Yet another... Build thread for an xj on 40s and one tons in norcal

[blondejoncherokee]

ya. We gotta meet at a local brewery so I can convince you to go 5.3 swap. Your XJ is way to bad-ass to be running the 4.0. I know all the ins and outs of making it CA legal and would love to help you with this swap.

I do appreciate the offer for sure. but I just dumped way too much money into getting this motor in here. I really hope this is a cheap fix like maybe timing or a bad cam...

What do you think your total cost was start to finish with the LS swap?

 

[Johnnie Walker]

I have a Spintech on my XJ and like it a lot. A maggy would do fine as well.

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[blondejoncherokee]

I am leaning towards a pinch tech right now- which spin tech did you use ?

 

[blondejoncherokee]

One thing I want to be considerate of - linking the rear this winter. I think maybe just a magna flow glass pack might work for that since its so much smaller and should tuck in easier. thoughts on a glass pack on a XJ ?

 

[Johnnie Walker]

I am leaning towards a pinch tech right now- which spin tech did you use ?

One thing I want to be considerate of - linking the rear this winter. I think maybe just a magna flow glass pack might work for that since its so much smaller and should tuck in easier. thoughts on a glass pack on a XJ ?

My spintech is a 14".
I have a maggy glasspack 22 or 24" on my MJ. I like the way it sounds. Bought it on amazon, IIRC.
I prefer the spintch though.

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[blondejoncherokee]

Ive been talking with the Tuner, Ryan Hogan. He is very concerned that my 2" downpipe is smashed around 50%. After talking with him about how much this head flows, and the increased displacement, I am going to up the exhaust to 3" all the way back. ordering stuff from Summit tonight.

 

[clydefrog]

I was thinking, what is the back pressure? Do you have a gauge to check exhaust back pressure? If not let me know, I have access to one.

 

[blondejoncherokee]

I was thinking, what is the back pressure? Do you have a gauge to check exhaust back pressure? If not let me know, I have access to one.

Ah thanks !

yeah I just ordered a bunch of 3" stuff from Summit. The only thing I am not sure about it is how to go from the 2" fitting at the collector to 3" without using reducers, I guess Ill just reduce from 3" to 2" and when I order a better exhaust manifold like a Gibson ill make it so it converts to 3" at the manifold.

I also put the K&N intake back on, and the trans was 1.5 qts low on fluid.

So I am hoping to wake it up a bunch with:
3" exhaust , muffler, high flow cat (replaced smashed downpipe and smashed muffler)
41 tooth speedo gear to fix shift points
K&N intake back on
1.5 quarts of trans fluid top off


I still need to check the Cam lift, and have Spencer Scan the thing and read it live to look for anything weird.

 

[Rob D]

Ah thanks !

yeah I just ordered a bunch of 3" stuff from Summit. The only thing I am not sure about it is how to go from the 2" fitting at the collector to 3" without using reducers, I guess Ill just reduce from 3" to 2" and when I order a better exhaust manifold like a Gibson ill make it so it converts to 3" at the manifold.

I also put the K&N intake back on, and the trans was 1.5 qts low on fluid.

So I am hoping to wake it up a bunch with:
3" exhaust , muffler, high flow cat (replaced smashed downpipe and smashed muffler)
41 tooth speedo gear to fix shift points
K&N intake back on
1.5 quarts of trans fluid top off


I still need to check the Cam lift, and have Spencer Scan the thing and read it live to look for anything weird.

Just my 2 cents worth on the cat. I had a high flow cat that I put on just prior to my smog and it passed fine. 2 years later it wouldn't pass any more. Had to install another new cat to pass. The exhaust guy told me that the high flow cat's tend to fail quicker than standard cat's. That was a few years back, so that may not apply any more, but just thought I'd mention it.

 

[blondejoncherokee]

Yeah i also have a brand new non high flow cat ill be keeping around just in case.

 

[GordoSmasho]

I got my delta 50 slim flowmaster for 50$ its boxed welded construction for the bruiser in me. And its only 3" thick. Fits well above the frame rails.

 

[blondejoncherokee]

I ordered a 3" Summit Brand Glass pack for now, I will probably change it out eventually but for 23$ I cant complain. Ill be cutting up the eBay Header and welding in a 3" header reducer thing so I can literally run 3" all the way from the header to the downturn. It should wake the thing up. My downpipes is 2" and its crushed to about 1" pretty bad, my muffler is crushed, lots of exhaust restrictions from years of cobbled together welding from previous owners, and I have a really small, very restrictive cat.

With this super high flowing head and additional displacement, Russ claims the horsepower should be amazing - like 300HP + and like 350 ft lbs + . So I am hoping between the exhaust, the right speedo gear, toppling off the trans, and scanning for lazy sensors , and putting the intake back on, that I can get closer to those numbers.

I am also thinking if that all doesn't do it, then ill be looking at a RAD shifter and maybe put the TC on a switch and just manually shift the thing so I can hold RPMS.

 

[clydefrog]

I think the exhaust work will help. Honestly sounds like an exhaust restriction (no codes, lack of power, doesn't shift right).

Still want to check that thing out, just saw it in passing that once....

 

[blondejoncherokee]

Slapped a 41 tooth speedo gear in last night from quadratech. Made a pretty big difference . Seems to hold the right gears at the right speeds and down and up shifts alot better and the speedo is dead on with 37s and 5.38s . Cut the muffler off in preparation for the new exhaust and that helped a litte too.

Once I get the 3" exhaust on im going to have to log data and have the tuner revise the tune.

 

[blondejoncherokee]

Yeah i really want to see your LS swap and spend time looking at it and maybe drive it Clydefrog.

 

[Skipper51]

I ordered a 3" Summit Brand Glass pack for now, I will probably change it out eventually but for 23$ I cant complain. Ill be cutting up the eBay Header and welding in a 3" header reducer thing so I can literally run 3" all the way from the header to the downturn. It should wake the thing up. My downpipes is 2" and its crushed to about 1" pretty bad, my muffler is crushed, lots of exhaust restrictions from years of cobbled together welding from previous owners, and I have a really small, very restrictive cat.

With this super high flowing head and additional displacement, Russ claims the horsepower should be amazing - like 300HP + and like 350 ft lbs + . So I am hoping between the exhaust, the right speedo gear, toppling off the trans, and scanning for lazy sensors , and putting the intake back on, that I can get closer to those numbers.

I am also thinking if that all doesn't do it, then ill be looking at a RAD shifter and maybe put the TC on a switch and just manually shift the thing so I can hold RPMS.

Let me try this again.
No one asked this question so I will.
You are a mathematician, how much more volume is there in a 2" pipe vs a 3" pipe?
If you go to a 3" pipe will there be enough back pressure for the engine?

 

[blondejoncherokee]

Yeah the exhaust will still scavenge. Scavenging is to remove the exhaust gasses quickly and completly. The 3" exhaust should do it for this given displacement, head, and HP.

 

[blondejoncherokee]

Some info on scavenging

https://motordyneengineering.com/exhaust-backpressure-and-scavenging/


Basically 3" is good and my crushed 2" exhaust is bad.

 

[Demonoid369]

Maybe it hasn't been asked but have you checked your transmission? You say it keeps getting low. There might be a chance that you're losing some power in the transmission if the clutches are worn.


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[blondejoncherokee]

Yeah it was low because i changed the fluid before the trip and didnt properly top it off I just dumped some fluid. Im sure the trans needs a proper rebuild .

So as for scavenging- there are diminishing returns to scale to run exhaust over 3" on my setup. But I will have the ideal smaller tubes at the header and larger exhaust all the way back out .