Beretta.net

This came out of.. NOWHERE! Wow, awesome work! Between you and jjanke, I am feeling really inspired to do a RWD conversion on my old Z -not that I have time or money to do that of course, but I have lots of inspiration now!

I run a 100% recirc "bypass" valve on my '90 Turbo 'Retta -because it uses both MAF and MAP (Speed Density) since it has an OBD2 harness and ECU. I don't want the MAF confusing the ECU registering air that is later dumped out to atmosphere every time I shift -on a higher performance car (the Evos are very high-strung cars that probably can't take much variance in air intake without major retuning, especially once they start getting tweaked even harder), that could easily cause moderate to severe driveability issues. I personally like SD because it is a little less finicky -but no, it isn't as precise either. The 3800SC in my GTU also has both MAF and MAP from the factory. Best guess is the MAF for accuracy, the MAP for reliability, although I know that is oversimplifying... My '97 Z-24 is a SD system, and where I used to live (9,000 feet above sea-level) I could run 9-12psi off my turbo with no problems on a stock tune. Now at sea-level, I am looking into swapping a MAF system onto it (limited to about 4-5 psi reliably right now), because my DHP doesn't support the Z-24's ECM and I refuse to buy HPTuners. It has a full-on BOV, very loud, very effective in preventing compressor-shock.

BTW, the early Berettas that had MAFs were '87 and '88 -by '89 they were all SD, and GM had released a software update that removed the airflow part of the MAF from the calculations on the '87-'88s, leaving it as just an IAT sensor (and air restricter ). And that didn't change until '96 when they had BOTH sensors in place, at least regarding the V-6s. As far as the throttle response on your Indy Jon, it is a 3.1 MPFI, don't blame the lack of power on the air metering system when it is really a mechanical limitation... I think that the later GM PCMs just don't work right when sensors are pulled -like the MPFI failsafe mode when the cam sensor drops out on the 3100s -it still doesn't seem to work as good as a 3.1 MPFI does in the first place, IMO.

3X00-Modified wrote:Because it is, well actually it's late 80's early 90's. 88-89 Beretta's had MAF's from the start but I think the technology was just too new for it to work well which is why the reverted them to Speed Density. Come OBDII in 96 and they moved back to the MAF which works great in my opinion... Not sure on the reason why Evo guys switch other than the fact that maybe their ECU's or their MAFs can't read what they are flowing. I have two MAF type cars, the Legacy which it turbo and the Beretta... The Indy is speed density and I just feel the throttle response just isn't the same. Never mind the fact that the ECU is estimating air flow all the time where the MAF is a true more accurate reading. I can easily revert my car to Speed Density by unplugging the MAF, its fail over is SD, and the car just doesn't run the same, but I'm not saying my SD tune is spot on either but I'm not sure what to change to make it any better.

I love the license-plate surround too -that is icing when that is all they see -that and the tail lights, of course! I'm watching with great interest, keep the pictures rolling!

its so awesome to see someone pursuing this project !!!!!!! the progress is looking awesome !!!!!! its really great to see another completely different way of attacking this ridiculous undertaking........ glad to see some one else not listening to all the people saying something cant or shouldn't be done !!!!!! keep up the progress and keep posting the pics!!!!!!!! when we both finish our RWD Berettas it will be awesome to see them together!!!!!!

Well.. thanks! Im glad i have inspired you you should go for it!


The only way it cant be done is if nobody ever does it! I actually totally forgot about your build, Ill have to check it out again. Ill be taking mine to bfest someday, I hope (been saying that for years). Thanks btw!

coleman racing hubs/spindles came today!










the bad.......... my wheels have a big enough bore for the oem c4 hubs, the coleman hubs are the same diameter. The issue is the coleman hubs are longer, the bore in the hub on the wheels has a "cap" I guess you could say. On the face its smaller than the hub so the center cap fits.. that needs to be machined off the wheel... if that makes sense. I shoud have grabbed a pic. basically bore the center of the wheels out due to a lip on the face. Its gonna happen..

small update, I got the wheels back from the machine shop and ended up buying the rest of my rotors and had them all redrilled.




no the spindle is not bolted on correctly, I just tossed a bolt in so I could see what it all looks like




fix one problem, find another!! with the new spindles, due to them being round, it hits the caliper bracket. Ill just grind the spindle down a little bit. Not a huge deal







progress should start to pick up again in the next week or so

Who made the C4 to C6 spindle to brake caliper adapter?

Is the back of the caliper painted? Almost looks like it is raw meta - compared to the front being finished saying Corvette.

Vansteel makes the brackets

That's a very good question... I thought they were painted but they look bare in the pic.. I'll look tomorrow lol.

Great stuff. Stopping by for some motivation for my poor beretta. That front suspension setup is so serious!

Sorry for the delay, no new updates. Been busy keeping my other cars together and the jetski needed some work.. should be back on track soon

But.. the calipers are painted on the back too, you can just see the machine marks through it.

Thanks! How's yours coming along anyways??

got a little more done, still juggling a few projects at once.



the hole!




needs to be refined but it will work for now till I know where the engine/trans will sit exactly.





notice the pedals.. it will all work out in the end. not a huge deal.



yeah... the t56 is really that big! I thought it was small till I put the belhousing on... its just sitting on the floor, the tail will go down for sure, I hope the whole thing ends up going down! well see what the suspension allows..












note the stock shifter location (written in sharpie).


ctsv tail housing on the trans, I have the parts for the GTO conversion. pictured is the GTO tail housing with a short shifter.. it sits too far back. the Fbody shifter is 2"? shorter.. (no kickback). I may have to go that route. and or move everything back in the car. pedals, steering wheel, seat, dash, ebrake. all very doable just not sure what route to take yet. Im going to try and spend half a day on it monday

If you turn that shifter 180* it will likely be pretty close to where you want it.

Awesome work man !!!! Keep posting the progress ....love to see what u doing

I am considering a wilwood or similar pedal box for mine. I moved the pedals over to clear the tunnel but I dont like them still. And my t5 isnt even as big as your t56.

I guess my reply never posted..

I never thought about spinning the shifter around, that could actually work i think! I'll give it a shot once the location is a little more set in stone. Thanks for the idea!

Thanks! I will for sure.

Have you seen the firewall mounted set anywhere? I did years ago but now all I see is the floor mounted set. Unless you go with one that's split up.


I did make a lot more progress on monday! I'll get the pics uploaded in the next few days when I get a chance

http://tiltonracing.com/product/600-ser ... -assembly/

Something like that. Its not cheap but pedals are really important.

I think I want an "overhung" setup. I guess it all depends on what I end up with for a steering shaft/location. Like this: http://tiltonracing.com/product/600-ser ... -assembly/