Looking for all the negatives to going this route.

thanks

 

I dont really believe there are alot of negatives to the swap over TPI if thats what your comparing. But since i've done the swap, I'll list a few things that come to my mind



1: is no EGR for emissions. There isnt a spot for the valve or anyway i can think of making one, unless its a remote system thats plumbed into the manifold but probly wont pass as it dont have a EO/CARB number or whatever. It is possible to pass tail pipe sniffer tests tho just not the visual part.

If visual emissions isnt a problem, then no negative here

2: It is abit taller than the TPI. It will fit under stock hood but on my Irocz, the TB hit alittle portion of the hood bracing, so you have to cut alittle bit out. Not a big deal but alittle something you have to do. If its a show car with a show underside of the hood, then HSR may not be for you.

3: Basic install situations. Lot of ppl have problems with the adj. holley fuel pressure regulator units. I havent yet, and some others havent either. basically they wear out fast and may leak out the back of the regulator. Some have problems holding consistant fuel pressure. Mine has been fine but i'm not gonna say its fine since its only been on the car for 4-5 months or so, not much over 3000 miles. Simple fix is running the Kirban billet regulator for 100-110 bucks. Really solid unit, very nice quality. Fits buick Grand nationals but also fits the HSR.

There has been some talk about the HSR sealing the rear china wall well. On some old castings the HSR china wall end is abit long and doesnt leave alot of room to seal the wall. you gotta make sure you use alot of RTV to get a good seal. ALot of ppl like myself have had NO problems with this, but if you search enough you may see some stories about this sealing problem. just be careful on the install and it should go well.

You gotta make custom fuel lines which is EASY to do and not all that expensive so its not really a negative but shows the hsr isnt just a bolt on using stock TPI lines

Need a thermostat housing that faces opposite of the TPI style one. basically a standard SBC one. Problem is most housings run a 1 1/2 inch opening for 1 1/2 inch hose. TPI radiator is a 1 1/4. I just ran a summit hose adapter kit for 8 bucks and it works fine. Just doesnt look as 'clean' as a proper hose size. But they may make proper sized housings i just didnt look hard enough.

4: Looks of the system. Some will say TPI looks far better and i think that may be true to a point. Just alittle downside if you really like the TPI look. HSR is somewhat plain jane but its performance makes up for it. Its look has grown on me, especially if you paint them with a color scheme

5: edit: I wanted to add this important little number so ppl dont get to confused. They say you will lose lowend torque/power with HSR. They tend to make a big deal about this lose of torque. Which may be partially true, you may lose some. You will make more PEAK tq with TPI setups, however HSR will make more overall torque at all other rpms and make a flatter torque curve which is a HUGE positive. SO yes alittle low/midrange peak tq may be lost, but its not a big deal since the car will be up on power everywhere else. Loses are offset by gains. My car actually launched HARDER with HSR over TPI. Track times dont lie. Flatter torque curves means more power under the curve which leads to better performance. The HSR losing low end torque arguement is a weak one at that. Just wanted to draw attention to that so no one tries to bring up that point as a negative.

6: I dont believe strut tower braces designed for TPI systems will fit over the HSR. YOu have to search to find out for sure as i think some ppl have been able to fit some brands over the HSR with some simple modifications to the brace. I know most of them dont tho without some sort of modification like raising the bar higher at the strut tower mounting points

thats about all i can think of at the moment for negatives.. there are far more important advantages/positives than negatives tho

 

d

 

Orr89RocZ hit most of the negatives, on top of that, you cant use a strut tower bar, and you must use a small cap distributor, the large cap distributors wont fit. And my holley afpr lasted a mere 2000kms.

 

Orr89RocZ nailed it.

Being that you have a Formula you MIGHT be able to get away w/o hitting the underside of the hood due to the power bulge, but I'm not sure. My TA required cutting the bracing away. I just cut it as wide as the intake and it is not even CLOSE to touching anywhere.

As for the waterneck, I ran the Mr. Gasket version alot of guys are running w/ a 85 carb Trans Am upper hose. I had to modify it slightly, but works.

My intake is sealing fine on the china wall as far as I can tell, but I haven't put more than 15 miles on it. I made sure to put PLENTY of RTV back there though.

There is not a strut tower brace that I have seen yet, but if there is I'm sure someone will weigh in yet.

Personally, the performance of the HSR FAR outweighs the negatives of the swap.

 

also doing the swap, to hsr, have the intake rails, injectors and throttle body coming in, my car is currently tpi. about the the water neck, ne1 have a part number, any other minor parts that i need to buy right off the back that i shoudl worry about, i wanna get all the parts necessary do a mock up make sure i have everythign i need, then take off and do some paint and polisign work

 

no rear coolant crossovers in the hsr i dont know what ur supposed to do i posted a new thread askin about this

 

That's not an issue. Just RTV up the gaskets around the ports, and tighten it down.

 

are u sure chris? lol yours worked out ok? it doesnt affect cooling system at all? so i can stop freakin out?

 

I didnt notice much difference in how my engine acted with the rear coolant passages blocked. Does TPI even have rear coolant passages? I cant remember. As long as the coolant enters the heads from one end and goes thru the entire head thru the passages, the motor should stay cool

if you dont like that idea, just drill and tap the HSR manifold for coolant nipples and run a hose to each side to ensure flow goes across to the heads. should work.

Option B is to have someone fabricate a rear crossover peice under the manifold to get flow to both sides

Either way i dont think it matters

 

ya tpi has rear crossovers so do the cylinder heads all 4 corners is what im tryin to say i guess. but if you guys are usin it without problems then ill be okay ,just concerned me a little thought it was weird i never saw a sbc intake like that