This has been said before but I will say it again...Whats his name was pretty much right except Im driving a basically stock turbo against my 89GXL with few custom mods...I will say that the turbo engine was smoking at idle but had a very good idle for one thing and another it boosted nice and smooth.
Its an 88 car with 89 engine but S4 turbo... blitz blow off , fuel cut and gutted cat thats it.

now First impression was holly **** this thing has less torque than my GXL. Yes it was a dog below 3.5k rpms but when boost kicked in u can really feel it. It was nice and smooth yet not impressed until 6k rpm I would feel even more boost come on all the way to 7.5k or whatever. Also the torque was evident as well..When I shifted the car grabed and jerked me in my seat instead of the soft feeling I get with the N/A. Time for a race..Ok..not to exciting. My GXL beat my turbo pretty good so its a little faster but in the turbo it feels like its faster... Weird. Anywayz theirs my thoughts. Having a blown engine doesent help but the car seemed to have ran great. And it only smoked at idle anywayz.

 

oh by the way..the turbo is alot funner to drive. I was smiling the whole time...5th gear was effertless and the car didnt seem to bog as well as pasing in 5th was much easier.

 

Your NA is faster than your Turbo ? What gives ?
Either your NA is VERY powerful, or the Turbo is not working properly...

and the boost is supposed to come way below 3K (something like 2,5K). I know because mine does the same thing (sudden boost at 3K), and I've been told that my wastegate must be a bit "loose"....seems like you need to check the turbo and its system (wastegate, BOV, IC, piping)

 

Modded NA cars are as fast as stock Turbo II's, but since our power is constant ans smooth the drive doesn't feel as fast because there is no sudden power gain.

 

I was driving the GXL for him and honestly that thing pulls pretty hard for an NA. It seems like a 15flat car and he only has minor BPU mods. Maybe its the weight reduction? Anyways, his car has beaten a track proven 15.5 3000GT so maybe he has a freak. Anyways it wasn't a clear cut race but I pulled a little in 3rd gear on him but the Turbo engine is blown more than me on prom night so hopefully when he fixes it then the performance will get a nice kick in the ***.

 

Something is wrong there, my s4 TII had full boost by 2000 rpm...
You are perhaps driving the worlds most gutless TII, or the worlds fastest GXL, I have both TII and N/A, both built up, and there is no comparison, the TII is kick *** compared to the N/a, get your motor fixed and then compare them...Max

 

something along those lines....

Full boost at 2K ? **** man, my turbo lag must make yours seems like premature ejaculation

 

Half-dead TII = modded to **** GXL...
I love it

 

This is a good example of broad power band (NA) over a peaky, big numbers horsepower car (turbo)...



-Ted

 

... you see half-dead, I see half-alive. TII's.... no spirit.

 

Get an s5 turbo to go with your s5 motor, then you will have a clear-cut victor when you race your two 7s.

 

Ya... I was honestly very surprised at the power that the lightly modded TII AE of Six Rotor's... I have raced TII's and smoked them... but that AE has very close to the same amount of power up high as my car... but bags more torque in the bottom end... it also pulls better in 4th gear than my car does (More overall torque)....
He said he was putting out about 205 at the crank.... felt like a tad more, but it sounds about right...

Yep... just a different feeling to drive.
Oh- and I had the opposite impression as you did von, the TII had lots more torque down low than my car, but my ported engine and locked up VDI doesn't help that!!

 

Thnx bam but like i said the engine isnt dead. It ran fine and had minor probs. Boost is supose to come on around 3 so nothings wrong with that. Below that its not as powerfull as my n/a for obvious reasons like lower compression for the turbo.. And It does make more torque than mine but only above that psi. And someone said they have two 7s a turbo and N/A and the turbo always spanks it? DId u race? it might feel like u spank it but your N/A might surprise u. And yes my car should run a 14.9 if I had a better clutch... Turbos are what like a 15.3 or something? THier ya go. The only way the turbo will be faster than my N/A (considering I finish my manifold porting and fuel tuning) will be with a full exaust , intake and Boost controler...Intake and exaust olone will not do it for this turbo 7. Its fun to drive but just cant beat a mid 14sec car with just intake and exaust. Still way more potential thou...

 

in a stock to stock comparison up to 60mph a TII won't gain anymore than 1 - 1.5 cars on an NA (depending on driver). But once you hit 3rd gear the NA would no longer be a challenge and 4th gear isn't even worth trying.

if you put BPU on your TII it will be night and day between your cars. When I first got my TII bone stock I wasn't really all that impressed with it compared to my friends 86 GXL. The fact of the matter is that they just aren't THAT fast from the factory. But with a few mods and TLC they will put many cars to shame.

Good luck with your new car

 

Thats just way too funny.

 

Like I've said before.

A SUPERCHARGED NA or TII is the best of both worlds.

 

IMO, it's not.&nbsp A supercharger causes parasitic drag, which the turbo will eventually become more efficient as RPM's rise.&nbsp The low-end on an SC engine is dramatic though.&nbsp The SC is physically limited by it's size to pump X amount of air for any given RPM; the turbocharger can produce more airflow by turning up the boost (to a point).&nbsp A properly sized turbocharger will give up very little to a supercharger.&nbsp Have you ever been in a 400hp turbo FC vaughc?&nbsp It's an eye-opener...no supercharged (kit) FC will come close to something like that, as most choke at around 250hp.

In my book, a properly sized and designed turbocharger system will make very close power to a supercharged rotary but will have far more power potential...


-Ted

 

AH, but I'm only planning to put 250ft-lbs of torque on the daily convertible FC (read fuel economy) and I want MAXIMUM streetability. That means boosted low end torque and a linear HP/torque curve.

I believe superchargedrex was getting ~250ft-lbs of torque on the NA engine from 8-10 PSI which is all I'm looking for

My only question is boost on the higher compression NA engine. Should I lower the engine's compression to TII levels to gain more efficiency from the boost (read ported & TII rotors) and will that effect low end torque ?

Now on the TII project .....

 

maybe someone can fill me in on how the FC's twin scroll turbocharger works.... but I thought it allowed the turbo II to get some torque down low....

...or does it simply just make the turbo spool faster, and doesnt really improve torque down low?

Does the NA really have THAT much more torque than a turbo at low rpms, like von is saying? Cause I thought NAs didnt make real power until way up in the rev range.

 

...WTF? Are you talking about the FC or the FD?

 

No, the FC has twin scroll.
The FD has 2 seperate turbos. (hence, twin turbo?!), a smaller one and a larger one.. they are operated sequentially by the ECU, the smaller one can be spooled up much quicker, and comes online first, at very low rpms.. the bigger one comes on once the smaller one is spooled up to to it's limit or so...
You don't feel ANY lag in the FD- it's great compared to the TII- feels like a direct throttle N/A!

The twin scroll in the FC (I THINK only 86-88??) is just 2 outlets in the exhuast manifold feeding the turbo- a large one and a small one... and a flapper valve over one (can't remeber which)
At low RPMS only one side is open.. so the exhuast flow is faster, and spools up the turbo quicker, untill both passeges open up.

A lot of people remove it though, and port out the manifold so both ports are the same size.... it apparenty makes a VERY minimal difference in low end turbo response... but frees up the manifold a lot in higher rpms...

On a side note... I beleive that the AE could spank me in 4rth gear....and probably in ultimate top speed (at least in getting up to it) but I know I'd dust it though the 1/4....

 

Almost, but not quite. There is only one passage in an 86-88 manifold. Its undivided. The twin scroll door is closed at low boost, covering one inlet of the turbine housing. It does get all in the way though.

 

Yes the twin scroll (ie 2 chamber single turbo) adds a good shot of torque down there. Boost comes on around ~2000 rpms (the series V/89+ has better/quicker low end).

What I'm looking for is maximum throttle responce in all gear & all rpms. I want the maximum large engine feel without the weight & lag penalties. A supercharged 2 rotor (or NA 3 rotor) will do that