I just had Gauges installed post turbo and was told not to go above 1000 deg. I pull a 32 5er with weight of approx 11000 and when pulling a steep grade 3 to 4 miles in length with outside temp in the upper 70's I reach 900 to 950 deg. It is auto tranny and was told it had the HY35 turbo which is 9cm. <br>My question is can I install a HX35, 12 cm and the temp drop enough to not worry about going over 1000 deg when the ouside temp gets in the 90's. I was told by a local turbo shop that the HX35 should drop the temp by about 300 deg.<br>I am running a power puck and 4&quot; exhaust, no other mods except for a K&amp;N drop in filter.

 

bsummit,<br><br>Let me qualify my comments by saying I drive a 1st Gen.<br><br>Having said that, I did some testing on the post turbo/pre turbo pyro mounts and temps.<br>Keep in mind this is a generalization but what I found was this..<br>Post turbo, up to about 20 psi boost, you would have a correction factor of roughly 10*F for every 1 pound of boost... so at 20 psi and a guage showing 900*F you would be right in the 1100*F range with correction.<br>However, once you enter into the 23-25+ psi range the correction factor goes off, and you will in fact see even more error. At 28-29 psi boost, with a gauge reading of 900*F you will in all likelyhood have an actual EGT reading of 1250-1350*F with correction. The higher you go beyond that, the more error you will have.<br>Pre-turbo does not have this error factor on the working side of the cycle, but on the cool down side. If you mount pre-turbo then when the guage says 350*F at cool down it's actually a bit higher and little extra time is needed to assure no damage to turbo bearings such as coking.<br><br>Last, the smaller the exhaust housing the more likely you are to have high drive pressures and with it, higher EGT's. A gated 14cm would be better than a 9 or 12cm simply because you could at least have a slightly larger inlet passage to the exhaust end (reducing drive pressures a tad) and it would be able to have &quot;longer legs&quot; at the mid/top end.<br>A hybrid turbo will give you excellent bottom end spooling, lower smoke issues, good mileage, and a nice top end all day long without &quot;running out of wind&quot; at the top end.<br><br>Bob.

 

To add to what Bushy said, you will have to install the whole HX35/14. The HY 35 and HX 35 have no interchangeable parts, save a few that wont do you any good anyway.

One more thing, the HX35/HY35 swap will not lower EGT 300F with your current boost and power levels. After installing a HX35/14 I would only expect 50-100F drop in EGT.

On a stock CTD, limit post turbo EGT to 900. Limit Pre Turbo EGT to 1250F. Once BOMBed, like Bushy said, the 350F delta is not accurate.

Heck, you are only running a Puck....egt's should not be high enough to hurt anything.