Basic MAFT translator with GM AFM. Who is running this setup in blow-through mode?

[tekdeus]

http://www.fullthrottlespeed.com/itemdesc.asp?ic=050SUPRA3MAFT

Just wondering how reliable the MAFT translator with GM sensor is in blow-through mode? Are you guys getting accurate and consistent A/F ratios, with the GM AFM positioned after your turbo and blow-off valve, under boost?

I know speed density and a standalone is the best option, but I'm looking into this setup for now as a way to vent my BOV to atmosphere and solve the mysterious stalling problems my BOV seems to cause even when recirculating. I've fixed all boost leaks and pull 18-19 HG of vacuum at idle.

 

[Rennat]

in the DSM world, anybody over 300hp is usually running one of those.. i've installed 3 of them, and i love them... as long as you have the other tools to tune, either an SAFC, or something else... and a wideband.

but for the money, take a look into the MAFT Pro Gen 2. its only 70 or 80 more, and you can tune with it a lot more precise than the "box" you get with the $200 kit...

 

[supraguy@aol]

I use this setup, have for 2+ years, never had a problem with it.
I don't currently have any other tuning device(aka- SAFR, SAFC), so I'm sure mine's not tuned as well as it could be. However, I have ZERO problems with hesitation, rich-running, or A/F flatspots, at least in the sense of driveability.
I am looking forward to improving the tune on a dyno, just to see what I can squeez out of it.

 

[viper92086]

mines in blow thru, me and iceberg have been trying to tune it in blow through with no success. i'm about to switch to pull through now . the problem that i was having is that my a/f's would go incredibly lean when i first stomp on the gas, then richen about 2 sec after. I didnt realise my problem until i got it on a dyno.... car pulled very nicely and made 290whp na-t, i just had some weird spots

 

[tekdeus]

Rennat, Supraguy, are you running the GM sensor in blow-through mode (after the turbo, under boost pressure), or in pull-through mode (before the turbo, no boost)?

I can tune with my SAFC and wideband.

 

[hottscennessey]

I ran this a couple years ago in blow through mode.. I was really impressed.

 

[black89t]

so you can us the GM sensor with the gen 2?

 

[iceberg319]

anyone else experience a lean spot around 4k rpm running in blowthru?

 

[dbsupra90]

i ran mine in blow thru for a while. be sure you hook the isc between the maf and t'body. i ran mine with an afc and was able to tune pretty well and ran smooth.

here is a dyno chart with the maf in blow thru on 11psi. this was a base line pull with no corrections. notice how much leaner it runs in the 4k range, as you mention. after tuning i was able to dial it in tho.

 

[tekdeus]

Thanks for the graph. I'm just wondering if, once retuned with the SAFC, do the A/F's remain consistent throughout the RPM range at all boost levels? I.e. 2 psi and 15 psi?

 

[pond]

i have my n/a t with maft pro 4.8 lc-1 and speed density. i haven't had any problems with it. i got a ct26 turbo that is a 53trim and it is at 15psi.it has a little lag but thats it.

 

[dbsupra90]

Thanks for the graph. I'm just wondering if, once retuned with the SAFC, do the A/F's remain consistent throughout the RPM range at all boost levels? I.e. 2 psi and 15 psi?

no. and you cant run 2 psi anyway lol. it really depends on the turbo tho. if you tune it for something under its efficiency range then run it up in the efficiency range it will be a big difference. example. tune a 70mm turbo at 8 psi then go run it at 28 psi. there is going to be a difference.

but really, do you really run at multiple boost levels? usually people stick with 1 or 2. one for daily driving and pump gas, one for race and race gas. the fpr will compensate to some extent, so again, it depends on what boost range you are talking about.

 

[iceberg319]

thanx for the graph, but when i mean lean it gets LEAN. for example, the car im working on(na-t ct26 with bolt ons and maft). lets say were cruising 4th gear (right when full boost hits)2600 rpm then i have my friend floor it as it approaches 4k rpm a/f goes up to 15-16 sometimes higher then drops to 10-11 a/f....its really odd and when i add fuel using the knobs it doesnt get any better. any ideas? could a safc fix this?

if you need more info on his setup ill ask him to chime in

as a comparison (not sure if it can be compared tho)......my car same setup but using a hks vpc same senario, the a/f would just go straight to my 11 a/f tune.