2.4 with a t88

[rdrkt]

Did people flame Shepherd when he first bolted on a Full T4 turbo??? rather than the 3rd world turbo 20g? No, they shut up and he ran a hell of a lot faster and now everyone is following the band wagon.

Actually Im pretty sure they did but he was well into the 10s at that point. So at least he had a frame of reference.

 

[rdrkt]

Go rev your 2.4 to 10k, let us know how that works out for you.

I have seen this posted a few times in this thread. I have to ask you guys. Who the hell is revving to 10k here? You can run WELL into the 9s ONLY revving to low 9k. You really only need that much rpms (low 9k) in first and second to help you stay in boost off the line. There are very few setups out there that are designed to flow efficiently at that level. Because that is well beyond the range of most intake manifolds, valve springs, cams, headwork, and most importantly transmissions.

Aside from a few isolated people I read about on the net I have never seen someone successfully be able to shift at that rpm without placing their syncros on a replacement schedule that most people here could neither afford nor tolerate.

 

[rdrkt]

I will have to say this from what I have seen for an all out race motor the 2 liter is better. The extra torque from a 2.4 or 2.3 isn’t needed as much at the track when you are only running in a very narrow rev range.

However you guys have to ask yourself are you REALLY building an all out race motor? On my setup with the tiny gt40 I can make 500hp on pump gas at 23lbs. I can spool that turbo very nicely and its more than enough power to run 10s in a 3300lb w/driver car. Even if I wanted to run 9s it would be a matter of a size or two larger turbo and some nitrous. All the while I can still maintain a nice powerband. So ask yourself what are your goals?

 

[rdrkt]

Dont confuse theory with a scientific anaylisis.

I would put science in quotes when you are talking about trying to theorize motor efficiency using pc programs. I have yet to see a program adequately be able to reproduce cams, head work, turbo efficiency, intercooler efficiency etc.

From what I have seen most 2.4s suffer from not having enough cam and in most cases not having enough turbo like my case. Which is why it seems that they cant make power in the upper rpms. Put a T72 on a 2.4 with cams like the 415 crowers or something larger and valve springs that actually work and I think you would see a VERY nice dyno graph that didn’t run out of steam.

 

[MNGSX]

I would put science in quotes when you are talking about trying to theorize motor efficiency using pc programs. I have yet to see a program adequately be able to reproduce cams, head work, turbo efficiency, intercooler efficiency etc.

DID I POST ANY OF THOSE RESULTS?

Piston G forces, Piston Speed and Friction losses ARE SCIENCE has nothing to do with cams, headwork efficiency etc...

That is really moot.. I did'nt get into the VE stuff yet because I just knew this would happen.

The graphs I posted will produce the same results no matter what cams, intake, turbo, etc... Rod stress and friction... that is it.

As for the accuracy of camshaft, headwork, turbo and IC efficiency.... You must not have used EAPro...

Secondly compairing two stroke lengths with the same settings for all other things is an accurate assesment of how each engine will be different.

Meaning the potential for error in both results is the same. Since Garbage in = Garbage out If you use the program right it is stunningly accurate. It has inputs for the most important turbo specs. Surge line and the efficiency island... No it wont tell you if you are over reving but it will also let you spin the virtual 2.4 to 10k and goes "Piston Speed impossibly high. With the turbo you just have to look at the actual CFM data at a given rpm and the PR for that RPM cell and plot it on a comp map your self to do the reality check.


You can enter in actual flow bench tests of heads with intake manifolds.. I am planning on running both engines with three "top ends"

Stock 1g head and intake using polks flow bench data.

Polk Stage 4 (I think) head with loner runners

Polk stage 4 with shorter runners.

This data was posted here.. I chose it because it was independant of anything I have done with intakes and heads and posted publicly here.

With the cams 2 cams will be run.. I cant get dead on with cams not because of the software but because of the cam companies. Comp has internal company EAPro cam files that are so accurate you could program them into a cnc machine and make cams. Gee I wonder why those dont circulate. So I'll run close as I can get to comp/fp 2's based on the cam card... Later in the article I'll get into specing the cams for each engines personality... Like FP4's (future) so its only a good guess at them on the 2.4 based on the '400 part number comps.. As well as some split duration tricks on the 2.1

The whole point is to be as independant as possible..

If I agree that a 2.4 makes more low end Tq than a 2.0(1) and people agree that a 2.4 has a lower rpm ceiling... How am I not being unbiased..

 

[rdrkt]

It has inputs for the most important turbo specs. Surge line and the efficiency island... No it wont tell you if you are over reving but it will also let you spin the virtual 2.4 to 10k and goes "Piston Speed impossibly high. With the turbo you just have to look at the actual CFM data at a given rpm and the PR for that RPM cell and plot it on a comp map your self to do the reality check.

In your experience how accurate are the compressor maps you have seen? In my experience they are pretty close but sometimes they can pretty off like the case of the 60-1.

You can enter in actual flow bench tests of heads with intake manifolds.. I am planning on running both engines with three "top ends"

Flow bench does not take into account velocity. You can port a head out real nice but your spool up is going to suck if you velocity takes a crap too.

With the cams 2 cams will be run.. I cant get dead on with cams not because of the software but because of the cam companies. Comp has internal company EAPro cam files that are so accurate you could program them into a cnc machine and make cams. Gee I wonder why those dont circulate. So I'll run close as I can get to comp/fp 2's based on the cam card.

From what I have seen most domestic cams rarely match their card. Comp is a little better than lets say crower but it isn’t anywhere near as consistent as lets say HKS.

Im not trying to be contrary just trying to show that as you said your program will only be as accurate as the data you put in it. Getting the proper data is the problem.

If I agree that a 2.4 makes more low end Tq than a 2.0(1) and people agree that a 2.4 has a lower rpm ceiling... How am I not being unbiased..

Never said you were.

Have you taken a look at the 2.1 that Marco built? As I recall the conclusion was the 2.1 worked better than a 2 liter but still didn’t spool the turbo or make as much torque as the 2.4 but peak power was nearly identical.

 

[MNGSX]

In your experience how accurate are the compressor maps you have seen? In my experience they are pretty close but sometimes they can pretty off like the case of the 60-1..

Yes but EAPros method of entering turbo specs makes desktop dynos look like crap. Also since the issue is'nt testing two turbos about the same size but stroke and its effect on the powerband none of that matters now does it... Since both share the same turbo specs.

Flow bench does not take into account velocity. You can port a head out real nice but your spool up is going to suck if you velocity takes a crap too. .

The software does take into account velocity it calculates the intake port velocity and gives you the mach #.. The best head porters measure velocity as well as CFM.. This subject is complicated enough to fill its own article.

From what I have seen most domestic cams rarely match their card. Comp is a little better than lets say crower but it isn’t anywhere near as consistent as lets say HKS..

I have seen dyno results of comps beating the HKS cams.. I also really cant find any differences in the production methods and equipment used by comp vs HKS. None...

Im not trying to be contrary just trying to show that as you said your program will only be as accurate as the data you put in it. Getting the proper data is the problem. ..

So long as its even steven on the accuracy of the data. Its a fair comparison.

Have you taken a look at the 2.1 that Marco built? As I recall the conclusion was the 2.1 worked better than a 2 liter but still didn’t spool the turbo or make as much torque as the 2.4 but peak power was nearly identical.

Run each engine two seasons and or the same # of miles on the street.. Do a compression and leakdown test and get back to me..


People like Hose need to read this... Many times probably to get it but read it still...

http://sportcompactcarweb.com/tech/0104scc_ssbbpart7/

 

[hose101772]

Run each engine two seasons and or the same # of miles on the street.. Do a compression and leakdown test and get back to me..

So you are building a street motor then,right?You kept on like this 2.1 was going to be a full tilt race engine cause it didnt have to spool quick.Which is it?

People like Hose need to read this... Many times probably to get it but read it still...

If graphs and papers were air and vapors,you'd be going real fast.

 

[MNGSX]

So you are building a street motor then,right?You kept on like this 2.1 was going to be a full tilt race engine cause it didnt have to spool quick.Which is it?.

In case you have'nt noticed picked a 2.0 displacement over a 2.4 even with an existing 2.4 crank... The whole point was the durability differences of the engines independent of their use. The shorter stroke will wear out slower even when reved high at the track or on the street...

The bore-to-stroke ratio of an engine can also affect the engine's power characteristics. Over-square engines, ones that have a bigger bore than stroke, have lower piston speeds and less internal stress at high rpm due to lower inertial loads. There is also more time to fill the cylinders because of the lower piston speed. Engines with longer strokes and smaller bores, called under-square, have more internal stress due to faster piston acceleration and higher piston speeds. This accelerates wear and can induce seal-killing ring flutter.

If graphs and papers were air and vapors,you'd be going real fast.

If the typo was nitro, you'd be driving a funny car.

If your suspension was like your reading comprehension you'd leave the tree rolling on three.

 

[hose101772]

affect the engine's power characteristics

Its affect----NOT dictate.

The whole point was the durability differences of the engines independent of their use.

NO-no it wasnt the reason.It was for FIA homolgation.

Just hurry up and build this thing so we can read about "why wont my motor take any timing advance".

Maybe you're program could you make us all one of those purdy graphs that shows the milli seconds your headgasket will last when you wick up the boost.

If the typo was nitro, you'd be driving a funny car.

Dude come on.My graphs and papers thing was so much better,makes me wish I had posted that on the "other" forum.It coulda been one of the quotes that pop up at the top.

 

[psychlow]

A tech argument devolved into a rapping battle.

Who'da thunk?

 

[Batty200]

IT IS.

There are 3 ways to build 2.1

1. bore out a 2.0

2.0 crank in 2.4

2. Regular G64 pistons custom rods 6mm longer.

3. Stroker G63 pistons custom rods 12mm longer.




#1 is the least expensive.

#2 is a waste because it costs as much as 3

#3 is best due to longest rods and lightest pistons.

At least we agree on this one. I have long stated the fact that I beleive a 4G63 stroker with a big bore to be better than a standard 64 for the exact reason 3 is best. LIGHTEST PISTONS. Some have told me I am a moron for wanting lighter psitons yet preach about the greatness of lightweight valvetrain.

I think a 2.1 would be a fun motor as well, but it cant do what a 2.4 can and when FP makes 2.4 Specific cams I think a whole new level of power will start to show and people will again be shocked. How many 2liter you know of going 126mph 1/4 miles and doing 500whp on pump gas?


Later

 

[killab443]

Back to topic but theres a guy on dsmtimes.org that runs 9.669 with the t76... no nitrous. Imagine with a 2.4 6 botl block- knife edged crank,Bored .040 over, and a ported head with oversized valves. If the 2.4 is bored .040 over doesnt that make it a 2.5? This motor could spool somethin mean

 

[nanokpsi]

In case you have'nt noticed picked a 2.0 displacement over a 2.4 even with an existing 2.4 crank... The whole point was the durability differences of the engines independent of their use. The shorter stroke will wear out slower even when reved high at the track or on the street...

My guess is that this has to do more with drivetrain longevity than does engine life. More torqe=need for more clutch=broken drivetrain.

 

[GPTourer]

NO-no it wasnt the reason.It was for FIA homolgation.

Great thread, but I think this is the point thats most important. Mitsubishi spent millions in R&D refining this engine to be the best 2.0L turbo on the planet. Not 2.1 or 2.3 or 2.4. By changing a few things we can show advantages in some ways and disadvantages in others, but until we get some more specific parts engineered for the 2.4 application, we won't be able to fully show any sort of clear winner - except the original.

But then again, how do people really know what's going on inside of Shep's motor, or any of the other top DSM racers? Are they really that open about their setups? And I don't mean what they post on their web sites. Do they tear them down for inspection after every run?

 

[TurboSpoolinIns]

I have seen dyno results of comps beating the HKS cams.. I also really cant find any differences in the production methods and equipment used by comp vs HKS. None...

Sorry, I just had to jump in here for the little that it matters. If you want to see my comparison of the two cams on my car, look in my profile pics between the two dyno chart's numbers. I didn't wanna post it before, but I'll let you guess what the only change I made to the car was.

 

[TurboSpoolinIns]

A tech argument devolved into a rapping battle.

Who'da thunk?

Hahahah.. good ones. Let's keep the flows going oh so slow youngn's. :laugh:


But on topic I guess. The way I see it, you could use a T88, it just better not be the 88mm one but the smaller Greddy T88. Lots of nitrous and a 2.4 with a good drivetrain, and it should work alright

A turbo I could realistically being used with a 2.4 would be a 71mm GTQ to see about 30 psi at low-mid 6000s off the nitrous. So if there is a proper motor to back it up, nitrous with a 71 or even a 74mm should be fine.

 

[peregrine]

But then again, how do people really know what's going on inside of Shep's motor, or any of the other top DSM racers? Are they really that open about their setups? And I don't mean what they post on their web sites. Do they tear them down for inspection after every run?

so are you saying that they could actually be running stroker motors and that the 2.0 is really going the way of the dodo? :laugh:

 

[MNGSX]

My guess is that this has to do more with drivetrain longevity than does engine life. More torqe=need for more clutch=broken drivetrain.

I think it has to do with the engine. The parts that mitsu (even on the EVO) uses on stock engines are a far cry from what most use in a 2.4.. Imagine the recall departments frustration with a 7bolt 2.4 crankwalk rates.


I dont hate 2.4's nor fault anyone for wanting or bulding them.. Both have their inherent differences, their strengths, and weaknesses...

I like engines that last longer and a wider power band.. I did'nt say it was as low in the RPM but with more available RPM range you can build a 2.0 with a nice wide power band across the upper rpms.

Imagine with a 2.4 6 botl block- knife edged crank,Bored .040 over, and a ported head with oversized valves. If the 2.4 is bored .040 over doesnt that make it a 2.5? This motor could spool somethin mean

If you spool a larger turbo at the same point a 2.0 spools a smaller one... Say 3500 rpms... You sure dont have anwhere near as wide usable RPM range now do you.

Since our cars dont have CVT transmissions the engine cant just sit at the peak power RPM the whole run.. Peak power numbers are no substitue for a big flat curve that matches what the car is geared for.

On my 2.0 I'll pump a bunch of the air out of my crank case to get my extremely low tension rings to seal better than normal rings and it will also reduce windage almost as much as a dry sump... Ever see wind in space?

This nets a gain across the board all things equal... Since it is across the board it adds to the low end.. How much...

With all that being said...

A tech argument devolved into a rapping battle

(imagine snoops drop it like its hot)

When the cops try to ticket you.....

Pull a Randy moss... Pull a Randy Moss

Local radio station.. Funny as hell..

 

[GPTourer]

so are you saying that they could actually be running stroker motors and that the 2.0 is really going the way of the dodo? :laugh:

I don't know. But I just think that with so many things that could be going on, like secret spec turbos, custom ground cams these people have access to things that aren't over the counter that their sponsors help make possible. ITs kinda like when I hear someone say they have the 14B dyno record or 14B record pass. Does MHI ship in a hermitically sealed turbo that's installed on race day ported under supervision and then removed for subsequent teardown and inspection after the run?

So saying that all the fast DSMs only have ~1997cc with stock blocks and stock cranks is just an assumption.

 

[anomalyinva]

Then a t67 or a t4 would be a better choose for my car? Why do you say that, I should better off staying with a 2.0 or 2.1 with a big turbo. And why would I ever think of going with a 16g? I want to make real power, not 300 or 400 hp. I really would love catch Shepard someday. I know that would be one hell of a thing but, that is what I want out of my dsm.

If you're asking this kind of a question, you have NO chance of doing that. 0% chance. It will NEVER happen. That being said, something in the PT67 range will put you over the 600whp mark. A local guy made 6xxwhp on a PTE 63.

 

[anomalyinva]

The bell housing wasn't the only thing that was wrong with the tranny the guy that owned the car before me tryed to do a redline drop and shattered the bell housing and destroyed first gear and the clutch and flywheel that was in the car. So don't start talking sh**about something you don't know anything about.

Quit while you've got some decent money in your pocket man. Go with a mildly modified car, learn on it, blown it up, and build something better.

 

[MNGSX]

Not going to happen...

I think you need to learn alot before you even make high 9 second claims.. Read the SCC article and alot of other good info around here.. Build a 10-12 second car first then talk smack.

 

[na90dsm]

not even that if you can afford that kind of budget to work on your car, it would be a feat in itself. youll need a lot of money to get your car to keep up with shep. not judging you in anyway and i dotn knwo if you can afford it but im saying, if you can ill commend you

 

[MNGSX]

He'd probably have to buy a trans from him to even run 2 car lengths behind him.