Thanks

 

K&N w/ Open lid, TB bypass
4.10 gears
headers, Corsa exhaust
Hotcam, ported heads

 

except for the open lid.

 

I vote for the open lid also. :)

Let me know if you need any help with any of this. We can help get you started in the right direction.

 

Here is what it comes to :

Stock LT-4 = 295-300 rwhp
add filter/lid/good catback = 305-310
add longtubes/high flow cats = 320-325
add hot cam kit = 345-350
add ported heads = 370-380

Catbacks : Corsa = no resonance , good quality , nice look, good fit, relatively small pipes (2.5")
B&B = relatively loud , resonates, good quality , look great, good fit, large pipes (3")
Power Effects = adjustable, sound awesome, good quality, look pretty good, expensive, stock size pipes (2.75")

Longtube Headers : TPiS and Exotic Muscle are very good , Hookers are good and less expensive. Get ceramic coating to help with heat. All seem to fit decently.

GM Hot Cam Kit : works very well with mild setups (like this) idles well sometime doesnt even require retuning (should be done though) and very inexpensive and well made.

If you are considering porting heads , then you are essentially going to full heads cam setup . I would probably not use the Hot Cam unless you are satisfied with 370-80, I only say this because 400+ is achievable. The Hot Cam seems to limit most to around that level (380ish). I would have my heads ported , intake ported/polished/matched to heads, and a more aggressive cam along with a good custom tune and all the bolt ons. I have seen LT-4's in the 400-415+ range like this that are streetable , fun and fast .

I will be going down this very road soon, and have been gathering this info so far......hope it helps....... :seeya

 

If you want the power effects, get the 1991 cat back part number. Then cut the the exhaust Y-pipes right after the stock resonator. The Power Effects will slide right on. The PE resonator is like $450 bucks. Total price would be around $1300 for the LT1/4 part number. No thanks. You can buy the L98 part number for $840. Joe will tell you that you will have issues with it falling off if you do it this way. Not in my case. Mine is very snug and even with one muffler clamp, it's not going anywhere.

 

I had the K&N with the Open Lid and switched to the SLP cold air. Not for more HP but because I like the looks.

TB Bypass on an LT4 is a free mod. Do it.

Corsas!

As for other mods it depends on what you are looking for.
If you are going to run DRs at the track go to 4.10s, if not then skip the gears. The other post showed the HP gains with recommended mods.

 

Thanks for the help guys. How much would the cam kit cost after installation and parts. As far as exhaust, is the B & B really that loud?

 

Im not sure about the hotcam kit pricewise (guessing around $300-400 for parts) But B&B's are really loud, some people find them TOO loud and they have a resonance problem. I still like all of them, especially Power Effects.

 

If you look at my sig, you can see I've done a few mods on my LT4 vette. After the cheap mods, open airbox/K&N filter, 160* t-stat and TB bypass, here's my favorite mods in order:

1.) Swaybars and poly swaybar bushings. $250 the handling difference was like night and day.

2.) Hurst Shifter. $125 to make a complete difference in the feel of the gearbox.

3.) Camber brace. $160 to make my Vette track much better in the turns, esp on bumpy roads.

4.) 4.10 gear. $325 + $200 labor, made my Vette accelerate 3-4 tenths faster in the 0-60.

5.) Computer reprogram by BV Performance. Cost was $200, after the gear swap this was mandatory, but Brian fixed the traction control and tweaked the PCM A/F under WOT.

7.) Poly bushings in the rear suspension. $90 to tighten up the car's handling, esp under acceleration.

8.) Corsa exhaust. $800 to make my Vette sound better. Did it give me 10-20 HP? I couldn't tell.

All cost don't include labor, because except for the actual gear swap (paid $200), I did it all myself. Now that the suspension is fixed, I'm ready to put the LT4 HOT cam in. I'll do the labor myself, so cost including some good rockers will be less than $600 (the stock LT4 rockers aren't the best).

Eric



[Modified by silver & red CE, 6:14 PM 7/12/2002]

 

i saw head work and cam, but nobody ever mentioned larger thottle body...since you are flowing that much more thru the heads, shouldnt the TB be stepped up as well? im just looking for any way to make more hp..hehe

 

A stock LT1/4 isn't going to make more HP from a 52mm TB vs a 48mm TB. I doubt it does anything for and LT4 with a HOT cam. Save your money until you're making more than 400HP.

Eric

 

I picked up a .10th with the 52TB before the head work. I'm happy with my Mods so far, but might go with a slightly bigger cam over the winter.

 

Rich,
What do you think about an LT4 with a stock cam?
Eric

 

no no no, not STOCK...i said since you are flowing that much more thru the heads blah blah (ie the internal work has been done). but at that point, after the upper assembly has been tweaked, bigger TB is better, yes?

 

a 52mm TB will not be necessary until you enlarge the motor, its doubtful that you will get any more out of a bigger TB. Once you bore it out to 355, 383, etc. then it will help a fair bit, possibly.

 

Last year I had all the same mods except for the head work and Hot cam (Should have said that) and the stock computer with a HPP3 programer. I ran a best of 12.5 and I think 111mph. I ran back to back weekends with Identical weather and track conditions and picked up a .10th with the TB as the only change. The breathing and exhaust were both improved from stock so I felt the TB should have helped and did.

 

thanks for the help guys. richs, saw your LT4 at e-town today..nice!

 

Check out these dyno numbers! http://www.hashmarks.com/dyno_page.htm

 

Check my sig, I just completed this mods and dyno programming.

Best dyno was first run at 342 rwhp and 338 torque.

I am happy with these numbers but my ultimate goal is 400rwhp
natural. Next I want new heads,which will probably yield 380ish rwhp. I should of did more research in cams and went with a bigger cam and chosen heads to match. I will scan dynos and post in a couple of days.