Fuel Mileage Dropped After New Turbo

[WKruger]

After I replaced my stock turbo to a High Tech, my mileage dropped 5-7 and my EGT's are 200-300 deg. higher. What caused my turbo to go is I was going to do a 1/4 mile. When I launched, I heard a pop, like one of the tubes blew off the intercooler. So is it a possibility that I have leak, or is it because I installed an aftermarket turbo.

 

[johncameron]

How is your boost? It sounds like your stock turbo wasn't dead? Did you blow a intercooler boot??

 

[WKruger]

I forgot some info, sorry. It made a noise like the compressor wheel was rubbing the housing. It only made 10 psi afterwards. But w/ my new turbo, the boost hovers around 5 psi and the egts are 800 driving down a level road @ 65. When I climb a faily steep hill, boost goes up to 12 and the egts sore up to 1200. I have to give some pedal to get 25-30 psi but the egts get up to 1300.

 

[DCreed]

do a pressure test.

 

[JasonCzerak]

do a pressure test.

NOT easy to do on a 3rd gen. If you remove the oil filter, you have some room to work with.

 

[WKruger]

I suppose a shop-vac would work? Nah to noisy. I hope it's as cheap as a boot. If not, give me a good excuse to get an aftermarket.

 

[WKruger]

Thanks for the help

 

[WKruger]

Just thought of something else. My cat is probably not helping the egt department any, among others. Thoughts?

 

[ENafziger]

Adding a large single turbo (SPS 66, etc) will cause mileage to go down around 1 to 1. 5 mpg. Smaller turbos will have less of an effect. I would suspect the new turbo is not the problem with your economy.

--Eric

 

[Mobius1]

800 cruising at 65 seems a little high. Sounds like you have a boost leak. I had a similar situation with my setup. Made a screaming noise and high boost psi. egt's were higher than normal. Turns out I blen an exhaust manifold to turbo gasket.



But your situation sounds like a boost leak. CAn you remove the turbo and see where it contacted the housing? I doubt that it did but when I first heard the noise, it sounded god-awful

 

[WKruger]

I'm hoping it's something small, like a boot. How big a leak does it have to be before the mentioned problems occur? I do appreciate the replies.

 

[Mobius1]

For my particular noise, I only heard it when I was on it pretty hard building about 50psi, so it really wasn't a huge boost leak, but it was enough to cause some problems. Double check ALL the boots.



The intercooler may have cracked as well. Does your truck have the plastic cooler? It sounds like you have a rather large boost leak.

 

[WKruger]

It's got the steel one. I don't know maybe it's normal w/ this particular turbo. Thanks for the support anyway.

 

[TCluff]

adding a larger single turbo will decrease in town fuel economy and raise cruise egt, i lost about 4mpg with twins but my towing mpg went up about the same, i have a very laggy top turbo but with huge injectors i have very little lag time, check for boost and pre turbo exhaust leaks as mentioned, there are many factors in egt and fuel mpg issues, also what size of exhaust housing does the turbo have...

 

[WKruger]

4'' I believe. I need to either gut the cat or remove it. That will help my mileage a little I know.

 

[Mobius1]

Cutting the cat may help a little bit for fuel economy and egt's don't expect a night and day difference. It will help the tone of the exhaust too.