Rymanrph Posted January 17, 2013 Share Posted January 17, 2013 So I have my '97 swap with over 200k on my 4.0l. I've re-geared to compensate for my larger tires, but my truck just doesn't have the get up and go like I feel like it should. I know down the road that I will either stroke or swap the engine, but for now, that's $3k+ I don't want to spend, especially when what I have runs and isn't really causing me any problems. What are my best upgrades for the buck? I'd like better throttle response, so would a larger throttle body or spacer benefit a stock 4.0? Header, new cat/exhaust? 1999 intake manifold, high flow filter? Also, lets says I invest in these parts, when I put a stroker in, will I be able to retain them? I've spent plenty of money on parts that I had to swap out later because of more upgrades. PS - anything to improve fuel economy would be extra bonus :thumbsup: Link to comment Share on other sites More sharing options...
AMCJeepMJ Posted January 17, 2013 Share Posted January 17, 2013 The larger tires which weigh more than stock size is more unsprung weight which has to be moved, geared or not. Greater weight for tires equates to slower acceleration and more energy used to keep it rotating at a constant speed [ex: 55mph]... it is easier to spin something lighter vs something heavier. This is will affect your fuel economy as you will be burning more fuel to get moving and to keep moving. For example, during the summer I run Silverstars with 235/70/16 all season tires, and in the winter I run Gamblers with LT235/75/15 studded snow tires. The Gamblers and snow tires weigh half again what the Silverstars and all season tires weigh and I feel an immediate drop in acceleration and response, and my fuel economy drops from 20 mpg down to 17 mpg in the winter. The summer tires and winter tires are the same rotational diameter yet yield different results due to the weight involved. Also, the Silverstars weigh less than the Gamblers despite a larger diameter, and are also an inch narrower. Link to comment Share on other sites More sharing options...
ratrapp Posted January 17, 2013 Share Posted January 17, 2013 i swapped a 99-up intake with a ho head and it didn't do much of anything but i think the intake helps on a stroker but not a stock 4.0 Link to comment Share on other sites More sharing options...
Biotex Posted January 17, 2013 Share Posted January 17, 2013 You can do this in steps. I would spend the money on getting the head to flow the best you can afford. Pull the head, and have a 3 angle valve job done to it, with new valve springs. Have some porting work done so you get them matched up. I'm not big on any polishing because we don't see the kind of rpms that it does much good. Just a waste of money. You want the head to breath well basically. All this work will transfer over to a stroker. Then get the better injectors those are cheap enough to do. Just this will get you enough HP that you should feel it. Then you can swap in a better intake or exhaust as money allows. So far all of this will swap onto a stroke build. I personally feel that a header doesn't do much good below 3000 rpm, but the technology has come a long way since I saw any real dyno numbers. In the 70's, a set of headers would actually lose you HP at low rpms. A certain amount of back pressure is good for scavenging the gasses, so I can't really say for sure if a set of modern shorties will give the same torque or more than the stock exhaust. Who was it that said" I don't have an opinion, I have a dyno"? Anyways, there is a lot you can do that is money well spent towards a stroker build. I'm going to do one in the future myself. I have been gathering parts. Link to comment Share on other sites More sharing options...
Pete M Posted January 17, 2013 Share Posted January 17, 2013 what gears? what trans? what size tires? Link to comment Share on other sites More sharing options...
desertmike Posted January 18, 2013 Share Posted January 18, 2013 Over the last 2-3 years I have done some upgrades that work for me. Valve job and shaved the head .008, Rustys K&N air filter tube, Clifford header and full redo of the exhaust system to 2.5 inch with a hi flow cat. I'm working on this now but I only have 3.07 gears and haven't seen 5th gear since 1988. lol. Anyway with the butt test and several long steep grades in the area I can tell that the upgrades work. Link to comment Share on other sites More sharing options...
HOrnbrod Posted January 18, 2013 Share Posted January 18, 2013 Butt dynos are notoriously inaccurate. They tell you what you imagine you want to be told. This thread will help with a few bolt-on modifications, as well as performance chips: http://www.jeepstrok...c.php?f=5&t=387 Link to comment Share on other sites More sharing options...
Rymanrph Posted January 18, 2013 Author Share Posted January 18, 2013 4.56 gears, 33s with an AW4 transmission. Link to comment Share on other sites More sharing options...
mountainman Posted January 18, 2013 Share Posted January 18, 2013 well hell it should run pretty damn snappy with that combo. Done a compression test lately? maybe its on the soggy side. Some engines last 300 some ive seen just don't make it that far. Link to comment Share on other sites More sharing options...
vaquaro Posted January 18, 2013 Share Posted January 18, 2013 The larger tires which weigh more than stock size is more unsprung weight which has to be moved, geared or not. Greater weight for tires equates to slower acceleration and more energy used to keep it rotating at a constant speed [ex: 55mph]... it is easier to spin something lighter vs something heavier. This is will affect your fuel economy as you will be burning more fuel to get moving and to keep moving. For example, during the summer I run Silverstars with 235/70/16 all season tires, and in the winter I run Gamblers with LT235/75/15 studded snow tires. The Gamblers and snow tires weigh half again what the Silverstars and all season tires weigh and I feel an immediate drop in acceleration and response, and my fuel economy drops from 20 mpg down to 17 mpg in the winter. The summer tires and winter tires are the same rotational diameter yet yield different results due to the weight involved. Also, the Silverstars weigh less than the Gamblers despite a larger diameter, and are also an inch narrower. Winter fuel has higher % methanol which also kills gas milage Too :smart: Link to comment Share on other sites More sharing options...
AMCJeepMJ Posted January 18, 2013 Share Posted January 18, 2013 Winter fuel has higher % methanol which also kills gas milage Too :smart: Indeed; another part of the equation. Link to comment Share on other sites More sharing options...
Eagle Posted January 18, 2013 Share Posted January 18, 2013 What are my best upgrades for the buck? I'd like better throttle response, so would a larger throttle body or spacer benefit a stock 4.0? Header, new cat/exhaust? 1999 intake manifold, high flow filter? Also, lets says I invest in these parts, when I put a stroker in, will I be able to retain them? I've spent plenty of money on parts that I had to swap out later because of more upgrades. PS - anything to improve fuel economy would be extra bonus :thumbsup: This is a joke, right? You want more power and performance and better throttle response out of a 200,000 mile engine ... AND you want better gas mileage? Not ... gonna ... happen. Just accept that your engine is tired, save whatever you might be tempted to spend today, and put it toward a rebuild. Personally, I'd go with a stock 4.0L with an RV cam rather than a stroker, but some people have made strokers work. Link to comment Share on other sites More sharing options...
88MJNC Posted January 19, 2013 Share Posted January 19, 2013 So did you add anything to pep up the ride? Link to comment Share on other sites More sharing options...
HOrnbrod Posted January 19, 2013 Share Posted January 19, 2013 Personally, I'd go with a stock 4.0L with an RV cam rather than a stroker, but some people have made strokers work. Ever install an 4.0L RV cam using the stock valve train and timing set? Just curious.............. Link to comment Share on other sites More sharing options...
cruiser54 Posted January 19, 2013 Share Posted January 19, 2013 Ever install an 4.0L RV cam using the stock valve train and timing set? Just curious.............. My buddy did and was very disappointed. I'm doing a stroker. Pretty much done. If I were computer literate, I would post photos. Link to comment Share on other sites More sharing options...
Rymanrph Posted January 20, 2013 Author Share Posted January 20, 2013 This is a joke, right? You want more power and performance and better throttle response out of a 200,000 mile engine ... AND you want better gas mileage? Not ... gonna ... happen. Just accept that your engine is tired, save whatever you might be tempted to spend today, and put it toward a rebuild. Personally, I'd go with a stock 4.0L with an RV cam rather than a stroker, but some people have made strokers work. Really, I don't want to lose any fuel economy, but if there is something that could help, it would certainly be worth it. My engine may be tired, but it really hasn't given me any problems. Other than a compression test, are there other ways to check the health of the motor? Link to comment Share on other sites More sharing options...
Bounty Hunter Posted January 22, 2013 Share Posted January 22, 2013 I'd like better throttle response, so would a larger throttle body or spacer benefit a stock 4.0? A 62mm throttle body will increase your throttle response and improve power. I have 62mm throttle bodies and spacers available for '91-'04 Jeeps if anybody is interested. The 62mm TB does not have the taper below the throttle plate as in a stock TB, so air gets past the throttle plate much sooner and power is instant, a very noticeable improvement. Take a look down a stock throttle body and slowly open the throttle plate, you'll see how much throttle movement is needed before air enters the engine. Link to comment Share on other sites More sharing options...
89Patches Posted January 22, 2013 Share Posted January 22, 2013 Really, I don't want to lose any fuel economy, but if there is something that could help, it would certainly be worth it. My engine may be tired, but it really hasn't given me any problems. Other than a compression test, are there other ways to check the health of the motor? You can also do a leak down test, it will tell you alot. Also if it isn't given you problems just drive it till your crank walks, haha. And remember "if it ain't broke don't fix it".. Link to comment Share on other sites More sharing options...
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