00t444e

I am looking to get better performance out of my 4.0. I am not looking for any big gains on the top end just some better low end power so it will hold overdrive better on the highway and better throttle response. I already have single chamber muffler and the exhaust dumped in front of the rear axle. I am thinking about doing an air intake, Bosch 4 hole injectors, and a 62mm throttle body. Will these mods get me a noticeable increase in power and torque? Is a throttle body spacer worth doing as well?

andrewmp6

If you still have those 31s or bigger re gearing it to match the tire size would be the best option but the most costly.

CobraMarty

TB spacer adds 1-2 HP.

Aftermarket header and 2.5" cat back exhaust will add 3-4 HP.

Harland Sharp 1.7:1 roller rockers will add 5-7 HP across the whole rpm range and extend your rpm to 4600-4700 instead of falling off above 4000 rpm like stock.

12 hole injectors make a finer atomization of the fuel and improved mileage, idle quality, cruising and mid range performance. They will not add more total HP.

Good quality ignition upgrade will help. Best is Performance Distributors upgraded coil, wires, cap and rotor. Ebay stuff is junk.

New NTK O2 sensors go a long way, keep your's as spares.

navysrt8

Harland Sharp only makes 1.6:1 rockers for the 4.0. Don't think you'll see much performance gains out of those, although they are probably much more stable.
Yella Terra, however makes 1.6:1 & 1.7:1.

CobraMarty

Stock rockers are crap. Stamped steel. Variable ratio at best, high friction, noisy.

Yella Terra no longer makes these roller rockers, in fact I think YT is no more or just not importing from Australia any more.

Harland Sharp does make non-adjustable 1.7:1 precision roller rockers, fit under stock valve cover, works with stock cam and valve springs, special order or need to know who to order from.
1.7:1 will add about 0.025" lift and 2-3* duration.

00t444e

I am not looking for peak hp gains just some better low end. I am aware that rehearing would be the most effective method but it isn't cost effective with just 31s.

CobraMarty

All the bolt on parts, all added together will only increase your power by +15rwhp and +15rwtq. That's all. Been there, done that, dyno'ed it.

CAI, 62mm TB, TB spacer, Injectors, synthetic oil, ignition upgrade, 1.7:1 roller rockers, aftermarket headers, high flow cat, high flow muffler, 2.5" cat back exhaust.
All together will add +15rwhp and +15rwtq as measured on a Mustang Dyno, Auto trans, 2WD, street tires, 3.55 gears.

If you add up all the costs for all these parts, the cost/hp gained is very high.

Forced induction, turbo or supercharger, is a whole different story. A 6 psi kit will add a real +60rwhp and +70rwtq as measured on a Mustang Dyno, auto, 2wd, street tired, 3.55.
Kits can install in a day, is easily removed if needed, cost/hp gained is much cheaper.

See these many different dyno results-
http://jeepm62superchargerkit.blogsp...g-page_15.html

Stock 4.0L, Bolt-Ons, Stroker, Turbocharged, Supercharged
rwhp/rwtq.....dyno type.....vehicle/engine details

STOCK 4.0L-
125rwhp/160rwtq corrected*(135rwhp/177rwtq Dynojet) XJ, 247k, AW4 3rd gear, 31.5"
128rwhp/169rwtq corrected*(142rwhp/187rwtq Dynojet) 4.0 Wrangler, stock air intake and filter
(130rwhp/168rwtq Dynojet) 4.0 YJ stock 210k Crawl Magazine
133rwhp@4650164rwtq@2650 Dyno-Mite 3rd gear pull '96 177k 5sp 3.73 31"
134rwhp/160rwtq Mustang dyno '89 AW4 ported '94 head cam '99+ int Renix header CAI no cat
135rwhp/160rwtq Mustang dyno, '99 150k stock
136rwhp/165rwtq corrected*(151rwhp/183rwtq Dynojet) 4.0 Wrangler, NO air intake tube or filter-unrestricted
138rwhp/167rwtq ?dyno '05 Wrangler auto CAI exhaust TB spacer
138rwhp/180rwtq corrected*(153rwhp/200rwtq Dynojet) '00 TJ 5sp MagnumPowers stock
138.3rwhp/172.8rwtq ?dyno stock '00 XJ auto 4wd
138.6rwhp/176.0rwtq ?dyno stock Banks 4.0L '05-04 Wrangler
140rwhp/179rwtq ?dyno '06 Wrangler 6 speed
140rwhp/183rwtq corrected*(156rwhp/202rwtq Dynojet) '00 TJ 31"
144rwhp/175rwtq ?dyno '97 ZJ 4.0

BOLT-ONS 4.0L-
133rwhp/165rwtq corrected*(149RWHP/183rwtq Dynojet) 2000 XJ, AW4 3rd gear, 60mmTB, headers, HAI, Catback, 0630, 30"
(150rwhp/186rwtq Dynojet) YJ 210K Crawl Magazine TB, Borla, K+N, Cat back, Jet Chip, Cat
(159rwhp/193rwtq Dynojet) above with the Mechanical Fan Removed
147rwhp/171rwtq corrected*(163rwhp/190rwtq Dynojet) K+N Factory, '97 XJ AW4 2WD 60k 2nd gear
148rwhp@4700/187rwtq@3100 Land+Sea Dyno, '01 WJ 4.0 106k, K+N FIPK, HF cat
149rwhp/190rwtq corrected* (165rwhp/211rwtq Dynojet) 4.0 rebuilt 0.030", header, exhaust, 62mmTB, CAI, Tune by Hogan
150rwhp/174rwtq Mustang dyno, '99 150k CAI, 62mmTB, cat back, ignition
153rwhp/180rwtq corrected*(170rwhp/200rwtq Dynojet) '88 XJ AX15 4WD Renix MegaSquirt3x 'mild' Comp cam
154rwhp/179rwtq corrected*(171rwhp/199rwtq Dynojet) K+N Factory, +FIPK (+7.9hp/+9.19tq)
159rwhp/209rwtq corrected*(177rwhp/232rwtq Dynojet) '00 TJ 31" + 62TB, CAI, EDGE Trail Jammer module (+21hp/+30tq)

SUPERCHARGED, TURBOCHARGED, STROKER, NITROUS-
141rwhp/184rwtq Mustang Dyno 4.6L Stroker log intake auto 37"MTR
156rwhp/266rwtq corrected*(173rwhp/295rwtq Dynojet) 4.7L Stroker '98 XJ
176rwhp/226rwtq ?dyno Turbo 6psi '95 AW4 4wd FMU MSD BTM no intercooler 'CSaddict'
182rwhp/239rwtq corected*(202rwhp/265rwtq Dynojet) '95 Wrangler Turbo 6-7 psi 12:1FMU boostapump meth inj
185rwhp/241rwtq 4.6L Stroker 9.56:1 0.043"quench stock head +5-6*timing mod 63mmTB 24lb injectors Hesco474/480 cam ?dyno correction 204rwhp/265rwtq
187rwhp/194rwtq corrected*(208rwhp/238rwtq Dynojet) Banks Turbo 6psi 4.0 Wrangler manual
190rwhp/263rwtq corrected*(211rwhp/292rwtq Dynojet) Boostwerks Turbo 6psi 4.2 MS 4.0head
191rwhp/265rwtq corrected*(212rwhp/295rwtq Dynojet) Boostworks Turbo 6psi 4.2L bored to 4.3L Megasquirt 99+intake
193rwhp/236rwtq ?dyno, 'Gradon's Stroker' from old post, 4.6L, 30cam, ported head
196rwhp/??rwtq ?dyno, 4.6L, auto, Sprintex SC, ?boost, stock cam, stock head, AEM tune
201rwhp/rw263tq ?dyno 240k 4.0 T3/T4 Turbo 6 psi tapering to 3-4 psi by redline(boost leak) 36 lbs injectors 99+ intake
202rwhp/258rwtq Dastek dyno, 'Cheromaniac's' '92 4.6L 'poor man's Stroker' '01 intake 65mmTB 9.25:1 ported head 5sp header
208rwhp/280rwtq Mustang dyno '01 TJ 5speed 5.0L Stroker 212/216 0.488"/0.498"cam stage II 505 head (supercharged below)
210rwhp/249rwtq ?dyno Banks 4.0L Turbo 6psi '05-06 Wrangler +66HP/+84TQ 35lb injectors, AutoMind tune, CAI
211rwhp/268rwtq DynoDynamics dyno '97 XJ M62 Supercharger Kit installed 6psi (crank 300HP/375TQ)
211rwhp/274rwtq Mustang dyno '98 XJ auto 4WD160k Sprintex Supercharger 6 psi(crank 300HP/375TQ)
212rwhp/278rwtq ?dyno TurboJeeper '90 Renix 4.0 Auto 60-1 Turbo 1.15a/r 5psi 36lb-5.9L injectors FMU No Intercooler (stock 142rwhp/228rwtq)
219rwhp/296rwtq ?dyno '01 TJ 4.0L stock with MagnumPowers Supercharger intercooled 8psi
220rwhp/260rwtq ?dyno, 'Mountaineer's' 4.0L Nitrous
225rwhp/275rwtq corrected*(250rwhp/305rwtq Dynojet) '00 TJ 4.0L 5sp MagnumPowers M90 SC 85mmTB water IC 10-11 psi (stock 138rwhp/180rwtq)
227rwhp/ ?rwtq ?dyno '06 TJ Rubicon manual 35"s Intercooled Turbo 7psi
230rwhp/257rwtq estimate (325hp/363tq engine dyno) 4.9L Stroker ported BV head 470 carb stock Clifford intake Newcomer Racing
237rwhp/317rwtq ?dyno '01 TJ 4.0L +Borla Headers and Magnum Powers Supercharger intercooled 8psi
243rwhp/360rwtq Mustang dyno '01 TJ 5speed 5.0L Built Stroker+Magnum Powers M90 SC 7.9"/2.75"= 13,932 SC rpm 6psi (N/A 208hp/280tq)
256rwhp/268rwtq estimate (361hp@5400/377tq@4800 engine dyno) 4.9L Stroker ported BV head bigger carb intake + headers
256rwhp/313rwtq corrected*(285rwhp/348rwtq Dynojet) 2WD 5sp 4.6L Stroker Vortech SC 5-7psi non-intercooler 42lb/hr injecors ECU tuned by FlyinRyan
263rwhp/353rwtq ?Dyno 4.6L Stroker Turbo 8.0:1 cam 10psi 'YJ + Corey'
268rwhp/375rwtq Mustang dyno '01 TJ 5speed 5.0L Built Stroker + M90 SC Magnum Powers 7.9"/2.75"= 13,932 SC rpm 7psi (N/A 208hp/280tq)
274rwhp/322rwtq ?Dyno 4.0L Turbo MS 36lb 50mm T3/T4 12psi 'Pseudosport Racecar'
307rwhp/402rwtq Mustang dyno '01 TJ 5speed 5.0L Built Stroker + M90 SC Magnum Powers 7.9"/2.75"= 13,932 SC rpm +85mm TB ?9-10psi (N/A 208hp/280tq)
322rwhp/405rwtq corrected*(358rwhp/450rwtq Dynojet) '00 TJ 4.0L 5sp MagnumPowers M90 SC 85mm TB water IC 20-21 psi (stock 138rwhp/180rwtq)
395hp/465tq@4500 Engine dyno Turbo 13-14psi '99intake cam ported head 105octane 74lbFP Blew Head Gasket 'Turbo Tom' Drag AMC
425rwhp/539rwtq Mustang dyno 4.7L Turbo 16psi, ported alumn head, 218*/224* 0.500" 114LSA 8.5:1 T76/.96 Air/Water IC 93octane, Methanol inj 4"exhaust
692hp@5000/777tq@4000 Engine dyno 5.0L Turbo 30PSI Air/Water 505 Perf

Some trends that I have noticed-
Stock 4.0L- 135rwhp/160-165rwtq (crank 190HP/225TQ)
4.0L+'All the bolt on's' +15rwhp/+15rwtq to 150rwhp/175rwtq (crank 210HP/240TQ)
4.6L Stroker- displacement+CR(+15%)+cam(+8%)+head work(+7%)--195rwhp/245rwtq (crank 260HP/ 328TQ)
5.0L Stroker- (+10% over 4.6L) 208rwhp/280rwtq
4.0L+BOOST 6pounds- 210rwhp/265-275rwtq (crank 300HP/375TQ)
Stroker4.6L+?BOOST 4pounds +25%--->244rwhp/306rwtq(estimate) 325HP/410TQ(crank estimate)
Stroker4.6L+?BOOST 6pounds +37%--->267rwhp/335rwtq(estimate) 355HP/450TQ(crank estimate)

Dynojet reads 10% HIGHER than Mustang Dyno.

Drivetrain loss- realworld numbers from numerous sources, no BS internet hype
AW4 4WD -29%
AW4 2WD -26%
5SP 4WD -24%
5SP 2WD -21%

These are real world, documented drivetrain loss result numbers for the Jeeps
Do not believe any inflated internet hype or 'rule of thumbs'
Internet BS of 8% manuals and 10% autos drivetrain loss numbers do not apply to these Jeeps.
They use these inflated numbers to stroke their egos. Only believe the facts

Supercharged Predicted HP/TQ = (1 + boost/16) x current Nat.Asp. HP/TQ
4psi=25%increase 6psi=37%increase 7psi=43%increase 8psi=50%increase 10psi=65%increase 13psi=80%increase 16-17psi=100%increase

Interesting Comparison- 4.0L vs 5.0L, stock vs built, N/A vs low Boost, High Boost
4.0L 138rwhp/180rwtq N/A Stock (stock cam)
5.0L 208rwhp/280rwtq N/A (built 212/216* cam big valve ported head)
4.0L 225rwhp/275rwtq S/C m90 85mmTB 10-11psi (stock cam)
5.0L 243rwhp/360rwtq S/C m90 62mmTB 6psi (built 212/216* cam big valve ported head)
5.0L 268rwhp/375rwtq S/C m90 85mmTB 7psi (built 212/216* cam big valve ported head)
4.0L 322rwhp/405rwtq S/C m90 85mmTB 21psi (stock cam)

00t444e

I wonder what the dyno charts look like on a stock 4.0 vs one with the bolt ons I mentioned. The peak up may not be that much higher, but will it build power quicker in the midrange.

CobraMarty

All the graphs are usually proportional gains across the whole rpm range, not just top end like other cars.

mikesignal

Not sure how much the bolt on super charger/turbo/forced induction costs, and not sure how much work is involved to install them; but there are HP cylinder heads that claim they will net you and additional 40-50hp. They cost around $650 and up.

CobraMarty

Big valve, ported head is only worth about 15-20 HP max. Don't believe the hype.

At over 4300 rpm there might be a 50 hp gain vs stock head because the stock head falls flat on its face at upper rpm and loses 50 hp. So 'gain' is that it doesn't lose hp.

Here is a dyno curve which shows stock vs Comp 232 cam. See how the power falls off.

navysrt8

I'm currently running a 4.0L with an M62 bolted to it. Have also done some fairly significant mods on top of it (head porting, rebuilt the M62, custom cam, 1.7 rockers, header, ported intake, ported the intake elbow on the m62, 68mm TB ...etc...etc) What have I learned?

I should have done an LS and 4L80 swap instead: Cheaper, more power, better support, can use HP tuners vice antiquated piggy back system (much easier to find a capable tuner), would have sounded better.

Don't get me wrong, I like having a Jeep motor in a Jeep, and there is definitely a "wow factor" to having a supercharged 4.0, but the power/ dollar ratio isn't very high with these things.

They still exist: http://store.yellaterra.com.au/categ...?sort=priceasc
Not sure about getting parts imported, I got mine almost a year ago.

CobraMarty

I have yearly emission inspections and have to be OBD legal.
And I like heat, A/C, cruise control and my gauges to all work.

Cummins93

I have never had a v8 in a XJ but I like my m90 L6. It's cheeky and delightful. Passes OBD2 inspection puts down plenty of power. I'm into it maybe 1400?

DSFB 96XJ

HAS ANYONE HEARD OF DW DESIGNS WHO BORES STOCK TB TO 62mm AND ARE THEY CREDITABLE? SECOND, WHAT WOULD BE A GOOD CAM TO PUT IN A STOCK 4.0L HO TO ADD POWER AND TORQUE?