TWM fuel injection

Mike · 10-07-06, 11:45 PM

Picking up on a thread from about 8 months ago (new house got in the way), here are the promised results from changing from 8 air cleaners to velocity stacks: "Rear Wheel nums" on a dynojet"
8 air cleaners (K & N) on squared off intake stubs: 347HP at 5900RPM, falling off, and 350 ft. lbs at 4500RPM.
8 90mm velocity stacks (air cleaners in body ducts); 365 HP at 5300RPM and an absolutely flat curve/constant 365 HP to lift off at 6500RPM, 370 ft. lbs at 4800RPM.
Note; Comp Cam is 236/242 int/exh/hyd. roller, advertised peak power at 6500, torque at 4900.
For the racers who want peak power up in the 7000,s, it seems a carb. on a high rise manifold/big plenums is the way to go (Ron Earp?) or really huge diam. intakes with low RPM drivability problems?

On a separate note, seems there are distortion problems with the (early?) TWM throttle bodies. The aluminum T/B's expand at a different rate than the linkage/butterflies. When they get hot, the balance goes to hell. Joe Leonard (of JC Performance) pointed this out and solved the problems I'd been having. An EMPI or equivalent type air flow gauge is an absolute must, along with real throttle springs to overcome binding in the linkage. Next project is to install a linkage fix (I believe Joe has one). Side note: Cold air boxes/turkey pans make it a real pain to adjust linkages.

Hope this is of interest,
Mike

Sandy · 10-08-06, 01:05 AM

Mike -

What was the size of the TWM bodies you were using?

Sandy

Mike · 10-09-06, 12:35 AM

Hi, Sandy. They're 48 IDA's. I seem to recall somebody writing in about 52mm intakes awhile back, but I don't remember the power numbers. They were quite high, maybe 6500RPM plus, but no comments on low RPM drivability. I think Ron Earp may have compiled a lot of info re. induction type vs. high RPM peak power to go racing.

Bill Musarra · 10-09-06, 07:15 AM

I have the big throttle bodies on my 351/408 and will have some numbers in a week or two. The car goes to the engine builder to let him finish the build and fire it up this week or next. They are also doing my exhaust in the RCR fashion, and some finish welding of stainless panels that I was not comfortable doing, if my builders assistant has recovered from a broken arm from a 4 wheeling accident. We plan to dyno both the engine and the drive train (when I can get that finished). Will post the #s on my build thread update.
I for one would like to know what the fix was that you mentioned. The linkage on mine seems to be very smooth. With heat that may change, but curious just the same.
What poundage/brand injectors are you using? Mine are 32# Accell. The heads are AFR 205s. Don't remember the cam specs right off hand.

Bill

Lynn · 10-09-06, 01:11 PM

Quote:

Originally Posted by mikegaan

For the racers who want peak power up in the 7000,s, it seems a carb. on a high rise manifold/big plenums is the way to go (Ron Earp?) or really huge diam. intakes with low RPM drivability problems?

I am hoping that this manifold system will solve this issue.

Ron Earp · 10-09-06, 04:28 PM

Mike, what size chokes are in those carbs? 44mm? If so, that would just about fit the theory perfectly.

Ron

Sandy · 10-09-06, 04:34 PM

For some reason I thought you were running EFI on the TWM manifold. My mistake, and yes I think with Ron that they are not going to make the ultimate power on a high rpm or larger cube motor as a 4bbl, but I guess it all depends on what power levels you are looking to hit ;-).

BillM - Which size if 'Big' on your throttle bodies? I think I have the 50mm for the TWM setup I have but it will not go on the car initially. Very curious how it works for you. I'm not sure of the injectors Lbs rating, they were 550cc/min from Russ Colins Engineering. I guess math might get the cc -> lbs thing

Sandy

Mike · 10-09-06, 05:16 PM

Hi, all. Sorry for the confusion. I AM running TWM fuel injection, with 48mm intakes. The "IDA " part was something the engine builder told me was the 'equivalent'. I have 34# Venom injectors, that seem to be working fine.

Bill, you have the new T/B's. Joe Leonard tells me they have the fix incorporated. Note the connections between each throat, which evidently allow room for expansion. My 'old' TWM's have a one piece casting/tube connection between each throat (linkage rod inside tube), and when the Al. expands, it evidently pinches the ends/binds a little.

Lynn. That's a wild looking manifold, but I'm not sure what goes on top? Where/how do the 8 T/B's go, or is it a dual Carb/throttle body set up? Also, will all that fit under the clamshell?

Alohas, Mike

Sandy · 10-09-06, 07:04 PM

Mike -

That sounds more like it, I re-read (again) the first post!

I have the 50mm late TWM IDA bodies like Bills. They assured me (TMW) that that I would not need the 56/58mm bodies, but will have to see (It was unclear if they would work on the SBF manifold either). I think one of the Roush racing engines is equiped with the TWM manifolds (TWM said they were). Might be worth a check to see what they are doing for HP/TQ.

Looking with interest to see how Bills motor does.

Sandy

[edit - the roush motor package is a 402cu making 500hp/500ft/lbs]

Mike · 10-09-06, 07:21 PM

Sandy, have you run your 50mm TWM set up yet? I'd be interested in the numbers. I assume they fit on the SBF with no problem?
Re. Rousch, I understand he was the main reason TWM 'fixed' the throttle linkage problem, i.e. for him.
Mike

Sandy · 10-09-06, 08:09 PM

Mike -

No, have not run it. I have a 4bbl on the engine at RCR for my car now. But down the road it will go on the car, have to have the stacks.

Don't know if Roush was the ones that made them fix the throttle bodies, but I had ordered mine and they were back ordered for a while, they ended up pulling one from the Roush allocation for me as I was told. It looks like a drop in besided port matching on the SBF (the maifold). I was going to try to get a test motor with them running before the carb manifold goes on (for another car), but I don't have the time to get things ready for it. The build does not have much experiance with EFI and I would have to handle it so likley not going to happen. I really wanted the 8 Stack EFI vs. the Victor and 830cfm shoot out test for this motor. If I could get Steve from TEP to come down and do it I might have a chance. I have a friend that knows him pretty well and might be able to twist his arm to give it a tune (A haltech fuel only ECU).

So far it looks like Bill is the closest to getting some numbers for the 50mm.

Sandy

Lynn · 10-09-06, 11:14 PM

Mike,

The part on the left goes beween the heads like the manifold for weber ida/idf carbs. The part on the right, with the runners, bolts to the valley manifold and accepts EFI injectors. The plenum that says Roush, connects the two large D shaped orifices on the runner section. What you can just see the point of on the "Roush" plenum is the large throttle body boss that is clocked 90º to form a diamond rather than a square with respect to the horizontal (or vertical for that matter.)

Below is a photo of one mounted on a Mustang that belongs to a buddy of the guy I bought mine from. As you can see, he is running a super charger through it. The way the Jack Roush Stage III mustangs set it up was with a cowl intake with a large K&N flat filter. As you can see also, this manifold would lend itself perfectly to placing two turbos just behind the 4-into-1 collectors of a "bundle of snakes" and routing the compressor outlets straight forward into the throttle body. (Down the road, maybe.)

Regards,
Lynn

Bill Musarra · 10-10-06, 07:11 AM

You guys just got the brain to working. I remember the Roush deal with TWM. My intake was delayed due to the lage order that Roush had with them. Seems he ordered everything they had for his engines, and my order was delayed. With the level of progress I have made since then, the delay sure didn't hold me up. Really itching to get mine finished since the Queen has given the go ahead.

Bill

Mike · 10-10-06, 03:34 PM

That original Rousch order evidently was returned because they wouldn't hold an idle (when hot...due to Al. heat expansion/binding), hence the 'fix'.

Lynn, the parts make sense now. I was trying to figure out how you got 8 stacks/weber look alikes on that set up. Ans: you don't. BTW, have you driven anyone's GT-40 yet? With some 400 HP on 2265lbs on car

? Twin turbos may be more than you'd want or like...except there's no such thing as too much horsepower, right?

Ron Earp · 10-10-06, 03:42 PM

That is Lynn's GT40 in his Avatar but he doesn't drive it.

Just kidding! He's got a nice car with a stock 5L at around 250hp or so, with mass air EFI which I've not seen on anyone else's GT40. Good stuff!