DoctorV8

My car was finished last weekend as the subject of an upcoming magazine article. I wanted to retain stock driveability and reliability, while unleashing some of the potential of the LS7.

Baseline: the car made 465 rwhp @ 6200 rpm and 432 ft lbs @ 5000

HPE mods:
Stage II cam
Patriot Gold valvesprings
Kooks 1 7/8" headers
High flow cats/ X pipe
Halltech air filter
Ported TB

LS7 edit tuning

Results: 516 rwhp/478 ft lbs, at the same rpm peaks as stock



1/4 mile results: Houston Raceway Park, 50 deg and intermittent drizzling

Stock: 11.8@ 123.5 with a 2.1 60 ft....lots of wheelhop issues with a cold track surface

After mods: 75 degrees and dry

First pass right off the street (170 deg oil temp),

11.503 @ 130.09 mph with a 2.05 60 ft, no wheelhop.

After a stern warning from the techs about not going faster, I waited for the oil temp to get down to 140, and the coolant was at 195:

11.35 at 130 mph with a 2.07 60 ft, shifting more aggressively.

Got booted at this point. Switched on the a/c and XM radio for the cruise home. No detonation, no clutch issues, no Check Engine lights, just stock like driveability, with more power and a MUCH more authoritative sound.

Car runs beautifully, and these mild mods really bring out the personality of the LS7. It will now run neck and neck with my LPE 415 ZR-1, and it feels quicker on he street than the procharged C5.

The effortless power at any RPM is intoxicating...it really roars above 4000, but I can pass smoothly at 1800 rpm in 6th. Cam has a very mild lope...enough to know something is going on, but not enough to be annoying in traffic.

Thanks to Chuck and Josh @ Horsepower Engineering for a great job, and keep your eyes peeled on the for the buildup article on the newsstand.

vegasdude

Pretty darn good. Soon the Z06 won't be allowed to run on tracks unless modified...................unbelievable! !

TetraU

I will be blunt: 50hp increase with all the mods listed is UNimpressive.

What would the stage I cam do? Add 10 hp?

If someone is getting 127mph trap stock. Your 130mph is really just good rounding number.

There are people making 500 whp with just headers and tune. I say you got ripped off.

camarodoctor

If the power peaks at the same RPM as the stock cam, it's obviously a mild grind. That's why it's so streetable. For a daily driver, this may be what this guy was looking for. To each his own. Maybe others have hit 127 stock, but since he only hit 123, this is not a bad increase. +7 mph with a mild cam and headers is not bad at all.

korvetkeith

There is only one way to find out for sure. And unless you learned how to drive two cars at once, you'd need some help to do it

DieL

I think those are great #s. im not reccomending anyones products, but if you went for such a mild cam and driveability.. then why not go with a 1 5/8th header? Assuming that is the other popular choice ( i might have forgotten whatever ) . i just dont see why you would go with a big header on a purposely driveability-minded setup.

C6USA

Nice #'s, a 130mph trap is great no matter what some other driver got in perfect conditions with a perfect run.

I wouldn't automatically assume that, he could be running a conservative tune, also the car still has cats. His goal to retain as much civility as possible doesn't constitue getting ripped off.

DDSLT5

Awesome numbers Sanjay!!!! I'm very impressed! Your 60' numbers are abysmal, as are mine!!! Still, it runs a low 11 second with big mph too. With some practice you'd hit tens all day long, that is for certain! Congrats, and enjoy that beast on the drive to work everyday!

Fredo

I too am impressed, especially for your first trip to the track. I am surprised you did so well with stock tires....nice job

cv67

Nice times.


Btw, 1-5/8 header for LS7....A tad small, I take it you were being sarcastic?

DoctorV8

I doubt ANYONE would go with a 1 5/8" header on a 427. Even the LG's are 1 3/4". Hell, I had 1 5/8" LT's on my 302 Mustang 10 years ago.

People are often afraid of a bigger header, but on a big inch motor, this is unwarranted. Given the restricted exhaust flow of the LS7 head, a 1 3/4 may be adequate, but I doubt the 1 7/8ths is costing me much. (See the recent link to the header comparsion by Katech at ls1tech.com.)

Plus, I have room to grow with head/cam changes in the future.

All of us stroker ZR-1 guys are running 2" primary tubes...and there is no lack of low end torque to move that 3600 lb beast.

Tree

I wouldn't be quite so harsh, but I agree. Since the baseline hp/torque numbers seem to be in line with what others have recorded, and some have gotten 500rwhp without a cam, is it really worth the effort and money to replace the cam/springs to get an extra 15 rwhp?

IH8PONYS

The Drag numbers dont lie though.....With a good 60' ft your in the 10's! Good Job Bro!!!!

DDSLT5

I hear THAT!

Also - even on a stock cube 350 cid LT5, the headers are using 2 inch primaries, and there is no loss of torque either!

I agree with the concensus that the 1 7/8 headers aren't going help much with the LS7, IMO. The problem with the LS7 is that the exhaust valve is no bigger than the LS6's, thus only so much can squeeze through that opening. This is also why you always see the horsepower dropping off after 6500 rpm on every LS7 dyno graph, whether modified or stock. Until someone gets a bigger valve in there, the exhaust will reamain constricted at high rpms.

I was thinking it would react like the LT5 does - when you go to headers it pulls strong right to redline (whether it is set at 7500 or 8000 rpm), and peak power is made right at redline, making for a wild ride. Maybe someone will come out with new heads sporting bigger exhaust valves down the road to match up to the LS7.

C6USA

It doesn't work that way, just because one z06 dyno'd 500rwhp that doesn't mean they all will with similar mods. Saying he gained 15rwhp with cams/springs is incorrect. This exact car can dyno 550rwhp on another dyno in different conditions.

I think a dyno should be used as a tool not for bragging rights, that is what a dragstrip is for. There are a ton of different variables (load, etc) on a dyno that if changed, or not set correctly will show higher/lower results.

ZZZZZR1

Nice work, Sanjay! Good to see that car being put to a proper use. I'll keep my eyes peeled for the upcoming article.

DoctorV8

Well said. In addition, there is no CAI on the car yet. This, plus more tuning, may yield another 10+ rwhp. Down the road, I'd rather do some head work than resorting to a lumpy cam that compromises streetability.

DoctorV8

Thanks Nick. It's hard to believe that it was nearly 5 months ago that you were there at my NCM delivery 11/23/05!

Sanjay

0Myhardtop

I will agree with TetraU, and also make a few points. Yes, you would think that higher gains would have resulted from such mods specially since me a few others are making 501rwhp or more with just a tune, VDr's headers and an air-charger CAI kit. Who knows how the car was tuned, and what type of driving skills the owner has? If you were making 465rwhp before mods and only trapped at 123mph, then I wonder if you are driving your powerful machine correctly taking in consideration track conditions and track officials.

Another HPE customer, Lance (the blk Z06 making 708rwhp on the juice and 554rwhp on motor), is one strong running machine. I see him just about every other week at a local meet, and he is usually smacking guys down with his killer. So, it all depends on the customer’s request/desire when it comes down to mods and abilty to handle it. Often, results from various mods are purely a sign of a customer's desire.

Me, personally, I am aggressive when it comes down to mods...to each it's own! Either way, congrats and enjoy your newfound power.

Tree

You're right. That's why I said his baseline numbers looked consistent with others'. And I agree with you that the dyno is only a relative tool, not absolute. To me, the proof is in the quarter mile trap speed, though even that is subject to several variables. Though I am not an expert, it seems that his 130mph is in line with his dyno figures. If that's the case, I still agree with tetrau.