im sure he wasnt trying to get 30,000-50,000 miles out of it.

 

Nope

People are just talking like 8500 is some kind of hard limit, other then Aaron.

 

B18C1 GSR 1.58:1 R/s- 10,500+
K24/20A3 1.54 R/s- 9,000 with some running higher
Kiggly 2.3 1.5 R/s- 92-9300 some oiling issues
Me, LR2.4 1.56 R/s- 8600 regularly
IHRA Pro mod- 1.38 or worse R/s, 8500

From what Kevin has posted and I keep bringing up the problem is main bearing oiling. They arent adequate without some mods and have a tendency to run hot and wipe. He even posted what he did to fix it.

 

Interesting read here-

http://www.1320techtalk.com/viewtopi...d7ef80fee275b9

 

I think I read tha he used a center bearing that was slotted<--(Not right terminology), and added weight to the crank in one way shape or form.

 

finally found it, i new i say this somewhere. maperformance's 2.4 1000hp stock ecu evo shifts as high as 9200rpm..

heres link to where he states is consistantly in the 9k range


https://www.evolutionm.net/forums/ev...ck-ecu-13.html

 

good find. However, this is a drag car. I also know someone who took their 2.4 to 9k in order to get into the 9's...again, a race car. I believe the op doesn not have a LR2.4, thus his rpm limit will be less. IMO 8200rpm. That's it.

 

Here's the real question.... how long do you think thats going to last?
Answer: not long

that thing is not a DD much less anything other than a garage queen brought out once in a blue moon

 

oh im doubting that at all, just thought id add some info, cause id remembered reading it somewhere.

 

well if you also follow map preformace like a religion you would have read they also stated in another thread its there drag car and they dont recommend the AVERAGE user to do this think he stated 8500 is more then plenty as john bradley has stated but lets be honest im not planning on spending 3000 plus labor again just so i can rev like im on a 2.0. You will make plenty of power up to 8000 rpms on right setup and tuning

 

I still have to read the ratio link but this is just my 2c .

For the life of me I can't understand why people build long stroke engines and feel the need to use big turbos and or cams in them .

Back to basics . I think Mitsubishi would have designed the 4G engine family with in line as well as transverse mounting applications . To go in sideways or east west as they say here there is a limit as to how long the block can be and still fit the engine in with all its accessories and offset on a gearbox .
When block length is limited there are limits in what size bores it can have withought compromising the blocks structural integrity .
So usually the stroke lenghts are made to have an engine with a good balence of power (torque/revability) . Over time cars tend to grow in size and weight and the engine capacity needs to keep up to maintain an acceptable power to weight ratio .
Usually the bore can't grow too much so longer stroke cranks are used with the assumption by the manufacturer that this will be a production engine only and not a race engine . Rod stroke ratios are probably more of a vibration issue for them so they use the typical high pin height pistons or taller blocks and longer rods .

This whole thing is about making low/mid range torque and they try to size everything around making torque at those sorts of revs because thats how most cars are used .

Now you can try to change the dynamic of where these engines make their torque and horsepower peaks but you are fighting a lot of what the manufacturer built into them .
Big turbos and cams are not going to make killer torque low down because the airflow rates at which they work don't occur at lowish revs .
IMO long stroke engines are not something thats going to have much of a life if you "beat on it" regularly . Its one thing to expect a high maintenance regime race engine to stand up to it and another to expect the same from a daily driver with number plates on it .

Short of time ATM but would I be right in assuming that Mitsy doesn't use main bearing shells with "oil channels" in the upper or block half ?
That was something done to BMC/Leyland Mini engines by people hotting them up 25 plus years ago . They basically have a channel or groove in the bearing shell either side of the oil hole which keeps a reserve of oil above the main bearing journals . The lower or cap halves take the compressive power loads and aim to have the maximum area availabe to support the crankshaft .

If it were me I would be looking at the largest practicle bore size because into large bores you can fit large valves which you need if you want to rev the thing .
I don't believe longer and longer crank strokes are the answer to ultimate power because of the mechanical limitations and the inability of the head/valves to flow any more .

With turbocharging the limits of the std frame turbo is certainly the turbine housing - or the gas you can get through the bored out outlet and the open wastegate anyway . Less but not insignificant is the air you can get out of the bored out OE or aftermarket compressor housing .
A serious uncompromised turbocharger won't be one based on a TD05 unit .
If it were me and I could afford it the T4 flanged TS twin gate FR manifold would be the go and I'd probably look at one of the BW turbos . GT BB Garretts are available but IMO their use of big trim turbines and at times compressor wheels don't go hand in hand with wide ranging twin scroll turbo engines . I think the mindset behind them was to use larger trim lower innertia wheels than the T3/T4B/E/S size/era wheels they replaced and head down the road of annular contact ball bearings in their performance/aftermarket range . Higher speed capable wheels running at higher speeds was one way to get more air and exhaust through them without increasing the size and weight of the overall unit . Material/production costs are another thing and its plain to see if you've ever layed out a GT BB turbo in bits next to the equavilent size bush bearing one . The BB one is actually simpler inside thean the plain bearing one and the parts count is less too if you count the bearing cartridge as one part .
Also many these things in HKS form have been around since the early 1990s which is a long time ago in the engineering scheme of things .
Just on the GT35R thing , I spoke to Geoff R a while back about GT3582Rs and the lack of twin scroll turbine housings for the things and the fact that they are a bit of a Garrett bitzer anyway . I think he put some research into them a came up with a F135R and I can't remember who was doing them . Anyway it used a larger I think turbine in a larger center section that Garretts one does and has twin scroll T4 flanged T housings std , worth a look I think .

Anyway for a powerfull roadie on a champagne budget I'd use the largest bore tallest block going and organise a std or at most 94mm stroke crank and rods for it . Very light weight high compression ratio pistons (9.5) would be good so you can get reasonable oomph off boost .
Turbo and cam wise you have to decide where it all comes together and makes strong torque , I don't think its a case of chasing numbers aside from where in the rev range you want it to haul from .
Road car with road rev range , probably 3000 revs . This fits in with production gearbox ratios and you get good torque why rev to the moon anyway . I wouldn't think a production based gearbox would like changing from 8500 revs and generally people can't live with dog change boxes in street cars for too long . So the right CR/cams/turbo/manifolds all designed to work together as Aron said above , a working set on a good 21-2200 should work better than a poorly speced 2400 and may not cost as much overall .
It would be nice to aim fror a 450/450 to maybe 500/500 (Hp/ft lbs) engine and work hard to get the torque numbers at or above the horsepower ones . I have to assume that unbalenced ones rely on lower torque and higher revs to get the high hp number , sounds peaky to me .

Evos maybe reasonably light cars but if performance is the number 1 then all the loungeroom pork has to go . I don't know US RS spec Evos but for Evo 6s they didnt get any of the hairdresser stuff std and were 100 Kg lighter than the 6 GSR version .

Your calls , cheers A .