Did the GN really crank out 245 hp?

[TurboDiverArt]

Originally posted by 86brick
Art, I could be wrong, but I'm pretty sure the heads on the TTAs were FWD 3.8 heads.....

You very well might be right. I think both yours and my point is that they are just a different production GM head used for clearance purposes and not meant to be a performance upgrade over the GN head.

 

[motorhead]

Originally posted by Razor
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.

Really?!

1) Will these rocker arms swap onto the 8445 heads?
2) Got some part numbers for me?
3) Or can I source these off of a junkyard 3.0L?

This is the ONLY interesting piece of info in this entire thread, IMO.

 

[TurboDiverArt]

Originally posted by Mr. T
Really?!

1) Will these rocker arms swap onto the 8445 heads?
2) Got some part numbers for me?
3) Or can I source these off of a junkyard 3.0L?

This is the ONLY interesting piece of info in this entire thread, IMO.

I have a feeling they are not a direct swap. I didn't know the rocker ratio was different but it's very interesting. Another option would be when porting a stock head, why not use a TTA head and the larger ratio rockers. That is assuming you can get the same or better flow numbers from a ported TTA head vs. the GN head.

This is the first I'm hearing that the ratio was bigger but then again, I probably wasn't listening before.

 

[Razor]

Originally posted by Mr. T
Really?!

1) Will these rocker arms swap onto the 8445 heads?
2) Got some part numbers for me?
3) Or can I source these off of a junkyard 3.0L?

This is the ONLY interesting piece of info in this entire thread, IMO.

They use a stamped rocker like a small block chevy cept the ratio is higher. Other thing is the heads appear to be identical to the the 3.0 FWD heads yet have a different casting number which is TTA specific.

Yes the rockers off the junkyard 3.0 will be the same. I sent a sample to Comp Cams to make a roller conversion and the rocker closest in ratio they had was the 1.7 Ford rocker..

Our heads are 25536702 for casting number..do a search under the NHRA..even Yahoo..Valves are the same size, same springs,different rockers,2 different head bolts,different VC's..

Glad I threw something meaningful to illustrate the possibility ..

 

[TurboDiverArt]

Originally posted by Razor
They use a stamped rocker like a small block chevy cept the ratio is higher. Other thing is the heads appear to be identical to the the 3.0 FWD heads yet have a different casting number which is TTA specific.

Yes the rockers off the junkyard 3.0 will be the same. I sent a sample to Comp Cams to make a roller conversion and the rocker closest in ratio they had was the 1.7 Ford rocker..

Our heads are 25536702 for casting number..do a search under the NHRA..even Yahoo..Valves are the same size, same springs,different rockers,2 different head bolts,different VC's..

Glad I threw something meaningful to illustrate the possibility ..

Are you saying that the stamped rockers from the TTA will fit a stock GN head? I certainly don't know but Iwould have thought that if the TTA with a 1.6 ratio would fit on the stock GN head people would have doneit a long time ago. I believe going from the stock 1.55's to 1.65 would yield something like an increase of .025 - .035 in lift which would definitely help a stock cam'd motor with an upgraded turbo or running higher boost. I think ATR sells a roller rocker upgrade but for the cost of $500 it's hardly worth the extra lift. If you could put on a set either from the junk yard or even buying a stamped set from Comp cams would probably be worth the money.

 

[ACME RACING]

Heads

I thought the TTA heads were a 3800 head so it would fit and the valves were unshrouded less due to the design, a little bit better breathing

 

[GNSCOTT]

Scott....there have been A4 LS1's that have gone 13.0 @ 104-106 MPH in bone stock trim. 98-00 A4 LS1's dyno ~275-280 RWHP (01/02 were mostly 290-300 ish). Keep in mind that M6 LS1's dyno ~15-20 RWHP higher than A4's. I use A4's in this example because all TTA's were A4's (of course).

Bob, my 2002 A4 WS6 cranked out 295 or 296 HP with the original oil from the factory. An LS1 can do a 12.9 with a professional driver and a light diet with an M6 and performance rear end OPTION, and even getting those times can only be acheived on certain off the showroom cars. I'm sure there were a couple of TTA's that could rip a 12.9 off and i'm sure there was a GN or 2 that could rip off a 13.6 or 13.7 with the right conditions. ET's arent the best way to determine this because of so many variables, so if ya want to use et's I think you have to use averages. I STILL say that a GN @ 16.5#'s of boost has just as much HP as a TTA running 16.6#'s of boost.

 

[Lee_Burough]

Responding to the initial question....

I went to http://www.speedworldmotorplex.com/calc.htm and put in 3750 pounds (a typical TR's weight with driver) and an E.T. of 14.2 seconds.

The calculator spit out 259 RWHP and 305 FWHP. I think the historical data will support the conclusion that some STOCK TR's were faster than 14.2 and some in the mid 14's. A typical TR would certainly be capable of 255 RWHP. (a 13.8 would require 282 RWHP and 333 FWHP)

What about a 3575 pound car (weight of my TTA [ A.K.A. God's Chariot ] myself, 7 gallons of fuel) and a 13.3 quarter mile.... that would make it 300 RWHP and 354 FWHP. Torque...?

You do not need a 15 year old dyno printout to figure this out

 

[GNSCOTT]

Lee, now add in 30hp for the GN running the extra 3#'s of boost.

 

[GNSCOTT]

Oh and not to mention you knocked the TTA's AVERAGE time down to 13.3 and moved the GN's up to 14.2.

Personally I don't think God would be caught dead in either car, he's prolly drive an electric one.

 

[TTA89]

Originally posted by TurboDiverArt
That's probably a good point. The TTA made more power stock but I think if we are bolting on slicks and racing the GN can hold more boost at the line and probably get a better short time due to the TTA’s rear disk brakes, just a guess. Is it enough to stay in front of the more powerful TTA, who knows.

The TTA launches as good or better than a GN. The Disc brakes make no difference. When I had the stock turbo on my car I could sit at the line using the e-brake and hold 20psi. I launched at 15psi all the time running low 1.6s when the car was "Tweaked Stock" on little 245/50-16 Nittos No Less. No Air Bags, No Bigger Shoes or Cylinders like the GN needs. Stock suspension and brakes without slicks.

This excuse is used over and over and I wonder why people think the TTAs don't 60ft as well as a Buick??????

My TTA has been mid 1.5s with the stock convertor and stock rear suspension. The TTA launches just fine, if anything its the Buick that needs help... to again catch Gods Chariot.

 

[Bob Cosby]

Scott....I suppose we shall agree to disagree. MPH is actually a much better indicator of power, but regardless, I still think 250 RWHP is about right, and likely won't be swayed unless someone can produce a truly stock TTA dyno to show otherwise.

Scott....I will agree that if you add a few lbs of boost to an otherwise stock GN motor, you'll likely get about same power as the TTA. If I missed this as a point you were trying to make, I apologize. My post was speaking on a truly stock basis.

lburou...those numbers are neat, but I'm afraid they simply aren't very accurate. For example....plug in my car's ET and MPH: 11.67 @ 114 mph weighing 3225 lbs. See what you get.

Actual chassis dyno RWHP was 312.

Needless to say, those calculators are a WAG, at best.

 

[TTA89]

For anyone interested, here are some pics of my Champion Ported TTA heads.

Heads from Gods Chariot

As you can see they look nothing like the buick heads.


I have a friend with a S2 TTA as well as a 9000 mile TTA, He had to replace the tires due to dry rot. The car is factory stock otherwise. He raced it last week and went 13.3@104mph. I will give him a call tomorrow and see if he will take it and get it dyno'd for us.

 

[GNSCOTT]

Nope Bob, my main point we are in agreeance with, and that is at the same boost the TTA and GN are right around the same HP, and of course you are right that stock for stock the TTA is about 6-10ths quicker, I just don't beleive the TTA's motor is any better than the GN's.

I also agree that mph is the best indication for telling hp, but on the same car. A GN is a brick compared to the TTA's desighn that was specfically desighned to cut through the air, and I think the TTA will trap alot less if you take away 3#'s of boost.

 

[Razor]

Originally posted by TurboDiverArt
Are you saying that the stamped rockers from the TTA will fit a stock GN head? I certainly don't know but Iwould have thought that if the TTA with a 1.6 ratio would fit on the stock GN head people would have doneit a long time ago. I believe going from the stock 1.55's to 1.65 would yield something like an increase of .025 - .035 in lift which would definitely help a stock cam'd motor with an upgraded turbo or running higher boost. I think ATR sells a roller rocker upgrade but for the cost of $500 it's hardly worth the extra lift. If you could put on a set either from the junk yard or even buying a stamped set from Comp cams would probably be worth the money.

No no no..will not fit unless you do a lot of welding, grinding, cutting, etc.. totally different design..thats why I said like a small block chevy..SBC use stamped rockers not rail mounted ones.

Yes they are higher ratio..by luck.

 

[Hyper]

TTA

Originally posted by TTA89
For anyone interested, here are some pics of my Champion Ported TTA heads.

TTA Heads

As you can see they look nothing like the buick heads.


I have a friend with a S2 TTA as well as a 9000 mile TTA, He had to replace the tires due to dry rot. The car is factory stock otherwise. He raced it last week and went 13.3@104mph. I will give him a call tomorrow and see if he will take it and get it dyno'd for us.

Man I didn't ever get to see a turbo trans am run that fast stock, I remember back then that the cars that where rated to run 13's simply didnt get it done. I seen them run low 14's and I thought I seen one 13:99 out of a TTA but I think he already tweaked it. I was running my GN in 1988 at warner robins raceway and with stock goodyears I ran 14:21@97 mph, of corse it lit the tires in the top of first and hooked back up in secound but it still only ran 14:20's. I then change the chip to a KB and added some MT sportsman "I" s to it and it ran 13.19@101 the next weeekend. This was at 16 lbs of boost with a good leave. I thought I had the fastest car in the world at that point. I also remember the Viper and it's 12 secound rep, never seen one run 12's stock. Low 13's yes 12's no. Same for the ZR1!! So I would have to see a stock TTA run low thirteens to believe it as you will never find another one that is stock down to the tires to test. Sure put on tires and it should but with the factory tires???? NA!!

 

[TTA89]

Sounds like you guys need some driving lessons down there

 

[Bob Cosby]

Originally posted by TTA89
I have a friend with a S2 TTA as well as a 9000 mile TTA, He had to replace the tires due to dry rot. The car is factory stock otherwise. He raced it last week and went 13.3@104mph. I will give him a call tomorrow and see if he will take it and get it dyno'd for us.

That would be great. I would like to stress that "factory stock" means just that - like it came from the factory. No "free mods", no tricks, no chip, no nuthin. And for the record...I don't consider replacement air filters, oil, or spark plugs as "mods".

 

[TurboDiverArt]

Originally posted by TTA89


The TTA launches as good or better than a GN. The Disc brakes make no difference. When I had the stock turbo on my car I could sit at the line using the e-brake and hold 20psi. I launched at 15psi all the time running low 1.6s when the car was "Tweaked Stock" on little 245/50-16 Nittos No Less. No Air Bags, No Bigger Shoes or Cylinders like the GN needs. Stock suspension and brakes without slicks.

This excuse is used over and over and I wonder why people think the TTAs don't 60ft as well as a Buick??????

My TTA has been mid 1.5s with the stock convertor and stock rear suspension. The TTA launches just fine, if anything its the Buick that needs help... to again catch Gods Chariot. [/B]

I've never owned a TTA nor do I know anyone that does, just going by what others say. You're the first one that I know that’s said a TTA can hold that much boost. I think it's cool if that's the case. I think the TTA's are damn cool looking!

 

[TurboDiverArt]

Originally posted by Razor
No no no..will not fit unless you do a lot of welding, grinding, cutting, etc.. totally different design..thats why I said like a small block chevy..SBC use stamped rockers not rail mounted ones.

Yes they are higher ratio..by luck.

I'm confused. The TTA’s rockers are not shaft mounted? I've never seen a TTA head but I just assumed the rockers were shaft mounted like the GN's.