Stock differential, power and racing?

soul_sword34 · Post by **soul_sword34** » Tue Dec 25, 2007 11:38 pm

Just throwing around a few options and was, maybe still am, going to put in a Quaife TBD. Now I'm thinking of just installing diff saver tabs and spending the extra grand on a bottom end rebuild. Reason? I have around $3,500 coming next month from my taxes and my wife gave me the go on the Neon project. Originally going to go Intake, Exhaust, Top end and Quaife rebuild. With the top end I was going to shave .030 off the head for the extra compression with a Crane 14. Now I'm thinking of just upping the compression with Modern Performance's bottom end kit 10.5 comp and maybe overbored. I'm thinking the Quaife could come later. Here's my main question. Will my stock differential with 74,000 miles stand up to 160 whp and racing conditions? Anyone have any testimonials to having that power or more with a stocker and it holding out? How about even with a 75 shot of nitrous on top?

SGT BRAD · Post by **SGT BRAD** » Wed Dec 26, 2007 10:25 am

honestly, i would spend the money on a dohc pistons, wicked p&p job, cam, intake and exhaust. keep the quaife idea if you are planning on keeping the car for a while. otherwise go with the phantom grip and diff tabs or an obx. with the dohc pistons you'll have the 10+:1 bottom end compression and you'll be doing it on the cheap. our bottom ends are good to 250tq so don't sweat the expense. maybe even knife edge and lighten the crank a little. oh yeah and throw an al fw/ clutch combo in there too. i think you'll see upwards of 170whp and be right at the point of diminishing returns. the extra 5 hp to make 175 suddenly costs way more money. just my .02 worth.

soul_sword34 · Post by **soul_sword34** » Wed Dec 26, 2007 7:58 pm

Hmmm...so what is the compression exactly from DOHC pistons? I mean versus a new head shaved .03? I'm shooting for 160 whp but 170 and I'd probably have to have sex with my car

soul_sword34 · Post by **soul_sword34** » Wed Dec 26, 2007 9:45 pm

http://forums.neons.org/viewtopic.php?t ... ompression
according to that thread the pistons have to be modified too?

SGT BRAD · Post by **SGT BRAD** » Thu Dec 27, 2007 9:56 am

are you going to be able to turn 7k+ rpms? if so then you'll want to file the pistons. for security's sake just follow the guide to filing the edge of the pistons and you'll be good to go. you'll get somewhere north of 10:1 with dohc pistons. be careful with the milling of the head. you'll soon see 11:1 and be bordering on having knock problems from detonation. plus you may run into piston clearance issues. if i were doing a budget build the above listed route is the one i'd take. it'll handle a 50shot of n2o without issue. it'll make great streetable hp. and, it'll be reliable instead of tempermental like my build. i believe it's the best bang for the buck. hp for dollar it can't be beat. to make more hp will cost ALOT more money.

soul_sword34 · Post by **soul_sword34** » Fri Dec 28, 2007 10:20 pm

Holy crap! Have you ever priced new pistons from Dodge? They cost more than new JE pistons?I searched for 1999 pistons, rings and bearings and came up with over $600

https://www.dodgeparts.com/oe_parts_cat ... 7c4272e960

03blackrt · Post by **03blackrt** » Fri Dec 28, 2007 10:40 pm

Chrysler doesn't sell just pistons, they are a piston/rod assembly, which is why they're so expensive. Also, JE's don't come with rings, neither do the Chrysler piston/rods.

Fedral Mogual have nice 'Sealed Power' DOHC pistons for $150ish a set. They even have a machined crown and skirt coating.

From the measurments I have (some of which are from multiple sources and are conflicting

), the DOHC pistons will net a 1 point raise in compression at standard bore. 10.8ish:1.

soul_sword34 · Post by **soul_sword34** » Fri Dec 28, 2007 11:45 pm

03blackrt wrote:Chrysler doesn't sell just pistons, they are a piston/rod assembly, which is why they're so expensive. Also, JE's don't come with rings, neither do the Chrysler piston/rods.

Fedral Mogual have nice 'Sealed Power' DOHC pistons for $150ish a set. They even have a machined crown and skirt coating.

From the measurments I have (some of which are from multiple sources and are conflicting ), the DOHC pistons will net a 1 point raise in compression at standard bore. 10.8ish:1.

Federal Mogul sounds good to me but how do you order any? Been searching for an hour now. Hmmm...according to this Federal Mogul modified the pistons so they aren't stock DOHC.http://forums.neons.org/viewtopic.php?t ... eral+mogul

03blackrt · Post by **03blackrt** » Fri Dec 28, 2007 11:59 pm

http://cgi.ebay.com/ebaymotors/Dodge-Ne ... enameZWD1V

Federal Mogul is were some of my conflicting specs are comming from.

So maybe they are different. If you use Chrysler specs, you'll get 10.8ish compression. Using Federal Mogul specs it's less than that.

soul_sword34 · Post by **soul_sword34** » Sat Dec 29, 2007 12:13 am

03blackrt wrote:http://cgi.ebay.com/ebaymotors/Dodge-Ne ... enameZWD1V

Federal Mogul is were some of my conflicting specs are comming from. So maybe they are different. If you use Chrysler specs, you'll get 10.8ish compression. Using Federal Mogul specs it's less than that.

well in that link they are saying the DOHC pistons from FM will net 9.8 CR in an SOHC

INVUJerry · Post by **INVUJerry** » Sat Dec 29, 2007 12:25 am

It's not. In a sohc, dohc pistons bring it up to about 10.2 or 10.3:1.

SELL ME YOUR ROTA'S!!!

03blackrt · Post by **03blackrt** » Sat Dec 29, 2007 12:41 am

^ I'll sell you my Rota's Jerry

My bad. 9.98:1 According to Chrysler specs... 10.8:1 According to "other" specs (that's were them conflicting spes come in

)

Here's a little chart I have of the piston types using Chyrsler specs.

soul_sword34 · Post by **soul_sword34** » Sat Dec 29, 2007 1:29 am

Yeah I'm not sure anymore. Might as well just shave my head.

kc2005ptgt · Post by **kc2005ptgt** » Sat Dec 29, 2007 11:27 am

be careful - at your age, shaved heads make you look creepy.

I have always heard that the DOHC pistons will raise compression up to about 10.2/3:1... what all else is involved that needs to be changed out to do the pistons? I have like 4 1gn DOHC neons with engines sitting in my pick'n'pull... been thinking about pulling the pistons out... I need rods, bearings, what? <-- sorry am dumb on names and terminology.

SGT BRAD · Post by **SGT BRAD** » Sat Dec 29, 2007 3:55 pm

dohc pistons will raise your cr to something b/w 10-10.5:1. it's been done many times. milling the head is never a good idea unless absolutely necessary. if you do any port work you run the risk of throwing the head away if it gets warped. on a non-milled head you could have it decked and retrued. my 02 is to switch pistons rather than milling the head.

soul_sword34 · Post by **soul_sword34** » Sat Dec 29, 2007 6:19 pm

SGT BRAD wrote:dohc pistons will raise your cr to something b/w 10-10.5:1. it's been done many times. milling the head is never a good idea unless absolutely necessary. if you do any port work you run the risk of throwing the head away if it gets warped. on a non-milled head you could have it decked and retrued. my 02 is to switch pistons rather than milling the head.

Well my problem is finding DOHC pistons. Chrysler sells em as a rod/piston set which is hardly a cost cutter, Federal Mogul sells em for a good price; however, I've been searching the other .org and they claim that FM has lowered the compression and then another states that the compression is actually higher. So how's that for a mind fuck?

kc2002acr wrote:be careful - at your age, shaved heads make you look creepy.

I have always heard that the DOHC pistons will raise compression up to about 10.2/3:1... what all else is involved that needs to be changed out to do the pistons? I have like 4 1gn DOHC neons with engines sitting in my pick'n'pull... been thinking about pulling the pistons out... I need rods, bearings, what? <-- sorry am dumb on names and terminology.

Don't really "need" anything. It's one of those classic, "since your in there", things. Might as well replace the rods and bearings.

soul_sword34 · Post by **soul_sword34** » Sat Dec 29, 2007 10:06 pm

Okay I've done the extra research, priced everything I need for the different ways I can spend my tax returns and I'm going with the Quaife build. Only because I can't find any DOHC pistons cheap enough or with the compression bump. Top end rebuild with the head shaved .030 is what I'm going with. I figure by the time I'm ready for that 150 shot of nitrous (direct port, progressive controlled of course) I'll be ready for the bottom end to be rebuilt. Will still have to redo the mag head though and probably go with another new unit and do that. That is unless they make forged pistons in standard size compression. Haven't found any yet.

pyro · Post by **pyro** » Sun Dec 30, 2007 12:03 am

About the sealed power thing. I can't say for certain, but I'm willing to bet Fed-Mog in their infinite cheapness only makes one piston for DOHC or SOHC, and uses the lower compression height for their own $afety.
The good news is, they will probably be so cheap/dumb as to spec the same one for NGC SOHCs, so those poor suckers will see a bump in compression.

soul_sword34 · Post by **soul_sword34** » Sun Dec 30, 2007 12:05 am

Are you following me? So anyways about the only two ways to go for a compression boost is to shave the head or go with forged JE pistons. Right?

So with the JE piston build it is going to bring me up to $1,552 that is including the following
$590 10.5-1 pistons with ring set
Main Bearings $39.99
Rod Bearings $29.99
Gasket Set $46.67
Oil Pump $89.99
Water Pump $81.25
Timing Belt $47.99
Crank Seal $5.53
Machine Shop (Hone block, Clean block, Polish crank, Balance assembly)$400?? Not sure on that one.
Without shop work+ $1,052, that I can handle.

Not really sure if I need that shops help on this one. I'm sure I can do all that if only I have done it once before. Could save me some cash.

kc2005ptgt · Post by **kc2005ptgt** » Sun Dec 30, 2007 12:21 pm

quick threadjack, what are diff tab savers? and can they be installed on the 3.94 tranny from an 02 or do I have them?

soul_sword34 · Post by **soul_sword34** » Sun Dec 30, 2007 6:13 pm

kc2002acr wrote:quick threadjack, what are diff tab savers? and can they be installed on the 3.94 tranny from an 02 or do I have them?

That is the mother of all threadjacks.

They keep your diff pin inside. They can be installed and you'll have to pull your bell off to see if they have them. Now get another thread or do a search.

INVUJerry · Post by **INVUJerry** » Sun Dec 30, 2007 6:38 pm

They only came stock on 04-05 transmissions.

They are not bullet proof.

soul_sword34 · Post by **soul_sword34** » Sun Dec 30, 2007 6:43 pm

Anyone have any tips or links I can read on doing your own bottom end rebuild. Mostly debating whether or not I need to take my block into a shop.

SGT BRAD · Post by **SGT BRAD** » Sun Dec 30, 2007 8:32 pm

if you're not rebuilding the bottom-end then don't take it apart. are you butchering a mag head to get the compression? if so then shame on you. pm me and we'll work out a deal on the extra std sohc head that i have. i can have the local shop rework the whole thing with a good p&p job for less than 400.00. it'll give similar perf if not better than a stock mag head and you can save the mag head until you're ready to do everything. trust me you'll regret destroying the mag head if you're thinking you'll just get another one later. they are getting harder to come by.

Post by **racer12306** » Sun Dec 30, 2007 8:42 pm

There is no concrete evidence that 04-05 trans's have diff tabs. Chris looked up an 05 and it was not there in the OEM setup.

soul_sword34 · Post by **soul_sword34** » Sun Dec 30, 2007 9:57 pm

racer12306 wrote:There is no concrete evidence that 04-05 trans's have diff tabs. Chris looked up an 05 and it was not there in the OEM setup.

Stop jacking my thread.

Anyways. Sarge, I just purchased a set of used DOHC pistons from Lorenzo for $45 shipped so now the worry is over, I'll be able to get that compression without touching my beloved.

My next thing is to do some research, help welcome, about taking the block to a shop or just prepping it myself, could save even more money. If I can save on the machine shop I can bring my total budget to about $4,200. Have the project started in February and burn rubber by May.

Post by **racer12306** » Sun Dec 30, 2007 10:15 pm

It's not really off topic since you were talking about the diff setup.

It wasn't like "Hey I need to make some power, what would you suggest."

response: "Can we get into a complete scientific explanation of why water appears to be blue but is really clear."

soul_sword34 · Post by **soul_sword34** » Sun Dec 30, 2007 10:17 pm

Post by **racer12306** » Sun Dec 30, 2007 10:23 pm

MoxHair · Post by **MoxHair** » Sun Dec 30, 2007 10:25 pm