How would u make it kick in much below 3000 rpm ??
What sort of mods are we looking at.
For the year 1986-19991 13B Turbo engines
Thanks

 

the 89-91 turbos are Twin Scroll which helps it spin up faster.
I'm not sure about other ways without modifying the turbo.
Maybe someone else has some mods to help it spin faster

 

I get 7psi anywhere above 2krpm (w/ engine under load, duh) and max boost is 10psi on cold night maxing out 5th. RB down/ midpipe, 3" alum. TID, FCD, Walbro fuel pump+rewire, Greddy A/F+Boost guages and PORTED WASTEGATE (to keep the boost down!) Even w/ boost down low, it still really pulls more after 3k rpm. Open exhaust and TID really help turbo spool responsively, It takes a bit of practice staying out of boost at first (I had a couple of adventures in the rain) after being used to the stock lag.

 

I believe all TII are dual scroll, '87-88 use a "dual scroll actuator" in the exh. man. to concentrate exh. gasses into one scroll for quick spool and then switches to both scrolls. '89+ ditches the dual scroll activator and its exh. man. is designed to put the turbo closer to the exhaust ports to maximize gasses impact on the impeller blades. I think all enthusiasts rate the '89+ as an upgrade.

 

Node, it is good to learn from what you read on the forum, but if you are serious about getting an FC you should get the factory manual and study it in preparation to getting an FC. I am not making fun of you for not having a car or anything; I think this would help you as you seem to have a sincere interest in FCs!

 

Yeah I want to get it, and get the Haynes manual. I'm reading corky bells book Maximum Boost.

 

I didn't think 87-88 T2s had twin/dual scroll.

 

So porting the wastegate is good? My friend is pretty handy at porting, and hes done some turbo porting stuff. Is porting the wastegate pretty straight forward? Maybe ill have him do that when I get my series 5 j-spec, or do I not have to worry about that with earlier turbos?

 

I'd save the money spent on Hayne's to go toward the factory manual. I have both and there is truly no comparison.

 

Yep, porting the wastegate is the only way to keep boost reasonable and have efficient open exh and intake on the pre '89. Porting is very simple and straightforward, removing the turbo can be a bitch. K2RD has excellant WG porting section w/ pics.

 

where is the k2rd W/G thing with pics?? I don't see anything. I really need to do mine.

 

http://k2rd.freeservers.com/FC3S/fc3s.html

Im pretty sure only the 86-88 TII had a twin scroll actuator.

 

Very good question. I was just there and it looks like they are reconstructing the site and took the tech pages out Hope they put it all back in. Basically, remove turbo, remove exhaust half of turbo or make sure no shavings/grit can get in turbo vitals, revove WG flapper rod, and use a rotory tool to backcut the passage so that it is concave leading up to the WG port and drill WG port to desired diameter. I have heard a good seal is not necessary, but I went ahead and made the WG hole big and machined an exh valve to cover the new hole, removed the original disc seal by drilling out the riveted back part and built up the end of the exh valve w/ weld (not welded to the pivot) so that it still had play to seal, but was secured. Works well, but apparantly not as good as '89+ dual passage as Rosh only gets 5psi w/ that and my ported does 7-10psi w/ slightly less free exhaust.

 

Yes, only '87-88 has dual scroll actuator, but dual scroll describes the casting surface surrounding the exhaust turbine. The dual scrolls allow exh. gas to hit the turbine at the most desirable angles on the specially shapped blades. I was under the impression the '89+ retained dual scroll turbo, but ditched the actuator in favor of a more direct path from exh. ports.

 

Check that link you provided under "comparison of 87-88 to 89+ turbo passages (or something close)" section and you will see that indeed the 89+ also has two passages leading to the exh. turbine making it dual scroll. Hmm, and the primary is bigger than pre 89-damn, didn't think about porting that when I had the turbo out. Good site!

 

My first J-Spec blew because of a boost spike. 1.2 Bar @ 6000 RPM
I ported the **** out of my wastegate on my second one, and the same thing happened!
Now I'm going to one of Crispeeds custom manifolds with a 40mm wastegate. That is still no guarantee that it won't blow, but it should help. Maybe it's time for a pop-off valve.

 

Mine did the same thing That autometer gauge was so off, I bet the bastard went up to about 15. My friend said he was watching it, and the A/F meter was all green, but the bastard blew anyway. I dont get it. Im going pop off valve for sure.

 

The HKS 40 mm wastegate works well. Just make sure to get one with a spring close to the maximum boost you want to run. I wanted to run at least 15 PSI. So I got the 14.2 PSI spring--closest thing the shop had. You won't have the spiking problem with the HKS external wastegates. They also sound cool if you don't route them into your downpipe.

 

What type of ECU were you using? 15 PSI with just a FCD and fuel pump upgrade can pop a motor. To run 15 PSI you need alot of fuel and a FMIC.