hope it's not an automatic burn for this post. I'm just trying to get an idea what I should expect I recently revamped my 89 Formula for the second time after the "speed shop" built me a **** motor that blew the top end. I just went for it and did everything myself and am in the process of tuning (or trying to) Here's the specs on the engine: TPI 355, SLP runners, stock plenum matched, 24lb injectors AFR Eliminator heads 180cc with Scorpion 1/6 rockers, Comp cam 08-302-8, gross lift of 0.48 for both intake and exhaust. Duration is 210 intake and 220 exhaust, lobe separation of 112, stock throttle body. Dyno don's ceramic headers, no cats, 4" exhaust from Summit. stock 5 speed manual, stock 345 rear end. Tuning the first gen EBL flash. Thanks guys.

 

Around 300-330whp around 5000rpm.

The heads will support more power but a stock style TPI will not. If you move to a Superram you'll jump about 20whp on the top end with only a minor peak torque loss, you'll still make more average torque across a longer power band though.

You will have great torque though, probably near 350-370lb/ft.

 

Originally, I was going for a Super ram or Stealth ram. One wouldn't clear the hood, and the other required new injectors, rails maybe more. I already had my injectors and SLP runners so I decided to keep the TPI. I just love the way the engine looks and I'm really not chasing quarter mile times. Just want it as good as it can be. Thanks for the reply, I really appreciate it.

 

Eh im gonna say 275-300 whp. Last one i did with hotcam and very similar top end on stock shortblock did 272 but thru an automatic. I did feel it had excessive blowby so not sure if ring seal was good or not but was a lower mileage unit so idk. 5 speed will pick up some so 300 would be fairly acceptable

 

I'm gonna agree with Orr on this. I am running a similar setup with stock block l98 with AFR 180 Eliminator heads, SuperRam, 24 /lbs Accel Injectors, 8-304-8 Cam (210/220 but on a 114 LSA) Scorpion 1.6 Roller Rockers, with Edelbrock TES headers, no CAT, and 3" exhaust, with a 3.42 4th gen rear end, and a customized ARAP bin.. I don't have any numbers to back it up but the car feels like it probably has about 280-300hp at the rear wheels.

 

Oops, missed that there was no mention of an upgraded TPI base. If its the stock base, no bueno on my original estimate, that will choke those 180's on the top end pretty quick.

Need an upgraded base, or a REALLY hogged out one.

 

I set one up in a friends 87 TA, 10:1 355, older Dart Iron Eagle 180 heads, LT4 Hotcam setup with a stock TPI and headers. It made 290 whp and 350 wtq through a TH400. Only modification to the TPI itself was an airfoil, EGR delete, and LT1 injectors. 165 ECM running Speed Density.

The 10.5:1 383 in my G20 van made 380/410 at the wheels with ported vortecs, reed custom grind cam, thorley tri-y headers into a dual 2.5" exhaust with a X-pipe. Ported plenum, siamese ported SLP runners and a ported/unwelded 3817 base.

 

When you say TPI base, you mean lower intake? if so she's got the Accel Big Mouth. the plenum is opened up a little to match the slp runners too. I actually just drove it after ironing out some wrinkles this weekend and it def seems to go pretty good. More than anything it just drives better than ever.

 

Accel big mouth is the best of the oem style bases.

look at the tpi shootout. Has all manner of combos including super ram,hsr ,miniram…etc.

 

great to hear! I really lucked out finding the heads and intake during covid. I bought the intake mostly for the choice in bolt holes.. AFR wasn't making anything at the time and I got an awesome deal for the heads on ebay but the holes wouldn't line up with the intake. Think it's worth buying the bigger throttle body?

 

Thanks for chiming in everyone, I appreciate you all helping me out.

 

The stock 48mm throttle bore size should not be a massive restriction. That same TB design supports 330+HP (at the wheels) on a mid-'90s Corvette.

In some magazine testing, changing to a 52mm TB alone netted a whopping 4.1HP. Changing to an improved cam (with stock rockers) netted a 58HP gain and 30 ft/lb. https://www.motortrend.com/how-to/13...-motor-part-2/

Simply bolting on a larger TB will possibly only make you THINK you have more usable power.

 

Not really, unless the old one is beat. If it drives good and the blades don't stick then its fine

 

Same throttle body came on the Ramjet 502 at 502 hp, although a 58mm and retune really wakes the 502 up. Nearly 60 hp on the one I tuned. Throttle body added ~40 hp and the subsequent retune to fix the slight lean condition and corresponding knock retard added another 20 hp.

 

Any input on getting any more out of this short of 383? Better cam? Bigger injectors?