GT and Onroad engine dyno reports !
 

So i have been testing some onroad and GT car engines as of late, made some interesting findings about header length and just how critical it is to engine performance and that a onroad engine using a offroad manifold may not be as powerful as a offroad engine on a offroad manifold... For the onroad engine to really come alive it needs a proper onroad manifold... this is critical for GT racing where you must run a offroad manifold.

As you can see the Picco EMX is a monster on a proper onroad setup, but once I swap to the 41032 offroad manifold power drops off quite badly..... then on a offroad manifold vs one of my stout Offroad engines the EMX only holds a slight advantage in the top end, everywhere else its heavily outpowered....The default manifold for the onroad test is the Picco manifold that came in my 2116 combo kit.... I tried all the Nova manifolds but they all lost power next to the Picco manifold...the 9886 pipe made the most power out of all the pipes I tested.

http://i107.photobucket.com/albums/m...psrrqsyyrg.png

http://i107.photobucket.com/albums/m...psjsrnjcfc.jpg

And here is the EMX in both onraod trim and offroad trim vs my Paloma LTD on offroad trim

http://i107.photobucket.com/albums/m...psxzdw0sdn.jpg

w

Very interesting and thanks for sharing. Are you testing the EMX-GT or the EMX-WC in the charts above?

Probably it is the resonance timing that does not match the exhaust timing, an offroad manifold is much longer than an onroad manifold because the needed lower rpm powerband range.

I am also interested to see what an offroad engine does on an onroad exhaust system.

this is the WC...I also tested the EMX-GT a few months back......

Exhaust timing..the higher the exhaust timing the shorter the manifold needs to be.....this is why onroad based GT engines aren't going to pull like offroad based GT engines..

Great information, love the graphs!

http://i107.photobucket.com/albums/m...ps2ecpauuu.jpg

both engines are modified !!!

Do you have the data posted on the EMX-GT? Any plans to get the new OS GT engine and give it test? :nod:

Friday Night and out in the shop playing with the dyno...currently modifying a Mito 35 WC..I have the engine up roughly 15% power over stock which is quite considerable considering how well done the Mito is from factory... Anyways here is my Mito 35GT vs a Picco Top Gun factory built Drag engine



http://i107.photobucket.com/albums/m...psamabqayq.jpg

I love my job sometimes...these onroad engines are a hoot to play with !

Do you have a standard Mito 35WC (onroad) not for GT, dyno results?

that is what this is..this is a modified Mito35-WC

I tried all the onrtoad tuned pipes, 9886 makes the most power and torque..so I posted the results from the 9886

I will do the Mito GT soon.....but from what i am seeing the onroad engines don't perform so well on offroad manifolds...they are beasts on the onroad manifolds, but they lose most of it when coupled to a offroad manifold..........

So what are they doing different with the GT class engines? I know they use a different liner and crankshaft but what's different with the liner? I'm going to be changing my GT engine to either the new Mito 35GT or the OS 21XZ-GT when it comes out. In the past I've always run the extra short or double-bend headers because I've gotten better top end with them. Should I be looking in another direction?

I need to re-test the EMX GT....I did dyno test one and it just didn't open up like I expected it to and since it was a customers engine I wasn't willing to push it further in fear of damaging the piston , my guess is the engine was just too tight to really open up and I did not have time to break it in further and do a retest !

So far based off what I am seeing on the dyno is that if we are using a offroad manifold I would opt more towards a modified offroad then I would towards a modified onroad. The header length is just too long for a onroad engine to reach its potential and they see a huge power loss as compared to how they run on their respective onroad manifolds..Whereas I can make a offroad absolutely scream on a offroad manifold and carry a huge advantage over the onroad engines !

Really appreciate the info you're providing. Its starting to take some of the "mystery" out of the GT engine class.

Not really the crank timing, I got Tesla 5 port GT engine, it share the same crank shaft with 7 and 9 port on road engine. The port timing I guess is different.

Anything new to share with the group? :)

Basically a few things


1. 9886 outperforms every single modern EFFRA approved pipe, more torque and more HP then every single one of them ....I have been testing everything I can get my hands on and with both onroad and offorad applications the 9886 makes more power then everything....So if in doubt just use a 9886 and tailor the manifold length to the engine, you will have more power and torque then any other combo you can buy from any of the manufactures bar none..This is universal on all engines too...not just Nova

2. Its all about the manifold !!!! matching the manifold length to the engine is critical... Basically sticking a offroad manifold onto a onroad engine kills its power..in a GT car with a offroad manifold you should not run onroad engines as the power will be down compared to a higher timed offroad engine with the same manifold... For a onroad engine to make its proper power and powerband it needs an onroad manifold........IMO this sort of makes some of GT engine rules arbitrary ..... one of my simple modified $300 offroad engines would decimate every single high end Onroad engine money can buy as long as they are both on a offroad manifold....swap to the onroad manifolds and of course it all changes !!!

The best onroad pipe is the 2013 but saddly it is forbidden to use...

Lots of torque. OK no top RPM but with a larger gearing high speeds are possibe. But most important on my Novarossi engines 30 to 45 secconds more milage!

Interesting. I was under the impression that the 9886 was just a reinforced 2015 for offroad use. Something definitely different between them with the results you're seeing. Sure wish they would get rid of the 7mm venturi rule. That would really open things up and let the GT class "fly".

Totally different pipes! The 9886 is 2 chamber and the 2015 is 3 chamber which is EFRA approved for noise reasons. We can't use the 9886 pipe in competition anymore due to the noise it makes. I agree though the power difference is huge!

I have the 2013 here.... I will test it on the onroad manifolds and see what I find.... I should retest it on the Nova offroad manifolds as well, as on the factory curved Werks offroad manifold it doesn't make the same juice as a 9886 does....

My JP R09 on a 2015 pipe was hardly reaching 5 minutes, with the 2013 I could reach 5:30. On the worlds in Cordoba it did save met a pitstop in the qualify and finals. Normally the 2nd geat is 20/46, I was running 20/45

I'm also wandering how the onroad engines perform when fitted with an offroad carb! I've seen a few people locally do this with mixed results.

There is no real power difference as far as I can see, however there is a definite difference in how quickly the tune stabilizes, the offroad carbs need a longer warmup for the tune to set

anybody on here has some experience with the WERKS engine line in the GT class? I have been using both the B6 and B5 on my MGT7, so far, I am favoring the B5 because of the higher torque, but need to test on a high speed track...

So, for GT, you would suggest a cheaper offroad motor that is modified with a bit higher timing, than an onroad style GT motor. And of course the 9886 pipe. Looking at all the 5 port GT motors that are made specifically for GT, they all have higher Power Bands in RPM. I guess this would be good for flowing tracks compared to break and gas. Biggest thing for GT is heavier car. I want more bottom end but still have good top end for the straight away in second gear. So, you think you can make an Elite5 into a powerhouse GT motor with 032/9886 combo? Or is the new stock MITO 35GT 5 port better? ROAR kills me with the 5 port 7mm restrictor limitation.

What engine is a mod32?

LRP 32 MT engine........just a cheap Taiwanese .32 , but it makes crazy amounts of power and torque

I sure do.... but the 7mm insert masks quite a bit of the difference and prevents the cream from rising to the top as quickly as it would have otherwise ...with the 7mm rule all the engines are choked back really badly and the faster engines lose more of their soul then do the slower engines ;)

Setup right they would be as nasty as anything out there.... of course the 7mm rule prevents any engines from reaching its peak including the B5 and B6..

what % nitro did you run through the picco top gun engine?

they aren't noticeably louder either.... from what I can see the EFFRA rules are more about grabbing cash then they are about reducing noise... The guy who came up with the rule has next to zero scientific data to base his assumptions on and from the talks I have had with them have no concern that the legal pipes seem no quieter then the illegal pipes.... From being a track owner myself the only complaints we ever got were from the PA system, not the nitro engines..... I am blown away that American racers so willingly accept these European rules without question... willingly accepting that their nitro racing experience has been watered down due to some rules that really only apply to a very few select tracks in Europe, talk about the needs of a very select few taking precedence over the needs of many....

I couldn't agree more. Just look how much louder OS 3 chamber pipes are now compared to the novarossi 9886 2 chamber!

Has anyone played with different 7mm venturi inserts? Red's has a new one with more of an oval shape to one side and so does PROTEK for their samurai motor. I know there have been several other venturi inserts that were off set to one side. Never used one before to know if they work? I think novarossi with Mito case was trying to accomplish something similar? However, they went back to a MITO C for high end on road motor.

my Mizer inserts make more power then a traditional 7 mm... but I fairly sure there would be complaints if people started using them... The Reds are offshoot of my design but have a round intake, not elliptical like my own.. the offset is to direct the incoming air around a more closed throttle slide, main purpose to increase fuel mileage.. For GT a standard 7 is probably your best bet...

The samurai motor distributed by AMAIN has an oval shape. Don't know why there would be complaints as long as the area is the same? Anyone know if REDS Venturi fits NOVA or OS motors?

https://www.amainhobbies.com/protek-...17610?v=301367

Nope, Picco inserts are shorter than Nova and OS.