Ask rich how many hours of tunning does he have

I have a bit over 100hours on mine though.. may where on a dyno but I gave up on the tunning on the dyno.

 

I just got my OBD1 comp in yesterday and it has a MTI sticker on it so I emailed the guy to see if it is already tuned or has been "untuned" I guess. I picked it up for $100 shipped so w/e. I will have a lot of tuning done before we take it to the dyno that way we can just really dial it in hopefully. Lata, Jarred

 

I still don't understand why 20# is so important. I can understand shooting for mid 9s or 600hp, whatever, but why 20# of boost? If you choke up the engine enough, you can see all kinds of crazy numbers on the boost gauge. However, I'll GUARANTEE that a stock head/cam LT1 w/ 20# of boost will be slower than a 350ci motor built for boost on only 10#. 20# on a S-trim (probably even a T-trim) will put it so far out of it's efficiency range that you'll hurt performance....if the pistons don't take a ****.

 

Each new config takes 20-30 dyno runs (usually a full weekend on the dyno including setup and various fixes while in progress) plus lots of fiddling on the street to get it right. This is NOT a plug-n-play kind of a deal.

My car has a total of over 200 dyno runs

Rich Krause

 

"My car has a total of over 200 dyno runs"

Man that's a lot of time on the dyno. Do you own one or have a friend with one or do you have to pay everytime? I was not saying I was trying to get 20psi on a completely stock motor. On my stock motor I am just going to run 6# which is what the kit comes as and then I am going to build a fully forged 355 that is 8.5:1 and go with a blower cam and stock heads for now. I was just wondering if I would be able to see 20# after the built motor goes in was all. Lata, Jarred

 

Mine has many.. but you tune on the dyno and you go leaner at the street..

 

I have a friend with a dyno and I "barter" some work for him with time on the dyno.

Rich Krause

 

If its big boost you're after.... go turbo. More expensive.... yes, but you can boost it to the moon (or until your motor takes the trip itself).

 

its the same thing as a supercharger... or you think that if you use an eclipse turbo it will boost to the moon?

 

Turbos aren't mechanically limited..... 1500* exhaust gases will spool that turbo to speeds far greater than that SC with pulleys and engine speed.

Typical SC impeller speed: 40-60,000rpm

Typical turbo speeds:100,000+rpm

You make the call

 

Who cares about the speed of the impeller... a turbo from a Eclipse will spool 100,000 rpms too... and do you think it will make 5psi on our engines???

A YS-trim spools 65000rpms

You make the call...

 

Ok, i'm not gonna get into a pissing match with you over this so stop with the sarcasm. SC and turbos are very different, believe what you want. Who cares about impeller speed?... impeller speed means potential when it comes to compressors. And also where in the rpm range it makes this speed is CRUCIAL. You match compressor size to turbine size to get the most out of your range of boost. You brought up the eclipse thing like you think i'm a ricer..... check the sig, been dealing with boosted engines for quite a few years, SC and turbo. In the big end the turbocharged ones went faster and made more power 9 times out of 10. I'm done with this matter.

Back to the original topic....

 

I wouldnt poke to much at the Eclipse community. There are 600hp cars running around with 2L motors. Not common, no, but it happens.

A YS-trim is good for 1500CFM at max speed, which most likely is set to 6500rpm or 6000rpm on your engine or whatever you shift at... Assuming a max RPM of 7000, at 3000rpm that sucker is pushing theoretically at most 800cfm...

Lets get logical here...

A $600 Mitsubishi EVO III 16g turbocharger, with a decent port job and proper setup is good for nearly 600cfm. Now if we can run this turbo on a 2L motor that's built for boost, and hit full boost by 3000rpm (and as much boost as the turbo is willing to make) with a standard dump header (as opposed to a more efficient tube setup) and 22psi of boost on this 2L motor without hitting the edge of the compressor map...

A pair of these, each pushed by 2.85L of force (most likely more CFM then a 4g63T straight as stock DSM heads/cams hold good vaccum and an all out 350 wont).. will probably hit full spool by 2200rpm at WORST. Now that'd be two turbos, now flowing a total of 1200CFM at 2200rpm...

Too small? Step up to a 750CFM ported 20g. It'll push out full boost on a 2L by 3500rpm at worst! So you're talking probably 1500CFM by 2400rpm with two of them on a 350...

It's not precise... but a pair of $800 turbos by the numbers will flow the same CFM as that YS-Trim, and certainly hit max boost faster. At 3000rpm on that engine the pair of 20g mitsubishi turbos are already pushing 1500CFM and then all the way to redline. At 3000rpm your YS Trim is pushing 800cfm... And dont forget...

Less parasitic loss

 

A turbo will sure make more boost at low rpm than a comparable sized centrifugal. But that's due to how it's driven. Put the compressor side of a centrifugal and a turbo side by side and they are hard to tell apart. Turbo will have the same limitations as a centrifugal with regard to max boost on a given motor. If it can't flow enough to supply the motor, the boost will drop and the ultimate hp output (peak) will be limited by the amount of air it can flow.

A comparable size turbo will make more hp than a centrifugal because of the hp it takes to drive the latter, but not more boost. If a given turbo makes a max 20psi on a 2L, it sure won't make anywhere near that on a 5.7L V-8. And the V-8 with that little turbo may not have much more peak hp than the 2L. You need airflow to make hp.

Rich Krause

 

Precisely.. the thing is that I get a bit tired of people saying that turbos are limitless...

On a civic they tested a similar flowing supercharger to a turbocharger and it yielded that the supercharger needed only 7HP more to drive it than the turbo... turbos are not all gains..