Well I bought and installed these two units, here are some pics of each stock vs flomaster


This is the stock downpipe:


http://www.dieselplace.com/forum/uploads/BumpinYota/2004-10-31_065703_Exhaust_Down_Pipe_Stock_vs_Flowmaster_LO WRES1.jpg


This is the flowmaster unit:


http://www.dieselplace.com/forum/uploads/BumpinYota/2004-10-31_065755_Exhaust_Down_Pipe_Stock_vs_Flowmaster_LO WRES4.jpg


This is an outside difference:


http://www.dieselplace.com/forum/uploads/BumpinYota/2004-10-31_065936_Exhaust_Down_Pipe_Stock_vs_Flowmaster_LO WRES8.jpg


Another shot from the outside:


http://www.dieselplace.com/forum/uploads/BumpinYota/2004-10-31_070019_Exhaust_Down_Pipe_Stock_vs_FlowmasterLOW RES.jpg


Now for the crossover:


http://www.dieselplace.com/forum/uploads/BumpinYota/2004-10-31_070100_Exhuast_Crossover_Stock_vs_Flowmaster_LO WRES_1.jpg





After I installed it, WOW a big difference and definately worth it! Im left wondering what the hell was GM thinking with that crazily crimped downpipe?? Oh well it's a great mod for 113 shipped to my door. For anyone wondering this is the '95-'98 6.5L TD kit and it WILL fit a '94 fairly closely....

Wow, yeah it looks like there was some sort of an accident like some one rolled over the original downpipes with a forklift and GM decided to save a nickel and install them anyway. What really blows my mind is that they aren't all bent the same even, some drasticly like yours and some not nearly as bad, which goes back to my forklift theory ;)

mine was just as bad. Replaced it and was amazed at the difference


I think Texas may be onto something--except I think their semi rolled over the whole load.

hahahaha, I like the theories!! Definately runs better than before and I can juuust make out turbo whine now.


Incidentially, I didn't break a single nut or bolt in the entire removal!! I do love a good penetrating oil put on a day in adavance and then a 1/2" 24" long breaker bar! :D

That has got to be one of the worst examples I've seen so far, gut the cat or skin it completely if you haven't done so already, and turn down the 1200W and you WILL hear turbo sing. How did you make out on cutting out webbing, I used a shortend(snapped off to correct length) metal cutting jig saw blade to cut out mine, less mess than a die grinder.


Have you been to Kennedy Diesel site www.kennedydiesel.com (http://www.kennedydiesel.com) and looked in the tips section how to get better flow to the air filter box, good info there. I also recommend the AMZOIL air filter, I've been running mine since I bought the truck, a LOT of debate over foam or factory which is best, I don't know the complete answer, but my oil test results do show low silica levels, so it must be working as advertised, I got it from Kennedy, several other vendors carry it as well www.lubespecialist.com (http://www.lubespecialist.com) is an AMZOIL dealer also. Check out Heath Diesel also carries a quality high flow filter www.heathdiesel.com (http://www.heathdiesel.com). Go to www.bankspower.com (http://www.bankspower.com) in their FAQs on Diesels and see why airflow is the KEY building block to making power.

Cool thanks for the links, and yes, I've ripped out the snorkel in front of the air box per kennedy's site so now the air is drawn from the whole fender. She still has a stock air filter, but that, a new 4" exhuast w/o cat, w/flow through muff, boost and pyro gauges are on next on the list...http://www.dieselplace.com/forum/smileys/smiley4.gif


I still havent gotten around to removing the webbing on the upper intake plenum yet. As this is mom's truck, I'm going to have to buy another plenum from a boneyarded diesel to do this to. I know she'd not approve of me doing that to a stock part on her truck no matter the reason...lol

where did you guys find flowmaster crossover pipes?

where did you guys find flowmaster crossover pipes?


right here:


http://store.summitracing.com/default.asp?target=esearch.asp (http://store.summitracing.com/default.asp?target=esearch.asp&N=100&Ntk=PartSearc h&Ntt=++FLO-17220+&x=10&y=0) &N=100&Ntk=PartSearch&Ntt=++FLO-17220+&x=10& amp;y=0


if that doesnt work search for FLO-17220 at www.summitracing.com (http://www.summitracing.com)

I recieved my crossover kit a few weeks back, went to attack the downpipe, BUT:


I can't remove the airbox. It has 2 (should be three) #30 torx-type bolts holding it down, but as I turn them the captive nut (or whatever is below the box) just spins. It's way under there, if someone knows what design it is or what I should try (tried a 10mm shorty open end, but fastener is in a well depression in molded box).


The 4 bolts at the outlet flange on downpipe are pretty bad, hit them with penetrating oil just now. I am heading to the parts counter to get replacement pieces as I bet I'll ruin more then 1 . .


Thanks !

those torx bolts dont loosen up. just pull the box right off of them. there is rubber around the hole that goes over the bolt. the air box just slides on and off of them.


when you get your downpipe off, test your glowplugs on that side. once you put the bigger downpipe on, it is awefully hard to get to one of them with the downpipe in place.Edited by: steiner43511

Hey Steiner, can you post of pic of it? My box isn't mounted exactly right, and I don't know what it's supposed to look like.


... just pulls right off those rubber dealies, eh? Hmm, I never thought to try that. I always turned those rubber dealies off with a pliers.Edited by: w_huisman

'Yota,


If you have to buy one, get one with out the raised EGR boss off an F engine truck. If it'll help, I'd take your old one. I'd like to have one to shorten for an IC piping.


On EDit: I just had to say, I love your first two compare contrast photos of the downpipes. I see more in them than is there, as if they have captured a glipmse of 1/0 (the individual and the void) or the timespace tunnel.


the stockpipe takes the cake. The worst I've seen and I have mine to look at! A '94 top and '96 lower.


http://www.dieselplace.com/forum/uploads/quantummechanic/2004-11-13_063637_downpipes.jpgEdited by: quantum mechanic

wade:


sorry i cant post a pic, i dont have a camera. they might pull off a little hard, but when your done they just press right back on. ive taken mine off probably 10 times since ive had my truck.


i see that you have a 95, it might be a little different. i dont know if it would be the same as bobt's 98 and my 97. Edited by: steiner43511

btw - when reinstalling the crossover a 2nd time replacing the lead doughnut seals I snapped off one of the bolts anchoring it. If anyone wonders the size, it's a 10mm coarse thread and the replacement had a 17mm hex head....Edited by: Bumpin' Yota

Thanks Huisman, I'll be pulling the downpipe later today. I told the local Chebby dealer that I needed all associated gaskets to R&R the crossover/downpipe. I ended up with 2 of the donuts, which are for the crossover, and 1 flat flange gasket (in 'Yota's first photo up top) for exit of downpipe. What do I NEED for the turbo end of downpipe?? Dang chebby parts guys. . . .


PO put a new OE crossover in just about a year ago, but I can see he needed 2 new bolts and i don't trust that he renewed those donuts . .

Down pipe at turbo has no donuts - it fits against the bevelled end of the manifold, and the OEM Clamp holds it in place. You're good to go there.


Hmm reading other threads on glowplugs, and after looking at mine a few weeks ago - you might want to check those on the passenger side while you have the downpipe off. Looks like I'll have to pull my downpipe to get to #6 - When and IF.... Have Fun!

yeah im runnin into the glowplug problem now. http://www.dieselplace.com/forum/smileys/smiley19.gif


becareful when removing the downpipe clamp. a replacement isnt cheap.

I installed the Flowmaster crossover & downpipe Sat. I had a buddy help me for beer – he connected the downpipe to the turbine exit as I worked the pipe from under the truck. I replaced the downpipe flange gasket, but not the donuts on the crossover.

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Comments: 1.crossover is only one year old, less than 15k miles, very good condition – if anyone needs a stock unit just pay shipping and it’s yours. 2. my downpipe was not nearly as mangled as ones I’ve seen pictures of here. 3. Performance is improved but not as dramatically as I had anticipated. I can’t see vast changes in turbo response and EGT’s. 4. I hear a ffffffffft ffffffffffft ffffffffffffft sound emanating through the glovebox that wasn’t there before, as well as the ‘whistle-down’ as the turbo ‘relaxes’. I am not 100% sure I don’t have a leak, but since I don’t smell diesel fumes or hear a blatant leak I will not be messing with it until I hit other house/car/bike priorities.

New: TRUCK runs alot better than I had first noticed:D . Turbo reacts faster and truck leaves the line without as much 'struggle' (ie 6000 lb pig doesn't feel as quick as a 2000lb sporty compact). No leaks, Enjoying the turbo whistle.

Hello, I have just replaced my crossover and downpipe and now my engine rev's up and down at all stops. any thought's on what I have done? The Flowmaster instructions said to use existing flat gasket and what are the "donuts" BobT mentioned. The OEM crossover did not have "donuts". Any thought's ?

Revs up and down? I don't think the exhaust caused that unless you're still running the cat and muffler, they could be plugged and usually are after ten years of use. ECT signal could be intermittent. Check the connection at the coolant crossover, jiggle the wires with the engine running.

I Cannont believe the restriction. My 3500 HD has no bends or crimps what so ever. I believe it is stock. It came from mass highway and i don't think that they would have replace it. Would removing the cat and getting a freeer flowing exhaust make a big difference on mine...

Absolutly. Ask Justin Taylor what difference the straight pipe I put on his made. I run mine with 8' coming off the downpipe with a turn down at the tip. The 8' joint and bend cost $25 at the local muffler shop. I think a 4" would be better and I've considered getting a 4" to replace the 3" with but I haven't found a shop that can do 4" yet(I have to go to the eastside).

MERRY CHRISTMAS QM, I am still running the cat and muffler, (California required) I will check the ECT this morning and let you know. Thanks

I like taking the old trap and welding it to the outside of the new exhaust pipe. You can't deny it's there, but it doesn't clog that way.
happy holidays!

I still havent gotten around to removing the webbing on the upper intake plenum yet. As this is mom's truck, I'm going to have to buy another plenum from a boneyarded diesel to do this to. I know she'd not approve of me doing that to a stock part on her truck no matter the reason...lol
Ok, I have no idea what you're talking about. What webbing? :eek: Where is it? If it's restricting the intake, I want to get rid of it...how do I get rid of it??

Here's the webbing on the underside of the upper intake thats being talked about, i think its only on models with the EGR but don't quote me on that, simple to remove with a dremel as i did.

Keep the thread alive!
I have the nice crossover and downpipe, but now want to continue to bastardize my truck! :D 1) can I run 3.5" all the way back, or should I use 3"? 2) can Midas or similar shop do this? It needs to jump over the axle and turn out the right side rear, and the hangers need to fit the factory locations. 3) what is the best way to open that cat or soot trap and re-stich it? I feel like I have a cork in the system as it is now! :eek: Thanks!

Ordered the Flowmaster Downpipe & Crossover kit #17220 from these guys (http://www.autopartsauthority.com/performance_exhaust/chevrolet%7Esuburban%7Eexhaust_system%7Eflowmaster %7Eparts.html) for $103.37 & free shipping - it says it's for a Suburban on their website but I talked to them & it's the standard Flowmaster #17220 6.5 kit.

Will change out my glow plugs with Quick heats from JK at the same time I'm installing the new pipe kit. I'm interested too in gutting my catalytic out - what's the best way to do it as I need to retain the shell since I live here in the Peoples Republik of Kalifornya.

You will have to order a kit and weld the trap over the pipe yourself or have one bent up local and take it home to install it. No shop is going to touch it because of the implied risk of legalities of removing/modifying factory emmissions equipment. Pre '94 "F" engine didn't have a soot trap.

Personally, I think soot traps are not needed on a high compression F engine with gm-x turbo. The boost comes up quick when sprung closed and soot formation is minimal. Soot traps are designed to collect particulate matter known to cause cancer when inhaled. The use of a small percentage of vegtable fuel oil reduces the particulate matter from the exhaust better than any soot trap. The DOE has some really imformative comparitive studies on soot traps and fuel blends in urban diesel powered equipment.

BobT,

I removed the cat, cut 4" holes on either side and repeatedly drove a piece of steel rebar (with ground point) through the ceramic honeycomb until I could remove all of the chunks and the fibrous material which encapusated the ceramic. Ran my 4" pipe through the cat and welded everything up...voila. Take that you Jersey DOT Commies!

BobT - I used a steel rod to bust all the way through down the center and then worked to the sides. I worked over a 5 gal. pail and wore a cheapy dust mask. I opened up the holes with a 3.5" hole saw and an angle grinder to get a tight fit on the pipe. I didn't want to weld to the aluminized pipe and create a potential rust problem so I put a self tapping bolt thru the top of the cat to provide clamping pressure on the pipe and dressed the seams up with JB Weld. Been a couple years now - no problems.

Thanks Spindrift, Minisub and all who assist me:) . On the Suburban and Tahoe, do you guys still use a muffler? If not, and if you exit the exhaust in a factory manner, is the cabin noise very loud?

I plan on upgrading the remaining system and modifying the soot trap, but need to know if I should plan on a muffler. Thanks!:D

No muffler and no cat on my 95 Sub. The length of exhaust where those two components used to be is now just a 3" straight pipe. Except for the Flowmaster downpipe, the rest of the exhaust is stock and exits right behind the right rear wheel.

Of course the truck is noisier than without the muffler and cat, but it's very tolerable and less noticeable going down the highway than toodling around in town. My wife even thinks it tolerable when going down the highway, so I know the noise is very tame. My first reaction when I fired the truck up the first time after removing both the muffler and cat was "Is that all the louder it is?" Guess I was expecting it to sound more like a gasser. The turbo makes a pretty good muffler.

BobT, I run the muffler with the baffles facing rearward (the "loud" position). I like the way my truck sounds both inside and outside of the cabin. It is noticeably louder outside and slightly louder inside. Unless I'm going over 75 mph I find cabin noise very acceptable (keeping in mind my last truck was a Toy pu running 33" BFG MTs that you couldn't listen to the radio in going over 50). I have toyed around with replacing the muffler with a pipe, but never got around to it. Others have reported that the Tahoe is so short, no muffler will get annoying pretty quickly, but I think the whole notion of the "right" exhaust note is very subjective.

Hi guys,

Why is the flowmaster downpipe kit restricted to the years '95-'98?

What will it hit on a '94?

What kinda of modifications where necessary to make it fit on your guy's '94's?

Thanks for your time,
-John

Hi guys,

Why is the flowmaster downpipe kit restricted to the years '95-'98?

What will it hit on a '94?

What kinda of modifications where necessary to make it fit on your guy's '94's?

Thanks for your time,
-John
Mine IS a '94 and it went on with no mods other than a whole lotta elbow grease getting that down pipe up to the turbo and those infernal doughnut lead washers for the crossover...

it will fit. mine slid in with a little KY.

Holy http://www.dieselplace.com/forum/images/smilies/censored.gif Yota. That's almost *exactly* what mine looked like before I started on it. I am getting at least a 3.5" with new downpipes and probably I will shoot for 4". Thanks for the pics!

cool!!

Thanks for the info guys. Im ordering my today!

-John