3" to 3.5" or 4" or 5" dp how much gain?

[Race Jace]

Ok,ok we got it already. Big pipe bad, small pipe good, engineers dumb , sweepies smart.

How do you teach a guy who knows more than the engineers, more than engineers that own companies that actually do this stuff for a living, more than the guy that wrote books on turbos and more than the actual fluid dynamic books.

 

[Joe Tiano]

has ANYONE confirmed a gain in E.T.,mph,torque or horsepower directly related the 5" elbow?.this is a kit correct?.seems to me the flow potential of a totally custom down pipe is in the fabricators skill to acheive what the engineers intended!
so a "your results may vary " will be included?

 

[norbs]

I think Rjc's results on his own car show that there is a benefit from his dp. I think he quoted a solid .2 and 2 mph over a 3.5" dp.

 

[scot w.]

DP size.

Increasing the down pipe size and exhaust would get rid of more exhaust quicker in return would lower your EGT temps if I was guessing.

*just my 2cents worth. scot w.

 

[Joe Tiano]

Ummm.I would think with ALL the variables involved..the results of jaces testing of the 5" elbow..is total B.S (IMO)..is jace the only one to report a measurable gain?..why not give this 5" dp to roy&laz or dave bamford or red armstrong to get more feedback?
please feel free to give me a physics lesson on how & why..nevermind.. its all in this thread correct? you can't fool mother nature! good luck joe

 

[TURBOTIMMER]

Its going to cost me at least $300 in bends and piping flange's to weld up a 3.5" downpipe. Should i just foget about it and keep the 3"?

Norbs, I'm planning on making a 3 1/2" exhaust from the turbo back. I found someone here locally that upgraded their exhaust on a 2004 Chevy Duramax. He's practically giving me the original stuff. It happens to be 3 1/2" mandrell bent stainless steel. The tailpipe from a 6.0 liter works, too, but only from the muffler back. They have some really nice bends, and are a heck of alot cheaper then buying individual bends from Summit or Jegs.

 

[Jerryl]

First off, I am NO expert and can’t even spell “ingineer” and respect both sides ....... but was doing some honest thinking ………

Is it possible that the larger down pipe will result in quicker spool resulting in better ¼ mile performance? In other words, you get quick spool but afterwards, it will "act more or less like" a 3.5" DP? If the exhaust system (after the DP) is necked down, the flow constraint of the motor may be the reducer (Depending on the exhaust).

So …….. Once the pressure in the 5” down pipe section equals the pressure in the exhaust after the reducer (there must be some level of pressure drop in the exhaust right?). Since the immediate available volume after the turbo is greater, there is less initial backpressure and increased flow, resulting in faster spool? (I DO have my double flaming suit on and this is an honest question). Is there MUCH more gain on larger turbo's since the volume is greater and provides less back pressure for a split second? Interesting.

 

[SloGN]

5 inch DP

hey guys


I'm no engineer or what have you by no means. I understand that velocity changes every time it encounters a change in pipe size. I don't really think velocity is the big issue here. Since the DP is not actually scavenging the engine as to a set of headers on a NA race motor. But really how much of a gain is there by going to a bigger DP. I agree with jerryl on the theory of it helping spool up of the turbo due to the pressure diffrence @ a low rpm. But when the engine is @ 6k 30 psi that DP can only flow what the rest of the exhaust system can handle. if that DP is connected to a 2" exhaust system it's limited to what a 2" exhaust can flow.


kinda like having a engine thats capable of making 1500 hp and feeding it with a 1/4 " fuel line.

FLAME ME I LIKE TO LEARN SOMETHING NEW EVERYDAY

 

[VadersV6]

Yes, it would provide quicker spooling just like i said, but who's to say it would spool quicker than an already over efficient 3.5" DP?

You have a Fuel pump which always flows X amount of fuel at Y amount of pressure. It has a 1/2" line coming out of it. It goes to a regulator (just a flow restrictor) which brings the pressure down after the regulator and increases pressure before the regulator. There is a 3/4" line after the regulator going to say, a tank....you cant flow more gas by going bigger and bigger and bigger on the line after the regulator. The 1/2" line is the header collector mated to the turbo. The FP regulator is the turbine. The 3/4" line is the downpipe. Now say you take that 3/4" line and neck it back down to 1/2" before it dumps into the tank. Velocity has come back up, but its flowing the same amount of fuel. This is the simplest way i can explain myself, if the tank analogy in the other thread didnt work. It looks like jason's necking back down of the big DP will get the velocity back up. But the velocity would have been the same had it stayed at that smaller diameter from beginning to end. Flow starts off fast going through the turbine, slows down into the big expansion, then speeds back up again when it reaches the neck down. Why slow velocity yet flow the same amount of gas?
There is a big difference between memorizing and reciting theory, and actually understanding it. People would argue about boost and how boost means power, bottom line. Some say boost is everything, and some say boost is just a measure of restriction and is meaningless. Engineers and all kinds of experts begin to argue. Ken Duttweiler walks in and says, (actual quote) "You have 60psi in a bike tire, and 60psi in a 18 wheeler truck tire. Are they the same thing?" It didnt take a 200 page thesis to make the point. Is kenny a degreed mechanical engineer? I would bet that a JPL engineer (where my mom has worked for 25 years) who had never met kenny duttweiler, had no idea what he did for a living, and started having a chat with him about race engines, would automatically think kenny is a moron compared to him because kenny isnt a rocket scientist and an engineer, and there is no way kenny could understand mechanical/thermo/fluid dynamics better than himself. He cant grasp kenny's simple yet effective way of thinking because JPL man suffers from "paralysis of analysis". Ask Mr. JPL to build a race engine based on all his years of mechanical theory and post graduate studies of thermodynamics and fluid studies, etc. More often than not, hands on, real world experience is a far better educator than all the professors and universities in the world can offer.

 

[Jerryl]

Yes, it would provide quicker spooling just like i said, but who's to say it would spool quicker than an already over efficient 3.5" DP?
...........

Guess that is the $1M question. Guess that all depends on the set-up of the OTHER components, i.e. a REALLY BIG turbo?
Like on my stock turbo'd 16 second Hot Air, a 5" DP is probably a waste of money ........ Now, if I ran a Mac Truck Turbo (See how much I know? ) it would probably help my spool into my 2" exhaust.

........... More often than not, hands on, real world experience is a far better educator than all the professors and universities in the world can offer.

Very true. Having said that ..... Paralysis of analysis i.e. "Haystack Syndrome" is a big issue. I think that RJ took the action and proofed on his car that his 5" DP actually works.

Like everything (including a simple camshaft selection) there will be good and bad arguments, and good and bad experiences. No other board has this level of knowledge and effort put into new ideas. It is truly a luxury.

 

[83ttypecooled]

Too Big?

Hi,
With no info to back it up, my gut instinct tells me that too much is just that, too much. I would say that over about 3.5 ",turbo spoolup has to suffer,regardless of turbo size. Pure race vehicles may be a different issue, but for street use, bog city has to be the result.Correct me if I'm wrong, guys.

 

[chevyII]

I just love all the guys running stock turbo and PT44 who have so much knowlege of racing engines. First off if your not running or have never run and tuned atleast a PT70Q or larger GO AWAY. This 5" and a 3.5" is totally out of your league. Another great product built JASON CRAMER thanks for your hard work. Maybe the guys how doubt should look at the competion chain saws and look at there exhaust pipes. Amazing ther identical just on a smaller scale.

 

[SloGN]

I just love all the guys running stock turbo and PT44 who have so much knowlege of racing engines. First off if your not running or have never run and tuned atleast a PT70Q or larger GO AWAY. This 5" and a 3.5" is totally out of your league. Another great product built JASON CRAMER thanks for your hard work. Maybe the guys how doubt should look at the competion chain saws and look at there exhaust pipes. Amazing ther identical just on a smaller scale.

Can i ask how the hell that really plays a factor. maybe some of us can't afford or really don't care run a race car. The tuning is still gonna be along the same lines. A/F knock etc. Now that comment my friend is total BS. I have tuned some very fast cars myself even tho i don't own a fast car. But maybe a car running in the 10.70's @ 23-24 psi of boost is slow.

As far as the exhaust goes on a 2 stroke chainsaw it's used to scavenge the engine by the velocity change at the end of the pipe. Can i ask how that compares to the Turbo buick exhaust. since it's the same effect hah

FLAME ON

 

[chevyII]

If a pipe is built to scavenge its smaller at the start and then gets bigger downstream. Thats why there called step headers there the exact opposite of RJC's pipe and the saw pipes. A pipe that is larger then goes smaller is called an expansion pipe and have nothing to do with scavenging exhaust gases. Maybe somone can test the 5" against the stock elbow

 

[scot w.]

Jason cramer?, would going with a bigger DP and exhaust LOWER the EGT temps? scot w.

 

[VadersV6]

Yeah, temperature drop usually goes hand in hand with a pressure drop. It may make tuning a little tricky if an EGT sensor is in that big expansion. Maybe not, but that would defy the world we live in. A sudden creation of condensation is another side affect. Thats what goes on with those condensation clouds you see bursting behind a fighter jet....not that this has much to do with anything here though. I was actually making the comment about the temp drop with expansions, and someone came at me with something along the lines of, 'physics dont apply to turbo buicks'. I also mentioned the greatly increased amount of surface area which may affect temps....but that would just be an issue with the temp of the surface of the DP, not the temps inside. The temps inside would cool down because of the expansion.
A pipe that necks down is not called an expansion pipe, btw. For the guy who said this
"I just love all the guys running stock turbo and PT44 who have so much knowlege of racing engines."
My combo is not the result of my knowledge and experience. Its mostly what the car had when i bought it, and Ive spent money fixing things that were wrong with it, rather than flushing 10 G's into going all out. I would rather spend my money on my house.
Isnt it called a PTE-44, a derivative of the TE-44?
I know alot about racing engines because I machined and built thousands of them in my engine days. (quit that work about 8 years ago cause it didnt pay)
Ever watch a nascar/winston west race on TV (CBS or another huge network), and the guy kicking everyones ass has an engine under his hood that you did all the block work on( a ton on these engines), and the head work? Ever go to willow springs as part of a top sportsman crew team, and the 6 leading cars all have engines you did alot of the work on? Ever go to an NHRA race and see several cars running your engines? Built engines for SCORE, MSRA, SCTA, SCCA, IMSA, NHRA, NASCAR, IHBA, IRRA, VARA, SCRA, APBA to name a few. Remember the beginning of the turbo import scene in the early 90's with these guys pulling 450whp out of a 1.8 liter motor that you did all the block work on, and the porting,/machining of the heads? Ever have car craft, hot rod and engine masters do monthly articles on engines built where you work? They still do...JMS racing engines.
I can keep going but whats the point. Someone who probably hasnt even rebuilt a VW engine is questioning my experience.
I dont know **** about transmissions, so you wont se me arguing with anyone about that. I do know a bit about engine building, and my experience is not limited to a "PT44 turbo buick". By the time I was 18, I had owned a 63 Nova, a 64 Nova, a 72 Vega with a SBC, a 70 cougar with a 4V 351 cleveland built to the ceiling, a 67 cougar....It didnt stop there. Did my first valve job when I was 12 and built my first see through, rotating and firing (LED's) model engine when I was 5. I was one of the first ones out there playing with the C headed cobra's, and developed intake manifolds that spoke for themselves. People across the country still consider me "the king" of these intakes. Go to corral.net and do a user name search on 32VHEMIJR, and the search word, "intake". Search in the SVT/DOHC forum. I'm no expert on turbos, but I have developed a feeling over time for what goes and what doesnt on an engine. Having a DTS dyno screaming all day 5 days a week for years in your face gives you a little insight. This is a stupid argument anyway....The people who think this DP is awesome need to go buy one of these 5" DP's, throw it on their car and test it.
I said since the beginning that RJC makes awesome products and I thought they were top notch. Ragging on someone who questions something is not the only way to prove a product.

 

[scot w.]

Wow!!

Yeah, temperature drop usually goes hand in hand with a pressure drop. It may make tuning a little tricky if an EGT sensor is in that big expansion. Maybe not, but that would defy the world we live in. A sudden creation of condensation is another side affect. Thats what goes on with those condensation clouds you see bursting behind a fighter jet....not that this has much to do with anything here though. I was actually making the comment about the temp drop with expansions, and someone came at me with something along the lines of, 'physics dont apply to turbo buicks'. I also mentioned the greatly increased amount of surface area which may affect temps....but that would just be an issue with the temp of the surface of the DP, not the temps inside. The temps inside would cool down because of the expansion.
A pipe that necks down is not called an expansion pipe, btw. For the guy who said this
"I just love all the guys running stock turbo and PT44 who have so much knowlege of racing engines."
My combo is not the result of my knowledge and experience. Its mostly what the car had when i bought it, and Ive spent money fixing things that were wrong with it, rather than flushing 10 G's into going all out. I would rather spend my money on my house.
Isnt it called a PTE-44, a derivative of the TE-44?
I know alot about racing engines because I machined and built thousands of them in my engine days. (quit that work about 8 years ago cause it didnt pay)
Ever watch a nascar/winston west race on TV (CBS or another huge network), and the guy kicking everyones ass has an engine under his hood that you did all the block work on( a ton on these engines), and the head work? Ever go to willow springs as part of a top sportsman crew team, and the 6 leading cars all have engines you did alot of the work on? Ever go to an NHRA race and see several cars running your engines? Built engines for SCORE, MSRA, SCTA, SCCA, IMSA, NHRA, NASCAR, IHBA, IRRA, VARA, SCRA, APBA to name a few. Remember the beginning of the turbo import scene in the early 90's with these guys pulling 450whp out of a 1.8 liter motor that you did all the block work on, and the porting,/machining of the heads? Ever have car craft, hot rod and engine masters do monthly articles on engines built where you work? They still do...JMS racing engines.
I can keep going but whats the point. Someone who probably hasnt even rebuilt a VW engine is questioning my experience.
I dont know **** about transmissions, so you wont se me arguing with anyone about that. I do know a bit about engine building, and my experience is not limited to a "PT44 turbo buick". By the time I was 18, I had owned a 63 Nova, a 64 Nova, a 72 Vega with a SBC, a 70 cougar with a 4V 351 cleveland built to the ceiling, a 67 cougar....It didnt stop there. Did my first valve job when I was 12 and built my first see through, rotating and firing (LED's) model engine when I was 5. I was one of the first ones out there playing with the C headed cobra's, and developed intake manifolds that spoke for themselves. People across the country still consider me "the king" of these intakes. Go to corral.net and do a user name search on 32VHEMIJR, and the search word, "intake". Search in the SVT/DOHC forum. I'm no expert on turbos, but I have developed a feeling over time for what goes and what doesnt on an engine. Having a DTS dyno screaming all day 5 days a week for years in your face gives you a little insight. This is a stupid argument anyway....The people who think this DP is awesome need to go buy one of these 5" DP's, throw it on their car and test it.
I said since the beginning that RJC makes awesome products and I thought they were top notch. Ragging on someone who questions something is not the only way to prove a product.

Holly sh*t!! This could have been a yes or no answer. Sorry to have asked a question. Damn!! And the EGT probe is across from the o2 sensor. in that vacinity anyway.

 

[VadersV6]

I wasnt even talking about you dude. Just the first paragraph was directed to you. ChevyII was talking smack without knowing what he was talking about.

 

[Garycar]

I've been doing the turbo Buick thing since 1986, going on 20 years. Its been my experience that most Buick venders do not provide hard date to support their products performance because it is extremely expensive and almost imposible to test a product on a variety of vehicles. Jason is offering one of his new products, a redesigned down pipe. If you like what you see you may purchase it. The decision is yours. I happen to like the product and intend to purchase one. I believe the level of performance increase will relate to the current performance level of the vehicle. However, lets not pick on Jason. I don't know of any other Buick vender who is able to provide hard data on their products. Remember, turbo Buicks are a minority. If you want hard data you should expect a significant increase in the cost of the product because the volume of sales to support extensive testing is just not there.

 

[Race Jace]

ChevyII was talking smack without knowing what he was talking about.

???? you of all people should not discourage people from posting lengthy BS replies to this post.

All of your questions have been answered by either me in laymens terms or in detail by Flyn Ryan. Please reread these replies carfully to understand the benifits of the 5" DP.

As for testing, I supply more testing of my products than any other Buick parts manufacture.

the problem is as Joe Tiano stated, since i am the manufacture some people don't believe it as they will think it is biased. I can understant that. People that know me personally know what i post or put on the websight is unbiased and correct and the results can be duplicated.

Is the 5" overkill for the TE44 turbo? yes The 5" DP is designed to be run with the precision .85 3 bolt housing. These are only really available on P trim wheels or bigger. I think that the smallest turbo with a p trim is a TE-63. I'm not positive about this but it is about that size.

Besides the before mentioned performance and fluid mechanics reasons (most pressure drop across the turbine and the conversion of helical gases to turbulent flow) there were some design constrainst that dictated that the pipe be 5". One of them was, 5" is the smallest dia you can fit all 4 bolts of the DP inside the pipe. 5" is the biggest you can fit between the fender and the turbo. Also 5" is the biggest you can get in a centerline raduis that is equal to the pipe dia. (This means 5" dia and a 5" center of the pipe radius bend)

This product is relatively new. I'm sure that after a while of them out there in the field, they will be the standard ultimate performace piece. Allot of my products had a little contraversy before everyone tried them and knew for themselves the claims were all true.