• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Twin charge questions

I would consider a dual turbo configuration.. small/big... Usually the mechanics is a bunch easier. Reality is anymore that a modern turbo will spool fine on any combination of antilag via the engine management.
 


darkhorizon said:
I would consider a dual turbo configuration.. small/big... Usually the mechanics is a bunch easier. Reality is anymore that a modern turbo will spool fine on any combination of antilag via the engine management.
Click to expand...

if your gonna suggest that then id probably suggest the better option of a VNT with a standalone controller or as part of the EMS (i didnt see mention of what your figuring on for the brainbox and control setup....id assume your not gonna go carb with a setup like this.....)

hell i think one of the fiero guys did one with a lockedout VNT ring...
 
That is a thought, VNT. I forgot about them. But I've not read anything where they worked as well as they were designed to. Not that they don't just that I have not read anything about it. If I should be able to hook up with a 6 speed Vette, I would change the rear gears up to something around the 4:10 4:56 range and rely more on the two OD gears to help out. Lots more 1st gear multiplication with those high gears. Would help a lot between the stop lights. 6th gear would be fine on the freeway. Then a little soft on the bottom end would not kill the enjoyment of the car.

Mark L
 
I have a fairly good sized turbo on my 1.6L, and i dont need to do much of anything passed 7000rpms... I think you are really underestimating modern turbos.
 


My 4 cylinder will be in estimated 3500 car. So it needs to have some low end torque. To get the HP am pushing for will require some big valves (only two per chamber), fair to large ports, a fairly big cam, and probably a 70-76MM turbo. That's all a recipe for soggy bottoms, LOL. I just don't want a real pig down low. But I really have to remember to ask my friend in CT that has the built 4 in a '64 Lemans convertible, how it feels off boost. That '64 is in the 3500 to 3600 lb range. I think I'll pop over there and leave a post on his thread.
This is a link to his build thread on the 4 cylinder. It is BIG but lots of good info in there.

http://www.pontiaczone.com/forum/showthread.php?t=23147



Mark L
 
Last edited:
Whoever told you turbo cars dont make low end torque were flat lying to you. Turbos are used on diesels due to their low end torque. If you are worried about "off boost" performance then change your driving style or tune because if you are in the pedal make sure you are in a boost friendly rpm.
 
I'm not talking about on boost lo end, I'm talking about off boost cruise or even of idle such as leaving a stop light. I know about turbo cars. I've had five of them and building another. The Buick Turbo T Regal was a little soft off idle. But not enough to care that much. Once the turbo would start to spool it was great, even at partial throttle. My Dodge Spirit R/T Turbo 5 speed was soft too but the manual trans/clutch made it much more manageable. Same with my '89 Supra Turbo. The Trans Am was a beast even N/A off idle so there was no noticeable off idle loss there, unless you wanted real hard acceleration right off idle. But in a split second it was light the tires time. I did talk to my friend with the other 4 cylinder Pontiac in the '64 LeMans which still weighted about 3200. He was running a Tremec 5 speed and not happy with the off boost soggy bottom end. You have to remember that it is a large bore stroke, yes but also it is not a 4 valve head. Just a two valve and the higher flow two valves have a tendency to have lazy flow at lower rpms, not enough velocity down there. They make it up on mid and higher rpms but low rpm/response uffers. Even the stroke at 3.75 is short versus most 4 cylinders at that or even 4.00 and over.
My goal is to try to make this Little Indian think it's a 455.

Mark L
 
Forgot to add for all you guys, thanks for all your input and thoughts. Have a Happy Safe New Years celebration. Enjoy the holiday and make lots of horsepower in the New Year.

Mark L
 


Yup saw that. Especially the loose strapping on the dyno. But thanks for throwing the link up for me. I appreciate your taking the time to help.

Mark L
 
Who's car was this?

Scottydoggs said:
how it looks on a grand prix.


TwinCharged.jpg
Click to expand...
 
You must log in or register to reply here.
Back
Top