LT4 Hot Cams

[Nick90vetteguy]

I'm looking to do a upgrade on my vette, I have Headman headers long tube runners with a custom exhaust piping(Thanks to everybody for the AIR Injection removal idea, I haven't removed the compressor or pulley yet cuz I don't wanna touch it), LT4 ECM (have pix to prove it), 58mm BBK Throttle Body, Fuel Rails with 42lb fuel injectors, NGK Spark Plugs with GM silicone wires, GM Performance Distributor and a PowerMaster starter(180lbs) And finally ported the intake manifold to "swirl" type-flow. So I figured I'd start working with cams and sh*t. I've heard pros and cons about the LT4 hot-cams, and I'm sure people have too, is this a reliable way to gain performance? Or just another modification to numerous parts of the head(s)? I'm all about the Low-end torque and I don't want to do any thing to sacrifice that power, I have a great setup on High RPM too with the computer and some help from TCI, a custom intake tube I made; and I'd hate to ruin that setup as well.

One last thing, My 700r4 has been rebuilt to a "T" any suggestions on torque converters?

Thanks agian for taking the time to thow in your two cents and have a great 4th of July!


375hp-414lb trq 13.42 @ 1/4 mile @ 104mph :W

 

[Hib Halverson]

The LT4 "Hot Cam" will not fit an L98 engine.

Also, if you don't want to decrease low-end torque, even if it would fit your engine, you wouldn't want the Hot Cam.

 

[BADDUCK]

The LT4 Hotcam will fit your L98 engine and run fine. It will not be the best choice for your TPI setup, however. If you plan to stay with the TPI something like a TPiS ZZ9 or LPE (Accel) 211 will work better. You can also add 1.6 full RR's and should add heavier valve springs when you do the cam. With any of these cams you will need a custom tune. A 2200 to 2400 stall should be about right once you get the cam. ( Opinions will vary on that BTW).

 

[Hib Halverson]

The LT4 Hotcam will fit your L98 engine and run fine. (snip)

"BADDUCK" is right. I don't know what the f**k I was thinking this morning...maybe I just wasn't.

The LT4 Hot Cam will fit an L98, but, as BADDUCK says, it's a pretty radical grind for any engine with an L98 based induction system. You'll never be able to use the cam's duration and lift because of the L98's intake being designed for low-rpm use. TPIS cams were suggested and there are many other choices but you want to stay down around 208-211 at .050-up on the intake with lift in the .475-.490" range.

Sorry about the bad info earlier.

 

[Nick90vetteguy]

Gotcha, thats what I heard about the "lift" man I love this site! SO far I heard nothing but great opinions I didn't know the LT4 hot cam does play a big role with the TPI, I would have NEVER guessed, makes sense though, lol don't worry Hib it happens lol thank you both, any suggestions on torque converters?

 

[Nick90vetteguy]

iF i INSTALL THE hOT CAMS WILL i LOSE THAT LOW END RPM? :confused

 

[Rex S]

iF i INSTALL THE hOT CAMS WILL i LOSE THAT LOW END RPM? :confused

I've mentioned here befor, call Comp Cams and explain what your plans are for the car. They are quite heplfull and haven't steered us worng yet. They will ask you questions you may not have thought about such as do you have power brakes and do you want them to work after the cam change It's a free service and if you want you can order all the parts from them directly.

 

[BADDUCK]

iF i INSTALL THE hOT CAMS WILL i LOSE THAT LOW END RPM? :confused

You will lose low end torque and horsepower.

 

[Nick90vetteguy]

crap

 

[BADDUCK]

Damn

crap

I've been telling you for a long time IT IS NOT THE PROPER CAM FOR YOUR CAR!!!

IF YOU WANT A CAM BUY ONE FOR YOUR CAR LIKE A ZZ9, LPE 211.

AND DO SOME RESEARCH!!!!

 

[Nick90vetteguy]

no ya know what, i didn't buy anything yet, in fact im seriously considering keepin the stock cam and maybe work on fuel delivery, lol sorry i didn't mean to make it sound like i bought it already I was really looking forward to the LT4 cams because id figure id get the low end trq, and make up whatever i wasn't making on top end with the LT4 cams, but yea I was looking to get at the XFI FAST management fuel system, its 1,000+ so Im just gonna get a set of 27lb trick flow injectors and a edelbrock fuel pump.

 

[G Winter]

New injectors good idea. Trick may not do that much good. I installed some Bosch III injectors from FIC , They are not new but nearly so , they are flow matched and have an excellent spray pattern. It improved my all around performance and economy.
If I were doing anything I would work on exhaust before anything else. What I see is exhaust is money well spent.After that work on the intake system.Camshaft change with stock exhaust you will not get the full advantage .

Glenn

 

[Nick90vetteguy]

New injectors good idea. Trick may not do that much good. I installed some Bosch III injectors from FIC , They are not new but nearly so , they are flow matched and have an excellent spray pattern. It improved my all around performance and economy.
If I were doing anything I would work on exhaust before anything else. What I see is exhaust is money well spent.After that work on the intake system.Camshaft change with stock exhaust you will not get the full advantage .

Glenn

EXHAUST CHECK!
Heldman Long Tube Headers CHECK
Corsa Cat Back system CHECK

Yea I'll be honest I really do love my stock cam, thanks for the heads up on the Fuel Inj. I was thinking of getting Accel, I have CHampion spark plugs which are great, I dont want to go to crazywith Hp I have 375whp @ 414trq with my set up(fuel injectors,exhaust,custom intake, GM pistions etc.) I guess I was just being picky

 

[500hp406]

no ya know what, i didn't buy anything yet, in fact im seriously considering keepin the stock cam and maybe work on fuel delivery, lol sorry i didn't mean to make it sound like i bought it already I was really looking forward to the LT4 cams because id figure id get the low end trq, and make up whatever i wasn't making on top end with the LT4 cams, but yea I was looking to get at the XFI FAST management fuel system, its 1,000+ so Im just gonna get a set of 27lb trick flow injectors and a edelbrock fuel pump.

Nick, if I may make a suggestion. Sit down and figure out what you really want this engine to be. Too many of us have just thrown money down the drain buying this buying that, and still the car runs like crap. There are some really smart guys on these forums, utilize them, there here to help. An engine is an air pump, what goes in must come out. Your engine has a very large throttle body that is not doing you any good, then you have a tiny weenie intake with very long runners, then tiny weenie heads and a large exhaust system. It is easy to see where the bottle neck is. If it we me doing it all over again I would first make a plan, then get rid of the TPI. (it takes rpms to make horspower, because of the long runners no rpm) get yourself something like the Mini-Ram, depending on which cam you purchase you can now spin to 7000 rpms if you desire. Now comes the heads, again the plan you made for horspower will determine the size/flow of the heads. When you made your plan the horsepower and torque you desire will now be determined by the heads and cam you choose. There are hundred little parts like rollers, 1.6 rockers, throttle bodys etc. But the intake, heads, cam and exhaust will determine what your going to have. After that then look to the fast system,( you don't want to be changing the tune to often) it's a good one, wide bands, and the such, that's the icing on the cake.

 

[WillC4]

Yeah, the LT4 Hotcam runs up to, and around, the 6000 RPM range. And if i remember correctly the TPI with enlarged runners/ported intake manifold is good to about 5000-5500 RPM (please correct me if im wrong). So, you wouldnt be maximizing the LT4 Hotcam's potential. A good, low/midrange cam such as the ZZ9 is probably better for your tastes.

 

[killer408]

I have done this in the past to a couple of L98 engines. Put a stock LT1 cam with 1.6 rockers and you will get a gain in torque/hp on the bottom end and gain some to the 5500 rpm of the intake limitations. Don't go to large with your injectors as you will over fuel and loose what you could gain.