LT1FUN

EDIT (Further down into this thread, I posted some additional photo's of the SLP's once they were installed)




After waiting nearly 6 weeks, they've finally arrived. SLP's 1 3/4 stainless headers/ypipe. I kept getting conflicting stories from both LM performace and SLP as to why it was taking so long, but they're finally here so I'm happy the ordeal is finally over.
This will be my first major mod on my '88 L98 Iroc-Z. I tried to promis myself I would leave this car stock and just use it as a daily driver but the "performance bug" has bit me yet again.

The Firebird won't be finished until next summer, so in the mean time, I'll mess around with the Z. I decided to go with the SLP's mainly because of the fact that they're stainless steel and with this city's tendancy to dump 100's of tonnes of salt onto the roads every winter, I wanted a set of headers and ypipe that would not rust out. This was the biggest deciding factor as this is a year-round car and I do drive it during the winter. No rust = No worries


Opening up the box, everything was packaged really nice with everthing seperated by giant polyeurthane foam "pillows" which makes it virtually impossible for these to get damaged during shipment. Nice.

After inspecting evething up close, I'm happy to say that I'm impressed with the quality of these headers. Both in the ceramic coating itself, aswell as the craftsmanship of the header's construction. All the welds are absolutely perfect. Looking inside the collectors, you can see just how smooth and clean everything is.
Some of the cheaper headers I've seen, usually have pretty sloppy welds. "Sloppy", meaning if you look on the inside of the collector for example or where the Air/tubes are placed, you can see all the excess material from the welding process, "getting in the way" as I like to say.

Not so with these SLP's.

I ordered them without pervisions for air, as I wanted to clean up the engine compartment as much as possible. Getting rid of all the air hook-ups will definetely clean things up a lot. The ypipe, is also a great piece though unlike the headers, it's not ceramic coated. All is well though, as I like the "natural" finish stainless steal.

A lot of people might complain that the ypipe isn't a full 3", and claim that you're leaving hp on the table by not going to a full 3". Whether or not this is the case, I wouldn't know as I've yet to see a single dyno which shows, for example, a 3" hooker ypipe, making more hp/torque than SLP's. I'm not too worried though, as I take comfort in knowing that SLP has been around a long time and probably knows more about 3rd gen's than any other company out there. The way I see it, they didn't design the ypipe to be a full 3" for a reason.....

Anyways, the ypipe has a 3" collector and that's good enough for me.

I'll probably put these on some time next week if I have the time. May as well buy new O2 sensors while I'm at it. Hopefully, the install goes well and I won't have too many problems with the ypipe's fitment, as the SLP's ypipe seem to have reputation for fitment issues. I'll update again when I have them installed.

Here are some pic's of the ypipe....

Enjoy.

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LT1FUN

and here are the headers...

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superGMman

Wow, your right, the welds do look really nice in that bottom-left pic in your last comment. I'm glad that your happy with your purchase(I'm sure everyone knows that feeling of paying for something and feeling like it's a waste).

G-Ride14

Those look good. Can't wait to get a set for my gta.

jim91gta

Quick fitment question. do the Headers line up with Stock exhaust. I have the same Headers(love them) but am looking to get Magnaflow dual cat setup and was wondering how far off the connections would be.

CraZ-28

Son of a........ That really pisses me off. I didn't get a sticker with mine!

LT1FUN

That's because SLP reserves their High Performace stickers only for their most valuble and important cliental.

People like me.


You're just not important enough. Sorry buddy. Better luck next time.



J/K


On a serious not, rumour has it these stickers are worrth between 10-15hp at the wheels. We'll see.....

Willie

iTrader: (1)

I didn't get a sticker either but then again, I got them about four years ago. Maybe SLP doesn't like Tucsonans......?? Whatever the reason, I think I'm going to take mine off and not credit them any longer...... wait..... I just did this. I couldn't use their headers for my new setup !!!

mw66nova

iTrader: (13)

willie, have you got any new track numbers with that combo yet?

AC

iTrader: (3)

Willie!!!! When did you go twin?? Absolute sickness...only way to cure that sickness is with bigger C.I.D.

85T/A

ive got a question
they woldnt fit an 84 chevy 350 would they???? and if they would would the lne up with my stock exhaust on an 85 T?A

mw66nova

iTrader: (13)

gen I sbc from 55-99(?) all had the exhaust ports in the same layout.
0 00 0
so it will bolt up to the motor with no problems. the y-pipe on the slp's should bolt up to stock exhaust without too many issues...though i would definitely suggest upgrading to an aftermarket catback of sorts.

Dyno Don

iTrader: (7)

Let's see how inpressed you are after you have to dent the left side to clear the steering.

1BADROC

iTrader: (1)

[QUOTE=Dyno Don]Let's see how inpressed you are after you have to dent the left side to clear the steering.

dont dent it there is no reason to just jack up your engine slightly. once you got just enough room to slide them in do it and lower it back down. once you get them between the steering and valve cover you got plenty of room. they flow really good i gained 9 tenths at the track with them and stealth ram.

CraZ-28

I think your right Willie. Then again, I've had mine for 7 years now and they may just have not proven the sticker/hp rating thing yet when I got mine. Oh well.

LT1FUN

I would never in a million years even consider denting headers to clear the steering shaft.

If I do end up having some minor clearance issues with the driver-side header and steering shaft (as some people have had) all it takes is 5 minutes and a dremal to grind out what little material of the shaft is in the way.

That's the smart way of doing it. It will not have any ill-effects on your steering or reduce the intergity of the shaft to be of anyconcern.

I too have read stories of guy's hammering the crap out of their brand new SLP's for more clearance.

I can't comprehend what on earth, these guy's are thinking. I guess they just get so frusrated, when things go wrong, they stop thinking, and resort to ham-fisted half-*** solutions like using a big hammer

5 minutes and a dremal. It really is that easy. I've seen it done a dozen times by now. So much more efficient then destroying an expensive set of headers...

Nah, my concern isn't with the headers. but with the ypipe. I'm almost certain it won't bolt up properly. All the ypipes I've ever installed, were the same....

mpayne

Well, you probably haven't installed them yet to say this. I've had the slp's on my car for about 3 years, rubbing the steering shaft the whole time. The only solution now is to dent them. I have put washers under the driver's side motor mount to move the header up and over, didn't work. I have moved the steering shaft over as far as it will go, didn't work. I don't want to grind on the firewall to move it further because in case of an accident I don't want to get speared with it. Grinding the steering shaft is a bad idea. How do you know that grinding it down will not reduce integrity? You would gamble on losing steering instead of putting a small dent in a header primary that probably wouldn't even reduce flow, I guess that's Darwin's Theory at work.

LT1FUN

If you've been driving your car for three years with the header touching the steering shaft, that must mean that the header is only barely touching the shaft (most likely, only "rubbing"), otherwise, steering your car would be VERY difficult, if not impossible.

So odds are, the header is just "rubbing" the shaft, so grinding down that tiny insignificant bit of material, to give you just enough room for clearance, won't be enough to cause any damage.

It's not as if I'm talking about grinding the steering down to half it's width

That probably wouldn't be a very good idea, but to just "skim off" a tiny bit of material (1/8" at most") there's absolutely no way in hell, that's ever going to cause the shaft to break, bend or be detremental to the life of the shaft. No chance.


On the other hand, you can bet that putting dents in your header will effect it's performance, Not to mention it looks pretty ugly.....


Heck, you don't even need a dremal. A small file will do just as good (though it may take a bit longer)

I'd really suggest you do it this way, as I said, I've seen it done numerous times before.

I'll put 'em on this week and post my results.

mpayne

Well I know you wouldn't grind it down to half its size, that would be funny. My header has rubbed the steering shaft so much that it did take away about an 1/16" of the steering shaft but it seems to just move back toward the header. But, hopefully you don't have any clearance problems, that would be awesome.

1BADROC

iTrader: (1)

my slp's have never rubbed since they have been on like i said i just jacked to engine up slightly to get past the steering if i grinded the steering it would be half gone. Once i got past the steering i have plenty of clearance but denting them is a retarded thing to do. I dont know why i have clearance and others dont maybe everyone else has a Lt1 thats been posting instead of L98.

mw66nova

iTrader: (13)

what difference does that make? the bolt holes for the headers on the lt1 heads are in the same spot as the l98 heads.

85T/A

WOW Controversial topic ..... lo

iceman02

iTrader: (1)

LT1, can you check the diameter of the ypipe (before it joins into the 3") with a caliper, if you have one? SLP swears to me on the phone it is 2.5", but other's have shown it's only 2 1/4", maybe 2 3/8" max.

ThirdGenLS1

Yep mine rubed pretty good when i put mine one, had to dent it a bit. Anyways, since when is it the worst thing you could possible do, what you gonna loose .5 hp with doing it LOL.

Justin

LT1FUN

Well, they're finally on

Finished the install yesterday and had the guy's at straight line racing weld up the ypipe to the cat.

So here's my review.

Probably the biggest pain, was removing the factory manifolt bolts as they were rusted so badly, that two of them were seized. That was a bit of a hastle, but they eventually came loose.
All the air fitting and hoses were removed and the factory ypipe was removed with a sawzall.
After getting all that out of the way, the install could begin.


The headers themselves, were a bit of a pain to install (as headers always are) due to the fact that there's very little clearance on either side of the engine to work with, but thankfully, both went in without too much trouble.
The driver's side header has about a half inch clearance between it and the steering shaft so that wasn't an issue at all in my case, as it has been with some other's who've bought these headers.

The brake lines had to be bent out of the way a bit, but I did that with my bare hands in 2 minutes so it was a non-issue.
The passeneger side though, was VERY cramped. As in, there was about 1/16 of an inch clearance between the header flange and and the frame.

It was pretty difficult to get those headers in there without scratching off any of that shiny coating but luckily, they're still in good shape..

Without all the emissions crap to deal with, the headers were installed in less time than it took to remove the old manifolds.
A new O2 sensor was also added since now would be the best time for it.


The ypipe on the other, not surprisingly, was a total right off

For some reason, SLP's ypipes are like, 6" shorter than everyone else's, so Andy at Straight Line, welded up an extention to mate the cat with the y and then welded everything into place.

I ended up keeping the cat since it's a high-flow 3" Dynamax unit so I knew it wouldn't be a restriction and would only smooth out the exhaust note and eliminate the popping and raspiness you normally get by running a straight pipe.

The first thing I noticed when I finally started the car, was that at idle, there was a very prominent vibration. It's only their at idle and dissapears under throttle which leads me to belive that the exhaust is making contact with the frame somewhere. My guess is that it's the passenger side header flange (I guess that 1/16 of an inch clearance wasn't enough after all

Anyways, it's nothing major, I can deal with that. The exhaust note while ideling, is virtually the same as when I was running the factory manifolds but under any type of acceleration, it sounds completely different then before. It's much deeper and aggressive but nothing crazy. It actually sounds pretty freakin awesome if I do say so myself.

But of coarse, the main reson why people get headers is for the performance improvment. These SLP's delivered on that big time.

At first, just strolling around town, I honestly didn't feel much difference. It wasn't until I got the car on the freeway that I come to realise just how much of an improvment they were over stock.

From 3500 and up, the car pulls so much harder now. I no longer get that "run out of breath feeling" I used to get when I'd hit the gas to overtake someone and change lanes out on the freeway.

For the first time, the car pulls all the way to red-line and it feels like a whole new animal. The sound and performance improvments really make this feel like an entirely different car.

I'm VERY satisfied with the final outcome.

The ypipe left a lot to be desired in terms of how it fit, but other than that, I'm more than happy.


BEFORE:


AFTER:







DRIVESHAFT CLEARANCE:

ThirdGenLS1

looks good man.

hotrodln

Those SLP headers seem to have lots of clearnace around the stearing shaft.......mine were hitting, so I installed 3 washers between the left engine mount and the block..........it tilts the engine just a tiny bit.....you wouldn't be able to tell, but it does clear with having to dent them........

cookie21

iTrader: (2)

if you dont mind me asking whats the going rate on those headers?

gray89vert

iTrader: (3)

very nice

urbanhunter44

iTrader: (3)

dremel the shaft

literally hundreds of LT1 guys have had to do that to clear their headers. I didn't.

Looks great btw, hope you're happy with the shorties!

And willie.. why all the chrome but the plenum is still the old stock cast?

Dyno Don

iTrader: (7)

[QUOTE=1BADROC]I don't need to dent them anymore, I decided to do something about it. Redesigned them.
See here:
And here: https://www.thirdgen.org/forums/sout...er-thread.html

JeremyNYR

iTrader: (2)

I ground down my steering shaft slightly to clear the drivers side header. It wasn't much material that had to be removed. The cross-section of the shaft looks like this (__) only i can't draw the top line. I basically ground down a 3 inch length of the shaft so that the cross-section was circular and the diameter was equal to the distance between the flat sections. The minimum radius of the shaft wasn't reduced, so I don't expect that it is any less capable than before.

scooter

iTrader: (11)

I too had it just barely rubbing, I needed new motor mounts. Fixed the rubbing problem. And I would have to agree if it was rubbing too hard it would be damn near impossible to steer. My Grant steering wheel adapter rubbed on the column and it was almost impossible to turn the wheel because of it.

This is most likely because you are supposed to buy thier cat adapter for this kit. Just another way for them to get more money out of you, lol. I just a few feet of stainless and welded in the difference

MdFormula350

nice job on the install, i remember way back when i did mine they looked that good.

after denting mine to clear, I put in prothane poly engine mounts in just recently and i got plenty of clearance now.

LT1FUN

Sorry, I didn't see your post earlier so I didn't get a chance to repond to your question. My appologies . ..

Unfortunately, I didn't have a caliper at the time of the install, but I did take a few picture's of the y-pipe's measurments.

The collector which hooks up to the catalitic converter, as mentioned earlier, has a full 3" diameter.

The two ends that mate to the headers themselves, well, have a look at the picture. Looks to be 2 3/8. Kind of a strange diameter huh

I'm sure SLP had their reasons...



On a side note, I put the car up yesterday to re-tighten all the bolts to make sure they were all snug, and I found that the collector on the passenger side header, was infact, making contact with the frame.

I repositioned the header flange just a bit, and started the car up.

Wow! What a huge difference that made. There was no longer any vibration and the car got so much quiter inside. The car itself just feels a whole lot smoother now that the exhaust isn't touching the frame.

These SLP's were a great investment. The car pulls so much harder at the top-end with these headers, I now have no choice but to upgrade the intake for even better breathing.... (hint, hint, hint stay tuned....

anesthes

iTrader: (12)

I can't believe you guys are actually grinding down your steering shafts..

-- Joe

LT1FUN

I can't believe someone would take a hammer to a $800+ set of headers and dent the crap out of them....

Don 79 TA

thanks for the info
i just got mine in and let me tell you, they are light years ahead of the 2055's as far as quality, again just comparing them hand in hand

i am hoping to get them in this weekend

did you use the cat adaptor?
have a photo of it?

it looks like it needs to be expanded a little to fit into the cat, or in my case test pipe.

the pipe is 3" and the adaptor seems to be 2.75, so there is some play there.

i'm gonna see if she can get it expanded at the exhaust shop

i hope to get time to also install the subframe connectors while i have everything apart too

got an under car shot of it hooked up?

nice photos

oh yeah... can someone show where this sterring dremling has to be done? i'm sort of unclear about it

LT1FUN

I don't have any under-car shots just yet, but I will when I install the UMI sub-frame connectors I plan on buying shortly. I'll post them as soon as I get them.

I didn't buy the catalist adapter SLP sells, I had my mechanic fab one up on his own. It cost about the same though, so you may as well buy one from SLP. Saves you the hastle.

Here's a pic from SLP's website of the adapter.



As far as moddifying the steering shaft, don't worry about it just yet. Some people do have clearance issues with their SLP's while others (like me) have no trouble at all.

I think it really depends mostly on the condition of your motor mounts. So long as they're okay, you shouldn't have a problem with driveshaft clearance. But if they're sagging, you're clearance will suffer.

Just install the driver side header and you'll see right away if there's a clearance issue with the steering shaft. If there is, just take a felt-tip pen and mark exactly what part of the steering shaft is rubbing against the header. Then just shave it down a bit. Just don't go crazy. Shave off just enough to allow for clearance. It's really not a big deal.

Hopefully though, you'll have a smooth install like I did.

Let us know how it works out.

RPOL98

my 1-3/4" SLP headers rubbed the steering shaft. slightly, but enough to annoy me. during my last major thrash, I replaced the factory motor mounts with Moroso steel mounts. alluvasudden, when the motor went back in, I had tons of clearance between my headers and steering shaft. unfortunately, since I also had the headers out during this evolution (no longer worried about trying to maintain that nice new appearance), I did some dent-tuning with the obligatory hammer to alleviate the clearance issue, not knowing I no longer had a clearance issue, oh well. I also wrapped the headers with thermo-tec wrap so I'm not frying the rubber boot on the steering shaft u-joint, although it's kinda already shot. well, I got lots a clearance now, even with the thermo-tec wrap.

anesthes

iTrader: (12)

I'd rather lose 1-2hp than, well you know, DIE...

But we've never been short of dumb ideas here so, I guess I shouldn't be surprised.

-- Joe

LT1FUN

x 1000

You're not going to die by rubbing off like 3-4mm of material over a 3/4 inch section of your steering shaft. Come on now. The steering shaft is made of steel, not styrofoam.

The integrity of the shaft will remain virtually the same. It'l still be 99.9999999% as it used to be.


If it's such a dumb idea, I don't know why it's got a success rate of 100% and no one has EVER had a problem with their steering afterwards......EVER!!

To each their own I suppose. I still think that delibratly vandalising an $800 set of stainless steel heads when there is absolutely no valid reason to, is a pretty dumb idea myself.

We'll just agree to disagree.

Cheers.

LT1FUN

"....Dammit! My SLP's are rubbing the steering shaft!.......Oh well, guess I have to go out and buy that new Vette now...."


J/K

anesthes

iTrader: (12)

Heh.

It's just. 10 years of driving me nuts. I still like the cars, I just have no desire to work on them anymore.

My sister has a '95 I bought in December. basicly reconstructed the whole car. what a nightmare. heh

-- Joe

scooter

iTrader: (11)

Don 79 TA

how does the header gasket go on?
there is like a lip on them
does that face the head side or the header side?

Don 79 TA

i'm going to try to complete the head upgrade this weekend.

does it matter which way the gasket goes on?
i'm not sure if fit only way, just noticed it in the box, figured i'd ask

do they clear the stock started fine? or do i need to remove it for the install
since i am taking the heads off, maybe i can lay the header in there then install the heads?

sofakingdom

iTrader: (1)

I doubt that it matters which way the gasket goes on.

I'm using Mr Gasket Ultra-Seal ones with my SLPs. The SLP ones look like they may not fit the flange on my heads correctly. Other heads may be different about that.

I can't believe people would either hack on their headers, or hack on the steering column itself, to fix the clearance problem....

All you gotta do, is take the column out (about a 10-minute job if you stop twice for cold ones along the way, less if you work straight through), and slot the 3 screw holes in the sheet metal piece at the bottom of it that bolts to the firewall, toward the pass side; if you slot them ¼", it moves the column by nearly ½" at the point where it interferes. Then slide that plate over toward teh driver's side when you put it back in. Very sanitary and unnoticeable after you're done.

Yes you can lay the headers in while the heads are out, that would make it pretty easy in fact.

They clear the stock starter. But that's no reason to avoid upgrading it.

SLP's cat adapter is stainless steel. Far better than typical muffler shop stuff. Using that, also avoids welding stuff up; at least, I know I sure hate it, when the only way to take my exhaust apart when I need to, is to cut it. I refuse to have an exhaust system welded, in fact I think it's a stupid thing to do, because that makes maintenance impossible. But that's just me.

The reason they make their headers that way, is so that they make ONE set of headers, and then the different little adapters to fit all the different cars; instead of 14 varieties of headers, or however many it would take to fit them all.

Don 79 TA

well
so far the install is so-so
left side is in, that was easy
just need some odd length bolts for the center and front tubes
i am using 5/16" ARP bolts, nice and easy to get at

i could not lay the headers in and install the heads as i could not easily get at the head bolts
so i slid the pass. header right in and alittle gasket finagling and it's almost done

the drivers side wont go in from top or bottom
motor mounts are in nice shape
i guess i may have to jack that side of the motor up

hopefully it wont take that much more work to finish, i want to get this done so we can get the car running

is it a big deal if i don't use those bracket supports that were on the stock exhaust manifold?
since the sepentine system seems sturdy, i'm wondering if it's ok to get rid of

am i missing something on the drivers side install?
should i put the 02 on before dropping the header in?
i also put the spark plugs in first before tightening the header
i'll try that on the drivers side too

maybe i'll see about taking the steering column off

LT1FUN

You'll be alright. I never re-used the bracked support either when I finally put the header in. There's really not much use for it in my opinion.

As far as the 02 sensor, I put it in place before I threw on the header. Made it a bit easier. As for the plugs, I put them on afterwards 'cause it gave me a little more clearance to position the headers in place. (didn't want to risk scratching the ceramic coating )

Sounds like the install is coming along nicely. Keep us posted on the install and how you feel about the difference in performance afterwards.