Patrick G

iTrader: (14)

Although many of you could care less, I’ve been wanting to try this for years: Make 100 rwhp over stock, but be completely stock sounding and acting to myself and the general public. That meant no lopey idling cams, no tinny sounding headers, no loud cat-backs, no crappy gas mileage and 100% emissions compliance. I wanted to have my cake and eat it too. I was going to use a lot of smarts and a lot of money to do it.

Geoff and Angie from Thunder Racing had the answer, their CheaTR (cheater) package. By utilizing AFR 205 heads with 60cc chambers and a specially ground cam designed to run well with stock exhaust, the package met all goals: Bone stock idle, bone stock exhaust sounds, bone stock NVH, bone stock fuel economy, emissions compliance, but 395 rwhp and 376 rwtq. The cam specs out at 214/230 .600/.578 117LSA. Basically, it mimicks how GM grinds their cams to run with stock exhaust. Think of it as a LS6 cam on steroids. It’s even pretty close to the new LS7 cam (211/230).

Bone stock, my car dynoed around 300 rwhp. Since I purchased the car last year, I’ve added an MTI lid, ported throttle body, LS6 intake, ASP UD pulley, 160 degree stat, SLP Dual/Dual catback, and HP Tuners tweaks. As delivered to Thunder Racing, my TA made 335 rwhp and 339 rwtq. Getting additional ponies with no downsides wasn’t going to be easy.

Click here for the before/after dyno sheet: http://www.guerragroup.com/2000TA_dyno1

As you can see from the dyno sheet, the power pulls strong to 6800 rpm. Ever see a 214 cam with choked-up exhaust pull that well? We also tried a pull with 100 hp jets in the newly installed NX MAF kit. We got 494 rwhp through completely closed exhaust. Too bad the clutch slipped, LOL.

Click here for the nitrous dyno sheet: http://www.guerragroup.com/2000TA_dyno4

Special thanks go to Shane and Stu at Thunder Racing for their expert care in the installation. Anybody with a C5/C6, GTO or Cadillac CTS-V should take an especially hard look at the package from Thunder Racing as it adds serious horsepower without compromising one bit of stockness.

pdd

iTrader: (3)

wow. great job on the stealth

ArcticFormula

Sweet numbers! I kind of went a similar route: out of box 205 AFRs, 222-222 .581 .581 xer 115lsa, and vig 2800. 376rwhp - 361rwtq
Have stock manifolds and a GMMG catback.
I'm considering QTP longtubes maybe next January. Anyway congrats on the setup, the car should haul ***!

blkZ28spt

That is badass. While a ***** out heads/cam setup can make 50-65 rwhp over that I have to say that I would love to have your setup on a car that looks like mine. Z28 with sport package ground effects and all badges removed....

ss rally red

iTrader: (8)

That is basically maximizing all the parameters of a bone stock motor and I am glad someone did it!! It's not my cup of tea but It's great to see someone go this route and have great results!! Congrats and props to you!!!!

blkZ28spt

I just saw that it made 494/510 on a 100 shot. That's bitchin.

fasteddyss

iTrader: (1)

Fantastic!!!

I am glad to see someone do this. I had thought of going that route myself, skipping headers and going with stock exhaust, a cam and ??

I suppose the main difference is cost? Headers vs nice heads?

I got great power out of my headers but fine tuning the fit on the y-pipe and loss of ground clearance makes me think about it again.

Great job!!!

Jared H

iTrader: (1)

Any idea how well that cam would work on stock heads?

Thx

jrp

iTrader: (16)

bad *** Patrick . anymore info your willing to give on the cam specs? advertised and .200 duration, icl, ect.

cyphur

iTrader: (10)

those numbers are badass. to have the same behavior as stock must be really nice for a change. my Spec3 and 9" w/full spool just doesn't really behave all that well sometimes......

gollum

iTrader: (1)

Thanks, I have been waiting on your results. Could you please answer a few questions for me

How well did this combo idle with the factory tune? Any surging at a quick stop or hot start surging with stock tune?

Did you have to delete(turn off) the rear O2 exhaust sensors? Any check engine codes?

Is the valvetrain noisier with the shorter duration, .600 lift cam?

amwellls1

Nice numbers congrats

Patrick G

iTrader: (14)

The cam would work great with stock heads. Just consider it a ballsier version of the LS6 cam or the LPE GT2-3 cam.
I have all of the cams specs (.006, .050, .200 with associated valve events and centerlines), but I'm not sure if Thunder Racing is ready for other vendors to copy their work just yet. That's is entirely Geoff's call.
We used factory timing tables, factory A/F ratios (with some minor tweaking), stock idle. The biggest change was raising the rev limiter. We were conservative at 6800, but in all honesty, the cam would have easily pulled well past 7000. There was a little shake at dead cold before tuning. Taking some fuel out at low temps fixed that. Hot starts are a breeze. No surging whatsoever. I can lug the cam down to 700-800 rpm in 5th or 6th no problem, just like stock.
I turned off the AIR pump and EGR valve because they cluttered the underhood look. Tuning eliminated the worry about codes.
Surprisingly, the valvetrain noise is hardly different at all. I was really worried about this point, but to my pleasure (and prediction), the lack of headers keeps the valvetrain clatter from being amplified.

jrp

iTrader: (16)

anyway you can PM the info, im curious of the lob profiles and VE's as compared to other TR cam cards i got and spec'd toward a great intake setup and restrictive exhaust.

Patrick G

iTrader: (14)

One interesting side note was the back-pressure issue of the cat-back. Thinking we might be leaving some hp on the table, we dropped the cat-back after the y pipe (since I don't have a cutout) and we made the SAME power. This proved to me 2 things. ONE, that the SLP Dual Dual is a good flowing catback and TWO, that the choke point of the exhaust must be in the manifolds. In the past, I've gutted the cats on these set-ups before and gotten 0 hp. So even though these '00-02 manifolds are pretty good, they're still a far cry from headers, LOL! But man, do they sound GOOD!!

a98ws6

iTrader: (48)

Nice to see a small cam making great power! A friend of mine has a 02 WS6 with just a GMMG, little T1 cam, and a lid and made 380rwhp! Still had stock manifolds/heads and only around 10K miles!

Spellbound

Congrats on the #'s

I was/have been curious as to how much power you could make and remain smog legal. I wonder how much it would make with lower compression and a smog legal blower??

Patrick G

iTrader: (14)

As long as you kept the overlap in check, I would think you could easily exceed 500 rwhp with a similar cam, lower compression and an intercooled blower. Heck, we hit 494 rwhp with little .052 jets. Had I invested in a better clutch and more fuel pump, 550 rwhp would have been a piece of cake.

Brandon Boomhauer

iTrader: (10)

Wow nice #s,
Seems like an easy way to make some $ races too

XLR8NSS

iTrader: (4)

Very nice results with factory manifold. HOLY SMOKES!!!