Headers for V8 cars, Please read
11-23-03, 04:09 PM
#1
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Thread Starter
iTrader: (2)
Lexus V8 HFVS Shorty Headers. Gathering Commitment for New Design
ClubLexus member JBrady has researched and located a master craftsman that is willing to build shorty headers for our 1UZ-FE V8 engine. He has already built some very nice headers for the 4.7 liter Tundra and is familiar with the construction requirements.
DESIGN: The HFVS Shorty Header
The stock exhaust manifolds are very restrictive. 1990-1997 are the worst with 1998+ cars being slightly better but still poor. It is obvious that better flowing manifolds are needed for true performance. ALL designs have compromises so the challenge is to pick the best design for the application. In my opinion the best design for the Lexus V8 automobiles is a High Flow high Velocity, Scavenging short runner exhaust manifold with merge collectors. aka: HFVS Shorty Header.
The design goal will be to produce a manifold that vastly outflows the factory manifolds and will fit all year and model Lexus V8 cars including:
1992-97 SC400
1998+ SC400
GS400
GS430
1990-97 LS400
1998-00 LS400
The HFVS Shorty headers will be designed as a bolt in for 1998+ V8 cars to keep the catalysts in their stock locations. This will require earlier cars to run aftermarket cats or at least move the stock cats. They will probably also fit the LS430s and SC430s but until they are designed and test fitted we will not know about space limitations for those vehicles.
Pre-1998 cars will require a change in catalysts location. Choices include relocated stock catalysts (under the car), aftermarket catalysts (under the car) or the possible use of 98+ catalysts. An aftermarket cat back exhaust system will be needed. They will also need an EGR flange welded to the header. The EGR flange will be an available option at a cost of approximately $50.
Expected power increase of 20+rwhp and 20+rwtq (probably more).
1998 and newer cars could use these headers with the stock exhaust system but full power gains will require a true high flow cat back exhaust system. On a car with a full complementing exhaust the HFVS Shorty headers are expected to outperform any available long tube design across the full RPM range.
REQUESTED COMMITMENT
Before these headers will be built we need to obtain commitments for 20 sets, NOT PAYMENT, just an agreement to buy them when available. No payment of any kind will be requested prior to the headers actually being designed and built and ready for ordering. ONLY If you know you will want to buy a set when available please send a confidential PM as directed below and you will be updated on progress and expected order dates. As of 11/17/2003 there are commitments for 14 sets of headers. With development and build time the expected availability is February.
NOTE: This is not yet an official group buy item on ClubLexus, but the builder needs to ensure that there is sufficient interest in this item before he moves forward with the design. ClubLexus feels these items will be of sufficient interest and value to our Lexus enthusiast community to gauge early interest of our members in this performance product that does not exist elsewhere. It is important to note that all responsibility for this transaction is with the buyer and the designer (not ClubLexus).
CONSTRUCTION
To keep pricing reasonable the Headers will be constructed of MILD steel (as are Tex's headers). Mild steel is actually less prone to cracking at the welds than stainless and with ceramic coating have a life expectancy of over 10 years. Pricing for the headers WITH Ceramic coating (recommended) should be under $600. Without the ceramic coating around $400 for the set.
DESIGN EXAMPLES
The picture BELOW is the C's headers built in Japan. They are NOT what you should expect rather they give the general idea of the layout of the planned header. In fact the headers below are for the C's 5.5 liter engine and are more show than go. Compared to the HFVS Shorty Headers we are designing they would likely make less power on our engines due to interference between runners and too large of a pipe diameter for our 4.0 and 4.3 liter engines. Again, the image below should help you get a mental picture of the design. The C's headers pictured below cost around $2500.
BELOW is an example of the work of the master craftsman. It is a picture of long tube headers for a Chevrolet but shows some nice work. This example does not use a merge collector but ours will.
PERFORMANCE EXPECTATIONS
As stated above we expect a conservative gain of 20+rwhp and 20+rwtq. Actual output will only be known after construction and testing and will vary depending on year of car installed and other enhancements used.
To get a good idea of what is available in our engines you may wish to look at the below dyno chart.
JBA built shorty headers for the 32 valve 4.7 liter V8 ToyotaTundra... remember, even though it is a 4.7 it is only rated at 245hp @ 4800rpm and 315tq @ 3400. This engine is a close cousin and shares many design elements with the 4.0 and 4.3 liter engines in our Lexus cars.
BELOW is the before and after RWHP dyno charts... remember, this test included a cat back exhaust system as is recommended for our cars. Notice the peak gain of 25rwhp and 38rwtq BUT notice around 4000rpm the gain is around 40rwhp and 50rwtq. Peak gains are good but more important are the gains across the entire RPM range. VERY important and a key goal for our design.
INTERESTED CAR OWNERS
If you appreciate the necessity of good exhaust manifolds to allow your engine to breathe and make the power it should and are interested in obtaining a set of the HFVS Shorty Headers for your car, please do the following.
Please post here if you have any specific questions not answered in the post above.
If you are ready to commit your interest in these headers, send a private message to JBrady with the following information.
Screenname:
Email Address:
First & Last Name:
Street
City:
State:
Zip:
Phone
Year & Model of your Lexus
These details will be kept confidential.
If you are interested in participating please send a private message to member JBrady (click here to send message )
-----------------------------------------------------------------------------------------------
IMPORTANT R&D Lexus Autos Needed
We will need one or more cars in the greater Phoenix area for design and fitment.
Expected time car will be in shop: 2 weeks
Expected date car will be needed: December or January
Car models needed:
GS400 or GS430
1998+ SC400
1992-1997 SC400
DESIGN: The HFVS Shorty Header
The stock exhaust manifolds are very restrictive. 1990-1997 are the worst with 1998+ cars being slightly better but still poor. It is obvious that better flowing manifolds are needed for true performance. ALL designs have compromises so the challenge is to pick the best design for the application. In my opinion the best design for the Lexus V8 automobiles is a High Flow high Velocity, Scavenging short runner exhaust manifold with merge collectors. aka: HFVS Shorty Header.
The design goal will be to produce a manifold that vastly outflows the factory manifolds and will fit all year and model Lexus V8 cars including:
1992-97 SC400
1998+ SC400
GS400
GS430
1990-97 LS400
1998-00 LS400
The HFVS Shorty headers will be designed as a bolt in for 1998+ V8 cars to keep the catalysts in their stock locations. This will require earlier cars to run aftermarket cats or at least move the stock cats. They will probably also fit the LS430s and SC430s but until they are designed and test fitted we will not know about space limitations for those vehicles.
Pre-1998 cars will require a change in catalysts location. Choices include relocated stock catalysts (under the car), aftermarket catalysts (under the car) or the possible use of 98+ catalysts. An aftermarket cat back exhaust system will be needed. They will also need an EGR flange welded to the header. The EGR flange will be an available option at a cost of approximately $50.
Expected power increase of 20+rwhp and 20+rwtq (probably more).
1998 and newer cars could use these headers with the stock exhaust system but full power gains will require a true high flow cat back exhaust system. On a car with a full complementing exhaust the HFVS Shorty headers are expected to outperform any available long tube design across the full RPM range.
REQUESTED COMMITMENT
Before these headers will be built we need to obtain commitments for 20 sets, NOT PAYMENT, just an agreement to buy them when available. No payment of any kind will be requested prior to the headers actually being designed and built and ready for ordering. ONLY If you know you will want to buy a set when available please send a confidential PM as directed below and you will be updated on progress and expected order dates. As of 11/17/2003 there are commitments for 14 sets of headers. With development and build time the expected availability is February.
NOTE: This is not yet an official group buy item on ClubLexus, but the builder needs to ensure that there is sufficient interest in this item before he moves forward with the design. ClubLexus feels these items will be of sufficient interest and value to our Lexus enthusiast community to gauge early interest of our members in this performance product that does not exist elsewhere. It is important to note that all responsibility for this transaction is with the buyer and the designer (not ClubLexus).
CONSTRUCTION
To keep pricing reasonable the Headers will be constructed of MILD steel (as are Tex's headers). Mild steel is actually less prone to cracking at the welds than stainless and with ceramic coating have a life expectancy of over 10 years. Pricing for the headers WITH Ceramic coating (recommended) should be under $600. Without the ceramic coating around $400 for the set.
DESIGN EXAMPLES
The picture BELOW is the C's headers built in Japan. They are NOT what you should expect rather they give the general idea of the layout of the planned header. In fact the headers below are for the C's 5.5 liter engine and are more show than go. Compared to the HFVS Shorty Headers we are designing they would likely make less power on our engines due to interference between runners and too large of a pipe diameter for our 4.0 and 4.3 liter engines. Again, the image below should help you get a mental picture of the design. The C's headers pictured below cost around $2500.
BELOW is an example of the work of the master craftsman. It is a picture of long tube headers for a Chevrolet but shows some nice work. This example does not use a merge collector but ours will.
PERFORMANCE EXPECTATIONS
As stated above we expect a conservative gain of 20+rwhp and 20+rwtq. Actual output will only be known after construction and testing and will vary depending on year of car installed and other enhancements used.
To get a good idea of what is available in our engines you may wish to look at the below dyno chart.
JBA built shorty headers for the 32 valve 4.7 liter V8 ToyotaTundra... remember, even though it is a 4.7 it is only rated at 245hp @ 4800rpm and 315tq @ 3400. This engine is a close cousin and shares many design elements with the 4.0 and 4.3 liter engines in our Lexus cars.
BELOW is the before and after RWHP dyno charts... remember, this test included a cat back exhaust system as is recommended for our cars. Notice the peak gain of 25rwhp and 38rwtq BUT notice around 4000rpm the gain is around 40rwhp and 50rwtq. Peak gains are good but more important are the gains across the entire RPM range. VERY important and a key goal for our design.
INTERESTED CAR OWNERS
If you appreciate the necessity of good exhaust manifolds to allow your engine to breathe and make the power it should and are interested in obtaining a set of the HFVS Shorty Headers for your car, please do the following.
Please post here if you have any specific questions not answered in the post above.
If you are ready to commit your interest in these headers, send a private message to JBrady with the following information.
Screenname:
Email Address:
First & Last Name:
Street
City:
State:
Zip:
Phone
Year & Model of your Lexus
These details will be kept confidential.
If you are interested in participating please send a private message to member JBrady (click here to send message )
-----------------------------------------------------------------------------------------------
IMPORTANT R&D Lexus Autos Needed
We will need one or more cars in the greater Phoenix area for design and fitment.
Expected time car will be in shop: 2 weeks
Expected date car will be needed: December or January
Car models needed:
GS400 or GS430
1998+ SC400
1992-1997 SC400
Last edited by DaveGS4; 11-24-03 at 09:11 AM.
11-23-03, 08:00 PM
#4
i really want in Dave, but my question is will these b availble in the sprimg time also or just as part of this group tryout buy? reason being i will ready 2 buy this mod by late spring i can't right now but want 2 know if it will b there when i'm ready? please let me know...
Adrian
Adrian
11-23-03, 08:11 PM
#5
Forum Administrator
Thread Starter
iTrader: (2)
A - I suspect once they're tested fitted and patterned, he'll be able to make more on demand. Don't know about any changes in price.
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11-23-03, 09:23 PM
#8
Forum Administrator
Thread Starter
iTrader: (2)
Originally posted by kyle3481
hey wasup Dave
sounds great, but 40 RWHP ? wow thats a LOT out of a header+ cat back isnt it?
hey wasup Dave
sounds great, but 40 RWHP ? wow thats a LOT out of a header+ cat back isnt it?
Originally posted by DaveGS4
Expected power increase of 20+rwhp and 20+rwtq (probably more).
Expected power increase of 20+rwhp and 20+rwtq (probably more).
. The 40RWHP you're talking about I assume is the actual dyno increase experienced in the Tundra, which is a similar engine to the GS. Certainly we can *hope* for that, of course. JBrady knows his stuff and from what I've read of other header systems 20 RWHP is a pretty reasonable target increase for a good breathing header design. We will not know for certain until they're actually built and dyno tested.J - I'll ask JBrady if he's come across anything about much louder the Tundra w/ header is.
Last edited by DaveGS4; 11-23-03 at 09:28 PM.
11-23-03, 11:11 PM
#11
Lexus Champion
Dave is correct in his responses.
Louder should not be much of an issue. These are shortys which like the stock manifolds do not have as much area as long tube headers to resonate so the external sound change should be very small. The rest of the exhaust system will determine how loud the final system is and that will depend on individual muffler choice.
John Brady
Louder should not be much of an issue. These are shortys which like the stock manifolds do not have as much area as long tube headers to resonate so the external sound change should be very small. The rest of the exhaust system will determine how loud the final system is and that will depend on individual muffler choice.
John Brady
11-24-03, 12:36 AM
#12
Lexus Test Driver
jbrady and dave, if it wont be too loud, definately count me in please! as for the power, i am just hoping 20 rwhp then i will b happy =)
thanks a lot guys
keep me posted
thanks a lot guys
keep me posted
11-24-03, 07:25 AM
#14
Lexus Test Driver
Originally posted by jbrady
Dave is correct in his responses.
Louder should not be much of an issue. These are shortys which like the stock manifolds do not have as much area as long tube headers to resonate so the external sound change should be very small. The rest of the exhaust system will determine how loud the final system is and that will depend on individual muffler choice.
John Brady
Dave is correct in his responses.
Louder should not be much of an issue. These are shortys which like the stock manifolds do not have as much area as long tube headers to resonate so the external sound change should be very small. The rest of the exhaust system will determine how loud the final system is and that will depend on individual muffler choice.
John Brady
Seriously, I want freer flowing but will not sacrifice the quietness for it.
in regardless