951 4" LINDSEY STEEL EXHAUST
Lindsey Racing Full Race / Street Monster 4 inch exhaust for the 951.
This exhaust is made from aluminized coated steel exhaust tubing and grows along it's length from
3", to 3.5", to a full 4" in diameter. Formed with mandrel bends making it free flowing throughout without pinch points and
collapsed tubing like the factory system. All tubes are
CNC mandril bent in one piece with no seams or sectioning.
Welding is limited to flanges and hanger brackets and
where we go from 3.5" to 4".
Do you need a 4" exhaust? Well, that depends. We think you
likely do if maximum HP is your goal. On a 2.5L with a long list of mods, but not the biggest
and best of everything, we observed a large decrease in exhaust
pressure measured between the turbo and cylinder head. With our 3" system and Edlebrodk RPM muffler, the
car produced 30 psi of exhaust back pressure at 20 psi of boost in
3rd and 4th gears clear to redline. When we installed the 4" DT system with Flowmaster Race muffler, that
exhaust pressure dropped
to 25 psi at the same boost level. That's a 5psi drop which is
huge! We expect to see a greater drop when we run without
a muffler and dump the wastegate to atmosphere for you serious
racers.
Above you two see dyno pulls. They are both done on the same car
9 days apart. The RED graph is our 3" exhaust and the
BLUE graph is our 4" exhaust. The turbo on this car is our
Sport turbo. Both pulls are through mufflers and with the wastegate
tied into the primary tube. The RED pull was done at 18 psi of boost. The
BLUE graph was also done at 18 psi, but was at 16.5-17psi by
redline. You could turn up the boost controller and it would
make no difference. We reached the limit of the Sport turbo
during our comparison testing on the exhaust. The RED pull
was done on a 94F degree day, and the BLUE 101F.
What's important to note though is this. By printing both pulls on the same dyno chart, you can see for yourself that by 4000 RPM, the engine
was making 75 more Ft. Lbs of torque at the wheels. It makes more
torque all the way up the graph. Also note that the engine reached
it's peak torque 350 RPM sooner on the graph. Take note that the
BLUE pull was started 150 RPM "later" than the RED pull. The numbers
are even more impressive if you take that into consideration. That would
become 100 Ft. Lbs more torque at 4,000 RPM and peak torque 500 RPM sooner. Either
way you slice it, the numbers are a HUGE difference. Even on a modest engine
and boost like this one.
This engine has a stock head and intake. With head and intake upgrades,
and/or a larger turbo, the results would be even more impressive with the
greater need to exhaust what's pumped in.
The 4" exhaust will give you more HP and Torque and give it to you sooner.
We feel the exhaust pressure needs to be less than the boost pressure.
You only need as much exhaust pressure and volume needed to give you
the required boost. Anything else is hurting you. One contact of ours
runs a record holding drag racer. They run 45 psi of boost with 8
psi of exhaust pressure. When you have higher exhaust pressure than
boost, the flow or air actually travels backwards through your
engine when valves are in overlap. It's called reversion. The more the exhaust pressure
exceeds the boost, the worse the reversion can be.
All systems come complete with copper gasket and band
clamps. Nothing else is needed for installation.
LR-951-EXH-41:
This 3"-3.5"-4" versions is identical to the EXH-42 only
we "do not" tie the wastegate outlet back into the primary system.
We supply a small slash cut 45 degree dump pipe for the
wastegate outlet. This is not recommend for a street driven
application. It's simply an option for the dedicated track
car wanting to save a little weight, cost and perhaps gain a
few HP.
LR-951-EXH-42:
Same as the EXH-41, only we "do" tie the
wastegate outlet back into the primary tube. We recommend this arrangment for a street and street/track car.
OPTIONAL 3" TURBO DOWN PIPE:
If you have been considering topping off your exhaust system purchase by adding our 3" Turbo Down Pipe,
this is the perfect time. When you select the Turbo
Down Pipe option now, we substitute the normal 3 bolt
triangular flange wastegate pipe inlet connection for the V-band connection that our Down Pipe uses.
Thermal Coating:
If you wish to have the exhaust
thermal barrier coated, select either the EXH41 or EXH42 with
thermal coating. That adds $150 to the price of a system.
Highly recommended for a track car. It will help keep the heat from entering the driver compartment. The thermal coating also
aids in keeping up the velocity of the exiting exhaust by
helping maintain the heat in the pipe rather than letting it
cool down as quickly and slow down. It will also add to the
life expectancy of the exhaust. With or without the thermal coating, the exhaust will give you many years of use. Mufflers and MRPs:
The systems do not come standard with a muffler. It's
an option you purchase separately. Some of you may already have a muffler you want to use so we don't force you to purchase
one. The dimensions of the mufflers we use are 19" overall length,
4" center in, and 4" center out.
- Magnaflow - A 7" round polished Stainless Steel blow through.
- Borla XR-1 - Multi Core Racing Muffler.
- Muffler Replacement Pipe - 19" Hollow pipe replaces muffler. Louder! "Race Only"
Optional Cat:
All exhausts have a cat replacement pipe included with them. It's the second pipe in the system. You can remove that
pipe and add our performance CAT at any time or
select it with you exhaust purchase.
Tips:
The standard 4" exhaust comes with an outlet pipe from the muffler which serves as the exhaust
tip. It's either plain finish or ceramic coated depending on what option
you select. These "optional" tips slip over that 4" outlet and dress it up with polished Stainless Steel if you
would like something with a little more bling. Just remember they
are not required since the exhaust already has an outlet/tip.
Pre-Muffler Muffler:
The 4" system sounds awesome with any of our muffler
choices. For some however, it may be a little to
loud. For them, we offer a pre-muffler muffler. This is a blow through muffler with little or
no restriction that goes in place of the second pipe
in our system. The piece is manufactured by Flowmaster
and is called the "Outlaw" muffler. The Outlaw was specifically designed for racing. The round case allows for installation in limited space
applications. The design incorporates sound attenuation rings without the need for packing materials.
- Optional Flowmaster "Outlaw" Muffler
02 Sensor Bung & Plug Installed:
If you plan on using a Wide Band Oxygen Sensor, we can WELD
the bung on the exhast pipe for you before shipping your system. The additional
charge is for the Bung & Plug Kit
and labor to install ( WELD
) the bung.
You can select this option when ordering your exhaust.
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