Sorry this is so long, be sure you are comfortable if you’re interested!
As many of you are aware, I have spent the past couple of months upgrading my ’00 SS convertible from a basically stock unit – Lid, STB, MAF and a few decals being the only upgrades – to a little bit meaner machine.
I had thought about it for a long time, and was also waiting to decide whether or not I would trade it in for 2002, and waiting to see what the 35ths looked like. Having decided to keep by beloved ’00 (and all the history we have been through together), I decided to proceed with the modifications.
I gave a lot of thought to what and how I wanted to modify, and had decided that I wanted to do bolt-ons only, naturally aspirated, and in a way that it could all be undone if necessary or decided. My goal was break the 375 horsepower mark, be able to pass emissions inspection, and keep a relatively stock appearance except for wheels. I also wanted to mildly modify the suspension – Lower Control Arms, Panhard Bar, and bolt on Subframe connectors (although they were not available).
The plan for performance was as follows:
Full length headers - TTS High flow cats – TTS (Random Tech) Cat back exhaust – GMMG Cold Air induction - SLP Performance programming – Custom – Rapid Motor Sports 180 Thermostat - Hypertech Underdrive pulley – ASP – 25% Mass Air Flow sensor - Granatelli Smooth Bellows - SLP Lid – SLP
The plan for appearance and suspension: American Racing Torq Thrust IIs ppainted like the GMMG cars – 9.5 front, 11 rear BFG KDs with 315s in the rear Lower control arms and an adjustable panhard bar Bolt on SFC when and if I could find them
Results:
Starting from my base dyno of 303 RWHP and using a conservative 10% for driveline loss, I needed to get to 337 RWHP to meet my goal of 375HPor an increase of 34 RWHP from the above mods. As we all know, these things are not cumulative, and work differently on every car, but when I finished the mods, I dyno’d at 333 RWHP and I think the dyno was low, and it doesn’t measure the effects from the CAI or fully account for the underdrive. From a seat of the pants perspective there’s a huge improvement, so I’ll call it close enough and say I have 375 on cold days with the wind at my back!
Issues and Lessons learned.
Headers
I took a great deal of time deciding which headers to go with. In the end, I chose TTS for quality, established product, ground clearance. The installation was fairly easy (mainly because Mike at Rapid Motor Sports did it!) – took three hours start to finish. I had to put a small dimple in the firewall because I didn’t want to cut the tab off of the block. I also got the 24” 02 extensions and I’m glad I did even though the instructions say you don’t need them. There was practically no way you were going to extend the harness far enough and the extensions give you good flexibility for routing. I used GM exhaust manifold gaskets, and re-used the standard bolts, Mike recommended against Stage 8s which I had purchased due to a potential breaking problem. I also replaced the plugs while we were in there. After the install, I had a great deal of problems with throwing 02 sensor codes and was getting to the point of removing the headers because I refused to ride around with an SES light or with my Autotap connected all the time so I could clear codes. For anyone planning to do mods, I strongly recommend that you invest in Autotap before you begin.
After about two weeks though, it settled into just throwing two specific codes – 1133 and 1153 indicating - that the 02 sensors were bad. I took it to the dealer and they said they tested all 4, and they were all bad. Now I have established a good relationship with the service department and a couple of the technicians, and so they replaced all 4 under warranty.
Exhaust
I took even more time with the exhaust, my choices were Corsa, Random tech, Hooker, SLP Dual Dual, Magnaflow, Dynomax, and GMMG. In my opinion Random Tech had one of the better sounds, followed by Dynomax, Magnaflow, etc. In the end I wanted the exhaust to be distinctive, but not overpowering (thus no loudmouth), no drone, and good flow. I chose the GMMG because they are established performance items – used on the GMMG cars - they are kind of reminiscent of the chambered systems on the 69, the sound is excellent, and because the sit even in the rear of the car, they look great from behind. Exhaust is certainly not an exact science though, and there was no way to know what it would sound like with the TTS headers and highflow cats.
When I got them installed initially, I had Megs oval tips and the noise was much too loud and there was quite a bit of drone at cruising speed. I was very concerned that I had made a huge mistake. Well interestingly enough, I couldn’t get the megs tips to sit right, so while I figured it out, I put the stock GMMG tips on. To my amazement, the exhaust was quite a bit quieter and the drone was gone. I couldn’t believe the difference from just different tips.
I wanted it just a little quieter still, and I wasn’t sure how to do it but I thought if just a different shape of tip could make a difference, if I could get a resonator tip it might be enough. The problem was that the tips needed to be about 11’’ long in order to fit without modifying the exhaust. I was able to find tips at StainlessWorks in FL that were exactly what I was looking for – 3” outside diameter – 2 ½” inside diameter (to match the existing tailpipes). The new tips take a bit of the edge off the sound and make it just about perfect.
Wheels & Tires
This started out as such an exciting thought – buy wheels, have them painted like the GMMG wheels, mount new KD tires and have a car that looked great and handled even better. Unfortunately that’s not the way it went. To begin with, I looked at a number of cars with 11” wheels in the rear and while the tires were close, they fit – mine didn’t and stuck out about 1/4'” from the wheel well – not the look I was after. They also rubbed the inside of the wheel well just slightly on hard turns so I knew it was not a backspacing issue.
I spoke to several people who had their wheels painted by their local body shop – mine wouldn’t – said they would chip and they didn’t want to be bothered. I found a couple of powder coaters in my area, but they wanted $150 per wheel, and I was not prepared to spend another $600 on getting them done. So I wound up doing them myself. It was a fun project – fairly time consuming – but they came out nice.
Now the tires were another story. It turns out, not only is there a fitment issue, but larger tires and wider wheels make the 4WD look that our cars have even worse. In addition, high performance tires it turns out - especially the ultra high performance KDs – change the suspension characteristics and make the ride much stiffer. This is because they build sidewall stiffeners into the high performance tires and as a result the ride is more harsh. Secondly, the KDs really grip so the steering is instantaneous. I found I had to be close attention to what I was doing behind the wheel all the time or you could wind up in the next lane in a hurry. So where tires are concerned, the lesson here was more is not necessarily better, and if you are primarily a drive for fun type with the occasional spirited drive or auto x, you may want to consider a milder tire. I wound up pulling the KDs off, and replaced them with KDWs. I did extensive measuring and testing and decide to go with 285s in the rear. They are a slightly taller and wider tire than the 275s, fill out the rear wheel well better and fit better on the 11 inch rim. My research showed that they should just fit under the rear wheel opening lip and offer a bit more protection for the rim than the 275s and that’s just how it worked out.
The new problem:
Well now with the tires solved, (buy the way I now have to decide what to do with a brand new set of KDs) I had the 4wd issue to deal with. Working with Raggs, we researched springs and found that the Hotchkiss appeared to offer the best choice – progressive front and rear, a mild initial rate (actually slightly softer than stock) and fairly stiff in the higher range with only a 1” drop (remember the headers). I got the springs and had them installed last week. The stance is excellent and for vert owners I would recommend that you don’t go any more than a one inch drop. As a matter of fact I may try to put a ¼” back in with some extra rubber seats (recommendations appreciated), but for now they’re fine.
What’s left?
Relocation brackets – with the car lowered now, the LCAs angled downward – not good.
A bit of fine tuning for clearance – again with the car lowered, I want to squeeze an extra ½ inch or so of clearance out of the y pipe.
Conclusion
There have many times over the past months when I have wished I never started doing the mods. I enjoyed driving a hassle free car with plenty of power. The car was working great and I enjoyed it every time I drove it. I just wanted a little more power and to add a little pizzazz to the looks. If I had it to do over again, and if I decided to go forward with the mods, I would take it much slower. Just do the headers, leave everything else alone, resolve any issues from the headers and then get a better idea of how it now sounds and what exhaust to go with. Each change affects the next so going with headers and cat back I went from a mild SS to a beast in one afternoon and then spent more than a month trying to adjust. I would take the same slow approach with each step.
Now that I have everything solved (almost) and I every time I get on the gas a bit I’m glad I did the mods, but if things start going sour I’ll be very tempted to put it all back. I have kept every piece I took off and made sure that I didn’t damage any of it in the process so if I want to go back to stock I can.
I have included some before and after pictures below. So anyway, I hope this little story helps any of considering any of these mods.
Rich
P.S. Many thanks to Kevin, Ralph, Chris, for your help and to all my SSOA friends for your support and encouragement on this project!
[ 26. April 2003, 07:21 AM: Message edited by: DaddySS ]
Posted by Hawkeye (Member # 88) on :
Nice write up - thanks for sharing I'm sure others will learn and follow from you trial & errors.
Now, I'm going out for a drive!! Posted by MaryandRalph (Member # 244) on :
Wow! I can't wait to see and hear it in person. It looks great in the pictures. Thanks for the write up.
Posted by JohnS (Member # 1073) on :
A nice summary, Rich, and great before & after pictures.
All that background work really paid off.
Posted by Xsta Z 28 (Member # 740) on :
Great write up! Definitely covers all the good and bad points that can occur during a change. It is a good learning expereince. Thanks for sharing!
Posted by 35TH ED/ed (Member # 1709) on :
Very sharp looking. Stock like till you see the rear end . Those tires look like they take up the whole rear. Glad to see that its done and a smart move to be able to go back Now go out and enjoy Posted by sscamaro (Member # 1330) on :
Looks great,Rich. My mods were not as extensive as yours,but I had no problems with anything. I never got any codes with my headers,nore did I need the sims extensions. I guess I was lucky everything went well. Bring it to Camaros at Carlisle,so I can see it.
Posted by DaddySS (Member # 848) on :
Thanks gang! I'm glad to be back to driving it and not trying to work out solutions, fix probelms or decide what to do next because something didn't go as planned. Now let's just hope it holds up! Posted by DanA_F99_1977 (Member # 118) on :
Great stuff Rich, Thanks for wharing the story. Not too long at all, exactly what we love to read. Congrats on you personalization!
Posted by ss_rs_z (Member # 1888) on :
Excellent job Daddy. The car looks great and ferocious. Love the decals and wheels. Since the upgrade have you increased your HP output? Have a great Sunday. Posted by WeaSSel (Member # 902) on :
Awesome update! I was waiting for this one. The reason I have not been more aggressive w/ mods is because I hate chasing problems and not having fun in the car anymore. Your information is going to help me a lot.
My questions are: 1. Did you have to change sway bars when you went with the Hothkis springs? I thought the bar should match the return rate of the spring.
2. Did you like the look of the 315 tire? Was it too much in your opinion or just the fit did not work out on your car?
3. Did you do any custom programming? This is another area that has prevented me from making major changes. I don't want to spend 1K for LS1 Edit and AutoTap on top of the parts. Did you consider FastChips for your programming?
The car looks great! I love the lowered stance you have. Those wheels really set it apart and make it look mean. Congrats on all the changes and thanks for the complete update.
Ryan
Posted by DaddySS (Member # 848) on :
quote:Originally posted by WeaSSel: Awesome update! I was waiting for this one. The reason I have not been more aggressive w/ mods is because I hate chasing problems and not having fun in the car anymore. Your information is going to help me a lot.
My questions are: 1. Did you have to change sway bars when you went with the Hothkis springs? I thought the bar should match the return rate of the spring.
2. Did you like the look of the 315 tire? Was it too much in your opinion or just the fit did not work out on your car?
3. Did you do any custom programming? This is another area that has prevented me from making major changes. I don't want to spend 1K for LS1 Edit and AutoTap on top of the parts. Did you consider FastChips for your programming?
The car looks great! I love the lowered stance you have. Those wheels really set it apart and make it look mean. Congrats on all the changes and thanks for the complete update.
Ryan
Ryan: 1. The Hotchkiss springs are a somewhat mild upgrade from stock, so I didn't consider (or have to I think) upgrading the sway bars. 2. all 315's are not the same - as I have learned - depending on the tread profile, the fit can be very different amoung brands. In the case of the KDs, the tread stuck out of the fender by about 1/4" and I didn't like the look. They were also a bit "much" for what I was trying to achieve. 3. I had Mike at Rapid do the programming. It was convenient since he did the headers and we had the dyno shop right down the street. I recommend Auto tap in any case - it's not all that expensive and excellent to check codes or just check on how things are working. I may invest in LS1 edit sometime down the road but most places (like Rapid) give you free programming going forward once they've done your car.
Posted by RagSS (Member # 1127) on :
Rich, Great write-up. This is exactly what people look for in these boards, ...others experiences to learn from. Nice job, ...and the car looks awsome!
Posted by 2002Z4CSS (Member # 1393) on :
That SS look great now! You must have been writing that story for quite a while. Posted by 01ss87iroc (Member # 1763) on :
Great write up! Glad to see you are finally able to enjoy the finished project. The car looks awesome! Posted by DaddySS (Member # 848) on :
Thanks all.
Another thing I have taken away from this process is tremendous respect for the engineers that design these cars and the ones involved in well thought out aftermarket products. After messing with their designs (and a lot of messing up) I have a whole new appreciation for their efforts!
Thanks for the nice compliments, I really appreciate it!
Posted by Z28-SORR (Member # 1565) on :
Looks Great!
I particularly like the grill insert. It cuts down on what I call the "fish mouth" look of the front. Its the only thing I don't like about the 98 and up.
![[Big Grin]](biggrin.gif)
![[Smile]](smile.gif)
. Those tires look like they take up the whole rear. Glad to see that its done and a smart move to be able to go back Now go out and enjoy ![[Cool]](cool.gif)