Aything actually released that would be good on a gt40 sized turbo with full headwork, oversized valves etc???

Was thinking map rev3 with boomba 75mm flange and boomba 75mm tb... however wondered what other options there are as all that along with spacer gasket etc works out alot of money, maybe it will be a better bet getting something aftermarket and not just stock modified.

Has cosworth actually released theirs?


Bronco.

 

If you're serious, idk why you're using a gt40 sized Turbo, its a waste. And if you've really got the engine etc for that, you're already 15-20k into it, and you're worried about a 650 manifold?

 

1) I am serious
2) when i say GT40 sized turbo I mean in that lbs/min bracket.... I'm testing a couple of turbos on a T4 setup inc a BORG Warner.
3) much more than 20k in
4) NOt worried about 650 but just stating it works out a lot more than that when you add 75mm TB, 75mm weld on flange and heat barrier gasket. So I was thinking if there is a decent aftermarket unit then why not spend some more and get that
5) is there anyone with something constructive to say or have any experience with afterkarket intake on the 4b11t?

 

1) I was being helpful
2) I do believe I qualify as having experience with this area
3) Some tests have been done, the gains have been subpar to this point. In the 10-15whp range. You decide if that's enough for you to spend the money. PM hollywood_x if you want more info, he has a 2.3 stroker and cosworth head and tested the map rev 2. Maybe that's enough experience to satisfy you

 

I did a half day of dyno tuning right before the One Lap event and found that the before and after test of the 75mm Boomba TB on a bigger plenum intake manifold was less than eye popping. There were basically no gains from just the hard parts swap with a conservative tune used on both. I'll have a full report of using a modified intake manifold with bigger plenum that had a 75mm flange welded on as well as upgrading the cold side IC piping to 3" this week. While I probably gained some "maximum potential" horsepower with the upgrades once I started dialing in the tune, the money spent was likely better allocated to other areas.

On the positive side compared to my old GT30 setup I only lost 200 RPM of spool with the GTX30 single scroll .83 housing combo that STM put together with a significant jump in power from 4500-8000. It's possible these intake manifold/TB/IC pipe upgrades would make more of a difference with a huge turbo but for me it was barely worth it in my mind. Best bet is to do a full before and after test so you know for sure what upgrades were good, bad or little change.

 

Hmmmm thats very helpful bud... So do you think I should just port the stock TB and use the cash on other bits? My setup is drag and top speed running 2.0l darton sleeved block as a base. Fully worked head using ferrea components and jun bronze valve guides with jun 272 camshafts. The stock intake manifold does look like it is a pretty solid design and I may use that cash towards some NOS instead.

Just to add I will be using 3" pipework, big intercooler so your findings with 75mm flange welded on with the tb is what I would really be interested in. So please keep us informed dude.

 

If you are not making over 700 whp going with bigger than 2.5 inch piping and a ported stock TB will only hurt you.


-Em

 

Cheers guys aim is 750-900hp trying a couple of different turbos and NOS

 

I would be interested to try this theory out. I have a 3" licp and no one has touched the fpred number my car produced on an actual dyno. I am in the process of getting back to a red and will give it a shot when I re-tune. I am sure your comment comes from a good place, but I typically have to see things on my own.

 

My only mistake I made when testing before and after is that I only left it as a conservative baseline tune between parts changes. The problem with that is some mods allow you to be more aggressive with a tune in order to show any power gains while other mods that are easier to measure just make more power with the same boost/timing/fuel settings.

It's possible that at higher airflow numbers that a larger diameter TB or intercooler piping as it enters the intake manifold can balance airflow better entering the combustion chambers, but that is pretty hard to nail down for gains. If you had unlimited time you could map out the effects of different IC and TB piping diameters as obviously there is a point where too small can be a real restriction, but when you are talking a difference of 5-10 whp there are just so many more things you can do to get more power much more consistantly. Since I was rushed to get another car tuned before the One Lap I couldn't really optimize each parts combo perfectly and the tailpipe wideband was acting up at STM as well which further complicated things.

 

Stock turbo X's have seen nice gains with ported 64mm TB's and my friend with a BBX on pump gas just saw some nice gains by going from the stock to a 2.75" LICP. I don't buy that under 700whp theory one bit.

 

This is definitely one of those cases where what makes sense on paper doesn't always pan out in the real world. After running my numbers and comparing to what happened in my before and after testing, here is what I would recommend:

Crank Horsepower Goals:
450 (350 - 600) = 60mm TB (stock)
500 (400 - 650) = 64mm TB (Bored out stock)
750 (600 - 950) = 75mm TB (Boomba)

This is just based on keeping the velocity between 250-450 ft/sec with the sweet spot being around 300-350 ft/sec for a good balance of velocity and flow.

When looking at your Cold Side IC piping you want to match the TB if possible but if your FMIC outlet is the restriction it won't help as much. I went with a 3.0" but likely 2.75" would have been fine for my current HP goals and I would have gained back 100-200 RPM's of spool & response.

Hot side IC piping you likely want to stay on the smaller side to keep velocity up, 2.5" doesn't hit 450 ft/sec until 700 crank HP so I left that alone.

So right now with a Boomba 3.0" TB I'm barely entering the range where it would start to make a difference at 600 crank HP which is likely why I didn't see much difference with a straight up swap. We'll see down the road when I build the engine with a 2.2L and potentially move to a bigger turbo.

On Emery's 800+ whp car that is likely just over 1000 crank HP, I would be really surprised if a dyno comparison failed to yield gains between a stock TB with 2.375" stock sized IC pipes vs 3" TB with 3" cold side IC pipes as that would drop the velocity from 734 ft/sec down to 450 ft/sec. Even 2.5" piping is at 642 ft/sec which which seems awfully high considering the car stock was only moving around 250 ft/sec. The odd part is I think he has already tested a few combos and they somehow didn't make enough of a difference to warrant the spool and response losses.

 

So do you think with my goal of over 750 crank hp it would be a good idea to use:

3inch intercooler inlet outlet
3inch intercooler pipework
boomba ported intake manifold
boomba port matched big tb flange
boomba big bore tb

Thing is if it wont really be benificial I am happy to stick with stock setup and not even port... I do know JUN use 64mm TB on their demo and saw gains. That is just over 600hp.

BRONCO

 

I personally ran a 3.5" AGP intercooler with a 3" LICP, Boomba 64mm TB, and a ported intake manifold. I ran it at close to 750whp when I was complete with my tuning. This is the same setup that I used on mid 500's with the FP Red.

 

4" or 5" thick FMIC with 3" inlets/outlets (can use 2.5->3" or 2.75->3" couplers for hot side)
2.5" or 2.75" hot side IC pipes (smaller for better response/slightly larger for better flow)
3" cold side IC pipes (matches TB)
Boomba Ported Intake Manifold with 75mm flange
Boomba 75mm TB

That should do well for 750 crank HP goals in my mind, a good setup for a Precsion 6262 turbo I think. Still that is quite a bit of supporting mods for what will likely be under 20-30 hp difference but if you are in there anyways...