Weight Savings and Custom Turbo Kit (87 Grand National and LS Engine)

LS-GN

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Jul 30, 2011
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Here are some things some talented friends did for me on my Grand National project. I first put these in the LS forum, I didn't even know there was a fabrication forum.

The car is a stored winters 87 GN with t-tops. It was purchased as a rolling chassis and came with a steel cage and a 9" in it. This makes it a very heavy car, especially when we put a V8 and a turbo in there. For this reason, the first step is to take a little weight out of the car. I chose a complete TRZ front suspension kit with a rack and pinion conversion. This would take weight out of the car as well as give us more room for our turbo system, by eliminating the steering box and linkage. This is the "street" version of the TRZ kit, which uses bushings instead of hiem joints.



The next idea I had was to put a fiberglass bumper on the front. Since this is a street car, I was uncomfortable with the idea of absolutely no protection at all in the event of a front end collision. For that reason we decided to make chrome-moly bumper mounts, and use a chrome moly tube to connect them together. This way we end up much, much lighter than the stock bumper and bumper shocks, but still have at least some amount of protection. This picture is from behind the bumper taken through the empty engine bay:



We also decided to do a custom chrome-moly core support. This was done in a way that it could be unbolted, and it also allowed the use of the stock hood release. I'm not sure how much weight it saved, but it did seem to be a decent amount. Anything helps because this is one heavy brick.



All the chrome moly fabrication is being done by PRE in Brownstown, MI. Unfortunately I do not have the skill set to do this stuff and Rich @ PRE is a master craftsmen. The bars fit perfect and the TIG welds are beautiful.

Here are the engine mounts:



Part numbers are:

Moroso 62530
Moroso 62630
Edelbrock 6706
 

LS-GN

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Jul 30, 2011
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Here's a front view of the core support and rack. You can also see the Wilwood Street/Strip brakes.



Here's a front view of the cradle. You can see where it was notched and boxed back in. It is as strong or stronger than it ever was from the factory.



This pic shows the way it sets in the car. It sits nice and low and far back, which will help the car work well and also give us more room for the headers and turbo system.



Headers under construction:

 

LS-GN

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Jul 30, 2011
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Headers and turbo system are built by my friend Pat in his garage. It's a pretty well equipped garage though.









 

LS-GN

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Jul 30, 2011
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We're going to get a custom radiator that will fit right behind the core support, in this 27x22" spot:

 

LS-GN

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Jul 30, 2011
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The system is almost finished here:



We still have to do wastgates and a blow off valve, but we ran out of time before the deadline to get the car into the paint shop. We took it all back apart and pulled the engine again. The car should be back from paint in about 5 weeks, then we'll put it back together and complete everything.

I just figured I'd post because other people's photos of their systems were very helpful when we were figuring this out. Let me know if you have any questions or comments.
 

LS-GN

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Jul 30, 2011
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Also, the hot side is all stainless steel except for the downpipe, which is aluminum. The cold side is all aluminum. The turbo is 80mm and the intercooler is a PT1000.
 

pacecarta

MAGNA
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Aug 1, 2003
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i have to say i dont agree with the plumbing choices youve made , craftmanship looks great but why the turbo placement with exhaust inlet on the wheel side of the frame ...and the side mount of the water to air IC causing the turbo to be cramped

having gone to a rack and pinion and seeing as how you have fabbed the crossbar and rad support (so the skills are there) you then chose to wrap the exhaust around the frame , I would have chopped off the front frame rails since they arent used for steering support, boxed the ends then run tubing to support the bumper and front end sheetmetal ...would have made the turbo plumbing a breeze and have a drop in weight
 

LS-GN

Member
Jul 30, 2011
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i have to say i dont agree with the plumbing choices youve made , craftmanship looks great but why the turbo placement with exhaust inlet on the wheel side of the frame ...and the side mount of the water to air IC causing the turbo to be cramped

having gone to a rack and pinion and seeing as how you have fabbed the crossbar and rad support (so the skills are there) you then chose to wrap the exhaust around the frame , I would have chopped off the front frame rails since they arent used for steering support, boxed the ends then run tubing to support the bumper and front end sheetmetal ...would have made the turbo plumbing a breeze and have a drop in weight
I have to say I disagree completely. Making the bumper supports and core support were easy (cheap) because all we had to do was match the dimensions of the factory parts. If we completely chopped off the front of the frame, we would lose that "index", and I don't think it would be worth the couple pounds it could save. Plus, if I wanted to, I could bolt all the stock stuff back on this car. I don't think I will though. The system is very serviceable and comes apart and goes back together really easy. The engine bay is massive, I don't think we need any more room?
 

pacecarta

MAGNA
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Aug 1, 2003
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if you had clocked the exh housing to say 4 oclock your plumbing from the headers wouldnt have to wrap around the frame
then clocked the turbo outlet to about 4 oclock you could have entered the IC from the lower tube and used the top outlet of the ic to feed the intake
 

slimtastic

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i like it alot. its very "outside the box" and im sure when you get it running itll turn heads......i would get all the hot side coated and then wrapped to keep the heat away from the tire though

LOOKS KEWL
 

oldsracer

Identity Crisis
Oct 20, 2010
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As a track car I like it but if you plan on taking hard corners Id be afraid of the rack breaking off the frame. Haveing a single attachment isnt the best way unless theirs more that arent seen. Also the steering through the fram looks great but again, I wouldnt be much of a fan of pushing the car hard becuase those holes really dont help the stability at all
 

usetaboost

SAY CAR RAMROD!!
May 4, 2005
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i will say the fab work is great, but i still dont get why people just dont use a n/a regal for these kinds of projects
 
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LS-GN

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Jul 30, 2011
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As a track car I like it but if you plan on taking hard corners Id be afraid of the rack breaking off the frame. Haveing a single attachment isnt the best way unless theirs more that arent seen. Also the steering through the fram looks great but again, I wouldnt be much of a fan of pushing the car hard becuase those holes really dont help the stability at all
This is the TRZ kit, it's been proven to be fine for a street/strip car. It definitely will never be pushed hard in corners, and will always have skinny "front runner" style wheels/tires on the front.

i will say the fab work is great, but i still dont get why people just dont use a n/a regal for these kinds of projects
Only because I love Grand Nationals and I think we're doing nothing but improving this car.

Paint work should be done soon, I'll post up some pics as it comes back together.

 

Chuck Leeper

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In reference to the ft steer rack: If the outer tie rod is in board of the lower ball joint, [as it appears in the pics], there's going to be issues w/ Ackerman. Drawing lines thru the tie rod end & the ball joint, and you will see that the lines that are supposed to meet at the rear axle center, are actually diverging.....
 

oldsracer

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In reference to the ft steer rack: If the outer tie rod is in board of the lower ball joint, [as it appears in the pics], there's going to be issues w/ Ackerman. Drawing lines thru the tie rod end & the ball joint, and you will see that the lines that are supposed to meet at the rear axle center, are actually diverging.....
Wow you've got a good eye...If this is strictly a drag car do you think it would matter much. the only turning would be around the track and on/off the trailer. Ackerman's "theory" i guess youd call it is really to correct for when you fully turn the wheel so both wheels point in different angles to correct for turning radius. Now if its only going straight with little turning do you think it would do anything? Im not trying to fight with you, im an engineering student so this what I do :D
 

LS-GN

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Jul 30, 2011
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Here's a link that may be of value...
We just discussed this same problem over on www.tri5.com. The builder had the outer tie rod ends out of "whack".. The general consensus was to put them as close to the correct location as possible.

Interesting information. I just never thought to question the front suspension geometry because this TRZ kit is used on some of the fastest stock suspension G-body cars at the track. Hopefully any ackerman issues won't affect handling at the top end, as we do expect to add some serious power to this car in the next couple years. The first combination will be pretty mild, but I'll post up if the steering causes any problems at the track. We hope to have this one out in May.

 

Pittsburghkid

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Mar 22, 2009
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Looks good but are you worried about raising your charge air temp with the charge pipe being so close to the hot side of the turbo?
 
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