New Intake

[Kalle]

Guys, I`m on E85 so my injectors are more than twice the size

Balance pipe? This is news to me. Where can I find more information? I have not time to change anything now but if I experience a huge difference in exhaust temperature I will abort the dyno session tomorrow.

-BB-

[Steve Arndt]

You said you removed an IDF style runner setup to switch to this. Can you compare the idle quality, smoothness, idle map, or even the "feeling" between the two? I'm considering switching from 45mm IDF ITBs with high mounted outboard injectors to your smaller manifolds (with a single TB in the center).

The only experience I have with Siamese intakes like these is Kadrons and ICTs. Neither of those will idle smooth compared to an individual runner carb. I'm wondering if their is a similar issue with this layout.

[Paul H]

Guys, I`m on E85 so my injectors are more than twice the size

Balance pipe? This is news to me. Where can I find more information? I have not time to change anything now but if I experience a huge difference in exhaust temperature I will abort the dyno session tomorrow.

-BB-

Don't worry the balance pipe is just a piece of half inch hose that runs between the two chokes-from this pipe you can take the MAP signal, pressure reg pipe, boost/vac gauge etc. It makes setting up the idle easier but makes no difference at full throttle.

[Paul H]

Paul,

My 1192cc with Pauter K8-ish cam idled fine on the 60lbs Siemens injectors even without balance pipe and the 51mm TB's.
Unfortunately, the rear main bearing seized at 6K rpm and 15 psi, so I have now abandoned the 1200 Challenge and revert back to a type 4 build.

The cleanliness of the design was a very nice added bonus though!

Walter

Sorry to hear about the bearing failure
I've been working on type 4 stuff myself recently

[Kalle]

You said you removed an IDF style runner setup to switch to this. Can you compare the idle quality, smoothness, idle map, or even the "feeling" between the two? I'm considering switching from 45mm IDF ITBs with high mounted outboard injectors to your smaller manifolds (with a single TB in the center).

The only experience I have with Siamese intakes like these is Kadrons and ICTs. Neither of those will idle smooth compared to an individual runner carb. I'm wondering if their is a similar issue with this layout.

Me? I used original VW intake manifolds with welded injector bunges. Ported to the max and of course matched to the heads. Mind you my engine is only a 1641ccm and I have yet to take a closer look at the fuel map in order to get it to idle better.

And guess what, the guy with the dynapacks just called and said he had to cancel. Nice? NOT! I have the possibility to use the Dynapacks on Tuesday but that is not the best day for me due to work. I will see what I do... and of course keep you posted. The easy and cheap solution would be to map it on the road using the log function but I prefer to have the car strapped to the Dynapacks instead.

-K-

[Steve Arndt]

Yes it's much simpler and neater to pipe them up.
We removed a set of 48idf tb's with cast ally pressure caps with stainless cross pipe and saved 4.5kg in weight

My question was regarding this previous post.

[Paul H]

You said you removed an IDF style runner setup to switch to this. Can you compare the idle quality, smoothness, idle map, or even the "feeling" between the two? I'm considering switching from 45mm IDF ITBs with high mounted outboard injectors to your smaller manifolds (with a single TB in the center).

The only experience I have with Siamese intakes like these is Kadrons and ICTs. Neither of those will idle smooth compared to an individual runner carb. I'm wondering if their is a similar issue with this layout.

The main difference between the Kadron/ICT setups and SP1's is the large volume chamber above the runners which will help buffer the reverb. With the butterfly closed the pressure wave can bounce off the butterfly and down the other side.
If you use the 58mm manifolds with a single throttle the back pulse fires straight into a 2.5 inch pipe and has no effect on the incoming charge which is similar to what the individual runner set up achieves.

I'm due to test 58mm SP1's with single 58mm throttle versus a set of 50mm ITB's on a 2180cc motor, I'll also test the 3 injector positions to see if there is any difference- sequential fuel, wasted spark, 4 x egt's.

[Paul H]

Here's a pic of the chargecooler/induction pipes for the SP1 52mm throttles

[Kalle]

Hi guys,

A long day together with the dynapacks is over and what a day it has been. I´m too tired to write a long summary and to download the pictures and movies from my camera so right now you better take my words for it.

We soon found out that my fuel map needed a lot of attention and we had to add a lot of fuel. With the new intake manifolds from Paul and my new plenum design we got 254 whp at 1 bar (14.5 psi) which is my base pressure (WG spring). With my old intakes I had 222 whp at 1.2 bar of boost so there is absolutelty no question that the new intakes makes more power.

-BB-

[Paul H]

Well done !

How did the mid range compare to the old intake ?

[Kalle]

Well done !

How did the mid range compare to the old intake ?

Thanks Paul. The mid range was so to say identical up to a certain point and from there they shined. We increased the boost step by step up to 24 psi but we experienced issues at BMEP and not matter what we did (decrease boost at BMEP, increase ignition, less igniton, lean it out, increase fuel) we could not avoid the dip at BMEP. After BMEP it picked up again and peaked. We both believe that my MSD 8241 igntion in combination with a .024 plug gap could not cope at BMEP. Apparantly wasted spark, E85 and MSD is not a good combo. The old result at 25 psi was 354 whp and we beat that at lower boost Not too shaby for a 1641ccm engine.

-K-

[Paul H]

Do you have a MSD ignition box or just the coil. I had no problems with wasted spark and one of those coils-32psi boost and nitrous in my bus engine

[Wally]

Awesome!!!!

[Kalle]

Do you have a MSD ignition box or just the coil. I had no problems with wasted spark and one of those coils-32psi boost and nitrous in my bus engine

Just the 8241 coil and wasted spark. What plug gap did you have at 32 psi and nitrous? I used nitrous as a cooling agent earlier and did not experience the same issues. That said, my 1641 engine have always had the dip at BMEP but not as obvious as we experienced today. Not sure why but we sure did spend a lot of time trying to fix the issue. The only thing that helped a little was increasing the coil on time from 3000 ms to 4000 ms.

@Wally: Thanks man!

[Paul H]

Do you have a MSD ignition box or just the coil. I had no problems with wasted spark and one of those coils-32psi boost and nitrous in my bus engine

Just the 8241 coil and wasted spark. What plug gap did you have at 32 psi and nitrous? I used nitrous as a cooling agent earlier and did not experience the same issues. That said, my 1641 engine have always had the dip but not as obvious as we experienced today. Not sure why but we sure did spend a lot of time trying to fix the issue. The only thing that helped a little was increasing the coil on time from 3000 ms to 4000 ms.

@Wally: Thanks man!

I think they were set at 30 thou, didn't pay much attention to it as there were no ignition problems to deal with.
maybe 100% E85 is the problem as it's very wet perhaps you should try blending some decent pump gas with it as at 25psi boost you will be safe