damn .. THAT SUCKS that the stud broke.Those studs dont usually break. A torch would be your best bet.careful not to burn anything else. Use anti seize when u put the new stuff on

 

Ok. Thanks. Ill let you guys know how it works out, Hopefully if I get the rest out without breaking anything, that one broken stud should not create a leak.

 

ok guys .. the verdict is in ...I ran at Irwindale speedway last night( 1/8th mile) and the results were disappointing...but the time slips dont lie. I ran nearly identical times from my stock y pipe and my WSP pipe. I did 2 runs and was sooo bummed. 11.22 @ 66 mph. The only thing I can think of is trying a smaller catback. 2" instead of 2 1/4 to get some torque back. BACK TO THE DRAWING BOARD !!!!

 

then something is either wrong with your car, or the air/density/altitude was way way different, or track conditions were different, etc. 1/4 mile tells more also... longer distance means you go through more gears.. spend more time at high rpm.

 

cape.. i have to agree w/ u on that one ....whatever the case,I know my car runs consistent times and the tranny is not slipping ...lol

 

Do you really think you're going to see a huge difference in times by bolting on an exhaust mod?

think again.


effing ricer math....

 

well... i'd always heard most people gain 15hp from it, which compared to 160, is a pretty substantial increase. so if it really makes 15hp more it should impact times some. maybe a tenth or a half-tenth, but still something. but you're right, you aren't going to drop a whole second from it.

 

HELL NO ... i`m not expecting to gain 100 HP or have my car do 9 second passes in a 1/4 mile.....lol C`mon now guys .. lets be for real !!! I was hoping t drop to 10.5-10.7 w/ the pipe and spacer ( realisticly)

*sigh* Damn ... building Small block Chevy cars were so much easier ...lol Anyway...Being a "small displacement." engine I think I went a lil overkill on some of the other mods. I`m lookin to check fuel PSI and timing to see if it helps.

 

so was there any improvement? you said you got 11.22 after... was it like 11.29 before or something of that nature? also what's your MPG looking like with the new ypipe

 

Last NOV. I ran 10.9-11.1 @67. My MPG did go up some ... I get an extra 16 miles on a 1/4 tank. As for average MPG .. have to calculate again at next fill up. Gas here in SoCal is a fortune ..=(

 

yea it way way way more in chicago.... it was a good 50 cents higher up there than it is out here in NC. but keep in mind that in november the air was COLD... moar cold = moar dense = moar gas = moar power = moar fast. air/density/altitude thingy is important for comparison, and iirc there is some sort of way to "compensate" your times based on a forumla or something

 

I wonder if we are still the highest in the nation or not.

 

Can I cause a stir and a flurry of commotion?? I'm sure this has been covered somewhere on site, but anyway:

Performance exhaust systems are really a "season-to-taste" kinda thing. Bigger pipe opens up breathing on the high end at the expense of low end, smaller pipe gets you better low end but can choke the top end. Example of this is a Chevy 350 of old: they had 1 1/2" headers available (still do somewhere) that were good for trucks and low-end torque (and gas mileage)- especially when cammed for low-end- but not for the track and high horsepower; 1 3/4" headers were good for high end HP/torque (if cammed for it) and 6500RPM or so, but not so good for 1500rpm torque; 1 5/8" a good middle-ground.

Do your geometry and check the % difference in area between pipe sizes.

I believe Warpspeed uses 2" down pipes, and I think Cattman used 1 3/4" down pipes when they were in production for 3rd gen. The dyno graphs I remember seeing on the VE were about 6-7 hp (?) up top and a slight tourque peak gain- Warpspeed over Cattman- but with some loss of low-end. Just about anything is an improvement over the stock design, but I wonder if 2" is a bit much, and if 1 7/8" wouldn't be enough for high RPM and better for lower end on a stock or externally-only modded engine. The 1 3/4" Cattman was certainly better than stock, and probably excellent at low-end.

It depends on how your engine is built, and/or what you want it to be able to do. In the case of the VE... if you want that top end... bigger (to a point) is better; if you are like me and want that awsome low-end pulling torque, and you drive below 4000 rpm 95% of the time... smaller (to a point) is better.

Do some searching and look up David Vizard. Worth reading when you find his articles on exhaust.

BTW: as long as the cat-back pipe and muffler are big enough not to choke the engine at top end, size won't matter much. Most- if not all- of the effects of exhaust characteristics on engine performance are over at the tail-end of the cat... on 3rd gens anyway.

My 2 cents. Flame me.

 

well said. i remember when i had my 79 Malibu. I went from 2.25 to 2.5 " dual exhaust and it was great mid to top end. Tho it was cammed for that. As for my Max... Due to current "financial limitations..lol" I have to hold off on any changes. I `m planning going back to 2" cat back or messing w/ the fuel delivery. We`ll see. I`m gonna install an air/fuel gauge and run it on the dyno to see if maybe i`m running lean. If so.. maybe ecu or larger injectors are in order.

 

Exhaust systems all have to do with airflow velocity. If your engine puts out so much exhaust at a given RPM, you want the best flowing bends (mandrel) in which the Warpspeed already kills over stock. Another thing is the size; rather than just "bigger" or "smaller" affecting low end, it really has to do with the velocity in which the exhaust exits the vehicle. You want it to be released quickly and smoothly.

With too large of a pipe, the exhaust has time to cool and expand in the pipe, causing turbulence, meaning at low/mid range RPM's where not as much exhaust is coming out, you'll have a noticeably different powerband. While if it is too small of an exhaust, you can create backpressure where the engine is struggling to release the exhaust quickly enough.

Taking those two things into consideration, the Warpspeed Y-pipe is almost perfect for both applications; and no matter how you look at it, is just better than the stock design which actually flows back into itself at the rear exhaust manifold.

 

Cool = contract. Heat = expand

 

except water->ice

but is that the real reason? because it has time to cool down? i thought it had to do with the fluid dynamics concerning adhesion of air particles to the surface of the pipe, and the surface area of the inside of the pipe, and thus, how many of those particles of air were clinging to the pipe's walls.

 

Water changing from liquid to solid

 

the 2nd paragraph was about exhaust, sorry to confuse

wrt the water/ice thing.. i was just citing the one exception for your "cool = contract, heat = expand" rule. ice is less dense than water. thus it expands when it cools.

 

true, but it is changing form as well. when form stays the same, the rule applies.
Ice actually has air in it usually

 

Exactly. And depending on what you want from your engine, a smaller or larger pipe size along with exhaust design- length of primary pipe/ size and size/length of the collector will or will not give you what you are trying to achieve.

Agreed: Warpspeed's y-pipe IS significantly (probably WAY) better than stock... it just may or may not be the "best" solution- depending on what you want out of it. Everything about a car and an engine is a compromise. Warpspeed's... or any other's... may not be the comprimise everyone wants.

Understood... I haven't done anythinng yet- and I might not get to it ever- though I'd probably do something different. I can't prove anything until I do. I *would* like to start with an old Cattman pipe, though.

 

Yeah, I would like to drive a VE with a Cattman too. The two and a quarter sized pipe sounds like it could be a better application for the VE.

 

JC93SE you said it, compromises are made in modifying cars. I personally don't mind the noise a VG makes so I can make my compromises there but my girlfriend wouldn't have a new laptop right now if I liked sacrificing low end torque for higher peak horsepower. I'll probably still do the y-pipe despite the scares I'm getting here. It would be nice to not have to compromise on where I get my power but thats not how it works.

 

It's not the 2 1/4" secondary pipe I'm interested in, it's the Cattman's 1 3/4" primary pipes- though the rear bank's pipe is really short and doesn't matter as much. The 2 1/4" *might* help a little there for that reason.

But again- after the cat, the size of the pipe is of lesser consequence as long as it's "big enough" to carry the volume of gases with out a pressure differential- as long as you don't try putting 4" pipe back there. I *think* that would matter. The key there is *just* big enough- for whatever one is trying to accomplish. 2 1/2" back there is probably not a real bad idea, but pressure testing on 2 1/4" would have to be done first to satisfy me on either size.

 

Well, I've heard people who have complete warpspeed 2.5 exhaust's say they have a pretty noticeable loss of low end power. While People with the 2.5" Y-pipe and stock Catback (2") are pretty content. So I'm thinking a straight through 2 1/4" straight through would be pretty nice for both low and high end; it would be similar to stock, slightly larger, but with all mandrel bends and a better flow pattern.

Primary pipe, huh? Is that another term for headers? If so.. I wasn't aware Cattman made headers for our cars?

 

2.5" catback straight pipe (crimp bends) had no low end, and wasn't terribly loud except at WOT.

 

Nobody makes headers for our cars last I heard, unless you consider Pacesetter's as headers. From what I've heard here about them I would throw them in the same category as intake vortex generators.

 

You can mix and match sizes and sometimes come up with the same results for different reasons. You might have better results with some combinations, but not necessarily the best results- depending on what you are looking for. The 2 1/2" before the cat and 2 1/4" might not be a bad idea, but I still postulate that WarpSpeed's 2" primaries may too large- "depending". Without dyno and pressure testing- and without me testing what I *think* would work better (for me anyway)- admittedly the best I can do is speculate and have things work really well in my head. Maybe someday.

Primary= pipe before the merge of other pipe(s). Not headers, but to an extent a y-pipe functions somewhat like a header. Best we can do if we're keeping the stock manifolds. Primary pipes come together at a "merge", the merge bcomes a "collector" (if done right) and the collector comes down to the final (or a decreasing) size pipe. The same basic principles of header design apply- just not as much as if you actually designed a true header. Think of the y-pipe on a Max as if you were designing an exhaust for a Harley V-Twin- just larger displacement. Again- depending on what you wanted it to accomplish- you'd use different lengths of different sizes of pipe- even in one exhaust. The y-pipe on a Max has to (and should) accomplish most of what a header would. You could probably make awesome headers for a 300ZX, a J30, or even a Pathfinder/X-Terra- but you just can't on a front-wheel drive V6... not easily anyway. But you *can* make a really decent y-pipe- and it has to do the best it can to be *like* a header.

 

At one time (still?) headers were made in Australia, I think. Some made it here. Heard they didn't get you much over a well designed y-pipe (law of diminishing returns?) Don't know what sizes or lengths the pipes were. Maybe too big? (here we go again)

 

If headers were to be designed for our cars, I think a 1.5 " primary would be idea. My friends Miata had those form factory. Being smaller displacement, having anything around 1 5/8 would be overkill. Our engines ( VE and VG ) dont produce enough velocity to utilize that.

 

I think that 1.5" would be a place to start. I'd have to do some calculation to see for sure- I think displacement-to-pipe area would be a good direction. For years 1 5/8" for a Chevy 350 has been norm except in higher perf engines or high torque applications- bigger or smaller respectively. I'd see what the displacement to area ratio is on a 350... then see what that calculation yeilds for a 3 liter 6 cyl. A VE might need a slightly larger size for it's wider operating range/powerband than a VG would. And, construction/size might be dictated by the port size of the head... not sure what that is (actually it's in an older thread of mine)- and it is also more ovaloid shaped than round, and a round pipe to cover the oval might really be too large.

AGAIN: it would depend on what you were trying to accomplish- a liitle more low-end or a little more top end. Also, I think the transverse engine orientation makes it difficult to build a really beneficial header. Compared to a good y-pipe, it might be a diminishing return situation.

BTW: The stock manifold outlet on a VE (where the y-pipe attaches) is just a hair over 1 3/4" if I remember correctly.

 

Preach on brotha.

Its a small portion of the exhaust your "freeing" up. Don't assume your exhaust is whats robbing your engine of HP.

You could have a complete intake & exhaust set up and still run times that will have you thinking something must be wrong.

 

just a suggestion. Keep your 2.25" and just plop one of these on there. All the top end breathing room you'll need

EDIT: forgot a link http://www.quicktimeperformance.com/QTEC/index.php

 

Finally got my y-pipe and cat installed. Had to pay $150 because I had to take it to a shop to torch the bolts. Didn't feel too good when I was under the car with a torch right next to my head. It was easy for them with the car above their head to get the old one off and the new one on. Anyways.

I now have a significant improvement in acceleration and the car is very quiet now. However the improved acceleration may be due to myself being used to my old leaky flex and not the y-pipe and cat itself but either way, a great improvement. I hope to get better gas mileage. I was getting 330 miles to the tank before and I hope this will help improve that. I also hope to pass emmissions with flying colors due to the new cat.

All in all I think it was worth the money for the pipe and cat as the car seems to run a lot better without a leaky flex. If my gas mileage improves to 350+ to a tank, I will be very happy.

 

Congrats on the gains. I have a feeling that your Y pipe did make the improvement and it's not just you. The stock Y in the way that it makes the rear manifold's exhaust make a U-turn per say to get back to the tailpipe just doesn't seem efficient from any engineering standpoint.

 

Seems efficient to me they were equalizing the Y-pipe downpipes, where as the aftermarket brands aren't egualized....

 

such is the world of compromise. i suppose you could always have them drop down, BOTH come under and face each other but before they hit, turn them 90deg to run parallel to each other, join them up, then send it backwards. equal and parallel. just alot more piping and less surface area to support the oilpan if you have to remove the xmember. except then you have alot more bends.

 

Doesn't sound like a good concept to me. I've always heard the less bends the better and the straighter the piping the better. To my the stock y pipe looks like it would be in a better place under a sink in someones kitchen thanks to the rear section following 2 90 degree bends right into the flow of the front section. If the whole intersecting exhaust gases in a t shape worked why do equal length headers have collectors rather than just welding one pipe to another one? To me it just seems like that is creating unneeded restriction.

 

I Just finish making and installing my own custom y pipe for my 91 VG, its 2 1/4 from the manifold flanges then it opens up to 2 1/2 for the cat and back into the stock exhaust, only because i need to get my car threw inspection and i need some more time to make up the cat back. i have notices a drop in low torque but its not that bad, RPMs are cleaner and engine feels smoother at ideal. better top end power. i wouldnt say i got a HP gain of anything over 5 but it does feel smoother. i am post the pics as soon as i get the chance to upload them. i plan on modding the heads in the future with jim wolf stage 2 cams lifters and springs.