paul_huryk

Out of curiousity, has anyone found any testing of the SLP package pertaining to top speed?

Have seen quite a few articles on the impact on 1/4 mile performance and dyno power, but nothing beyond that. Obviously with an increase in total power and power above 4500rpm, there has to be some sort of gain.

Anyone?

92GTA

iTrader: (11)

I have never seen any review of the SLP Package that mentions and actual tested top speed.

Top speed wasn't really that important to Americans back when these cars were made from what I can tell from all the media I've read over the years.

Alex

TTOP350

iTrader: (8)

I have some old old stuff I'll check out and see if the info is in print.

:edit: did some reading and couldn't find anything.

86TA355SR

iTrader: (1)

My 91 has the dealer installed SLP package.

I would be interested to hear how many other cars are out there with it. I know it was installed after dealer delivery, so probably impossible to know. Additionally, Summit used to sell all the parts to do it yourself. Easy for someone to pass it off as, 'came that way'.

To think I traded a T-Ram for heads once almost makes me sad sometimes. But, someone else is enjoying it and that is enough for me!

92GTA

iTrader: (11)

Hard to replicate the SLP decal that went on the radiator support with the punch outs for the parts installed with the package, and the C.A.R.B. emissions stickers that went on the passenger doors of the CA cars without good originals to copy Plus some dealers, mine did, included a supplemental window sticker which included the package and it's cost over MSRP. My cars buyer however ordered the car and the package at the same time and financed it all together.

86TA355SR

iTrader: (1)

I was lucky enough to have the same situation. Nice to see someone else have that package on this board.

92GTA

iTrader: (11)

Interesting story on mine too, the original selling dealership in Santa Rosa bought it back from the original owner after a year or so. They removed all of the SLP parts and put it back to stock prior to selling it again. In 2002 when I drove it to Roseville for Trans-A-Rama, I drove by the original dealership for a photo-op (they let me pull it onto the grass next a 2002 Trans Am for pics). They gave me an old set of original dealer license plate holders and also copies of all of their records which is how I found out it had the package installed. Took me another year to locate all of the correct parts and get it 100% correct. I got the VERY last SLP LB9/Auto PROM in the entire U.S. dealer inventory from a dealership in Wisconsin, talk about lucky! I also made friends with Kevin Woodruff at SLP who provided me with an extra package decal and CARB decals, very last ones SLP had he said. I ended up selling them to a collector a few years ago.

Alex

TTOP350

iTrader: (8)

Here is a pic of mine as I got it, JY formula 305 5spd. You can see the dealer sticker on it if you look. I have the paperwork and this was dealer installed/financed together.
Has everything but the cold air kit, K&N filter but nooo SLP airbox.

86TA355SR

iTrader: (1)

Very cool!

Love the story also, what are the chances of you stopping in there and finding all that out? Slim to none in my book! Otherwise, you would have never known what you had! Love to hear stories like this!

Here are pictures of mine. I have everything but the cold air package. The intake plumbing is off my ProCharger for another car. Also, my headers are the early 'tri-y' design. Anyone else have those? Curious...

Car has 42K original miles by the way. Second owner.

86TA355SR

iTrader: (1)

Also, as said above, does anyone have articles about this or the package in general? I have read a few things on Frankie's GTA Source Page, but that is the only literature I have saw.

I'll see if I can find some more. Thanks!

TTOP350

iTrader: (8)

Yup, I have the Tri-Ys on the yellow one in the above pic. For some reason I think the air box was optional during a certain time frame. It looks like someone punched bigger holes in your decal b4 they installed it instead of tearing out the little punched area.
Veeeery clean car !!
I have several binders full of SLP parts and testing info but I cant find any top speed stuff.

86TA355SR

iTrader: (1)

Thank you!

Would you mind scanning/sending a few articles to me via PM? That would be awesome, would love to read them.

Thanks!

paul_huryk

From 3rd gen blog:

\

TTOP350

iTrader: (8)

I have those articles also. If you look at the air box, runners, muffler and tips you'll notice its one of the very 1st designs.
The airbox is aluminum, runners have one pair on each side opened up all the way thru, the muffler is a steel offset inlet/outlet and the tips are a cool oval shaped instead of angle cut.
I have one of the oil pans. I ordered it about 94 or so? He sold the company years ago and the pans are made across the pond now.

86TA355SR

iTrader: (1)

Awesome, thank you for posting the article, I really enjoyed reading it.

paul_huryk

Her's an old SLP article from 1990:

92GTA

iTrader: (11)

NICE! I've never seen that article!!! Thanks for posting!

Alex

paul_huryk

One last one...

RockinGTA89

what i don't understand is why couldn't slp continue with production of the stainless 409 exhaust headers? They are so hard to find! From what i heard, they were probably the best matched exhaust header system for 3rd gens. I'm sure they were specifically made for them anyways to fit confined space in the engine bay area. Even the Formula Firehawks are equipped with them. I'm sure now, they are fetching a bit of money, that is if you ever see them posted for sale.

However, I have to say those are some very cool reads, so thanks to all who posted! My uncle owns a 89 GTA convertible that has that special sticker for the installation of the slp components. The only thing the original owner installed was the Cold Air Induction system. Which makes me wonder, why didn't he (or she) just go all the way or at least add a few more go fast goodies. I'm sure the price was already high with just the convertible, but still...if it was me, I couldn't pass up buying at least getting the runners or even the exhaust system!...i'd finance them through GM anyway! haha!

92GTA

iTrader: (11)

I agree, the Tri-Y's are an amazing header design, and the craftsmanship, the welds, ****ing art! However, that is why they were discontinued. Cost to produce was insanely high. The labor involved was almost cost-prohibitive. They never designed a Tri-Y for the LT1 so once sales slowed and all the tight-asses buying the much cheaper 4-into-1s, yeah goodbye

paul_huryk

Definitely good quality along with a really neat design.

But as you mentioned, labor and material costs would make them too expensive to sell for a profit.

I'm under the impression that once competitors brought shorties for lower prices to the market, SLP started phasing them out. Except for race headers, no one else made them for 3rd gens...

paul_huryk

Found the answer to my own question on SLP's website (in bold):

About SLP

Providing OEM-quality performance, handling and appearance components for late model Detroit-based Performance Cars (Camaro, Corvette, Mustang, Challenger and Charger) and Full-Size GM Trucks and SUVs is what SLP is all about.

Prior to forming SLP and dating back to 1970, Ed Hamburger first became well known for his unique product line of performance engine components, developed exclusively for small block Chrysler-equipped race car applications. His company was also one of the first Chrysler Direct Connection Performance Parts Distributors in the country. That company was sold in 1988.

The next chapter on this interesting journey, which eventually led to forming SLP, was the creation of another well-known company in the Performance Parts Industry, Hamburger's Oil Pans, which Ed formed in 1975. Over the next 20 years, Hamburger's Oil Pans were the dominant performance oil pan used in Winston Cup (now known as Sprint Cup) racing and NHRA Drag racing, with over 85% of participating race cars using his oil pans. By the time the company was sold to another well known performance parts manufacturer in 1995, more records were set and races won by cars equipped with Hamburger's Oil Pans in sancationed motorsports events throughout the country, than any other oil pan manufacturer at that time.

SLP's intial claim to fame was having the distinction of being the very first company in the Performance Parts Industry to develop and manufacture a totally integrated and emission legal (in all 50 states) performance package providing a serious performance gain, while also improving fuel economy for late model V8 Camaros and Firebirds. The package included SLP's stainless steel headers, SLP's stainless steel cat-back exhaust system, SLP's high-flow intake runners, SLP's cold air induction system and an SLP revised PCM E-Prom. Installing this package on a TPI 350 CID engine-equipped 1988 Camaro resulted in a 50 horsepower gain, a one full second reduction in 0-60 MPH times, a 6 MPH increase in top speed, and a 2 mile per gallon improvement in highway fuel economy.

The next milestone for SLP was the addition of limited production specialty vehicles to the already impressive line of performance parts. SLP's initial efforts were rewarded with the GM-approved 4th generation RPO (Regular Production Option) Camaro SS and Firebird Firehawk/WS6/Comp TA Specialty Vehicle programs that began in 1995. Over the next eight years SLP produced over 55,000 GM specialty vehicles for GM and its Chevy and Pontiac dealers, out of its 140,000 sq. ft. Montreal-based assembly facility. They included Camaro SS and RS models, along with the Firebird-based Firehawk, WS-6 and Comp T/A models.

In August of 2002, GM ended production of the 4th generation Camaro/Firebird, along with SLP's Camaro SS and Firehawk Specialty Vehicle Programs. SLP then focused on expanding their product line of performance, handling and appearance products for all late-model Detroit-based performance cars including Camaro, Corvette, Mustang, Charger, Challenger, and Full-Size GM Trucks and SUVs.

Once GM announced its intentions of producing the 5th Generation Camaro, to be introduced in the late 2009 as a 2010 model, SLP started product development of it's own powertrain, suspension, and body components for their upcoming 5th Generation ZL Supercharged Camaro Specialty Vehicle Program. SLP focused on getting to market as soon after GM started shipping cars, with start-of-production beginning in October of 2009, and continues to this day in their Toms River, NJ and Troy, Mi facilities.
In January 2012, SLP added production of its new 525HP Supercharged Escalade Sport Edition and 610HP Supercharged ZL610 Corvette to its already impressive Camaro Specialty Vehicle Programs. As of June 1st, 2012, SLP started production of its 2013 supercharged Sport Edition GM Truck and SUV Specialty Vehicle Programs. SLP's Specialty Vehicles are only available through GM dealers throughout the US and Canada.
This website celebrates over 25 years since the company was formed in 1987, and showcases all of the unique products currently available from SLP Performance Parts, Inc.

92GTA

iTrader: (11)

NICE FIND!!!

Copperhead

I seem to recall a magazine roadtest in 1987 when the 350 IROC came out, with a red IROC and red Mustang GT in a shootout. IIRC, top speeds were 149 and 148 mph, respectively. Road & Track, perhaps?

TTOP350

iTrader: (8)

I knew I had seen that before but for the life of me I couldn't remember where I saw it!
Nice work!!!

AmorgetRS

iTrader: (6)

The article is posted on this site:

https://www.thirdgen.org/rt_october1...s_camaro_irocz

njmick24

iTrader: (3)

You said EARLY tri y design, so are their more than one? If so, whats the difference?

TTOP350

iTrader: (8)

2, 1" 5/8s tri-Y designs. older ones have a multi piece flange and the newer ones have a 1 piece flange.
2, 1" 3/4 tri-Y designs. older ones have a multi piece flange and the newer ones have a 1 piece flange. (accel brand)
2, 4-n2-1 designs. One is 1" 5/8s and other is 1" 3/4s. 2 different flanges, stepped on the 1 5/8s and flat on the 1 3/4

Edited to include another tri-y design change I found.

njmick24

iTrader: (3)

So the Tri-Y 1 5/8" are the "early" 1st SLP design followed by the 4 into 1 shorty style which was available in either 1 5/8" or 1 3/4" . The Tri-Y 1 5/8" were the ones on the firehawks with the dual cats. I have a set of Tri-Y that go into a single 3" cat, but the other day online I saw the same ones I have only the Y-pipe to it looked different. Now looking back at what I saw I realize the Y-pipe must have had some type of repairs done to it. I think I read elsewhere in the forum the Y-pipes on the Tri-y sat to low and scraped often. Thanks TTOP350.

1MeanZ

iTrader: (9)

...so back to the original question. As far as I know, 700R4 transmissions won't shift into overdrive at WOT, at least F-body ones won't from my experience. I didn't see anything about them modifying the transmission, so how was this possible?

If you stay under 75% throttle they will stay in OD. Were they topping them out that way and measuring the increase in speed in OD at 3/4 throttle?

TTOP350

iTrader: (8)

That's a good question.
If I remember correctly, SLPs shift kit helped that issue with the autos buuuut it wasn't part of the 50 state E-legal kit.

92GTA

iTrader: (11)

I have that mod done to my 4L60, the parts are from the Chevy Caprice police vehicles.

Maybe I'm missing something, but why are you guys referring to 4-into-1s as a 2nd gen Tri-Y? They are not. Be simple definition a Tri-Y is a 4-into-2-into-1 design. Also, the Tri-Y's I had on my GTA were also single 3" cat version and yeah, my y-pipe even before lowering my car, got smashed to ****ing **** a few times and repaired. Finally a bad accident damaged the y-pipe and the headers so badly I had to remove them and I'm just running 4-into-1s now.

TTOP350

iTrader: (8)

I'm not saying 2 Tri-Y designs. Only 1 design and it was the same as the Firehawks used. (maybe a A.I.R. tube inlet bend change but that's all)
There are however, 2 of the 4 in to 1 designs.

I have a tri-y Ypipe that has some damage and I'm looking for some messed up stuff to fix mine.

paul_huryk

Early model 70R4 and some non performance motored cars of later years would not shift into OD at WOT, but all the L98 cars did... B&M used to make a valve to allow any 700R$ to shift at WOT - had one in the rebuilt trans in my 84...

1MeanZ

iTrader: (9)

I don't think thats true. My '89 L98 GTA wouldn't go into OD at WOT, I tried it, and I know for absolute fact it was the original trans and had not been modified. A buddy claimed his 87 L98 GTA would go into OD but thats the only car I know that would do it. My 86 LB9 IROC as well as my buddies 86 LB9 IROC wouldn't go into OD either, we tried them both.

Maybe others have experience to verify?

paul_huryk

My 89 GTA does - but I can't verify if the trans is original since I only bought it last year and never looked into it... My buddies 89 L98 IROC did (trans was original at that time) too.

Copperhead

I dunno what the gears were, but we went 140 mph every weekend back in 1988 with one of those early L98 IROCs. I don't think you could do that in 3rd gear.

paul_huryk

I never for a second believed the GT would go 148mph in stock trim, low 140's sure. Rememeber seeing this article when new and I was stunned.

Considering the atrocious aerodynamics of the Fox stang and the power level, it is just can't keep up with the L98 cars in top speed. Maybe in a t-bird turbo coupe body, not something as "dirty" as the Stang.

TTOP350

iTrader: (8)

My 89 formula 350 would bury the speedo very easy and would run 155mph ish. 140mph marked on the bird speedo but needle stops at a true 145mph. It took some pedal work to get it there because my trans wouldn't let me go a true full throttle in OD, close but not quite.
My car holds OD full throttle these days..

AmorgetRS

iTrader: (6)

You are saying 155ish bone stock?

1MeanZ

iTrader: (9)

OK that is exactly what I'm talking about. By my definition I used earlier, your car does not upshift at WOT. My GTA would do the same thing as would my IROC. With my IROC I rolled in slow enough to keep it in high gear, I got to probably 80% throttle and it kind of slips into a vague neutral kind of thing. Ease up a tad and it' would go back into OD again. My GTA did the same thing.

1MeanZ

iTrader: (9)

LT1 4th gens can go 157 if I remember the article in Super Chevy correctly. They tested a Vette, Z28 and a Pimpala SS. Even the big Impy went over 140 I believe.

TTOP350

iTrader: (8)

Yes, we have loooong open strait flat roads around here. We aren't road limited, its easy to just stay in it and roll out..

874ME

iTrader: (1)

NFW your car went that fast in drive. It didn't happen and wont happen unless you can go WFO in OD. I have had my 87 IROC 305 to 130ish several times in the mid 90's using the same feathering the throttle tactic. What I found was if you gave it to much throttle it would down shift and maintain the speed. GM wasn't going to let some one over rev the engine.

I do know for a FACT that a bone stock 87 IROC with a 5.7 will push the needle past 150MPH. I also know for a fact that car would shift into OD at full throttle and hold it all the way up. I was riding shotgun in one ( my moms car, my younger brother was driving) when this happened several times. The transmission was in OD from 130ish up though. We had 3 people in the car, the guy in the 88 mustang GT convertible next to us was not able to keep up. My memory isn't great but that 5.0 mustang fell by the wayside around 135MPH and could go more than 140. The speedo on my moms car went to 145 or 150 IIRC. The needle pushed well past that, my guess was 155mph. Then again, my moms car was ( still is) a strong runner. It had 3.23 gears and had a lot of torque.

My mom sold the car to my younger brothers father in law. It now sits in a garage on Whidbey Island. She sold it with around 38K miles, it now has around 60K.

Copperhead

I also recall, back in the day, going 140 mph in my buddy's 87 IROC pretty much every weekend, one easy hand on the wheel . . . super easy to drive fast.

3.8TransAM

91 Formula 350 will go 150.

91 GTA 350 will go 150.

89 TTA, its just starting to work hard at 150

This is when all above cars were stock and performed on the drive(s) home.

Had to repeat it for valid results later as well.

TTOP350

iTrader: (8)

Never ever said my car went that fast in D. It would do that in D if I had a set of 2:41 gears.
I did have to play with the pedal to find that sweet spot in OD to keep it running top end without it downshifting or losing trans oil PSI and then the trans..

FYI for everyone again:
The speedo needle will stop at 145 in the Birds. It CANNOT go any farther unless you modify some things in the speedo. Soo my true top speed is a guess of 155mph by how the speedo came back down, tach and a friendly officer.
I'd bet its the same in camaros