I have a Gen1 TVS with a 2.4 upper and 10% lower and I make 17lbs of boost. I have a pmas intake and full exhaust. Boost numbers seem kind of low considering what this set up is supposed to be on the Gen 2's. I put down 609hp/715ftlb on a mustang dyno. I made peak hp at 5300 I assume because I haven't got rid of the stock throttle body yet. That restriction should bring the numbers up allot once gone. The car made decent numbers but does that amount of boost sound right? On a gen2r it should be around 21lbs I haven't seen any charts for the Gen1
Gen 1 Vmp
- Thread starter wildbillcody
- Start date
Had a Gen1 with 2.5, IW 10%, Twin 72mm TB, CJ 123 CAI, 1-7/8 headers, O/R X, which netted 20 psi boost. That TB has to be killing your numbers.
No I'm about 1500ft elevation. The boost number was the only thing I was worried about since I'm not familiar with the 5.4 I've done allot of 4.6 cars I just didn't want to run too much boost with 93. The numbers are lower due to the stock throttle body for sure its like it couldn't flow anymore after 5300RPM. Maybe I have a bad boost gauge. Ill order a new one and probably go ahead and step up to a 2.5 pulley to be safe.
I looked back at the messages from the guy I bought it from he made 19.5 psi with this blower and almost the same setup but didn't have long tubes and he's about 700ft elevation so I should still be good on the boost the extra elevation and long tubes and 3 inch exhaust is probably what's dropping it down a little so I should still be safe.
Long tubes are definitely going to drop the PSI but they will help build torque. You could *possibly* be having a slipping belt. The OEM S/C belt tensioner isnt know for its long term robustness. I noticed last week my PSI was only at 11 when I went WOT. I thought about it and it hasnt been as savage as it usually is when my foot is in it.
It was maxing the boost gauge when I first put the pulley on. Granted the gauge is notoriously innaccurate, but not THAT inaccurate. I noticed a lot of belt dust around the area of the S/C snout. I promptly ordered a VMP belt tensioner and a BPS idler bracket assembly to replace the 90mm idler in the factory position.
The drastic HP to Torque numbers DEFINITELY indicate a restriction. That OEM 60mm TB is seriously a power killer. A swap to a 65mm and up TB or even better a mono blade should get that HP back to normal.
It was maxing the boost gauge when I first put the pulley on. Granted the gauge is notoriously innaccurate, but not THAT inaccurate. I noticed a lot of belt dust around the area of the S/C snout. I promptly ordered a VMP belt tensioner and a BPS idler bracket assembly to replace the 90mm idler in the factory position.
The drastic HP to Torque numbers DEFINITELY indicate a restriction. That OEM 60mm TB is seriously a power killer. A swap to a 65mm and up TB or even better a mono blade should get that HP back to normal.
Yeah above 18lbs isn't good for 93 but I find it odd that the previous owner only saw 19.5 also. I know headers wont drop it by much usually by 1lb and usually you loose roughly .5psi for every 1000ft. So based of his results and mine me being in the 17 to 18 lb range would sound about right. I know the gen1's weren't as efficient as the trinity tvs's. But also very odd to be 3-4lbs lower than most on this setup. I don't think it has to do with belt slip because it jumps up there and holds between 17 and 18 and I have an aux idler. But when we have had a cool spell I have had it jump up to 20lbs which all boost cars gain when its colder. I may go ahead and try another boost gauge just to be safe.
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