my dyno runs 7mgte

[supraguru05]

stock boost versus 13 falling to 11 psi run. motor is stock just rebuilt with MHG. this is my autocross/ nasa road race car

heres the vids





i pegged the wideband at 10:1 the whole way through so i might buy a safc and run it at 11.5:1 which should get me about 20-30 more horsepower.

note this is on a dyno dynamics dyno which is significantly under what a dyno jet would say. using the conversion it puts me at exactly 300 whp on a dyno jet

 

[thebadz32]

Nice lookin good, but im curious what all is done because mine will be out very shortly and i wanna know what kind of power ill make heres what i got

Completely rebuilt 7mgte bored 0.020 over
mhg
arp head studs
custom 3inch dp with divorced waste gate and open dumpe tube
13psi
cone filter
lex afm
550cc injectors
wideband
and safc tune

 

[supraguru05]

my car is on a stock rebuild with NA compression and 11 psi

so i imagine youll be considerably higher on power

 

[mk3tattoos]

my car is on a stock rebuild with NA compression and 11 psi

so i imagine youll be considerably higher on power

why did the compression get so high, to thick of a mhg?

 

[suprahero]

a thicker head gasket will lower the compression.

 

[supraguru05]

why did the compression get so high, to thick of a mhg?

rebuilt the motor on NA pistons. it helps low end torque for autocross. as long as i keep the timing in check and dont get insane with the boost it wont hurt anything, at least not for power levels less than 350 which is where im going to stay on this bottom end at least

 

[arizzle]

nice numbers, what mods are you running?

 

[supraguru05]

depends on what you would consider mods. its really just stock with a MBC set at 11 psi

 

[7MGTEsup]

depends on what you would consider mods. its really just stock with a MBC set at 11 psi

I would think if your pegging the wide band at 10:1 then a good wot tune will release a good 20 - 30hp

 

[supraguru05]

I would think if your pegging the wide band at 10:1 then a good wot tune will release a good 20 - 30hp

yea thats what the guy at the shop said. i picked up a used safc2 for 90 bucks which was a steal so ill porbably put it on and have someone tune it next year but this car is undergoing massive reconstruction to get it ready for next years race season. my last concern is power

 

[mk3tattoos]

rebuilt the motor on NA pistons. it helps low end torque for autocross. as long as i keep the timing in check and dont get insane with the boost it wont hurt anything, at least not for power levels less than 350 which is where im going to stay on this bottom end at least

oh ok that makes sense! sounded goog and strong to.

 

[Jefftopgun]

Quick question on those graphs. I was wondering why power was falling off so bad up top? Is it just because you've got boost tapering up top because of the MBC? I guess the 10:1 to 1 peg could also be something stupid like 8 or 9 to one, as long as the plugs are fresh, it will still burn, or at least it does on our dyno, lol. Do you have the timing retarded more than the stock map (assuming its a GTE with GE pistons in it and your running stock GTE electronics)?

 

[supraguru05]

Quick question on those graphs. I was wondering why power was falling off so bad up top? Is it just because you've got boost tapering up top because of the MBC? I guess the 10:1 to 1 peg could also be something stupid like 8 or 9 to one, as long as the plugs are fresh, it will still burn, or at least it does on our dyno, lol. Do you have the timing retarded more than the stock map (assuming its a GTE with GE pistons in it and your running stock GTE electronics)?

after tearing down the car for winter rebuild i noticed a slice in a intercooler coupler from one of the belts on then engine. it did not appear to go all the way through but it could have been a slight boost leak. the psi fell toward the top of the graph i figure thats the main cause of the power loss. the timing was set at around 8 a year before the dyno run, but i measured it on the dyno around the factory 10 so i belive it might have migrated on me a little bit. its on complete factory turbo electronics. basically a turbo motor without oil squirters and with higher compression.

i have a SAFC2 ready to go on but im pretty sure it will give me to much power for the class in nasa racing im looking at running.

 

[Jefftopgun]

after tearing down the car for winter rebuild i noticed a slice in a intercooler coupler from one of the belts on then engine. it did not appear to go all the way through but it could have been a slight boost leak. the psi fell toward the top of the graph i figure thats the main cause of the power loss. the timing was set at around 8 a year before the dyno run, but i measured it on the dyno around the factory 10 so i belive it might have migrated on me a little bit. its on complete factory turbo electronics. basically a turbo motor without oil squirters and with higher compression.

i have a SAFC2 ready to go on but im pretty sure it will give me to much power for the class in nasa racing im looking at running.

I'd get the fuel right, and dial back the power with the timing, a little bit of retard will help spool the turbo, and while leading to slightly increased EGTs, keep the peak cylinder pressure down, and the motor really happy.

Just don't wanna see you washing those walls running 10:1 and below.

 

[dumbo]

turbo cams or NA cams???

i dont think you'll wash the walls at 10:1 maybe 9.5

 

[Jefftopgun]

He said he was pegging it, and those are dyno dynamics (Same company as the one I use on a daily basis) graphs, ours flatlines at 10:1, and as the sensor ages (at least on ours), the leaner it reads, just food for thought, as a newbie I don't expect to be taken to seriously, I understand I have to build my credibility, just throwing possible issues out there to whoever is listening.

 

[supraguru05]

turbo cams or NA cams???

i dont think you'll wash the walls at 10:1 maybe 9.5

motor was NA cams but at the track the power fell off so hard up top i couldnt deal with it so i put in the turbo cam.

 

[dumbo]

motor was NA cams but at the track the power fell off so hard up top i couldnt deal with it so i put in the turbo cam.

did you notice you lost much down low??

i got a similar setup as yours and i'm putting turbo cams in too, to see what the difference is, was the change worth it? i'm nervous that i'll loose my low end torque/quick boost. when did you reach for boost? wich was 11lbs you said.

 

[Supra28]

Your car sounds like it's running strong. Sounds really good too, thanks for sharing.

 

[supraguru05]

did you notice you lost much down low??

i got a similar setup as yours and i'm putting turbo cams in too, to see what the difference is, was the change worth it? i'm nervous that i'll loose my low end torque/quick boost. when did you reach for boost? wich was 11lbs you said.

switching from the na cam to the turbo cam i didnt notice the power loss down low because your only there for a split second i definitly noticed the gain up top however.

my answer is that the turbo cam is better for BOTH autocross and road racing than the NA cam. i have 5 years of autocross under my belt with a 7mge for 4 of them and the 7mgte for last year both with the NA cam and turbo cam and the the turbo cam made a big difference. also switching from 4.3 rear gears to 3.73 helped in autocross to my suprise.