Attention: TDR Forum Junkies Not long ago I saw a picture of the ATS cast iron exhaust mainifold on JRE's website at www.jannettyracing.com. According to Ted the ATS manifold flows 20% better than the stock manifold... although he has had no personal experience with it. But beware if you visit his website because the ATS manifold is GORGEOUS and once you see it you may, like me, want to try it. So, unable to help myself I yielded to the temptation and bought one. After I bought it I sent it to Jet Hot Coating to have their thermal coating applied. Several days ago it came back and over the week end I installed it in my 12v (which has endeared itself to me over and over again since I bought it new in 1994).
Impressions? The ATS manifold makes a SIGNIFICANT difference in the engine's ability to breath above 2000 rpm's. How significant? Previously, my '94 would rev to 2500 rpm's or so. Now it easily hits 3,000 rpm's and I have to be careful not to exceed red line! Remember this is a '94 and 94's did not rev like later models did. However, I believe it will make a similar difference on any engine because all 12v's share the same exhaust manifold as do all 24v's and I now consider my experience proof positive that the stock exhaust manifold is quite restrictive... especially at higher rpm's. Do I think it adds hp and/or torque? Yes, I do. How much? I'm not sure because I have never had the truck dyno'd so I don't have a baseline... but I'd estimate maybe 15 hp and 50 ft. lbs. of torque. I know I'm on shakey ground here because I understand the torque curve on the stock '94 12v engine peaks at around 1700 rpm's and what happens 1300 rpm's beyond that I just don't know. All I know is that my already lively truck now accelerates considerably further into the rpm range than it ever did before.
I'm convinced the best way to get air INTO the engine is with a Psychotty Air system. I'm also convinced the best way to get air OUT of the engine is with an ATS manifold and 4" exhaust. What you do in between by way of injectors and cam plates is entirely up to you. Those who take performance serioulsy will want to look into this as a significant performance option.
Once again, it seems like there's no end to what these trucks can do. Wouldn't drive anything else.
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'94 SLT 2WD, 5 Spd. , TST #6(250/635), 215 HP Injectors, Calibrated Pump, 14. 5 cm2 Turbo, ATS Exhaust Manifold, 3. 54, all Synthetics, By-Pass Filtration, EGT & Boost Gauges, Psychotty Air System, 4 " exhaust, BD Exhaust Brake, Horton Fan, Prime-Loc, Cummins Chrome Kit, Homeless Cat, Air Lifts, Rancho RS9000's, PIAA's, 255x85Rx16's and copious amounts of 12v Pride.
Impressions? The ATS manifold makes a SIGNIFICANT difference in the engine's ability to breath above 2000 rpm's. How significant? Previously, my '94 would rev to 2500 rpm's or so. Now it easily hits 3,000 rpm's and I have to be careful not to exceed red line! Remember this is a '94 and 94's did not rev like later models did. However, I believe it will make a similar difference on any engine because all 12v's share the same exhaust manifold as do all 24v's and I now consider my experience proof positive that the stock exhaust manifold is quite restrictive... especially at higher rpm's. Do I think it adds hp and/or torque? Yes, I do. How much? I'm not sure because I have never had the truck dyno'd so I don't have a baseline... but I'd estimate maybe 15 hp and 50 ft. lbs. of torque. I know I'm on shakey ground here because I understand the torque curve on the stock '94 12v engine peaks at around 1700 rpm's and what happens 1300 rpm's beyond that I just don't know. All I know is that my already lively truck now accelerates considerably further into the rpm range than it ever did before.
I'm convinced the best way to get air INTO the engine is with a Psychotty Air system. I'm also convinced the best way to get air OUT of the engine is with an ATS manifold and 4" exhaust. What you do in between by way of injectors and cam plates is entirely up to you. Those who take performance serioulsy will want to look into this as a significant performance option.
Once again, it seems like there's no end to what these trucks can do. Wouldn't drive anything else.
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'94 SLT 2WD, 5 Spd. , TST #6(250/635), 215 HP Injectors, Calibrated Pump, 14. 5 cm2 Turbo, ATS Exhaust Manifold, 3. 54, all Synthetics, By-Pass Filtration, EGT & Boost Gauges, Psychotty Air System, 4 " exhaust, BD Exhaust Brake, Horton Fan, Prime-Loc, Cummins Chrome Kit, Homeless Cat, Air Lifts, Rancho RS9000's, PIAA's, 255x85Rx16's and copious amounts of 12v Pride.
