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Did the GN really crank out 245 hp?

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Originally posted by GNSCOTT
I STILL sticj with my beleifs. I said why the IC isn't much help, I've said why the headers aren't any help (ATR headers don't even help a stock TR), and I know Tom at champion has flowed both heads and said the TTA heads flow a little more but not what people are claiming. I deffinately do not beleive in a butt dyno, because my Iroc's beacause they had such a rough ride always felt faster. When I drive my vette sometimes i look up and i'm doing 100..It doesn't feel that fast because the ride is so much better. The web site you posted is exactly like you described, people sticking up for their own vehicle. 3#'s of boost will feel faster and is problably 2-10ths, 200#'s is another 2-10ths. I failed Physics, but i'm sure the aerodynamics helps at least a 10th, so there's a half second minumum right there..


I think the board and particularly this section is here for these kinds of conversations. I still think that both running 16 or 16.5 #'s of boost, these cars have the same HP. STILL jmho.

One point you miss on the head flow is a substantial one..rocker arm ratios. While the cam was the same..what happens when you increase the lift and duration of the stock cam by meerly using longer rockers. Stock TTA rockers are 1.67-1.7 vs 1.5-1.55 for the GN..

May not mean a lot..but add the extra boost, higher timing of the factory TTA chip, better fuel lines(less bends), better IC, and headers..lower rear end gears..little at a time..it adds up big time..So flow may be comparable at .400 lift..but if the factory cam is .398 for the GN..the TTA is more like .418..as an approx.

That is why they MPH better..I wouldnt trade a GN for my TTA at 140 MPH..or a handling situation...but I love the street manners/getting in and out/daily driver scenario of the GN..

My .02 :)
 
Originally posted by pat83t
WOW! I didn't know the TTA had the heads re-worked by McLaren, or the ceramic impeller, ball bearing turbo.:rolleyes:
You've pointed out 2 alleged differences. Obviously the heads are different since TTA heads are TTA specific. The A/R ratio on the turbos are exactly the same and it's been documented the ball bearing turbo and ceramic impeller give scant/if any performance improvements over stock. I didn't say "exact", I said "essentially". C'mon.... :rolleyes:
 
Originally posted by GNSCOTT
I didn't consider it a pissong match. I considered it people discussing the differences/non differences between the TTA and GN. I don't think anybody said either one was better than the other, and if they did its obviously just an opinion.:)


I'll say it :D

From a Performance standpoint the TTA OWNZ :D :D
 
Originally posted by BuickPower3800
Correct me if im wrong but isnt a GNX faster than a TTA?
Depends on who's driving. There's a 1/4 mile shootout in a magazine where 3 runs were made against each other in factory delivered form. The first two the GNx won, the 3rd the TTA won. According to the magazine that did the test it was due to the driver of the TTA "learning how to launch without frying the tires".
 
I'll still bet on average, if you put em both on the dyno with the same amount of boost you may have a 10hp difference. To me, thats not screaming performance compared to a GN, thats just wicking up a GN motor.
 
may I bring in my.........................

73 Super Duty T/A in this converstion, or my Stage 1 71 Buick.............haha just kidding fellas:p
 
Re: may I bring in my.........................

Originally posted by JOHNDEEREGN
73 Super Duty T/A in this converstion, or my Stage 1 71 Buick.............haha just kidding fellas:p

You would'nt really want to compare them as the old cars where not rated at "net" horse power. 300 hp in a GN is like 425 in your "old" car. Dont get me wrong I love the old cars, My next one will be a 69 Z. :D :D
 
This is nothing more than bench racing at it's best. Everyone can toss around unsubstantiated numbers and tests and believe lburou and I are in the best position to judge this since we own both. The factory performance on average of a TTA vs. the GN in stock form puts the Pontiac about 1 second quicker in the 1/4 mile. There's a 200lb. difference between the cars and a bit of aerodynamics. Together doesn't come close to adding up to a full second difference in 1320 feet. The TTA simply puts more HP to the ground stock for stock. Is there a difference in factory boost, sure. There's a multitude of differences in the cars including boost, but we're talking stock vs. stock, not modified vs. stock or "if this had that".
 
I think we are comparing the same motor under the same conditions. If you drop a TTA motor in a GN do you think you'll run a 13.4 with stock GN 13.5 #'s of boost....I don't think so.. I think at least i'm trying to point out the HP differences between the two motors with the same boost to determine if one engine has more HP than the other and I beleive the is little to no difference. If you are comparing both motors at the same level of boost, you are comparing apples to apples. People think the TTA magically has 40 more hp than a GN and that is far from the truth. I think this is a good healthy, clean debate.:D
 
i was just kidding

about bringing the 2 old "dinosours" into this conversation. I have also owned 2 Gn's. They are all quick but the 3 cars all go about it in a different fashion:D
 
Oh and TT, you forgot 3#'s of boost along with 200 lbs and aerodynamics. Like mentioned before each # of boost is 10hp so there is 30hp, and each extra 100#'s of weight is a tenth, so there is a half second right there, then add in at least a tenth for aerodynamics and there is 6-10ths, and I beleive the difference in the twos performance. I think 1 full second difference is stretching it. again JMHO:D
 
If you're going to up a GN motor to 16.5 lbs of boost your taking chances on pump gas. The TTA chip and ECM are reprogrammed to handle the boost with more stability on pump gas than a GN motor. Boost is one of only about a dozen differences between the 2 engines, most of which are performance enhancements. Pontiac DID NOT take a GN engine, polish it up and put it in a TTA with different heads. Let me re-reference:

Technical Highlights
What makes the 20th Anniversary Turbo TA so special is that it is a complete mechanical package, and not just some tape stripes. Starting with the engine, Pontiac borrowed Buick's 3.8 liter (231cid) V6 turbo powerplant from the fabled 1986-87 Grand National. Some difference exist between the TTA motor and the GN version. Different heads were necessary in order to squeeze the motor between the strut towers. These heads, adapted from the transverse FWD version of the 3.8 liter motor, have the added benefit of improved exhaust flow and combustion chamber design. Subsequently, different pistons were required in order to maintain combustion chamber volume. Other changes to the TTA motor are a cross-drilled crank, larger 12 fin/inch GNX-style intercooler in place of the GN's 10 fin/inch design, specially-designed stainless-steel headers, higher-pressure Bosch 237 fuel pressure regulator, and a recalibrated engine control module.

Mark Grable, writing in the March 1989 Motor Trend, noted the Turbo Trans Am's "250 horses...seem much stronger than run-of-the-mill horses." The reason is simple. Although Pontiac officially rated the engine at 250 HP, in reality it developed an honest 301 HP on the GM dyno.
 
I think its all true, but I don't think the heads, pistons, crank, ic or headers did anything to add HP over the GN motor. I explained why in a previous post and i'm sure you don't wanna read it again.:) I beleive the upped boost (and a GN motor can handle 16.5#'s on a stock chip) the 200# difference, and the aerodynamics make up the power differences, and I agree it is a big difference that adds up to a little over a half a second in the 1/4. My point was and is, that I don't think there is anything magical about a TTA motor over a GN motor but 3#'s of upped boost and MAYBE 10hp from all the magical parts.
 
Well, if you're correct then PAS wasted countless man hours engineering and building that version of the LC2 for the TTA project.
 
I remember a article from Lassiter in the GS-XTRA many years ago. It was some guy from Buick (I think wrote a letter to RL) but anyway said that production T-Rs dynoed at like 280-290 at the crank. I'm not going thru 12 years of mags to find it but that's what it said.

Personally I believe it! He has connections at Buick anyway despite what you may or maynot think of him. AND despite what the bias mags said there WAS "some bone stock" T-Rs running high to mid 13s outta the factory(with good drivers). Not saying that everyyone did but more ran better than others.

My buddy Richard Clark (the guy that did the hydro brake seminar for Kirban) told me and a buddy with 2 TTAs at dinner one night that the TTA has the same exact intercooler as the GN. He as done a LOT of research on these cars and has the largest private T-R parts and car inventory than anyone. He has done no-tellin how many test on parts thru the years. So I believe him on that knowing his background and attention to details.

I hate when people start these kind of threads asking these kind of questions and then everyone has there own beliefs and it ends up in a flaming match!:(
 
I haven't seen any flames in here. I think we all have been having a discussion. No point in having the discussion if we all agree.:)

I think they had to spend all those man hours on the LC2 to get it to fit in the engine compartment.

Don't know if a TTA IC is a GNX one or different shaped or whatever, but I know if it has the same neck as a GN/GNX it would have to be huge to make a difference, because the neck on the IC is what limits it, an xtra row isn't gong to help much.

I think a fair figure to put on a stock GN was a 14.0 and a fair figure for a TTA at 13.4. Sure you could get more /less out of them from different drivers, and some cars run better from the factory than others.

Which brings me to my point that I still beleive that the TTA's exta 6-10ths come from 3 xtra #'s of boost, 200#'s lighter and better aerodynamics, not the heads, crank, headers or intercooler. I think they are just different, not necessarily better..Now my disclaimer.....JMHO :D
 
Well, everyone's theorizing or quoting 2nd or 3rd person sources. No one here has any hard data or dyno tests to prove anything. The only hard evidence is the testimony of two owners of both cars, me and lburou. We're both in agreement on this. The performance between the two cars is night and day. From throttle response to the pressure it's pushing you into the seats. Now it could be both our imaginations but I don't think so.

I know the times of both cars varied based on many conditions, but I think the most accurate 1/4 mile times for stock examples would be low 13's for the TTA and low 14's for the GN.

I've got a long weekend coming up so I could waste some time and count the fins per inch on both intercoolers.....:o
 
I think the hard evidence are the magazine times that show a TTA is 6 tenths faster, and a stock GN compared to even my 02 WS6 isn't what i would consider night and day.
 
I've seen magazine articles vary in TTA performance from as low as a 13.1 to a 14.3 which is evidence they're completely inconsistant. So I refer back to those who've owned both vehicles in unmodified form.

Here's just a sampling from what I could find in 10 minutes. My magazines show times differing from these:

Car Craft, December 1988-Volume 36 Number 12-pp. 94-95, 97
1989 20th Anniversary Pontiac Trans Am
0-60 5.4 sec, 1/4 mi 13.5@103 mph
"We feel its performance has set the high-water mark for the decade."

Car & Driver, June 1989
20th Anniversary Pontiac Trans Am
0-60 4.6 sec, 1/4 mi 13.4@101mph
"This is a car for muscle-car mavens, pure and simple."

Hot Rod, November 1988-Volume 41 Number 11-pp. 90-91, 93
20th Anniversary Trans Am: Pontiac's Excitement Package
0-60 6.0 sec, 1/4 mi 14.21@97.8mph
"With all the power and handling you could ask for in a production performance car, it definitely qualifies as one of the absolute best buys of '89."

Motor Trend, March 1989-Volume 41 Number 3-pp. 50-52, 54, 55, 58 Pontiac 20th Anniversary Trans Am 0-60 5.4 sec, 1/4 mi 14.18@95.8 mph "A drive in this killer Pontiac is the most fun you can have with your clothes on."

Road & Track, January 1989-Volume 40 Number 5-pp. 92-94
Pontiac Turbo Trans Am
0-60 5.3 sec, 1/4 mi 13.9@99.5 mph
"...this 20th-anniversary rocket can't decide whether to pace at Indy or enter." "An excellent coupling of turbo engine and auto trans."

Turbo & Hi-Tech Performance, May 1989-Volume 6 Number 3-pp. 40-43, 63 White Heat-Pontiac's Turbo GTA: The New Pace In Performance 0-60 4.89 sec "...we took a leisurely drive...overall performance was to say the least...impressive."

High Performance Pontiac, December 1989-pp. 16-18
GTO vs. GTA Shootout, Who's the Boss?
1/4 mi 13.74@101.8 mph

Motor Trend, November 1989-Volume 41 Number 11-pp. 42-46, 48, 52-55, 58-59, 62, 64, 66-68, 72, 76
Bang for the Buck
0-60 5.11 sec, 1/4 mi 14.18@98.86 mph
TTA takes top honors in points after six phases of testing among seventeen cars.
(Don't you love it when they split up an article into nine sections!)

Muscle Car Review, July 1989-pp. 24-26, 57-59
GNX vs. Turbo Trans Am Shootout: Boost -Bird vs. bad-to-the-bone Buick
Here's the lowdown on the article that everyone's been wondering about. Two individually owned cars, each untouched, with less than a 150 miles on them. Roy West brought the GNX and Lee Gorman brought his TTA. Both drivers also own other Buick turbo cars which are raced on a regular basis. After some warm-up, the cars stage for round one and the GNX takes a decisive win. Round two proves to be much closer but again the GNX takes the win by the narrowest of margins. But don't despair fellow TTA owners, read this quote from the end of the article: "By the time class racing rolled around, Lee Gordon had gotten the hang of launching the Pontiac. He rolled over the competition-including the GNX-to win his class."

Muscle Cars, November 1989-Volume VII Number 6-pp. 52-54
GTO vs. GTA Shootout, Who's the Boss?
1/4 mi 13.74@101.8 mph
1965 389 Tri-Power GTO 4-speed vs. a TTA at Englishtown. The classic GTO was no match for the modern muscle of the TTA, which won every run fairly easily. Some good photos, although all in B&W, including a photo of Ed Kozinski's TTA vs. the test report TTA. Also see article under Individually Owned TTAs for more details on Ed's car.

www.89tta.com:
performance: 0-60: 5.5 sec
1/4 mile: 13.5 sec
60-0: 139'
roadholding: 0.86g
weight/hp: 13.4:1
 
thats why i gave the average, and i think its fair to say the average for a TTA is 13.4. I;'ve also driven in a TTA and it FELT faster than my WS6 and ran a 13.8. Older more unstable cars feel faster because the ride is so much more rougher, Take a 14 sec. pass in a 66 GTO and it feels like your breaking the sound barrier.:D

I think its a stretch to say the TTA on average ran 13.1. Put 2 stockers on a dyno with 16.5#'s and i'll bet they are both right around 300 rwhp.

Do you think a GN would run the same #'s with a transplanted TTA motor?? I bet if ya turn the boost down to the stock 13.5#'s it doesn't pick up a thing.
 
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