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· Senior Privileged Member
4,104 Posts
Discussion Starter · #1 ·
I finally got the time to do a PRELIMINARY report on the Supermaxx header experiment I am conducting with the help of the folks at MTI Racing. The results so far have been ok but not spectacular (on their own), relatively costly, but particularly fruitful in their range of impact.

Reese and his guys did a “before” series of dyno runs last week so we would have reliable “before” and “after data. Unfortunately, the weather has not cooperated. The “before” runs were done in mid 60s temperatures, and then the weather has warmed up a lot in the interim, so the “after” dynoing was done at 80+ degrees. Those of you experienced in dynoing know that although the dyno manufacturers provide “correction factors” for differing ambient conditions, REAL engines do NOT compensate well for higher temperatures, and our cooling-impaired SSRs are particularly vulnerable to this. Nevertheless, as you will see below, the results I got were surprisingly consistent with those of another member of this board.

I did the headers at this point in my SSR modifications plan for several reasons:

 I plan to also alter the exhaust later, and since I am not certain of compatibility between headers and each exhaust system out there, and the exhaust is much easier to modify to fit than the headers are (!!), I wanted to do the headers FIRST.

 The headers are a costly but absolutely essential improvement to the “in and out” air flow capabilities of the engine. In any engine “system”, there are several POTENTIAL bottlenecks to air flow: air intake system, air filter, throttle body, mass air sensor, intake manifold, heads, exhaust manifold, catalytic converters, and exhaust system. If you have ever compared a factory exhaust manifold to aftermarket headers, you will have seen why a factory uses the manifold instead: MUCH less costly to build, much easier to install, and quieter. Unfortunately, these “advantages” extract a BIG price: the exhaust manifold is usually very much an air flow “cork” compared to headers. If you ever get a chance, put a stock manifold beside an aftermarket heder for the same vehicle. There is a VERY striking difference between them in sheer size, as well as quality of air path.

 I have been able to satisfy myself that the Supermaxx headers are well thought out and well constructed, and I have been able to find two examples of “before and after” for them in trucks. One of them was right on our SSR board (see my “Scientific” posting), and another in a truck magazine in which they did an install, and before and after on a Dodge Ram pickup. Both examples showed worthwhile, if not spectacular, improvements in power curve.

 I have NOT yet been able to satisfy myself that air filters, air intakes, and exhaust systems actually perform anywhere NEAR as well as their makers promise or imply. Until I do, I’m not spending my money!

 Hopping up an SSR is a program of individual projects that requires professional support to do the more difficult installation tasks, and ALL the installation tasks when you are living in a hotel like I am right now on this contract assignment in Atlanta. I am fortunate in that through my friendship with Paul and now Reese at MTI, they are willing to absorb some of the heartache associated with any new development program, as long as I am also reasonable in MY expectations, and this kind of experimental / developmental partnership is hard to create and maintain. It takes people of special skillsets and personality to work through the inevitable surprises and disappointments. Since we have that relationship right now while I am physically here in Atlanta, it makes sense to do some of the tough stuff first. With the nature of computer consulting, I could be in NYC or California on my next assignment (or unemployed), so you move while the circumstances are right to do so!

I used the Dynatech Supermaxx header system pn 115-735-300S, which includes hi-flow cats & Y-pipe, all stainless steel components, and “factory” fittings to connect to the exhaust system. The "S" in the part number is critical, as that is what signifies that it includes the hi-flow cats. Without the “S”, you get a reducer pipe instead of the hi-flow cats. I wanted cats to be able to pass emissions testing AND get proper closed loop feedback from my 4 O2 sensors, and I wanted HI-FLOW cats so that I removed ALL the corking. A fair price for this system seems to be $1275 at most places. The cat-less system goes for just a but more than $1000, so these cats are not cheap. But, Reese’s people say they work well. This cost does not of course include installation.

Reese’s team did not find the install particularly hard, but any header install on the SSR is time consuming (much longer than installation of headers on a Corvette, so be warned!). The full color, laser printed Dynatech instructions were beautifully detailed and even included full color photographs, but Reese noted that they required among other things, removal of the front wheels and inner fenders, removal of the transmission support crossmember (and jack support of the transmission of course), the engine sparkplugs, etc. This was a LENGHTY process. Because I forgot to tell the crew that my wheels had been dynamically balanced on the vehicle at Butler Tire, I had to return to Butler to have the balance rechecked after the install. If I had remembered to warn the crew, they would have marked a bolt hole and its matching hub bolt on each wheel, making a balance recheck unnecessary, so remember that if you do these headers!

This brings up the first big negative with these or any other headers on an SSR: install time and cost.

I think Reese lost time of the actual time spent on installation, as he played with my SSR on the dyno a bit because it was an opportunity to see what an SSR is all about, and because he wanted an accurate “before” baseline, since we plan a string of mods on my SSR, which he and Paul view as their development vehicle for their potential SSR program. Then, he did a good “after” dyno session to analyze the results. In addition, the Dynatech instructions warned that the O2 sensors are very prone to stripping their threads when removed, and sure enough, we had one stripped. That added $89 or so to the bill, AND Paul had to make a special 110 minute run to the only Chevrolet dealership in Atlanta that happened to have the correct sensor (you have been warned!), which I was not charged for (Thanks, Paul).

Reese also personally test drove my SSR before and after, and also diagnosed the noise that appeared after my driveshaft and rear end gear ratio changes (both done elsewhere). Because he has PERSONALLY done lots of rear end gear swaps (including 87 RACE cars done within 3 months when he was a crew chief), I respect his opinion. He told me that my theory on backlash clearance is correct. He always sets it much tighter than the 0.008” that was done per Motive Gear’s specifications. He shoots for a minimum of .004” and not more than .006”. He will re-shim my rear end soon, as he says the noise level can be reduced a lot.

All in all, Reese charged me a grand total of $900 for ALL of the above, and then the next day put the SSR back on a lift to recheck all torques and to readjust a cat pipe that was a little too close to a floorboard., at no charge.

So, I spent $2200 to get the headers, the installation work, and the dyno work, and while this makes the extra horses I got some of the more costly ones I have ever bought, I cannot with any integrity complain to Reese or Paul, as I feel that for what they and their crew did, I got a BARGAIN. I just point all this out so that anyone else embarking down this path understands that on an SSR this is NOT a “simple and fast bolt-on”, regardless of what a sales person may tell you. Reese told me that these kinds of development efforts are hard enough that he would not normally do one on an SSR with a client, but was pursuaded by my attitude of patience and fairness. (In a separate posting, I’ll tell you guys the sad story of the client who came to MTI insisting that HE (the client) had a program all mapped out to increase his car’s power by 150 hp via bolt-ons!).

There is a header retailer who is not a sponsor of this website, so I am not going to mention the name here out of courtesy to our sponsors (you need to PM me for details), who offers actual installation at a location in Texas for a true bargain fixed price ($250). I assume he can do this because he does nothing but headers each and every day (I imagine you get pretty good at it then!). Anyone anywhere near that retailer’s location would be foolish not to take him up on that offer!

Ok, so what results did we get?

Well first of all, the SSR now has a “sound system”!

I significantly underestimated the effect the headers would have on sound level and quality. In fact, on start-up, you do get fooled, because you hear NOTHING new at idle (well, maybe a tiny bit, but nothing significant). But, as SOON as you TOUCH that accelerator, you now get instant audible feedback. This is a mixed blessing for me. I love the sound, but “before”, my SSR with its 4.56 gearing and nimble feel was a sort of “stealth” machine, That cover is completely blown now. If you want quiet, don’t do headers!

On the dyno, well, here’s an opportunity for me to illustrate to the innocent ones out there just how badly power improvement claims can be manipulated!

First, I’m going to pretend I’m an aftermarket parts retailer. To be “competitive” in that role and “do what the other guys do in THEIR advertising”, I would say, that “in an actual before and after test, Jim G’s SSR gained 15 hp and 17 ft lb of torque!” Regrettably, that would be a deceiving statement.

A more honest and complete SET of statements would be:

At one point in the power curve, Jim G’s SSR gained 15 HP.

At one point in the power curve, Jim G’s SSR gained 17 ft lb of torque.

The AVERAGE gain in HP across the entire portion of the power curve that was actually dynoed before and after (3800 rpm to 6500 rpm) was 10 HP.

The AVERAGE gain in torque across the entire portion of the power curve that was actually dynoed before and after (3800 rpm to 6500 rpm) was 10 ft lb. Although ONE of the 2 post-installation dyno runs actually recorded an average gain of 11, THAT dyno run also only showed a PEAK gain that was 2 HP lower than the other post-installation run! (So, not fair to quote the “best” from each run! Pick ONE of them to use as the comparison)

The PEAK horsepower rose by 12 HP.

The PEAK torque rose by 16

They say that the computers on our vehicles “learn” after changes are made. I would have to agree. The FIRST run after the install showed a peak gain of 10 HP. The second run just 7 minutes later showed a peak gain of 12 HP.

Later analysis of the before and after power curves showed something VERY significant: the largest gains in torque and horsepower were made in the 3800 to 4800 rpm range. In that RPM band is where those larger 15 HP and 17 ft lb gains noted above occurred.

Why is this significant? Well, if you read my earlier “scientific” posting, you will recall that the 4000 to 5000 rpm range is where my SSR, with its 4.56 gearing, spends the vast majority of its time in getting from zero to 60 and zero to the ¼ mile marker! Therefore, this header system happens to be a really good match for MY SSR (those with stock gearing might or might not have the same result. I haven’t done that kind of analysis on a stock SSR).

I’d love to say that this was the way I planned it, but in all honesty, it’s a pure blessing from The Lord! Perhaps Dynatech designed this system with that in mind, but that would also just be speculation on my part.

Still, I’ll take the happy result. My modeling software says that this change in the power curve (note that I said power CURVE, not PEAK power!) will reduce my 0 to 60 time and ¼ mile time by about ¼ second. My 0 to 60 time goes from 6.5 to 6.25 or thereabouts. So, I’m half way to my first performance target: 0 to 60 in the high 5’s.

I also noted after the fact that my new peak horsepower is pretty much exactly what our other board member got when he had HIS Supermaxx headers installed. His GAIN was larger because his starting point was lower. It appears that we are both encountering another “cork” in the system that is stopping our 5.3 Liter engines at 266 hp.

Note also that another board member who put these headers on his 05 SSR got a substantially greater improvement – about 31 to 32 HP peak improvement. I suspect this just verifies what we all know: the 6.0 liter Corvette engine in the 05s has already had more of the other corks removed, and so the replacement of the factory manifolds had a proportionately greater impact. Both Paul and Reese are predicting that I will see big gains with 2 other mods that Reese has planned for my SSR, that will capitalize on this header install.

Do I consider this mod a success? Yes, but with reservations.

I did get an improvement large enough to make a ¼ second difference, and there appear to be (at least so far) no adverse byproducts (provided you like to hear exhaust sound). However, on the newly minted Jim G scale of “Dollars per tenth second”, this mod cost about $880 per 10th second when all costs are truly added in.

Since my gearing change cost under $100 per 10th second (actually about $80 per 10th for me), I’d have to say that gearing is by far a better bang for the buck.

The BEST bang for the buck so far is changing the shift points from the stock 5600 rpm to about 6000 to 6200 rpm (let’s be conservative and easy on our engines, even though mine has demonstrated that it is happy at 6500 rpm). THAT got me 3/10ths, and costs you NOTHING if you shift the automatic manually, but realistically, since the tach lags so badly, you need to reprogram via a microtuner or via HP Tuners software, which WILL cost you some money, but not much (zero cost if you own your own microtuner – are you listening, Buffy?).

Likewise, tightening up the shifts probably would reduce the times appreciably, and again costs little (if you have a shop do it) or nothing (if you use a microtuner).

Now, on a more common value scale, dollars spent per HP gained, the headers look a bit better, but still costly:

 Headers: $180 per HP gained

 K&N Aircharger (Aircharger, not filter): $75 per HP gained

 Gearing: Can’t use this measure, since you don’t gain any power, you just redistribute it.

Knowing the outcome, would I do it again despite the cost. Yes, for a few reasons:

 I know I would need to do the headers at some point. You simply can’t flow enough air through those factory exhaust manifolds to make real power. This way, I got the cost and the hardest work done early, and got a tangible benefit that gets me halfway towards my first target.

 This is only one step in a multi-step program in which Reese and his team will discover what works, what does not, and what works BEST, when applied to an SSR. It will thus build a program of packages that MTI can then offer with some ASSURANCE to SSR clients.

 Most people would like the new sound.

 It’s satisfying to the engineering physicist in me to know that those clunky and underperforming, cheap looking manifolds have been replaced by stainless steel works of art that work a lot better.

 I also value what this rather demanding installation (compared to Corvettes!) showed me about Reese, Paul, and their people: They do things RIGHT, they take responsibility for changes to schedule, and they treated me the way any person would like to be treated. Reese in particular is a very busy and focused man. The time and attention he has put into this speaks volumes about his trustworthiness and reliability as a development partner.

Would I do this as the ONLY power enhancing modification? Definitely not on an 04 SSR. If you are trying to do just one or a couple of mods, I cannot honestly recommend headers in that solo or near solo role. There are less costly ways of getting a few extra horses. But, if you want to keep the door open for more mods, you can’t really avoid doing them at some point.

The situation is different if you own an 05 SSR. If you can really get 32 HP and the nice “sound system” for a couple of thousand dollars, that IS justifiable as an only mod.

I still have to evaluate the fuel mileage impact and longer term performance of these headers. But so far, looking decent.

MTI and I have lots more planned. Stay tuned.

Jim G

· Registered
156 Posts
Good Post

Can't wait for your and MTI's next Mod's. I hope it's DANAMAX. Also that 20 deg diff in inlet air on the dino hurt which leads me to another thread where we where talking about the cold air charge that a Ford Lighting has on it's intake. Do you know of an aftermarket kit that will accomplish a consistant low air intake temp?

· Senior Privileged Member
4,104 Posts
Discussion Starter · #3 ·
Bad Asphalt: I don't know of a true cold air kit for the SSR.

The K&N Aircharger and the upcoming Vararam system both TRY to isolate the incoming air somewhat from the engine compartment behind the radiator, but what is really needed is an intake that draw air from outside, like from in front of the bottom of the radiator via an intake scoop.

By the way, today I had the SSR, with headers, in true, prolonged (30 mnutes) stop and crawl traffic. The temperature guage never got above 210, and was often just BELOW that, so evidently the hader pipes are not adding too much heat to the engine compartment as I feared they might.

The transmission temperature guage (I have the auxiliary guage package) never got above the 12 o'clock position either.

The next mod at MTI is going to be really simple.

Jim G

· Registered
156 Posts
100 degrees

Jim where I live south of Las Vegas, this summer It's going to get hot. It will most likely be 100 plus. I just read about Vortech's Igloo. Then I read a long thread on another forum that said if you isolate an alumimum intake tube with rubber on both ends and then rap it with an insulating material, it acts like a small inter cooler. I believe for every 10degrees drop in inlet air temp you gain 1% of engine HP. So if thats true we could gain quite a bit of HP if we droped the temp say 40 Deg's. Would you run the numbers on your software and let us know. Just found this link.

· Senior Privileged Member
4,104 Posts
Discussion Starter · #8 ·
Bad Asphalt: While there is a certain amount of theoretical truth in what those postings you refer to are saying, in practice, there are several fatal flaws:

- The air being ingested in our SSRs is hot to begin with, because we don't have a cold air intake

- The short length of intake tube is insufficient to cool air any appreciable amount without mechanical or chemical assistance

- After a rather short time, despite the insulation which would slow down the eating process a bit, that intake tube would be at underhood temperature, without mechanical or chemical cooling

To answer the 64 thousand dollar question: IF you somehow reduced incoming air temperature by 40 degrees, and IF your formula is correct (that each 10 degrees gives you 1% more power), you would get 4% more power which is about the same amount as my headers got me, so about 1/4 second improvement in 0 to 60 time.

The link to the "heat" people is very interesting, but they use a cinsumable (CO2 gas), and as a matter of practicality, I won't build a solution based on a consumable (it's enough hassle stopping for gas, let alone CO2!)

Jim G

· Tu-Tone club member
5,996 Posts
Jim, great report.

Some of your conditions flashed back to items I went through when my headers were installed a month ago. The shop that did mine initially quoted me $200 to $225 to install.
After a whole day in the shop to complete, test drive, and insure no leaks occurred they charged me $400. Was not surprised, nor disappointed when they highlighted, as you found out, issues they ran into.
The instruction booklet was a major guide in performing the task. The 02 sensors were delicate to remove, i.e. two of the four were replaced as warranty items, vs the two original ones which were "bears" to remove with out damaging.

I did not have mine ceramic coated, and also, have not noticed a temperature increase approacihng the 210 degree level on the gauge while idiling in traffic.

Comments about the sound when complete are accurate. Somewhat more throaty but still quiet. I did find after 1000 miles on the headers they become more mellow and down shifting in lieu of braking provides cracks and pops which did not occur with the stock system.

After the Magnaflow exhaust system was installed replacing the stock exhaust (last week)made quite a difference in both response and "NOISE". Just clearing out the remaining airways provides response the stock system was stifiling. I could live comfortably w/o this much sound, but that is part of the result when you makes changes.

Would like to get a K&N filter system, but don't like the way it looks installed. Appears like they left off the cover for the filter. I know thats for air flow purposes but....WTH. Hope Vararam gets into gear finishing their product as it may be the answer for my tastes.

Keep up the great work, Jim, look forward to your reports.


Peace :flag

· Senior Privileged Member
4,104 Posts
Discussion Starter · #10 ·
Purple Penelope: I have dyno data now for the K&N Aircharger system. 5.4 hp maximum gain. I will provide many more details once I have cleared up my backlog of stuff to do.

But, the K&N system is not a "killer" mod by the looks of it.

Jim G

· Senior Member
224 Posts
Jim G: Performance Guru

WOW...What a post!! Jim, thanks for taking such an interest in researching the most effective (and econmical) ways to add horses to our "trucks." Very logical (and practical) analysis. Your threads (have you settled on a name yet?) have added a tremendous wealth of information to this forum, making it the best source of SSR-specific performance information available anywhere. I know that I will be watching your collaboration with MTI Racing closely, waiting for the next pearl of performance information (Jim G's Performance Pearls?).

I still have my unboxed Dynatech headers in the garage until I figure out what to do with the rest of the exhaust (Magnaflow?, Corsa? or other). Thanks again for pushin' the envelope!

· Senior Privileged Member
4,104 Posts
Discussion Starter · #12 ·
Kevin: You might want to hold off on the exhaust until Reese has had a chance to try an exhaust solution that he claims has already worked on another SSR.

Like I've aid before, stay tuned.

Upcoming threads I have already planned include:

- How gearing affects the rpm band to target (stock 3.73 SSRs do NOT have the same 4000 to 5000 rpm dwell time as my 4.56 equipped SSR)

- K&N Aircharger versus Vararam

- Exhaust choices & comparisons

- Microtuners versus full blown tuning software

I can only go as fast as (1) my time, (2) Reese's and Paul's time, and (3) my finances, will all allow. This is just like "air in and air out" of an engine I described above: whichever factor happens to be the current bottleneck becomes the "cork" for the whole system!

By the way, I really like your idea for the name. We appear to be getting many good name suggestions, but the administrators of the forum have remained silent on the idea so far!

Jim G

Jim G's headers

Jim, thanks for your report, I have done some of the same things. I had the dynatech supermaxx headers instaled by Race-Prep here in the desert. They are located in Indio, ca. They dynoed before and after. The work was done on 3/8/05, conditions were; temp. before 87.88, 30.13 in-hg, humidity; 23%, Max power= 321.78 max torque 335.83. With the headers instaled, which took one and a half days; temp.87.71, 29.95 in-hg; humidty; 17%, Max power 332.32 and max torque=344.17. I have not done anything else
. they do not have soft ware to tune it and clame it is running very lean, I am weighting for that to happen so that I can have them change the rear end to 4.56. I also put a green filter on, but it looks like you did very will with the K&N. I love the new soond, very mellow. I forgot to say that it is 2005 aqua blue with Gost flames. Rod

· Registered
40 Posts
Great posts!!

I'll probably never do any of these mods, but it really reminds me of my teenage years reading HOT ROD mag and dreaming of the high performance cars, racing, etc.

These posts are great reading. Please keep up the great work. It has to take a lot of time and thought to write up these postings, but they are worth every minute and every bit of effort, IMHO.

I read several other automotive forums and NONE comes even close to the great information found here on the SSR Fanatic forum.
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