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-   -   Regarding sound of Weldon fuel pump on GN/T-Type (http://gnttype.org/forums/showthread.php?t=13293)

Kahn35 11-15-2009 07:08 AM

Regarding sound of Weldon fuel pump on GN/T-Type
 
Hello!

I am a long time GN/T-Type lover. I have never owned one but had the chance to test drive one several years ago and I've yet to experience another car like it.

To the point, I am in need of some advice. I am researching a very specific setup on a turbo regal for a sound/media project and I would like to know what I could realistically expect out of the car performance-wise and any quirks it might exhibit with these modifications. This setup has far more to do with how the car sounds and feels than it does with performance numbers.

The car would be a 1986 or 1987 Regal T-Type (turbo) or Grand National, not any other variant. It would have to look fairly stock, perhaps with the factory wheels, so no oversized drag tires and small front wheels. It would be able to do a 10-second quarter mile time on a single turbo. Most importantly, it must use a Weldon fuel pump-- or any Weldon fuel pump with a characteristic buzzing drone each time the car is turned on.

I am thinking the model #D2015-A would be what this car would be running, since it is rated to 1000HP/160PSI and the car probably would be around 500-600HP.

Questions:

1) Exactly what would the *minimum* horsepower be in a 10 second street driven GN with a loud Weldon fuel pump? To justify using a Weldon, in other words?

2) Can the factory GN or T-Type rims be retained at this power level even if larger series tires are used?

3) How loud are Weldon pumps from both inside and outside the car? I'm looking for personal impressions. Could you hold a conversation inside the car while the engine is running or is it just too loud for this with any of their models?

4) In general, would a turbo Buick with a Weldon pump be considered "streetable" or "barely streetable"?

I don't need to know many more specifics than those. Again, this is for a media/sound project and not an actual project car. It's a specific sound and feel that I am looking for.

Any help and advice to this end would help me out tremendously, guys and gals. Thank you! :)

-Craig

kenmosher 11-15-2009 10:24 AM

Re: Regarding sound of Weldon fuel pump on GN/T-Type
 
Strange request, but I think I get it ...

A 10 second quarter mile is achievable, but some of the factors that will affect your goal are:

1. Weight ... if the car is one of the lighter ones (i.e. no power windows, seats, no T-Tops or Astroroof) it gets easier. Replacing the steel bumper supports with aluminum ones (or if it's for the track only, replace the bumpers with fiberglass ones), lighter wheels (like the GNX style wheels), taking out the sound proofing, etc. all reduce weight.

2. Traction ... you're going to need sticky tires, preferably slicks or DOT drag radials. A lot of the quarter mile is going to be in the launch.

3. Tuning ... you can't just say "shazam" and slap a turbo on and go 10s. The fuel pump is part of the equation, but injectors, heads, cam, bottom end all factor in as well.

So, with that in mind, in answer to your questions:

1. Normally you'll need somewhere around 550 HP *to the wheels* to run 10s consistently. That means 620 or more to the crank. This is for a full weight car (i.e. 3700 lbs or so). If the car is around 3400 lbs, you can subtract about 10HP per 100 lbs of weight reduction. Deep into the 10s (say 10.50s requires close to 700 at the crank).

2. Yes. The biggest limitation is the rim width limits the tire size some. You can actually get stock GN wheels widened though to allow for a wider tire (rears).

3. No idea, since we generally try to keep the "sleeper" value of the car and loud fuel pumps are frowned upon. The in-tank pumps we use aren't really even audible in the car and only a very faint buzz in a quiet garage at idle. A single in-tank Walbro is just enough to touch the 10s with a light car. Most folks in the 10s will want a "double pumper" (staged dual in-tank pumps). Back before we had in-tank choices, I used an external Bosch puller pump but took pains to mount it with rubber isolators and such. There was more of hum outside the car, but it wasn't really very audible even so.

I don't know how loud you are looking for, but you could "tune" the sound by how and where you mount it. If you mount it directly to the trunk floor pan, I imagine it'd be obnoxiously loud. By adding rubber washers, you could reduce the buzz.

4. The fuel pump is not the determining factor in "streetable". There are Turbo Street Modified class cars in the low 9s (I heard someone just broke into the 8s?) that use the stock block and are definitely streetable. You'd be hard pressed to know that some of them are that fast.

That said, high 10s with a "stock appearing" car is considered pretty common place. Low 10s/high 9s is where the money gets bigger, the sneakiness grows, and the compromises become bigger.

Keller 11-15-2009 11:50 AM

Re: Regarding sound of Weldon fuel pump on GN/T-Type
 
Somebody making a video game? :lite:

- While the 7" OEM wheels are a wee bit small for the rear tires you'd want on a 10 second car (high or low 10 car), the old American Racing "Vector" wheel of the past (Think "General Lee" Dodge Charger Charger) is a 99.9% replica and was available in a small GM bolt pattern, as well as 8.5" and 10" widths. Just look over the site for pictures of these very wheels compared side-by-side. However, these wheels get HEAVY in the larger sizes and would not be the first choice of a racer.

- The use of a Weldon depends much on the target ET of the car. 10.99? Not likely. 10.0? Maybe. But it still seems like overkill, and I can think of twenty 10.x TRs, and none of them use one. They are loud, require larger lines, wiring, mounting considerations, etc. It just isn't that hard to make a 10.x TR, and a decent flowing intank pump is widely available.

After all, you only need that max flow for...oh...10 seconds or so at a time. :winkgrin:

http://www.weldonracing.com/product/...outlet%29.html

Kahn35 12-18-2009 04:54 PM

Re: Regarding sound of Weldon fuel pump on GN/T-Type
 
Keller and Ken... thank you both for your clarification. I know it was an odd question. Work, moving and a nasty flu have kept me from checking back on this thread until now.

It looks like most of what I am looking for can be achieved as long as I am thinking of a 10.6-11.0 second car. Maybe it is easier to just go with another set of wheels as well-- GNX style or another. The use of the Weldon pump was something I heard (I am pretty sure) in videos of Chris Chow's twin turbo GN. As well as on a couple of 9 second V8 dragsters. Why my insistence? Although Turbo Regals are known for their sleeper status, when I heard the sound of the loud, droning external Weldon fuel pump in conjunction with the TR's turbo spool when trans-braking... combined with the looks the vehicle is known for... it had, to me, the perfect sinister sound.

One of my pet peeves is portraying something with accuracy so, not owning a GN of my own to be familiar I needed to ask a few questions to see just how this combination would be straying from plausibility.

It sounds like using a Weldon on one of these cars would be a very crude and antiquated way to achieve what many people do with less trouble or complexity. If it's not too crazy of a suggestion, however (just a little but not terribly for a 10.6 second car as per your advice), I think I am going to go with it.

It sounds as if I could also localize the loudness of the fuel pump to be heard mostly from the outside very easily-- which for my purpose is a good thing. The interior can still be made very sedate. For weight, I am just going to assume I am dealing with a middleweight or heavyweight 3700lb version, so I'll stick with Ken's 600-620+ crank horsepower figure.

Thank you both and I'd love to stick around the forums. These are really amazing cars.

kenmosher 12-18-2009 05:26 PM

Re: Regarding sound of Weldon fuel pump on GN/T-Type
 
OK, now I HAVE to ask ... what's the project? This is obviously some sort of TV/Movie or video or something?

Kahn35 01-05-2010 02:41 AM

Re: Regarding sound of Weldon fuel pump on GN/T-Type
 
Ken,

Pretty much ;) I can't go into details beyond the car but I'll say it's not some lame F&F ripoff. I'm sorry to be cagey about it :P

kenmosher 01-05-2010 10:56 AM

Re: Regarding sound of Weldon fuel pump on GN/T-Type
 
Well, lemme know if you need some help ... we did a little sponsor work with the Setup TV show a couple years ago ...

PaCemkr86 01-05-2010 10:39 PM

Re: Regarding sound of Weldon fuel pump on GN/T-Type
 
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