2.5 inch exhaust vs. Open header **DYNO**

[Teamdiesel]

Originally Posted by 2fastGSR You are being completely biased to your own opinion and very ignorant to the situation. 32 hp by dropping your exhaust? Did you have a 270hp 86x95 and run a stock dx exhaust or something? Come on man, while I am not discrediting your extremely rare scenario, it is by far the norm. The fact that you keep going ON AND ON about it shows your complete lack of knowledge in the area. My car = Lost around 3 hp with my 3 inch exhaust. My friends 85.5x95 lost 3 hp with a 3.5 exhaust. Can more be gained on MOST cars by tuning open header? Absolutely. But to the sound of 30+ hp, Highly doubtful. So do you think it was my tuning ability that allowed me to free up 32whp or was it a once in a lifetime situation . The exhaust I was using was a free flowing 23/4" system by Skunk. It flowed good, but the car liked open header better. It's all bout the right length and diameter of backpressure pipe used (that is all) .

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[2fastGSR]

Originally Posted by 2fastGSR

Can more be gained on MOST cars by tuning open header? Absolutely. But to the sound of 30+ hp, Highly doubtful.

Guess you missed the part where i said MOST . . .

Maybe your car wasnt tuned all that great to begin with. So when you dropped the exhaust and tuned it you picked up quite a few. Maybe the dyno read wrong on the baseline. Or maybe your car really did pick up 32hp. More power to you.

I was not negating the fact that you have proof your car picked up the hp you claim. I dont know you or your build so I wont assume you are lying.

But I do have a problem with you being so adamant about every car you have ever seen picking up enough hp to drop almost a full second off their track time by just dropping the exhaust. And you are setting unrealistic expectations for some of the people that read honda-tech.

Sorry to hijack this informative thread JDogg. . .

[Teamdiesel]

Originally Posted by 2fastGSR

Guess you missed the part where i said MOST . . .

Maybe your car wasnt tuned all that great to begin with. So when you dropped the exhaust and tuned it you picked up quite a few. Maybe the dyno read wrong on the baseline. Or maybe your car really did pick up 32hp. More power to you.

I was not negating the fact that you have proof your car picked up the hp you claim. I dont know you or your build so I wont assume you are lying.

But I do have a problem with you being so adamant about every car you have ever seen picking up enough hp to drop almost a full second off their track time by just dropping the exhaust. And you are setting unrealistic expectations for some of the people that read honda-tech.

Sorry to hijack this informative thread JDogg. . .

I said MY car cut down that much time , and many others got atleast .3 from the change. I am sorry if you think that I am putting people astray, but it has been a proven fact on atleast 25 different hondas where I am from. If that is not enough proof for me then I don't know what will be enough. As I said, it will work if the PROPER lenght and diameter backpressure pipe is attached to the header. THAT IS A FACT. Sorry if my experiences offended you .

[2fastGSR]

You said there is proof.

Show us this proof. I would like to see the dyno graph of these 25 cars where you can UNDOUBTEDLY prove what you speak. . .

Until then you are doing nothing but cluttering a thread with your biased, unproven rants

[VtecKiDD]

again, a PROPERLY MATCHED EXHAUST can be equal to running open header.

Ive dynoed prob close to 100 cars with different setup in the last 7 years. The difference between a MANDREL BENT 2.5in exhaust and OPEN HEADER on a 1.8L an under is MINIMAL at best. I think the most i have seen was 5whp, and thats assuming you tune both setup to the max.

On 2.0L engine, my car 2.0L LSVTEC made 237whp open header with a 3 foot extension pipe, and it made 236whp with a mandrel bent 3in exhaust that i had custom made. The gains in the midrange were minimal at best in opn header, nothing over a 1 whp difference.


32whp, come on, thats C R A P. Ive used the SKUNK2 Mega Power R exhausts an they are really nice. THere is no way you gained that kinda power by dropping that exhust an going open header. Maybe if you had some EBAY 2.25in crush bent exhaust you might see 15whp MAYBE 20, but 32whp? thats rediculous.

ANd how are you comparing a 12:1 motor versus a 11:1 motor? was the dyno dont on the same day? same specs? same everything?

Lets be realistic, MOST PEOPLE will see a 1-3 whp gain by going open header over their off the shelf NICE(SKUNK2, APEX) exhaust system.

Most people will THINK its faster open header because its , well, obnxiously loud.

[DonF]

So what is the correct backpressure? 1 1/2 PSI, 2 PSI? I cannot get 32 WHP when going from stock "R" headers to SMSP's. Where am i losing the tune? Is it because I used a new headgasket, have the syncro's in correct , actually figured out how to set the belt tennsioner? You really do need to contact Skunk if there EX system loses 32WHP. Hell, my daughter's stock GSR will make 200 WHP.
Your tune must be so bad that the open header tried to help it. Or your "pal" that told you you could re-use your HDgasket 5 times, and fixed your trannie, put a potato in your EX system.

[4dooritr]

Originally Posted by DonF

So what is the correct backpressure? 1 1/2 PSI, 2 PSI? I cannot get 32 WHP when going from stock "R" headers to SMSP's. Where am i losing the tune? Is it because I used a new headgasket, have the syncro's in correct , actually figured out how to set the belt tennsioner? You really do need to contact Skunk if there EX system loses 32WHP. Hell, my daughter's stock GSR will make 200 WHP.
Your tune must be so bad that the open header tried to help it. Or your "pal" that told you you could re-use your HDgasket 5 times, and fixed your trannie, put a potato in your EX system.

I believe it, Look how pig rich his car was running with the exhaust 9-11AFR around his 32HP "gain"... when the engine burnt off all that fuel it was around 3-4hp.. what you would normally get...

tuned afr vs tuned afr and claim 32hp, yeah... now you'd be smokin crack..

[Teamdiesel]

Originally Posted by VtecKiDD

again, a PROPERLY MATCHED EXHAUST can be equal to running open header.

Ive dynoed prob close to 100 cars with different setup in the last 7 years. The difference between a MANDREL BENT 2.5in exhaust and OPEN HEADER on a 1.8L an under is MINIMAL at best. I think the most i have seen was 5whp, and thats assuming you tune both setup to the max.

On 2.0L engine, my car 2.0L LSVTEC made 237whp open header with a 3 foot extension pipe, and it made 236whp with a mandrel bent 3in exhaust that i had custom made. The gains in the midrange were minimal at best in opn header, nothing over a 1 whp difference.


32whp, come on, thats C R A P. Ive used the SKUNK2 Mega Power R exhausts an they are really nice. THere is no way you gained that kinda power by dropping that exhust an going open header. Maybe if you had some EBAY 2.25in crush bent exhaust you might see 15whp MAYBE 20, but 32whp? thats rediculous.


ANd how are you comparing a 12:1 motor versus a 11:1 motor? was the dyno dont on the same day? same specs? same everything?

Lets be realistic, MOST PEOPLE will see a 1-3 whp gain by going open header over their off the shelf NICE(SKUNK2, APEX) exhaust system.

Most people will THINK its faster open header because its , well, obnxiously loud.

Ok, here is an example. I ran my car at the track on street tires and full Skunk2 Mega R exhaust, and did two back to back 13.9 runs. I parked the car in the lot and jacked it up, dropped the exhaust and attached the "piece of pipe", rolled on the track and did three back to back to back 13.5,'s with a .2 worse 60ft.

[Teamdiesel]

Originally Posted by 4dooritr

I believe it, Look how pig rich his car was running with the exhaust 9-11AFR around his 32HP "gain"... when the engine burnt off all that fuel it was around 3-4hp.. what you would normally get...

tuned afr vs tuned afr and claim 32hp, yeah... now you'd be smokin crack..

That is where the car liked it, so that is where i put it! I straightened up the a/f and then shifted the whole graph until max gains were realized. The engine loves fuel , so I give it fuel. Remember, not all motors like 13.5 a/f ratio.

[DonF]

Originally Posted by Teamdiesel

Ok, here is an example. I ran my car at the track on street tires and full Skunk2 Mega R exhaust, and did two back to back 13.9 runs. I parked the car in the lot and jacked it up, dropped the exhaust and attached the "piece of pipe", rolled on the track and did three back to back to back 13.5,'s with a .2 worse 60ft.

Really bad tune with the Skunk Exhaust. The open Exhaust tried to help you out, as I doubt you tuned it between runs.

[Teamdiesel]

Originally Posted by DonF

Really bad tune with the Skunk Exhaust. The open Exhaust tried to help you out, as I doubt you tuned it between runs.

If you call 210/150 with conservative ignition a bad tune, then ok . I went straight from the dyno and unto the track when I did that time.

[blacK_Dc4]

Originally Posted by Teamdiesel

I think that maybe there is something wrong with your car then. I can gaurentee that if you tune with exhaust and then tune open header (with the RIGHT length of backpressure pipe), and go to the track your car will run a faster time open header. No matter WHAT the dyno says, it will run a faster track time open header, PERIOD. The graph i posted above is a perfect example. The red line is full Skunk2 Mega R 70mm exhaust, fully fuel, ignition, and cam gear tuned with 12:1 compression. The blue line is OPEN header, with 11:1 compression and ONLY a quick fuel tune. That is a 32WHP and 32WTQ gain from LESS compression and OPEN header!

I can agree with you that more than likely , most cars will benefit from open header , some right away and some after they tune it FOR open header. It depends on the exhaust system used. But saying that something is wrong with my car jus because I lost power when i dropped the exhaust is very ignorant of you. You know nothing about my car yet you judge it based on that. I even said in my previous post that my tuner said that i can pick up a few hp after he tunes it for OPEN HEADER. Its jus that i lost power right after i dropped the exhaust without tuning it . So are you saying that my 85x87.2 on 91 Octane making 247 whp and 156 tq through a muffler on a dynojet will gain 32 whp and 32 tq after i tune it for open header ?? IS something wrong with my car because its ONLY making 247 whp through a muffler ?? All jokes aside , If i even gain 10 whp and 10 tq it be a miracle for me already and i already doubt that. Seeing a 257 whp and 166 tq on 91 oct for a 85x87.2 is rare. I think the exhaust sytem that i have is already correctly sized so even with tuning , dropping the exhaust might not help me as it has helped U ( + 32 hp and + 32 tq ). Maybe you should be a little more open to education and stop basing everything on your one time experience. I m not talking down on you or saying that the gains didnt happen to you , Its jus that every car , motor , setup , most importantly the exhaust system is different so it wont always be the same .. but it seems you're too stubborn to face that fact jus because you gained 32 yourself on your exhaust and engine setup..

[Teamdiesel]

Originally Posted by blacK_Dc4

I can agree with you that more than likely , most cars will benefit from open header , some right away and some after they tune it FOR open header. It depends on the exhaust system used. But saying that something is wrong with my car jus because I lost power when i dropped the exhaust is very ignorant of you. You know nothing about my car yet you judge it based on that. I even said in my previous post that my tuner said that i can pick up a few hp after he tunes it for OPEN HEADER. Its jus that i lost power right after i dropped the exhaust without tuning it . So are you saying that my 85x87.2 on 91 Octane making 247 whp and 156 tq through a muffler on a dynojet will gain 32 whp and 32 tq after i tune it for open header ?? IS something wrong with my car because its ONLY making 247 whp through a muffler ?? All jokes aside , If i even gain 10 whp and 10 tq it be a miracle for me already and i already doubt that. Seeing a 257 whp and 166 tq on 91 oct for a 85x87.2 is rare. I think the exhaust sytem that i have is already correctly sized so even with tuning , dropping the exhaust might not help me as it has helped U ( + 32 hp and + 32 tq ). Maybe you should be a little more open to education and stop basing everything on your one time experience. I m not talking down on you or saying that the gains didnt happen to you , Its jus that every car , motor , setup , most importantly the exhaust system is different so it wont always be the same .. but it seems you're too stubborn to face that fact jus because you gained 32 yourself on your exhaust and engine setup..

I am sorry for saying that about your car. It was rude of me and i apologise. I just find it hard to believe that expelling more air, faster, when tuned, will not give you adaquet gains.

[oldskool teggy]

Originally Posted by VtecKiDD

again, a PROPERLY MATCHED EXHAUST can be equal to running open header.

Ive dynoed prob close to 100 cars with different setup in the last 7 years. The difference between a MANDREL BENT 2.5in exhaust and OPEN HEADER on a 1.8L an under is MINIMAL at best. I think the most i have seen was 5whp, and thats assuming you tune both setup to the max..

...Lets be realistic, MOST PEOPLE will see a 1-3 whp gain by going open header over their off the shelf NICE(SKUNK2, APEX) exhaust system.

I agree with what you are saying. open header or 3" exhaust systems will ultimately help tose that need the most flow. However I do think that even a 1.8L can hbenefit from a 3" exhaust.
these are my own personal results, all tuned by Todd at CAT. Maybe i just have a different motor than others i dunno. Yes, their Dynapack reads more generously than others, but this is still a 1.8L with OEM pr3 pistons and I still see quite a drastic difference between open header and my 2.5" exhaust with 2.5" test pipe. the lowest line is the 2.25" with carsound. as you can see even with the 2.25, the car still made good peak, but got owned in the midrange.

its is quite a generous increase after 7k rpm as you can see open header vs. 2.5". of course this is all depending on the setup.. with ITR cams.. peak power was only 200whp, but the dip at the 6-7k was gone. it's only after adding s2s2 cams that we get the results we see here. text book cam swap characteristics of top end vs mid range cam

this is original setup vs. s2s2 cams and ported head on a 1.8L. exhaust at the time was the 2.25" with carsound cat.. after replacing the exhaust and cat, and re-tuning. we got the results in the first dyno chart

this isn't a bible or anything, every setup will be different.



Modified by oldskool teggy at 3:19 AM 5/25/2008

[BIGTUNA]

Why does every thread with Team Diesel make my head hurt....

[Teamdiesel]

Originally Posted by BIGTUNA

Why does every thread with Team Diesel make my head hurt....

Maybe because I am right there with a hammer trying to pound some sense into it

[BIGTUNA]

Hahahaha

[VtecKiDD]

Originally Posted by Teamdiesel

Maybe because I am right there with a hammer trying to pound some sense into it

you mean giving out horrible WRONG info? ok i agree with that.

[Teamdiesel]

Originally Posted by VtecKiDD

you mean giving out horrible WRONG info? ok i agree with that.

That is your opinion and you are intitled to it, but I speak from personal experience along with what i have SEEN. If the info is wrong to you, then so be it, but I will continue to get solid ET's running open header .

[ekBlackHatch]

maybe you should see a optometrist and not take everything you have "seen at face value, however maybe all the proven tuners such as don are wrong along with the rest of us and we should listen to what you have "SEEN". if thats the case.... /ends my life.

[VtecKiDD]

Again you miss the point.

No one is saying that you couldnt run faster open header, what we are saying is your claim of 30+whp is, well, C R A P

Ive been doing this for seven years, ive dynoed prob well over 100 cars, built well over 100 cars.

I know what works an what doesnt.

[4dooritr]

Originally Posted by VtecKiDD

Again you miss the point.

No one is saying that you couldnt run faster open header, what we are saying is your claim of 30+whp is, well, C R A P

Ive been doing this for seven years, ive dynoed prob well over 100 cars, built well over 100 cars.

I know what works an what doesnt.

the car was in the 9's AFR vs leaner open header at the same rpm range

its possible to lose 30whp with fuel dumping in like that

its not a 30whp gain when you were previously losing 25whp with so much fuel

[ZeroTraction]

This thread delivers. Teamdiesel just give up dude. You're wrong it happens to the best of us.

[mar778c]

Originally Posted by Teamdiesel

Maybe because I am right there with a hammer trying to pound some sense into it

Easy, one data point does not make a line. Two, data points are not a sample. In other words, gain a little more experience.

[BIGTUNA]

Originally Posted by Teamdiesel

I will continue to get solid ET's running open header .

Hahahaha solid ET's with 2.3 60'