Hot Cam experience

[Fick]

I'm considering having the Hot Cam installed but can't do LT headers because it won't pass smog in Cal. What kind of performance gain can be expected from the Hot Cam alone? Are there other mods required with the cam?

 

[Hib Halverson]

I can't cite any numbers but there will be a decrease in the effectiveness of the Hot Cam run with stock manifolds. You can help the situation if you put an aftermarket cat-back exhaust on the car when you go to the Hot Cam.

 

[Fick]

I can't cite any numbers but there will be a decrease in the effectiveness of the Hot Cam run with stock manifolds. You can help the situation if you put an aftermarket cat-back exhaust on the car when you go to the Hot Cam.

Thanks Hib, I do have a Corsa cat-back exhaust on the car now; just don't know if the Hot Cam would be much of an improvement.

 

[Tuna]

What are you rear wheel dyno numbers now?

I'm seeing 330 at the rear wheels on my Hot Cam and LT4 modified LT1 in my '92 with Corsa Exhaust. That's through the stock LT1 manifolds, throttle body and 24# injectors.

I think a 'real' LT4 might do a little better.

 

[ZumZum]

Doesn't Cali allow the shorty headers? I know they're not much improvement over the stock manifolds, but at least they are some improvement.

 

[Fick]

I haven't had my car on the dyno so I don't have baseline numbers; I think most LT4's are putting out about 290 at the rear wheels.

I do think that Cal allows shorty headers so thats something to consider.

 

[Tuna]

I haven't had my car on the dyno so I don't have baseline numbers; I think most LT4's are putting out about 290 at the rear wheels.

I do think that Cal allows shorty headers so thats something to consider.

Check out www.grandsportregistry.com and pull up the dyno sheets posted there (left frame about half way down). Many 'stock' LT4 are showing 295-305 at the rear wheels.

When I did the LT4 and Hot Cam conversion, I still had the stock exhaust on my '92. It dyno'ed at 306. I added the Corsa and redid the dyno and gained 22 HP. Part of that was a little more break-in and part was the exhaust.

 

[Hib Halverson]

The way the law is written, anything other than stock manifolds or a manifold with an EO number are illegal.

In practice, most of the time, you can get away with "shorty" headers as long as the stock cats are also in place.

I have shorty headers on two vehicles which also retain stock cats and both of them have been through the enhanced smog check several times.

Now, if you get bagged as a gross polluter or get nailed for "tamering" you're going to end up at a state referee station and they'll zing any non-stock exhaust manifold without an EO.

 

[EtaoinShrdlu]

I did the HotCam on my LT1. With the stock exhaust system and stock heads and intake, it took less than a tenth second off my quarter mile time. When I subsequently did the exhaust system, with LT headers, it took off three tenths from my quarter mile time. The headers alone would never have given this improvement without the HotCam.

 

[tpivette89]

my LT4 has the stock exhaust system, save for muffler elims, as well as the hotcam and a tune. the car put down 344rwhp and ran 12.2 at 116mph in the quarter

 

[91 Black Convertible]

Inquiring minds want to know...

Quote:
OLD VETTES
89' white/red coupe (L98/auto w 3.07s)
- minor boltons
13.16 at 104,79 w 1.75 60ft

40th anniversary coupe (LT1/6spd w 3.45s)
- free mods
266rwhp... 13.32 at 107.63mph w 2.04 60ft ":Quote

So you're saying that the L98 auto with 3.07's was quicker in the 1/4 mile than the LT1 6 speed with 3.45's ?

How was that possible?

Inquiring minds want to know...

 

[ZumZum]

Quote:
OLD VETTES
89' white/red coupe (L98/auto w 3.07s)
- minor boltons
13.16 at 104,79 w 1.75 60ft

40th anniversary coupe (LT1/6spd w 3.45s)
- free mods
266rwhp... 13.32 at 107.63mph w 2.04 60ft ":Quote

So you're saying that the L98 auto with 3.07's was quicker in the 1/4 mile than the LT1 6 speed with 3.45's ?

How was that possible?

Inquiring minds want to know...

If you look at the 60' times. It appears the LT1 wasn't hooking up very well. The LT also had a higher trap speed, so it must have been making more hp. Just couldn't get it to the pavement.