stock clutch or a more aggressive racing clutch. This is NOT an everyday driver, but I live in the DFW area and traffic can grind to a halt at any time around here…am I going the hate the racing clutch?
5. Higher pressure fuel regulator …. I was told this alone could and 7-10 HP.

Later I will also put in a more aggressive cam and flash the computer….and maybe a 4.10 rear end. (though I was told they are not available for my car….I think that’s wrong however…we’ll see)

Any idea what I might expect in HP increase?
Any thing else I should consider doing?

Thanks for any and all comments!

=)

 

[Krash]

18 views and no replies? =(

I have been reading thorugh the old posts and see that my questions have been asked before....and so I have aleady been helped in my exhuast choice...think I'll go for the Corsa.

I would still like some thoughts on the clutch and other questions though. I want to go to the agreesive clutch..but I have been told it will make it much harder to engage...and it'll wear you out in stop & go traffic...anyone have experience with that?

Thanks for any replies! =)

 

[Krash]

I posted this in the LT4 forum before I noticed the mod forum...thought I might get more help here.....thanks =)

Hi y’all, it’s been awhile since I posted here about my purchase of a ‘96 LT4, but now I’m looking for a little advice. It’s stock except for a K&N air filter. I want to do a few mods but want the most bang for my buck. Here is a list of what I’m thinking about . I would appreciate any input.

1. 52mm throttle body.
2. Headers “shorty”
3. Corsa…or B&B cat-back exhaust….this is the hard one for me, I want a good throaty sound at idle and when revved but I would like it quiet at cursing speed .
4. Clutch…also need help here. I’m torn between going back to the stock clutch or a more aggressive racing clutch. This is NOT an everyday driver, but I live in the DFW area and traffic can grind to a halt at any time around here…am I going the hate the racing clutch?
5. Higher pressure fuel regulator …. I was told this alone could and 7-10 HP.

Later I will also put in a more aggressive cam and flash the computer….and maybe a 4.10 rear end. (though I was told they are not available for my car….I think that’s wrong however…we’ll see)

Any idea what I might expect in HP increase?
Any thing else I should consider doing?

Thanks for any and all comments!

=)

 

[Ken]

I merged the two for you Krash.

And I'll add an opinion to help bump it back to the top to try and extract more response for you too.

The "shorty" headers. In my opinion, they're pretty much a waste of money; that is, they're not much better than stock. Of course, as I stated, it's just my opinion.

You're on the right track though, "breathe in, breathe out..." That's what the engine does, and anything you can do to help that is a plus. Just remember, everything must work in concert.

 

[WhalePirot]

I had SLP SS shorties, but never ran them. SLP claimed very little diff between them and long tubes, for what it's worth. Jim 'jstkrsn' has them now, as I had no Y-pipe to finish MY exhaust system. Perhaps he'll chime in.

My experience with wrapped vs unwrapped headers lends backup to Ken's comments. The improvement in thermal efficiency with wrap would seem to apply to tube length, too.

mike

Now if I could just get motivated to drop the system, wrap the new ones and install it all!

 

[vetteguy]

I'm not sure where you heard 4:10 were not available but I believe they are. I know at least one guy w/ LT4 that has them. Guy

 

[SPANISHVETTS]

Maybe the lack of replies is due to the fact that the LT4 is so damn good to start with that not many people mod it.

I don’t know Jack S. about your motor, but all of the old rules apply.
Shorty headers = Stock headers, that is why they both begin with S, just like S#!%.
The bigger TB is only going to help you if the intake, heads and exhaust can handle the air flow.
Exhaust is a science unto its own. A setup that is perfect on one car, makes resonance, rattles, and sounds anemic on the next. Find a shop that is willing to work with you.
Clutch, I would rather have a circumcision without painkiller than drive a competition clutch on the street.
More HP = More $

Your production line HP is about the same as my ¨Supped-up¨ L98, so all of my comments are null and void.

 

[Krash]

Thanks for the input all.

Yeah I would rather do long tube headers but the cost is much higher and lots of adapting I hear....is there something in between?

And yes the LT4 is nice just the way it is...except it won't hang with a Z06.. =( (at least that's what I'm told...haven't tired it myself yet)

I guess that's my goal...to get at least equal to a stock Z06..

I'm also thinking that going back to the stock clutch is the way to go...I have 50k on the car and the clutch is starting to slip so I have to do one or the other.

 

[RedRagTop]

1. K&N filter and box cover.
2. Free-flow exaust
3. Chip?

 

[Hotred94]

I had a 59 with the competetion clutch and the 4.11 rear end. Killer combination but it was so hard on my knee that I almost always put it into neutral at stop lights.

The shorty headers are too short to give you the exhaust sucking feature that headers are all about. It's a timing thing. Short tubes lose the exhaust charge into a collector before it can develop or are out of sync with the cylinder it came out of, hence, no effect except for smooth flow and lighter weight.

Good luck

 

[vettered91]

As far as I know The best that you can do with your LT4 is let it breathe because this engine is already fast in stock and the main limitations are in the intake-exhaust area. So, maybe you should go for the 52 mm throttle (with a nice cold air intake), long tube headers, the Corsas and the 4.10s.
After this mods, if you are not satisfied; stop playing around and save $ for a nice supercharger (maybe the ATI).
Put one of those things in your vette and the Z06s won't see more of you than your borla's!
I am telling you this because with all the $ I have spend in "little mods" in my L98 first and my LT1 now, I could have a supercharger intercooled in my vette and they really make a difference! I have been "thinking" about it for two years now and in the main time spending much money in small tricks.

Just my opinion.

 

[Krash]

Thanks agian all...this is what I have decided to do.

52mm TB
Corsa cat-back
Slightly more agreesive then OEM clutch.
Open filter cover...Has K&N already

I'm passing on the shorties....may put long tubes on at later date.

Also some time in the future a cam and maybe even a Super Charger....thanks for the idea.. =)

I just Dyno'ed it today...and even with a slightly slipping clutch I got 297 RWHP and 293 Torque.

Can anyone tell me what that would be at the flywheel?

And does that torque seem low?....maybe the clutch?

Anyway, I'll post my after numbers.... I'm thinking between 20-30 HP gain.....no?...yes?....

 

[SPANISHVETTS]

Normal drivetrain loss is 15% - 17% so 297RWHP = 342 – 348 HP at the flywheel. That is about 15 – 18 HP more than the General claims for the LT4.

Yes the slipping clutch will add to the drivetrain loss when it is slipping. If it engages and holds at some point there is no loss afterwards. Does the clutch slip when they load the Dyno?

You should clean up and polish the plenum at least or better yet port and polish the complete intake and heads. After that a new set of rear gears and cam will give you the go you are looking for. The day I got my 3.07´s I thought I got in the wrong car. I almost popped the hood to see if they slipped in a BigBlock while I wasn’t looking.:confused

I spent over $3K to get about the same HP out of my L98:crybut I will kick your butt on torque by over 100ftlbs. A SBC will give you whatever you want as long as you know what you are asking for. I grew up in the 50´s – 60´s, I need that low-end kick in the A$$ that only lots of cubic inches and wide open intake and exhaust can give you. Frankie gave me that and keep it Smog legal. The new SBC’s are revving well of 6K while living long and happy lives. You just got to love that engine!:love

 

[johnny]

it is my advise....so think what you want

If I had a LT4......reverse cooling and a high end engine.....wauw.....I would buy a 3" B&B tri-flow exhaust with longtube headers 1 5/8".

 

[Ken]

Johnny, your signature image is a little too large. Please reduce the size.

 

[johnny]

hai Ken

this one?

 

[Ken]

That's cool, but you don't have to go that small. Check out the guidelines in the FAQs section.

_ken

 

[vettered91]

I just finish the installation last friday in my LT1 of Headman long tube headers and there's a HUGE performance change. It feels like I am seated on top of the engine with no weight to drag and it goes from iddle to 6000 revs in no time. 3 Weeks ago I went from 2.59 to 3.54 rear axle and I was just about to get used to it and now I'm going to need more time!

Now I know this last two mods are the best ones I have made, and should be the first ones (of course with the intake ones) in my next Vette. In the main time I am saving for the Hot Cam Kit.

This are the ones that I can feel the most in my neck.

Just wanted to share this with you because I'm very happy!
(I burned one spark plug cable with the headers but yet I'm happy)