PT 69 Pontiac Custom S

[boss_hoss]

All in the bolster weights 17.9lb. Haven’t pulled the other booster/master to compare but if you want to weight your own this should give you a good idea.

[boss_hoss]

Started fitting the ibooster. First little hurdle was that the holes firewall bracket didn’t line up with the studs on the firewall. No big deal I attribute this to the normal variation in factory and aftermarket parts. A little work with the Dremmel and the booster slid right on. Getting the bolts on the firewall studs to secure the booster bracket Is a major PITA, just not a whole lot of clearance and Ive got big ol sausage fingers. Once it was mounted to the firewall everything is pretty straight forward. The offset pushrod adapter does in fact allow you to use the factory power brake hole on the pedal arm. I had some concern I was going to have to fe bend my brake lines but the new ibooster set up appears to be the same
Overall length as my old vacuum booster set up because the brake lines went right back into place perfectly. Fitment is pretty tight to the inner fender but there’s no interference anywhere and there’s definitely more clearance in the engine side.

[boss_hoss]

All in the bolster weights 17.9lb. Haven’t pulled the other booster/master to compare but if you want to weight your own this should give you a good idea.

i weighed the vacuum booster/master set up and it came out to 15.5 lb. So not much lighter but something to consider if you’re concerned about weight.

[Vimes]

Thanks. According to the Dodge website my master cylinder with booster weighs 16.4lbs, but also takes up a TON more room than that tiny little thing. Plus, I spy with my little eye an adjustable rear proportioning valve, which is a bonus.

Weight loss is important, but only because it means I can add weight where it'll do the most good. Can't wait to hear your before and after observations on this unit.

[boss_hoss]

Thanks. According to the Dodge website my master cylinder with booster weighs 16.4lbs, but also takes up a TON more room than that tiny little thing. Plus, I spy with my little eye an adjustable rear proportioning valve, which is a bonus.

Weight loss is important, but only because it means I can add weight where it'll do the most good. Can't wait to hear your before and after observations on this unit.

I’m curious how it’s going to work out too. The weather in Oregon in the winter is hit and miss but it’s suppose to be nice enough I can take it in a quick test drive in the next few days.

The reason decided to go with the Ibooster is I could never get my vacuum boosted brakes to work the way I wanted. Tried different masters, different booster, different brake pads and just couldn’t ever get the bite I wanted out of the brakes. They worked fine around town but never responded well to aggressive braking and for the life of me they would never lock up even when I really jumped on them. I’m hoping the combination of the 1-1/8” master and the iBooster will get me the volume and line pressure I need to get the brakes to perform the way I want them too without wearing out my right leg.

[boss_hoss]

Ol Mother Nature gave me a few nice dry days so I decided to test out the Ibooster today. All I can say is WOW. It’s exactly what I was looking for. I actually had to re learn how to dive my car a bit. With the old vacuum booster set up I had to use quite a bit of pedal travel before I really got the brake to clamp down. With the Ibooster the pedal is super responsive, and starts to engage right off the top. The pedal travel is pretty short and pedal effort is also light. It felt a little twitchy initially but it’s because I was so use to my old brakes. Once I figured out how much input I need to get what I wanted it was perfect. Feels like a new car which makes sense given its modern technology. I’d say if you were going to track your car and like a really progressive pedal feel this might not be for you but for my purposes, which is mostly cruising and spirited driving on windy rural roads this is awesome. I’d highly recommend it over a vacuum set up. I have not experienced a hydroboost set up other than my big HD truck but I’d imagine it would be pretty similar without the complication of tying your braking system onto your power steering.

[boss_hoss]

The other thing I forgot to add. The one other big improvement was consistency With my vacuum booster set up the pedal never quite gave me the consistency I wanted even though everything was in good working order. With the Ibooster it’s perfect and repeatable every time.

[boss_hoss]

Now that the brakes are all sorted out I’m addressing the 200-4r transmission. It’s a great transmission but I’ve never been happy with the lockup. The 200-4rs in my experience and from what I’ve read tend to get up to 4th gear pretty quick and lock up which is great for cruising and economy but Unfortunately they don’t downshift and unlock very quickly. I can get down to 35 mph and it’s still not unlocking so the engine tends to lug. Not terrible with a Pontiac engine since it has good low end torque but it’s annoying. I’ll be installing a B&M lockup controller and Superior solutions vacuum switch hopefully to help control the converter lock unlock characteristics to get it the way I’d like.

[stevehoj]

Boss, looks like Newport?? We get there often.

Great project and love you kept it Pontiac powered and the modern electric booster update.

[boss_hoss]

Boss, looks like Newport?? We get there often.

Great project and love you kept it Pontiac powered and the modern electric booster update.

You're right on the money; I've lived on the coast a long time. Weather this time of year is a bit dreary but give me plenty of time to work in the garage. When the weather is nice though there's some great twisty backroads to play around on which is what it built the car to do.

I'm glad I kept the Pontiac Powertrain too. I get the urge every now and then to go for a big Power LS but for what I do the Ponco 400 has plenty of power and with the EFI, Overdrive, and other modern updates its more than enough to put a smile on my face. I'll probably do something stupid before too long here and drop some serious coin on a top end package from Butler Performance to bump the power up from around 350 to 450 HP. Thats about all my drivetrain is built to handle before I really have to start beefing things up.

[andrewb70]

Ol Mother Nature gave me a few nice dry days so I decided to test out the Ibooster today. All I can say is WOW. It’s exactly what I was looking for. I actually had to re learn how to dive my car a bit. With the old vacuum booster set up I had to use quite a bit of pedal travel before I really got the brake to clamp down. With the Ibooster the pedal is super responsive, and starts to engage right off the top. The pedal travel is pretty short and pedal effort is also light. It felt a little twitchy initially but it’s because I was so use to my old brakes. Once I figured out how much input I need to get what I wanted it was perfect. Feels like a new car which makes sense given its modern technology. I’d say if you were going to track your car and like a really progressive pedal feel this might not be for you but for my purposes, which is mostly cruising and spirited driving on windy rural roads this is awesome. I’d highly recommend it over a vacuum set up. I have not experienced a hydroboost set up other than my big HD truck but I’d imagine it would be pretty similar without the complication of tying your braking system onto your power steering.

This feedback makes me very excited to see how the iBooster works in my 70 GTO. Mine is the 1st Gen unit, but I have to believe it will be very similar in function.

Andrew

[boss_hoss]

This feedback makes me very excited to see how the iBooster works in my 70 GTO. Mine is the 1st Gen unit, but I have to believe it will be very similar in function.

Andrew

I need to drive it a bit before fiddling with but the only thing I might do is play with the pedal ratio. I remember seeing yours when you first installed it in the GTO. If I recall you drilled an extra hole just above the stock power brake hole on the pedal arm and moved the pushrod clevis up. I’m thinking of doing the same thing on mine to increase travel a bit to improve modulation.

[boss_hoss]

The weather in Oregon is miserable and I’m board so I’m finally starting to work on closeout panels for the trunk. My grand plan is to mimic the design in the center of the door panels but we’ll see if my skills can match my imagination.

[AngryBird75]

Great build