Yesterday I had Thunder Racing install a cam in the Z. Dyno tuning was accomplished this morning.
Specs are: 227/224 .569/.563 114 LSA
After doing quite a bit of homework on the subject, I decided on this cam over the larger 230/226 type cams for two reasons:
1. With a 114 LSA, it will be smoother at idle and have better low RPM drivability.
2. With less lift and duration, there's less of a chance of a valve meeting a piston, and less wear and tear on the valvetrain.
The baseline dyno before the cam was 373rwhp/365rwtq with a Halltech T-1, Shaner S2 TB, FLP headers (offroad pipes), and Borla Stingers. The fuel and timing tables in the PCM were still stock at that time.
Thunder Racing installed an ASP pulley during the cam swap, since the pulley had to come off anyhow. The whole job took them about 8 hours start to finish.
This morning we straped the car on the dyno, and got SAE 410rwhp/380rwtq. This was with STOCK tuning!! The wideband O2 showed that it was too lean in the low to mid-range, and rich up top.
After tuning with LS1 edit, they re-dynoed, and it pulled SAE 423rwhp/393rwtq with stock heads!!
My dynos beat two other C5's that dynoed today with heads and cam, across the entire RPM band, by a considerable margin (~20rwhp). The maximum power gain was roughly 50rwhp at 6500 RPM over the stock cam and pulley.
There were no gains to be had by tweaking the timing- the stock timing is pretty much dead-on. All the tuning gains came from tweaking the fuel/air ratio.
The drivabiity on the cam is great- I'm very pleased and pleasantly surprised with how well it drives. I had a 98 TA with a 218/224 cam, and this cam drives considerably better. The idle is pretty lumpy- it's not what I'd call a stealthy profile, but its not overly choppy like the 112LSA cams I've heard. I get a little RPM surging below 1000RPM in gear, when I start the car on a hot engine, but it only lasts for a few seconds before it smooths out.
The pull at WOT is awesome. I gained so much mid-range torque that the pull is quite a bit smoother/more linear than stock, and it pulls HARD in every gear. On the way home, on a deserted highway, I hit a speed somewhere slightly North of 170MPH and the acceleration wasn't showing any sign of letting up. It was pretty unreal.
I would definetly recommend this cam to anyone. I'd also like to say that Thunder Racing treated me GREAT. They definetly know what customer service is all about. If anyone is thinking about doing a cam, and you think you might be interested in the cam I went with, give Thunder a call and they'll take care of you. I can't say enough good things about my experience with them.
Hopefully I'll get her to the track soon! With this cold air, I'm expecting some really good trap speeds! :cheers:
(BTW- for anyone that was wondering, the steering rack does need to be removed to get the crank pulley off, and the entire rack comes on and off in one piece realatively easily)
Edit: Here are the dynographs from 2 consecutive pulls.
![Image]()
![Image]()
:cheers:
Specs are: 227/224 .569/.563 114 LSA
After doing quite a bit of homework on the subject, I decided on this cam over the larger 230/226 type cams for two reasons:
1. With a 114 LSA, it will be smoother at idle and have better low RPM drivability.
2. With less lift and duration, there's less of a chance of a valve meeting a piston, and less wear and tear on the valvetrain.
The baseline dyno before the cam was 373rwhp/365rwtq with a Halltech T-1, Shaner S2 TB, FLP headers (offroad pipes), and Borla Stingers. The fuel and timing tables in the PCM were still stock at that time.
Thunder Racing installed an ASP pulley during the cam swap, since the pulley had to come off anyhow. The whole job took them about 8 hours start to finish.
This morning we straped the car on the dyno, and got SAE 410rwhp/380rwtq. This was with STOCK tuning!! The wideband O2 showed that it was too lean in the low to mid-range, and rich up top.
After tuning with LS1 edit, they re-dynoed, and it pulled SAE 423rwhp/393rwtq with stock heads!!
My dynos beat two other C5's that dynoed today with heads and cam, across the entire RPM band, by a considerable margin (~20rwhp). The maximum power gain was roughly 50rwhp at 6500 RPM over the stock cam and pulley. There were no gains to be had by tweaking the timing- the stock timing is pretty much dead-on. All the tuning gains came from tweaking the fuel/air ratio.
The drivabiity on the cam is great- I'm very pleased and pleasantly surprised with how well it drives. I had a 98 TA with a 218/224 cam, and this cam drives considerably better. The idle is pretty lumpy- it's not what I'd call a stealthy profile, but its not overly choppy like the 112LSA cams I've heard. I get a little RPM surging below 1000RPM in gear, when I start the car on a hot engine, but it only lasts for a few seconds before it smooths out.
The pull at WOT is awesome. I gained so much mid-range torque that the pull is quite a bit smoother/more linear than stock, and it pulls HARD in every gear. On the way home, on a deserted highway, I hit a speed somewhere slightly North of 170MPH and the acceleration wasn't showing any sign of letting up. It was pretty unreal.
I would definetly recommend this cam to anyone. I'd also like to say that Thunder Racing treated me GREAT. They definetly know what customer service is all about. If anyone is thinking about doing a cam, and you think you might be interested in the cam I went with, give Thunder a call and they'll take care of you. I can't say enough good things about my experience with them.
Hopefully I'll get her to the track soon! With this cold air, I'm expecting some really good trap speeds! :cheers:
(BTW- for anyone that was wondering, the steering rack does need to be removed to get the crank pulley off, and the entire rack comes on and off in one piece realatively easily)
Edit: Here are the dynographs from 2 consecutive pulls.
:cheers:
