Did the GN really crank out 245 hp?

[Hyper]

tta

Originally posted by Mr. T
So?! At least it is getting the misinformation problem fixed!

Plain and simple: Stock vs. Stock the TTA is faster.

There WERE improvements to the LC2 and it shows.
You can't deny it. If you do, you're a fool.
And why wouldn't there be? The engine was 2 years older, had 3 years of aftermarket tuning in it, something had to improve, right?

Let it be at that.

Oh FWIW, my Turbo T @ 20psi on propane is only running mid-13s @ 103.Xmph. These are stock GNX and TTA numbers, and I had to do a lot of simple bolt-ons to get it here. There is something to be said for the pump gas numbers the TTA and the GNX put down, there were clearly improvements.

Granted, my car can't get a 60' below 2.0 to save its life.

If you are only running 13@103 with 20psi of boost something is way wrong there. Hell I ran 13:21@104 in 1988 with a kb chip in pump gas and sportsman "I" tires, nothing else not even a fuel reg. So you need to do some checking to see why you cant run any faster than that. I after that added a adjustable fuel reg, magacore wires, kb ram air, lock up converter switch, LC mag 4, with stock turbo, intercooler, injectors.. .. I ran 12:19@109 mph, this is with the stock turbo and intercooler....so there is something wrong in your car. I think the TTA was faster than the GN becasue of the traction and the boost increase. Other than that it is all what you do to one. Today I bet I could put my car back to stock, turbo and all and just by tweaking it run 13.00's all day. We have to all remember that these are all buick powered cars and we dont need a bashing match just because we like our GN's better than the TTA's. The TTA's guys are our friends, and without us they have no one left. The TA crowd dosn't like them because they make the trans am's look bad by out running there own kind with a buick power plant. So we need to keep this to a friendly tread and remember our buick family.

 

[Lee_Burough]

I feel amicable toward the GN fans.

and without us they have no one left.

I don't know that there is "nobody" out there who can appreciate a TTA. A neighbor six doors down literally cracked my back Saturday with the low end torque of his Cobra And, he wants to cruise a bit in the TTA There are always people out there who appreciate a rare car. They may be ignorant, but, some of them are educable

 

[GNSCOTT]

If Pontiac did such a great job refining it, they made it as fast as a GNX weighing 250#'s less and alot more aerodynamic. Sounds to me that Pontiac engineers should take a class at ASC if ASC was able to do that w/out refining a TR longblock.

I'm still not in disagreeance about the TTA being faster, thats obvious, but I'll bet you any TR out there that sheds 200#'s out there will pick up two tenths and they will pick up another 2 tenths if they turn the boost up 3#'s.

 

[brandon87gta]

Pontiac didn't really refine the TTA, PAS did. Pontiac sold them

Brandon

 

[TurboDiverArt]

Originally posted by brandon87gta
Pontiac didn't really refine the TTA, PAS did. Pontiac sold them

Brandon

What's PAS? Meant to ask that before.

 

[brandon87gta]

PAS, Inc., was an engineering firm led by Jeff Beitzel. Beitzel and his team did most of the TTA development work. They built the V6 turbo engines at their plant in CA. The engines were then shipped to Van Nuys, CA to be installed in GTAs on the GM assembly line. The now, TTAs were then shipped back to PAS for final assembly, testing, and quality control.

PAS also built the Syclone/Typhoon for Chevy.

I think they went under in the mid 90's and no longer exist. I could be wrong on that though.

Brandon

 

[TurboJunky]

Originally posted by GNSCOTT
If Pontiac did such a great job refining it, they made it as fast as a GNX weighing 250#'s less and alot more aerodynamic. Sounds to me that Pontiac engineers should take a class at ASC if ASC was able to do that w/out refining a TR longblock.

I'm still not in disagreeance about the TTA being faster, thats obvious, but I'll bet you any TR out there that sheds 200#'s out there will pick up two tenths and they will pick up another 2 tenths if they turn the boost up 3#'s.

If you crank up the boost from the stock 14.5 on a GN you're cheating since you'd be at 17.5 and a stock TTA is 16.5.

I'm curious here. Lets raise out hands for those who've driven/ridden in a stock TTA and/or GN.

Driven STOCK TTA -
Ridden in STOCK TTA -
Driven STOCK GN -
Ridden in STOCK GN -

Copy and paste your personal experience in your responses, smile = yes, frown =no.

 

[1BADDAM]

Re: tta

Originally posted by Hyper
The TTA's guys are our friends, and without us they have no one left. The TA crowd dosn't like them because they make the trans am's look bad by out running there own kind with a bucik power plant

Man ain't that the truth, without our G-body cousin we have no friends Were not to appreciated in the F-body clubs, 3rd or 4th gen, mainly because we kick most of there as ses , sucks to sometimes have a "freak V6 firebird"

 

[sr71gn]

stock gns were set for 13.5 but this would vary between cars as everyone knows these gns are not all the same stock- also years back there was a good test of stock gn heads showing they also varied in cc's- thats why one stock gns with the same short times would vary 3 to 4 tenths at times-

if the 3800 heads were better than a gn's why didnt all the "guru's" switch to them over the years??

back when pas was testing their first tta's they had several of them at milan drag strip in mich on a wed test & tune day

at the time my gn which was stock except for- chip- 237 regulator-test pipe- m&h 8.5 racemaster tires only- was running 12.90's with high 1.8 60 foot times- (front sway bar off)one of their engineers come over to look at my car and i discussed some of the things i had done to it- he said the only reason they used the heads was because they could not fit the stock ones in-not for a power advantage- in fact he told me their big problem was making everything fit into the different body style- they werent trying to improve on power but they felt 16.5 lbs of boost was not going to hurt the engine and they had enlarged the wastegate hole slightly so they could make sure and control boost

 

[Captain Mark]

I have in my hot little hand a dyno sheet from the former owner of my TTA. Results are as follows:

Stock condition: HP at the rear wheel - 255 hp w/ 362 torque

Slightly modded, and in it's current condition: 328 hp

K&N. 3" ATR exhaust and down pipe, Walbro FP, stock boost, turbo, injectors with thrasher 92.

And for the record, I had never heard of the TTA until about a year ago. I was on the lookout for a TR/GN and the TTA just appeared and I bought it. Glad I did, I love the car. But The only reason I bought it was because of the Buick power plant. I have always been a Buick lover, and always will be. I also own a big block 455 car. I wish I had a '65 Riviera! Anyway, I will own a TR/GN one day. But the TTA is a keeper. Most fun car I have ever owned. Hope this helps.

 

[GNSCOTT]

My GN bone stock with original turbo and aftermarket guage pegged up to 13.5 than dropped to 13psi, and I beleive that was the factory setting. 1 psi of boost is 10 hp, so I think (or know) a GN will pick up 2-10'ths with 3#'s of boost, and ANY car can pick up 2-10ths by dropping 200#'s.

I still say at best the TTA longblock may have 10 more HP than a GN longblock, but then there is the GNX issue. What psi did the GNX run stock??. With the added suspension parts, and all GNX's being loaded it had to weigh at least as much as a GN, and if the TTA had an improved IC, ecm, and exhaust like the GNX, why isn't the TTA faster than the GNX seeing how the GNX weighs more and has that non PAS worked long block??

 

[GNVAIR]

Someone had asked what would be required to install the TTA/FWD 1.7 rockers:
Basically you need the TTA/FWD heads. These would be the 3.0/3.8 FWD heads AND not the 88-up 3800 heads.
You will also need the heads, crossover and down pipe from a TTA since the TTA/FWD have exhaust ports that are flush with the head. Valve covers ,push rods and 2 accessoryt support rods are also different.
TTA/FWD heads have stud mounted rockers as someone else noted where as the RWD Buick V6 has shaft mounted rockers.
I have a local friend that has a TTA engine in his 87 Turbo T. It fits and works fine. He used all the TTA plumbing (headers, cross over and down pipe) to make it work. It actually fits a little better than the regular Turbo Buick engine.
I might also make a correction to TT/A1233; the ecm is the same identical unit in the TTA as used in the 86-87 Turbo Regals and some select 3.8 powered front wheel drive cars. The prom chip was unit.

 

[TurboJunky]

Well, I havn't actually done electronics tests to determine the validity of what I've read but here's a snipit from www.89tta.com regarding the ECM. I know there's no PHYSICAL difference but it was reprogramed for the differences between the engines. As far as all this debating, perhaps PAS was all wrong, perhaps the documentation on the better flow of the heads is all wrong and this is a mass conspiracy to inflate the #'s on a car that didn't sell well in 1989.

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.

 

[TTA89]

Originally posted by TT/A1233
Well, I havn't actually done electronics tests to determine the validity of what I've read but here's a snipit from www.89tta.com regarding the ECM. I know there's no PHYSICAL difference but it was reprogramed for the differences between the engines. As far as all this debating, perhaps PAS was all wrong, perhaps the documentation on the better flow of the heads is all wrong and this is a mass conspiracy to inflate the #'s on a car that didn't sell well in 1989.

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.

Right, the calibration is done in the Chip thats seated in the ECM, not the ECM itself as there is nothing to recalibrate.

 

[GNVAIR]

As for the differences in the head casting number (last 3 digits 702), that could be something as simple as different valve seats, etc. Anytime GM made even a slight change to a casting, the casting would get a different part number.
I think the additional performance of the TTA is just an accumulation of a lot of small tweaks that made a difference.
Heads
Headers/cross over
Rocker ratio
Prom chip
Higher boost
More fins per square inch in the intercooler
aerodynamics
weight
drivetrain loss (TTA = 9 bolt rear GN = 8.5 10 bolt)
Bottom line is that both cars are probably within 20-30 horses of each other on a dyno. Not a big deal to me.

 

[pat83t]

Let me sum all this up by saying: It isn't really important what kind of car it appears to be, what is really important is that it is BUICK powered.

 

[RobR]

Been pretty interesting read. I had a 87 GN and now have a 89 TTA. Even with the mods on the GN, it just didn't "feel" as fast. And it wasn't as it only went 13.6 back when I had it at the track, back in 1990. Bone stock, it ran 14.2 on 235/60/15 BFG Radial TA's. When I bought the TTA with 17K miles, it had an ATR chip and 160 thermo, along with Firestone Firehawks. The ATR was way too aggressive, so a Thrasher 92 went in. I took it to the track and ran 13.0 five straight times! If I would have locked the converter or upped the boost, I would have had a 12 sec. car for $30!

Mine doesn't rattle like most 3rd gens, but has its squeeks. The GN had a nice one also from the windshield.

I loved the ride of the GN and still wish I had that car. I hated the brakes and the lack of cornering ability. And man did that car get the head turning The TTA is more subtle. Its just a GTA for most people looking. At the track its a head turner because its quick and quiet.

As for the differences, there are some. I think its the package that makes the difference. But about this weight thing, the gearing in the GN, I would think, more than makes up for it. 3.42 vs 3.27. I know the boost gauge isn't that reliable in the GN, but mine would tickly both red lights and then go to one, then none in 3rd.

Sorry so long...

 

[Rogue Leader]

As I have owned both a GN and a TTA my sentiments are exactly the same as TTA 1387. no need to re-hash. The GN is definitely higher in the cool and stylish factor, the TTA is much higher in all around performance.

Just a couple notes..

Firstly while drum braked from the factory the GN 8.5 rear is FAR superior to the TTAs 7.5 rear... these f-body rears are like glass compared to a good 8.5 10 bolt.

That said... can this thread ever just DIE already????

 

[Razor]

Originally posted by Rogue Leader


Firstly while drum braked from the factory the GN 8.5 rear is FAR superior to the TTAs 7.5 rear... these f-body rears are like glass compared to a good 8.5 10 bolt.

That said... can this thread ever just DIE already????

Show me a broken 9 bolt rear .. I've seen more broken posi's and bent axles with the GN than with the TTA.. Granted the gears are smaller 7.625 and tweak under extended hard launches, and the Posi's are pricey as hell..but very durable rear..unlike its 10 bolt 7.5 brother made of glass.

Plus no C-clips

Chip had a completely different calibration due to gear ratio differences and optimization of engine flow..bigger cam(increased lift cuased by higher ratio rockers)

And no 3.8 had center bolt heads..only 3.0 FWD castings 7515,2408,6702.. difference..who knows exactly for sure..they all look the same.

ECM was the same..including the calpak chip. Eprom was different.

 

[buickman69]

Originally posted by TT/A1233
If you crank up the boost from the stock 14.5 on a GN you're cheating since you'd be at 17.5 and a stock TTA is 16.5.

I'm curious here. Lets raise out hands for those who've driven/ridden in a stock TTA and/or GN.

Driven STOCK TTA -
Ridden in STOCK TTA -
Driven STOCK GN -
Ridden in STOCK GN -

Copy and paste your personal experience in your responses, smile = yes, frown =no.

I HAVE ridden in AND driven a "BONE STOCK" TTA and GN.

TTA
GN

That same TTA "STOCK" with "stock chip" and everything ran 12.95 in BG KY "July heat" Howvever, he DID have the airbox/filter removed with a pair of his wifes panty-hose rubberbanded over the MAF. Hey, we had to see....