Max turbo boost on a 305/555 ?

[ECappleman]

Only getting around 23-25lb stock or with Quad chip.

I am under the impression that the mechanical wastegate trucks are not influenced with a chip?



Would a boost bolt help for a little more power and lower EGTs? (more boost)



Thanks

 

[JCleary]

I could hit 34 psi with the quad on 140, 28-30 psi on 100, and 26-28 on 60. . Usually I'm at 24 or so stock. With the BDDL I see only about 26.



With our tiny turbos anything over 24-26 psi is just hot air, so you're not getting any additional cooling (though I'm sure someone will disagree).

 

[sfr1047]

JCleary,

Would those boost numbers hold steady or just peak momentarily and then come down to the waistgate setting of 24 #s?



Dave B

 

[JCleary]

Those numbers are sustained at about 2500rpm and above. Repeatable in the top four gears. I couldn't stay in it long enough to see boost like that in 2nd gear.



I never saw egt's over 1250 either, although I didn't get over 95mph.

 

[Jengle]

My stock turbo will hit about 42psi, then settle in at a steady 38. I just have the supplied boost elbow from TST. I didn't make any adjustments to it, since I don't have the fuel to go higher with it. I have to put it on a good hill to see 1200+, never got to 1300 yet. Most times the max I see on flat runs is 1100. That will probably change when I get a fuel pump on it.

 

[ASchwartz]

Stock run is 24 and on level three (100hp) it maxes at 28-29.

 

[LightmanE300]

My stock turbo with the quad race on 100 would spike to 28psi and then quickly settle back down to 23-24psi... I couldnt get a higher constant boost number, but as posted above, much above 25psi on the stock turbo is worthless anyway.

 

[ASchwartz]

Stock run is 24 and on level three (100hp) it maxes at 28-29.

And holds at 28-29 until about 110-115mph when the fuel runs out. Fuel pressure gauge is at 0psi for about 30 seconds before the stuttering begins.

 

[ECappleman]

Ok, just curious.

Thanks for the replies.



I see that the 600 trucks max at about 36.

I guess they have bigger turbos?



I was looking to lower EGTs when towing, and thought this might of been a simple way.

 

[ASchwartz]

For a simple reduction in egt's try a cold air intake or the ceramic coated ats exhaust manifold. With the stock turbo any boost higher than 28psi is just hot air and hot air in = hotter air out. To delay the wastegate with the boost elbow and increase boost pressures would not help in the egt department. You could even add geno's muffler elimination kit which would get rid of any backprssure reducing eft's. All of these items are more expensive and more difficult to install then the boost elbow, but I feel combined they result in lower egt's and quicker spool up.

 

[CraigJones]

42# with Stock Turbo ?

I just replaced my stock exhaust so now I have 4" exhaust from turbo back. I also added a boost elbow to control my waste gate and a ATS exhaust manifold . My question is I see a lot of threads saying that anything over 30 psi is just heat but I can tell that my boost goes to 42# them levels out at 38# but my egts are down a lot. I can't get my EGT to go over 1350 on the highway at WOT. From a dead stop my EGT before would 1400 when I hit 70 mph and I would have to back off. Now my EGTs will max out at 1350 then drop to under 1200. I haven't heard any turbo bark so I'm wondering if 42# is to much should I drop it down so my boost won't go over 38#.