My friend who has a exhaust valve dump for his STI wants to sell his 2.5 inch cutout to me , so he can get a bigger one.
If i put it in my cattman y-pipe, and before the main cat. Would i gain or lose power when i opened it ? Will it be to much flow ?
This would be like taking off everything after my y-pipe.
Please give me some insight ,thanks Chris

 

Thanks for the reply , it has a button i can open and close from inside the car.
You only think getting rid of main cat and catback is only worth a couple hp ?! I hope thats not true , whats everybody else think?

 

EVD=no backpressure=BAD.

 

Someone hasnt read the 4th Gen FAQs....

 

Will i get power from this?

 

?

Explain.

 

I thought some backpressure was necessary to still have low RPM torque, but NO backpressure was bad. Is this only true in the VQ engines or for other engines too?

The purpose of a larger diameter exhaust is for smoother flow. But when fully eliminating any and all backpressure, you don't lose any low RPM torque?

 

I suggest going to the track and making a few runs then unbolt your muffler and make some runs. If you see a measurable difference in MPH and ET (assuming same 60 foots and shift points) then you can determine if a exhaust dump it worth or not. You could do the same thing on the dyno if you have the money to rent the dyno for about an hour (~$100). Years ago I ran around without a muffler for about 15 minutes (just for fun). It was insanely loud and I couldn't tell any difference in performance, just ringing ears.


Dave

 

It's funny how so many people have their guesses, but they dont have a cutout on their Maxima. Anyway, YES it helps. YES it's loud. YES you will lose low end power. YES you will gain back the loss in low end and be faster in the 1/4 mile.

I recently got a 2.5" cutout with the McCord Power Plate. I went to the track to do some testing. As most people know, since I am SO into bracket racing, I know my car's consistancy. I was on average .15 faster with the cutout open than when closed and stock catback.

But when comparing an open cutout to a straight thru muffler and custom Bpipe, the cutout won't be much faster. It definitely won't be slower than a nice aftermarket catback.

My setup right now is Ypipe, testpipe with cutout welded in, stock Bpipe and stock muffler.

I believe this to be the best exhaust setup you can possibly get in a Maxima. Since you are quiet for the street and you don't get slower on the track. I love it.

Krismax, what brand cutout and what brand electric valve is it?

 

Aaron92SE:

Could you point me in the direction of some Dump Valves?

I know a while back I stumbled upon one where it was a switch/valve you had to turn insdie of the car in order for it switch over

But I cannot seem to find any around anymore, Specificaly ones that can be switched while in the car, I would love an electronic one but would settle just to find some.

Thanks.

JP

 

No problem. Check out these sites:

http://www.mccordcg.com/mpp/mpp.htm

http://www.quicktimeperformance.com/

Both of those companies sell electric valves. DO NOT get any other type of cutout valve. I mean, don't get the one that you've seen on ebay that opens up with the pull of a cable. They won't seal and you will have a MEAN exhaust leak.

You'll need to get a cutout first.... summitracing.com, jegs.com sell Flowtech cutouts. Personally, I just got the Summit Racing brand 2.5" cutout. I paid $35 shipped for it. You can find a Flowtech cutout cheaper on ebay sometimes.

If you don't want to spend $100+ on an electric valve, then just get the regular cutout that unbolts at the track. That will work just fine and will seal great.

 

Thank you, I have now been edgemucated.


So in the end, the only gain that you get is in sound, and mabye more high end, but less low end. Go figure.....

 

Thanks i told him i didnt want it because of what everyone was saying.
But your saying with the ED you gained .15 , over a exhaust with no cats ,i think thats great ill try to get it now .
I dont know what company but its made for WRX's.Ill find out.
My friend runs a 12.7 stock with his STI!

 

Aaron...did you ever try starting out with it closed and then opening at a certain gear or point on the track??

 

if you are going to be at the track make sure they allow non muffled cars... if they don't they might kick you because it is LOUD.

 

Oh yeah, I tried it. But I have my theory on it, since you lose low end, it would make sense to open it up after 4K rpm. But with my 22" Toyo's, my gearing is SO nice that I have no low end problems anymore. I torque brake to 1800 at usual, which is the highest I can stall up to.... launch hard, I get a chirp and it winds up so fast now, that 2K to 4K is so fast. So, even with the cutout open all the way during the launch, it's not a big deal since the loss of low end is so insignificant.

But I tried it first with cutout closed, 15.88, then cutout open 15.69, did variable cutout like you mentioned 15.75, then I did cutout open again for my last run, 15.71.

My 60's were all the same reguardless of cutout setting, but with the cutout open, my trap speeds were 1 to 2 mph higher.

So, I can safely say that on average I shaved .15 in the 1/4 with a cutout rather than having stock catback. But when comparing cutout to a good aftermarket catback, I'd have to say they are the same. But I'm the quiet one on the street. AND for less money spent. That's why I LOVE this mod so much.

 

Some tracks do have certain street legal racing events and open headers isn't street legal. But there are MANY big block V8s out there that run open headers. But I think I have heard of one track that doesn't allow more than 100 decibels b/c it's located in a neighborhood. But reguardless, my car is LOUD! lol

 

Cutout with boost...mmmmmmm.

 

12345678910

 

Call me cooky but why even waste the time with a cutout? If this mod is as effective as it's suppose to be, why not take a 14mm socket, 10 minutes, and pull the muffler when racing at the track? You'll reap the performance benefits and you'll dump ~25lbs off the rear of the car? I'd never do it simply because it would be bit funny to hear a 14/15 second Maxima sounding like an obnoxiuous fart screaming down the track all for the sake of .1 seconds. In 10-second and below cars I can understand, but not in a 11+ second ride. It's way too FnF.

As for the turbo guys, this mod won't be near as loud because the turbo itself tends to muffle exhaust noise. It would probably increase power nicely too because turbos tend to like the biggest exhaust possible.....within reason.

Dave

 

This mod will bypass Bpipe too. Plus, you can EASILY push a button and open it up. You won't have to get underneath your car. Plus, I don't have to sound like an obnoxiuous fart screaming down the road everytime I want to drive my car daily. I have found a way to be quiet on the street and make more HP on the track. Who really cares if you're loud on the track. There is a time and place for everything and being loud on the street isn't one of them. By the way, this is coming from a normally aspirated automatic 1992 that is almost as fast as you. So I must be doing something right.

You don't have to get a cutout, but I realize that it's a way to be quiet on the street and still remain just as fast as I was before with a LOUD straight thru muffler. The straight thru muffler is almost as loud as my cutout. Almost

 

IMO, I'd feel like a clown pulling up to the line and revving to 4000rpms making everyone around me deaf and then only run a 14.3. I've got have some dignity when racing. I'd be no better than some FnF Honda running a 17.8 with a big wing and fart cannon.


When did a 15.1@91mph at 1100' (same elevation as my track) with a 120lbs removed from the car and short 22" track tires become almost as quick as a 4th gen running 14.4@97-99mph with stock height street tires, the spare removed, and 45lbs of SFCs dangling from below I know you're very quick for what you have, but don't get ahead of yourself. Dropping .6 seconds and adding 6-8mph would take a hefty shot of nitrous or a turbo.


Dave

 

This is all coming from a person that said that no VE Auto will ever make it in the 14s without major internal engine work. I see that 13s are possible for me without major work. But I'm prepared to listen to your BS flaming.

Keep drinking that HaterAde. lol

I ran the 15.1 without the small tires or cutout. I didn't do this cutout to be faster in the 1/4 mile. I did it so I'm quiet once again on the street and won't be considered rice like I was with that loud muffler I had. Who REALLY cares if you are loud at the track. I don't. Like I said, you're aloud to be loud at the track. I really don't care what others are saying. When they see an old 4door auto run the times I'm running, then they somewhat accept that the noise level is ok. But reguardless, it's rediculously loud, but it's one of the smartest moves I ever made.

After I removed the 120 lbs, I am still heavier than you are. But with my latest mods, 14.8s are easily attainable at 1100 feet. I'm sorry for comparing my old automatic to your times. I know I'm not worthy. lol jk man

 

Dave B likes *****

 

Aaron -

Do you have a picture of it installed? Which way do you have the cutout pointing? To the side, or down?

 

Yeah I got some pics. But none of it installed. But after seeing these pics, I'm sure you get the picture of how it looks installed.



You see in that pic, I cut a section out of my testpipe and welded it in with some auto zone couplings. When it's installed on my car, it dumps towards the passenger side of the vehicle. And since it's in the space where the cat should be, I had a lot of room to play with. So I angled it as high as I could before hitting the cat heat shield or underbody.

If you look at that pic again, you see where the bottom of the electric valve is? .. the flat part? That is perfectly parallel to the ground. So that is how I have it installed. I'd say it hangs about 1" lower than the testpipe. Probably not any lower than the catalytic converter is when installed.

This might be a good mod for you since you are a track ***** like me.

Here are some more pics when I first got it:

 

Cool, thanks. You don't think the temp of the exhaust causes problem (melting)?

Not only am I a track *****, but I'm a boosted track *****! I need a new exhaust next spring, and may incoperate one of these.

 

The electric valve is specifically designed to withstand even the worst exhaust heat. Some put them in their header piping. McCord Power plates are the cheapest and one of the best. They have been around probably just as long as Quicktime Performance. Quicktime is about $30 more and it's about identical. I did some research on other forums to see what others thought about electric valves and that is why I decided on McCord.

 

No, I'm more concerned about the car's undercoating, wiring, etc. Not the exhaust itself.

 

Oh I see. Are you planning on having this cutout open for more than like 30 minutes? Probably not unless you want to get pulled over. But maybe for long road courses, it might can build up more heat on the undercarriage. But that is something that Quicktime and McCord would know.

The reason I use this mod is to open it for no more than 20 seconds. So I'm VERY sure it's perfectly fine since thousands of people use this product on other cars. All the serious Grand Nationals have a cutout. I myself searched a bunch of domestic V8 forums and found a lot on the topic.

 

Could you please dig up the post where I said this because I never remember saying anything like that plus why would I even care what a VE auto can do? I really don't understand what your problem is with me because I not flaming you. I don't agree that your removed headlight intake dropped .4 from your ET nor do I believe this cutout will do everything you think does. I'm just disagreeing and not flaming you so there's no need for the attitude.


My car's race weight with me in it is ~3160lbs with me on board or 2975lb without me.

14.8s? Attainable, but I wouldn't say "easily". It will take a very strong 60' or some other work to get that 14.8. If you're running 15.6-15.7 with the extra 120lbs, the short tires, and cutout, then you've got a long way to go.

Big deal my Maxipad runs 14.40. I was just pointing out your 15.1 at the same elevation is not what most of us would consider close in performance. That's like saying a 99+ Mustang GT is comparable to an LS1 F-Body, ~.6 and 6-7mph. I used your 15.1 because it's the same elevation as I run in so it will give a more accurate comparison. We both know that 1100' will account for about .2 and 1.5mph. Now that you've moved and have experienced higher elevations you know how much it sucks.


I just think it's a bit rediculous to pull up to the line in a 14/15 second car and sound incredibly loud. That's all. I'll drop it.


Dave

 

If it comes off that I have an attitude, it's b/c I do. You flame everything I've said so far and I am trying to state pure facts. Shaving .15 with a cutout versus a stock catback is NOT hard to believe. Why can't you accept that? In fact, it could have shaved 2 tenths. But I like to estimate conservatively.

And I did my 14.83 with a 2.3 60'. So no it doesn't take a STRONG 60' to get that in my automatic. I have different gearing than you do.

About the intake in the headlight deal, I might have said 4 tenths in the past sometime. But when I got into bracket racing, I started to realize how consistant my car can be. I keep a strict logbook. So, I take back the 4 tenths with intake in the headlight. It's more like 2 tenths in 50 degree weather.

Also, I bought my car in Vegas (2010' and hot temps). I ran 17 flat stock in Vegas. I run 15.2s in Vegas now. So yes, I know what how bad elevation can suck.

Well, I ran 15.6s in Vegas (once again 2010') with a full interior and my normal headlight setup. Those things ALONE shave almost 4 tenths. You're so stuck in your ways, that I know you won't consider trying these cheap and effecient mods. Check out Jime, he knows what's up.

As for that post, here it is:

http://forums.maxima.org/showthread....9&page=1&pp=30

It's right on the 1st page. It's hard to forget something that someone says to bring down a fellow Maxima. I was able to pull this thread back up b/c I saved it. It's one of favorite threads on this forum b/c everyone doubted me and I did 14s with minimal mods. If I get TC, ECU, slicks, and lighter rear wheels and tires, then 13s are even possible. I still have more mods after that too.

You are just coming off as a hater since the very first time I read your posts years ago. I am sorry for having an attitude. I hope we can get along especially since you truely have a quick car. We can possibly learn something from one another.

I don't really like to count my chickens before they hatch, so we'll see when I finally hit the track in SoCal this Dec sometime.

 

Put a turndown after the Y and on the end of the turndown put the electronic cutout so the exhaust gas is pointing at the ground. Just an idea.

 

Oh yeah, i forgot about turn downs. Yes, that is the whole reason for them. But with the electric cutout, the valve plate will still go on the cutout as usual and THEN the turn down will bolt on. But with the summit racing cutout, it has such short bolts that are welded on that you will have to replace those bolts. You can look into other brands of cutouts.

 

OMG, you really can't be serious with this, but I'm glad you found the thread. In that thread (nearly two years ago) I wasn't even talking about your car. The guy swore he was going to go 14s with minimal work when at the time he was running high 15.8s in his VE auto. I don't see anything that I said that's out of reason, especially at that time when people were getting 15.7s in thier modded VE autos. I simply stated he had a lot more work to do to get 14s. Over ONE YEAR later you finally start running 14.8-14.9 in Fayeteville, NC. Granted it took most of the bolt-ons and a gutted interior to get there, but you did do it and you proved me wrong that it would take loose torque converter to get there.

As for the "bringing down a fellow Maxima owner", take a look at your post on the 3rd page. Here's what you said to the guy claiming to run 14.8s:

And you call me harsh.


Dave

 

HAHA... well this guy didn't run a 14.82, so it's different. I don't doubt your times and I'm sure you don't doubt mine since I have the info to back it up. We are even, I hope we are cool.

But I know you weren't talking to me, I wasn't under that impression. But I had the same mods as he did and was running the same times. So the stuff you said apply especially since Dirk doesn't deserve such harsh treatment.

But I'll tell you what, when Don Cooper was in his prime as far as on this community, he kept advertising that you will get a 6 tenths gain in the 1/4 mile with VB mod. You were right, I personally might have gotten ONE tenth.

I'm still interested in raising my converter's stall by 1K rpm. That will be considered somewhat lose but still very streetable. All the mods I've done so far make my car more fun to drive. Sorry for going off topic. We are suppose to be chatting about exhaust cutouts. Atleast there is some good cutout info on this thread for the first time in the history of this forum.

 

Seeing that you're concerned with getting the most out of your car at the track, I think you could definately live with a 3000rpm stall converter as long as it's a good quality unit. I think the ProTorque stalls up to 2800rpms behind a bolt-on VQ, so I'd assume it would stall about the same behind the VE. I'd think you could order a 3000rpm stall from ProTorque for a little more money because they have a tech sheet that you send in with data like your current stall, 60', 1/4 mile, dyno plot, gearing, etc. I'd think with the 3000rpm stall and 23" slicks (you'll need them with all that torque multiplication), you could dump .5 seconds and gain a couple mph.

Just wear some ear plugs when you stall that baby up


Dave

 

all i have to say is this will sound very horrible, when i installed my y-pipe i started and reved my car once to see how it would sound and man i dont know what i would do if i had todrive around like this. And also ithink you will loose hp from this and it will burn out your valves.

 

Yeah, the highest stall I can reach with torque braking is 1800. I want to be able to reach 2800. That would be SO sweet especially since VE Autos have NO low end. And YES I would need slicks. I have my eye on 22" MT slicks ONLY if they will fit on 15x6 Millenia wheels. If not, I will have to get 23" slicks since I KNOW they will fit. 22" slicks will be good until a 100mph trap speed. I am FAR of from that. But since n20 MIGHT be in my future, I might wanna start preparing for the best gearing.

But a half second shaved with slicks sounds within reach with the RIGHT TC. That is why i've inquired about the Edge Racing Converters in SoCal. They are one of the oldest and most experienced in the nation. They recently hooked up a 2K3 G35 5AT with a higher stall. They can do anything.

The interior sound isn't bad at all. But watching from the stands is DEAFENING. It's BAD and it doesn't sound good AT ALL. But as far as I'm concerned, what ever it takes to shave .15.