stock engine max rev limit

[91-gsx]

I was wondering what the maximum redline I could have on a stock internal engine 1g. I want to shift the car at 8500 rpms because I am going over to a t3 setup and sc6152 in a .63 a/r housing before the end of this year. I heard for high rpm shifting the balance shafts should be taken out for increased oil pressure, so I am going to do that when I change cams and put in the ARP's, thinking about crower 64414's, was thinking about comp 200's. What do you guys recommend? Second I was wondering if the rod bolts could be shifted that high? I was also wondering if I should upgrade the valve springs and retainers at the same time as cams for the increased rpm limit, or could I just upgrade the springs without the retainers because it is about half the price? Or could I get away with shifting the stock springs and retainers a little past 8000rpm?
thanks for the help

 

[BISHILVR]

I would'nt dream of revving a stock engine that far for the long run. I would suggest forged internals, arp rod bolts, balance shaft elimination at the very least. You have almost 600 posts on here, this question is asked almost weekly, I would think that you would know some of the answers already. People have turned the stock valvetrain at 8500 rpm, but I'm just not one to do it. I would strongly suggest a kevlar timing belt also.

 

[91-gsx]

So what do you guys think would be the max I could rev this thing to? If I rev to 8000rpm would that be to far? See the reason I asked this question is in hopes of having those people that are revving high on the stock internals give me some input. I do not have the money for built internals, but did not think that you needed built internals just to rev higher. I know that they are required at power levels past about 500hp for reliability. Basically I would like to hear from people that do rev the stock internals that high, not the ones who would not dream of it happening.
thanks

 

[tbTalonES94]

There are a lot of people on here that rev stock internals that high. If all your parts are in good condition and you have a good tune, then you should be able to get away from it. SHOULD...every engine is different. I would suggest some ARP rods bolts, ARP head studs if you haven't got those already.

To speak for myself, I have revved to 8,000rpms on my completely stock 6bolt motor with comp 101200 cams and haven't had a problem. All i had was a Cometic HG and ARP head studs. Ran a 12.0@114 i think on that run.

Looks like you don't have much for a mod list. You still have the stock intake manifold I assume? It won't do MUCH good to rev that high on a stock intake manifold. They make peak power around the 6,500 range...or close to the stock rev limit. If you are revving that high to maybe gain some more MPH, i can tell you from first hand experiance if you aren't making full power to where your revving...you won't gain much mph if any at all. I revved to 8k in every gear for one run and trapped 114mph....next run shifted at close to 7 every gear and still trapped 114mph with a quicker ET. Gotta be able to flow the air revving that high.

Just me .02

 

[BISHILVR]

"I would like to hear from people that do rev the stock internals that high, not the ones who would not dream of it happening." BUT, thats not the question that you actually asked! You seem to have changed your rules in the middle of the game since you did'nt get the answer that you wanted. You probably wont get alot of people that run their engines stock in excess of 8500 rpm. Instead of buying a turbo so big that you have to rev to 8500 rpm, you should have done your homework and bought a turbo that was capable of using what you could afford for internals. Now you have your nipple in a wringer it looks like. Build the engine first and THEN add power to it. Trying to add power to a worn stock engine will only lead to threads such as: "My engine just shut off, any suggestions?" or "@#$*@ Mistubishi junk" (one of my favorites) Good luck though.

 

[91-gsx]

"I would like to hear from people that do rev the stock internals that high, not the ones who would not dream of it happening." BUT, thats not the question that you actually asked! You seem to have changed your rules in the middle of the game since you did'nt get the answer that you wanted. You probably wont get alot of people that run their engines stock in excess of 8500 rpm. Instead of buying a turbo so big that you have to rev to 8500 rpm, you should have done your homework and bought a turbo that was capable of using what you could afford for internals. Now you have your nipple in a wringer it looks like. Build the engine first and THEN add power to it. Trying to add power to a worn stock engine will only lead to threads such as: "My engine just shut off, any suggestions?" or "@#$*@ Mistubishi junk" (one of my favorites) Good luck though.

If i was misunderstood because of the way i labeled the question, my bad. But i was looking for people with more of a first hand experience at taking the stock engine to higher redlines. I do not want to run in excess of 8500rpm, 8000rpm is good enough for a good power band with this turbo. I just do not want to have horrible transient response between shifts, which does happen at too low of an rpm, but 8000rpm would be good for that too.

Instead of buying a turbo so big that you have to rev to 8500 rpm, you should have done your homework and bought a turbo that was capable of using what you could afford for internals.

First off I have not bought this turbo yet. Second, this is my homework .
My engine is actually in good condition, perfect compression. A few things here and there but nothing wrong internally. Ofcourse this is as far as I know.

See, what i wanted to do is make 400-500whp with the stock internals. A sc6152 should easily do it at lower boost levels that can be easily held to 8000rpm and beyond. So sense shifting at 8000rpm does sound a lot safer to me then shifting at 8500+, that is probably what i will do. Now i do not think that I need higher pressure valve springs and retainers to do this simply because the stock fuel cut is 7500rpm, and i am going to 8000rpm, I'm pretty sure the stock springs are more then capable of making up that extra 500rpm. So I think a 8000rpm redline, along with no balance shafts, a set of comp 200's or crower 414's, a sc6152 in .63a/r, and a smim would be a great combination. Along with the ARP studs that i already have ofcourse.
thanks for the help

 

[BISHILVR]

Yes the valvetrain should be fine, its one of the least of your worries. The stock engine if it is in good shape can handle 450 or so. I would definately go with a kevlar belt though.

 

[tbTalonES94]

What is "lower boost levels" to you. 400-500hp is a big jump. What kind of low boost do you think you can run while achieving those levels of power? I sure hope it isn't like 20psi...### that isn't going to happen, specially with stock internals.

 

[DSM90AWD]

I was wondering what the maximum redline I could have on a stock internal engine 1g

A loaded question that has alot to do with age/condition of engine and valvetrain.

I heard for high rpm shifting the balance shafts should be taken out for increased oil pressure

You heard wrong. The BSs spin 2x the speed of the engine so removal is more a safety concern than a way to increase oil pressure.

Certain cams require stiffer springs due to the radical ramps. FP2s (which I have) / Comp200s do not require them. Obviously installing an upgraded spring / lightened retainers vs 15-16yo stockers will give you added safety

 

[Reese92tsi]

With the 60 trim I revved mine to 8500 with the stock valvesprings and stock bottom end with no problems. Just make sure to get rid of that stock flywheel as they don't like rpm

 

[Smokin80]

you better hope your tranny is absolutely perfect. There is not a real good chance that you will be able to shift a stock tranny at 8000 let alone 8500. My old tranny...stock 2g didnt even like going into 3rd at 7500. I would try to make as much power before 7500....it will be more reliable and much cheaper.

ive said it before and ill say it again....CHEAP, FAST, RELIABLE...pick 2 because you cant have them all.

Smokin

 

[TAI92GSX]

I shift at 8500 in every gear with the stock valvetrain when I'm racing my car at the track. It should be fine shifting at 8500. But like others say, depends on the condition of the valvetrain, if its making power up that high to make worth taking it up that high, if your transmission can shift that high, etc.... You know your engine best, so try it and find out.

 

[Kevin Jewer]

I'll add another datapoint. I've been taking stock DSM heads to 8500 rpm for the last 4 years out of the 6 I've been doing this. John hit the nail on the head about the bashaft speed. The bearings like to spin at that rpm level, and that can take out other parts doing the real damage. The oil presure thing is a non-issue IMO. I've never seen any measureable gain in oil pressure with removed shafts. They don't lose that much oil.

The bottom end of the motor can take it. Stock cranks in built motors are going over 10k rpm in some of the fast cars. 6 bolt rods are pretty stout as well. If the bottom end was built for a 195 hp car and can make 500+ at the wheels, I'm not surprised that there is a little more room left in the valvetrain too.

I run to 8500 at the track (weekly), and drop the rev limit to 8000 on the street. I've never had a transmission that couldn't do 8500. The stock EVO transmission seemed to have trouble with it, but it turned out to be the clutch. With the Exedy twin disc is shifts flawlessly. A Shep or similar transmission should do even better based on past experiences.

 

[91-gsx]

This is all great to hear. Like I said my engine has perfect compression, actually abit higher than stock in each cylinder, but the same none the less. It also has 115,000 miles on it, and it was all stock when I bought it, and after taking parts off and on all the time, it seems to have always been stock. 8000-8500rpm would be a perfect redline for the sc6152 that I wanted to get. Then cams, and then a smim. I believe with this setup and water injection I can do pretty well on pump gas at the track and streets.
thanks for the input guys

BTW: What cams do you guys recommend for a setup being revved that high? Cannot be lobey because it will be daily driven.

 

[91-gsx]

I'll add another datapoint. I've been taking stock DSM heads to 8500 rpm for the last 4 years out of the 6 I've been doing this. John hit the nail on the head about the bashaft speed. The bearings like to spin at that rpm level, and that can take out other parts doing the real damage. The oil presure thing is a non-issue IMO. I've never seen any measureable gain in oil pressure with removed shafts. They don't lose that much oil.

I have read this web page about the free way to eliminate the balance shafts.
http://www.ecanfix.com/~mdhamilton/balanceshaft.html
Do you guys recommend I use this way or another way? It basically tells you at the bottom of the page to leave the front shaft in unless you are going to remove the engine to do this. The rear shaft is cut off and the gear, as far as I could understand, stays in their so that it could still be spun by the oil pump gear. Now, is their a way I can remove that gear all together so that the oil pump does not rotate anything? I'm worried because that gear will spin just as fast as it use to but now the balance of it is gone because no matter how you hack the shaft off it will not remain in balance unless done perfectly by machine.
Thanks for the help, again

 

[SleeperG]

I have read this web page about the free way to eliminate the balance shafts.
http://www.ecanfix.com/~mdhamilton/balanceshaft.html
Do you guys recommend I use this way or another way? It basically tells you at the bottom of the page to leave the front shaft in unless you are going to remove the engine to do this. The rear shaft is cut off and the gear, as far as I could understand, stays in their so that it could still be spun by the oil pump gear. Now, is their a way I can remove that gear all together so that the oil pump does not rotate anything? I'm worried because that gear will spin just as fast as it use to but now the balance of it is gone because no matter how you hack the shaft off it will not remain in balance unless done perfectly by machine.
Thanks for the help, again

the OEM mitsu stubby shaft is available through slowboy for only like 12 bucks.
12 bucks man.
i mean yeah i guess you could saw the rear shaft down.
but in my mind having an OEM part for pocketchange seemed to make more sense.
its not like ANY balance shaft removal will be free. you can't get around paying for a new front cover gasket. so whats another 12 bucks?

and as far as making power up there w/o lope. the 264/272 combo will improve yoru high rpm v.e. without devestating your idle.
most guys don't complain about the 272's, but i myself have never heard a complaint of a 264/272 idle.
cams are the next upgrade for my galant, i plan on going with the DKS 272's

 

[Kevin Jewer]

I have done the rear stubby shaft and left the front shaft in place more than once. Works well, and no worries about porking the offset bearings.

I saw no difference in idle quality between 264s and 272s, so I find it unlikely that the combo would be any different. They all idle about the same. Of course, this is with DSMlink. With huge injectors on an AFC or something there may be a noticeable difference, who knows. I've been running 272s on the 2g and now on the EVO. The 272s will do fine to 8500, the intake manifold becomes the next bottleneck.

 

[91-gsx]

I have done the rear stubby shaft and left the front shaft in place more than once. Works well, and no worries about porking the offset bearings.

I saw no difference in idle quality between 264s and 272s, so I find it unlikely that the combo would be any different. They all idle about the same. Of course, this is with DSMlink. With huge injectors on an AFC or something there may be a noticeable difference, who knows. I've been running 272s on the 2g and now on the EVO. The 272s will do fine to 8500, the intake manifold becomes the next bottleneck.

I would not mind putting a "stubby" shaft in, but how much does it cost from mitsu and what is the part number for it? Also, how much does the front seal cost.
thanks for the info guys, really appreciate it

 

[Kevin Jewer]

It's around 10 bucks. I don't carry the part number around in my head, but it's from a mirage. I'm sure some searching will turn up the part number. The front seal was a bit expensive IIRC, 20-30 bucks. As a side note, if you replace the oil pump cover and gears all seals are included in the new cover.